app: [macOS] make the app delegate optional

Inspired by the discussion at golang.org/issue/70089, this change makes
our particular NSApplicationDelegate implementation optional.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

.builds/apple.yml

@@ -29,7 +29,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl -s https://dl.google.com/go/go1.19.11.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl -s https://dl.google.com/go/go1.24.2.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - prepare_toolchain: |
      mkdir -p $APPLE_TOOLCHAIN_ROOT
      cd $APPLE_TOOLCHAIN_ROOT
@@ -71,4 +71,4 @@ tasks:
      CC=$APPLE_TOOLCHAIN_ROOT/tools/clang-macos GOOS=darwin CGO_ENABLED=1 go build ./...
  - test_ios: |
      cd gio
-     CC=$APPLE_TOOLCHAIN_ROOT/tools/clang-ios GOOS=darwin GOARCH=arm64 CGO_ENABLED=1 go build -tags ios ./...
+     CGO_CFLAGS=-Wno-deprecated-module-dot-map CC=$APPLE_TOOLCHAIN_ROOT/tools/clang-ios GOOS=darwin GOARCH=arm64 CGO_ENABLED=1 go build -tags ios ./...

.builds/freebsd.yml

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: Unlicense OR MIT
-image: freebsd/13.x
+image: freebsd/latest
 packages:
  - libX11
  - libxkbcommon
@@ -16,7 +16,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl https://dl.google.com/go/go1.19.11.freebsd-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl https://dl.google.com/go/go1.24.2.freebsd-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - test_gio: |
      cd gio
      go test ./...

.builds/linux.yml

@@ -40,7 +40,7 @@ secrets:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl -s https://dl.google.com/go/go1.19.11.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl -s https://dl.google.com/go/go1.24.2.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - check_gofmt: |
      cd gio
      test -z "$(gofmt -s -l .)"
@@ -80,6 +80,8 @@ tasks:
      unzip -q ndk.zip
      rm ndk.zip
      mv android-ndk-* ndk-bundle
+     # sdkmanager needs lots of file descriptors
+     ulimit -n 10000
      yes|sdkmanager --licenses
      sdkmanager "platforms;android-31" "build-tools;32.0.0"
  - test_android: |

.builds/openbsd.yml

@@ -10,7 +10,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl https://dl.google.com/go/go1.19.11.src.tar.gz | tar -C /home/build/sdk -xzf -
+     curl https://dl.google.com/go/go1.24.2.src.tar.gz | tar -C /home/build/sdk -xzf -
      cd /home/build/sdk/go/src
      ./make.bash
  - test_gio: |

app/GioView.java

@@ -65,8 +65,8 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 	private final InputMethodManager imm;
 	private final float scrollXScale;
 	private final float scrollYScale;
+	private final AccessibilityManager accessManager;
 	private int keyboardHint;
-	private AccessibilityManager accessManager;
 
 	private long nhandle;
 
@@ -259,6 +259,10 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 	}
 
 	private void setHighRefreshRate() {
+		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
+			return;
+		}
+
 		Context context = getContext();
 		Display display = context.getDisplay();
 		Display.Mode[] supportedModes = display.getSupportedModes();

app/app.go

@@ -3,9 +3,16 @@
 package app
 
 import (
+	"image"
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
+
+	"gioui.org/io/input"
+	"gioui.org/layout"
+	"gioui.org/op"
+	"gioui.org/unit"
 )
 
 // extraArgs contains extra arguments to append to
@@ -20,23 +27,88 @@ var extraArgs string
 // On Android ID is the package property of AndroidManifest.xml,
 // on iOS ID is the CFBundleIdentifier of the app Info.plist,
 // on Wayland it is the toplevel app_id,
-// on X11 it is the X11 XClassHint
+// on X11 it is the X11 XClassHint.
 //
-// ID is set by the gogio tool or manually with the -X linker flag. For example,
+// ID is set by the [gioui.org/cmd/gogio] tool or manually with the -X linker flag. For example,
 //
 //	go build -ldflags="-X 'gioui.org/app.ID=org.gioui.example.Kitchen'" .
 //
 // Note that ID is treated as a constant, and that changing it at runtime
-// is not supported. Default value of ID is filepath.Base(os.Args[0]).
+// is not supported. The default value of ID is filepath.Base(os.Args[0]).
 var ID = ""
 
-func init() {
+// A FrameEvent requests a new frame in the form of a list of
-	if extraArgs != "" {
+// operations that describes the window content.
-		args := strings.Split(extraArgs, "|")
+type FrameEvent struct {
-		os.Args = append(os.Args, args...)
+	// Now is the current animation. Use Now instead of time.Now to
+	// synchronize animation and to avoid the time.Now call overhead.
+	Now time.Time
+	// Metric converts device independent dp and sp to device pixels.
+	Metric unit.Metric
+	// Size is the dimensions of the window.
+	Size image.Point
+	// Insets represent the space occupied by system decorations and controls.
+	Insets Insets
+	// Frame completes the FrameEvent by drawing the graphical operations
+	// from ops into the window.
+	Frame func(frame *op.Ops)
+	// Source is the interface between the window and widgets.
+	Source input.Source
+}
+
+// ViewEvent provides handles to the underlying window objects for the
+// current display protocol.
+type ViewEvent interface {
+	implementsViewEvent()
+	ImplementsEvent()
+	// Valid will return true when the ViewEvent does contains valid handles.
+	// If a window receives an invalid ViewEvent, it should deinitialize any
+	// state referring to handles from a previous ViewEvent.
+	Valid() bool
+}
+
+// Insets is the space taken up by
+// system decoration such as translucent
+// system bars and software keyboards.
+type Insets struct {
+	// Values are in pixels.
+	Top, Bottom, Left, Right unit.Dp
+}
+
+// NewContext is shorthand for
+//
+//	layout.Context{
+//	  Ops: ops,
+//	  Now: e.Now,
+//	  Source: e.Source,
+//	  Metric: e.Metric,
+//	  Constraints: layout.Exact(e.Size),
+//	}
+//
+// NewContext calls ops.Reset and adjusts ops for e.Insets.
+func NewContext(ops *op.Ops, e FrameEvent) layout.Context {
+	ops.Reset()
+
+	size := e.Size
+
+	if e.Insets != (Insets{}) {
+		left := e.Metric.Dp(e.Insets.Left)
+		top := e.Metric.Dp(e.Insets.Top)
+		op.Offset(image.Point{
+			X: left,
+			Y: top,
+		}).Add(ops)
+
+		size.X -= left + e.Metric.Dp(e.Insets.Right)
+		size.Y -= top + e.Metric.Dp(e.Insets.Bottom)
 	}
-	if ID == "" {
+
-		ID = filepath.Base(os.Args[0])
+	return layout.Context{
+		Ops:         ops,
+		Now:         e.Now,
+		Source:      e.Source,
+		Metric:      e.Metric,
+		Constraints: layout.Exact(size),
 	}
 }
 
@@ -63,3 +135,15 @@ func DataDir() (string, error) {
 func Main() {
 	osMain()
 }
+
+func (FrameEvent) ImplementsEvent() {}
+
+func init() {
+	if extraArgs != "" {
+		args := strings.Split(extraArgs, "|")
+		os.Args = append(os.Args, args...)
+	}
+	if ID == "" {
+		ID = filepath.Base(os.Args[0])
+	}
+}

app/d3d11_windows.go

@@ -60,10 +60,10 @@ func (c *d3d11Context) RenderTarget() (gpu.RenderTarget, error) {
 }
 
 func (c *d3d11Context) Present() error {
-	err := c.swchain.Present(1, 0)
+	return wrapErr(c.swchain.Present(1, 0))
-	if err == nil {
+}
-		return nil
+
-	}
+func wrapErr(err error) error {
 	if err, ok := err.(d3d11.ErrorCode); ok {
 		switch err.Code {
 		case d3d11.DXGI_STATUS_OCCLUDED:
@@ -84,7 +84,7 @@ func (c *d3d11Context) Refresh() error {
 	}
 	c.releaseFBO()
 	if err := c.swchain.ResizeBuffers(0, 0, 0, d3d11.DXGI_FORMAT_UNKNOWN, 0); err != nil {
-		return err
+		return wrapErr(err)
 	}
 	c.width = width
 	c.height = height

app/doc.go

@@ -8,21 +8,20 @@ See https://gioui.org for instructions to set up and run Gio programs.
 
 # Windows
 
-Create a new Window by calling NewWindow. On mobile platforms or when Gio
+A Window is run by calling its Event method in a loop. The first time a
-is embedded in another project, NewWindow merely connects with a previously
+method on Window is called, a new GUI window is created and shown. On mobile
-created window.
+platforms or when Gio is embedded in another project, Window merely connects
+with a previously created GUI window.
 
-A Window is run by calling NextEvent in a loop. The most important event is
+The most important event is [FrameEvent] that prompts an update of the window
-FrameEvent that prompts an update of the window contents.
+contents.
 
 For example:
 
-	import "gioui.org/unit"
+	w := new(app.Window)
-
-	w := app.NewWindow()
 	for {
-		e := w.NextEvent()
+		e := w.Event()
-		if e, ok := e.(system.FrameEvent); ok {
+		if e, ok := e.(app.FrameEvent); ok {
 			ops.Reset()
 			// Add operations to ops.
 			...
@@ -32,7 +31,7 @@ For example:
 	}
 
 A program must keep receiving events from the event channel until
-DestroyEvent is received.
+[DestroyEvent] is received.
 
 # Main
 
@@ -51,18 +50,12 @@ For example, to display a blank but otherwise functional window:
 		go func() {
 			w := app.NewWindow()
 			for {
-				w.NextEvent()
+				w.Event()
 			}
 		}()
 		app.Main()
 	}
 
-# Event queue
-
-A FrameEvent's Queue method returns an event.Queue implementation that distributes
-incoming events to the event handlers declared in the last frame.
-See the gioui.org/io/event package for more information about event handlers.
-
 # Permissions
 
 The packages under gioui.org/app/permission should be imported

app/egl_android.go

@@ -17,9 +17,8 @@ import (
 )
 
 type androidContext struct {
-	win           *window
+	win     *window
-	eglSurf       egl.NativeWindowType
+	eglSurf egl.NativeWindowType
-	width, height int
 	*egl.Context
 }
 
@@ -45,9 +44,8 @@ func (c *androidContext) Refresh() error {
 	if err := c.win.setVisual(c.Context.VisualID()); err != nil {
 		return err
 	}
-	win, width, height := c.win.nativeWindow()
+	win, _, _ := c.win.nativeWindow()
 	c.eglSurf = egl.NativeWindowType(unsafe.Pointer(win))
-	c.width, c.height = width, height
 	return nil
 }
 
@@ -55,7 +53,7 @@ func (c *androidContext) Lock() error {
 	// The Android emulator creates a broken surface if it is not
 	// created on the same thread as the context is made current.
 	if c.eglSurf != nil {
-		if err := c.Context.CreateSurface(c.eglSurf, c.width, c.height); err != nil {
+		if err := c.Context.CreateSurface(c.eglSurf); err != nil {
 			return err
 		}
 		c.eglSurf = nil

app/egl_wayland.go

@@ -38,7 +38,24 @@ func init() {
 		if err != nil {
 			return nil, err
 		}
-		return &wlContext{Context: ctx, win: w}, nil
+
+		surf, width, height := w.surface()
+		if surf == nil {
+			return nil, errors.New("wayland: no surface")
+		}
+		eglWin := C.wl_egl_window_create(surf, C.int(width), C.int(height))
+		if eglWin == nil {
+			return nil, errors.New("wayland: wl_egl_window_create failed")
+		}
+		eglSurf := egl.NativeWindowType(uintptr(unsafe.Pointer(eglWin)))
+		if err := ctx.CreateSurface(eglSurf); err != nil {
+			return nil, err
+		}
+		// We're in charge of the frame callbacks, don't let eglSwapBuffers
+		// wait for callbacks that may never arrive.
+		ctx.EnableVSync(false)
+
+		return &wlContext{Context: ctx, win: w, eglWin: eglWin}, nil
 	}
 }
 
@@ -54,22 +71,12 @@ func (c *wlContext) Release() {
 }
 
 func (c *wlContext) Refresh() error {
-	c.Context.ReleaseSurface()
-	if c.eglWin != nil {
-		C.wl_egl_window_destroy(c.eglWin)
-		c.eglWin = nil
-	}
 	surf, width, height := c.win.surface()
 	if surf == nil {
 		return errors.New("wayland: no surface")
 	}
-	eglWin := C.wl_egl_window_create(surf, C.int(width), C.int(height))
+	C.wl_egl_window_resize(c.eglWin, C.int(width), C.int(height), 0, 0)
-	if eglWin == nil {
+	return nil
-		return errors.New("wayland: wl_egl_window_create failed")
-	}
-	c.eglWin = eglWin
-	eglSurf := egl.NativeWindowType(uintptr(unsafe.Pointer(eglWin)))
-	return c.Context.CreateSurface(eglSurf, width, height)
 }
 
 func (c *wlContext) Lock() error {

app/egl_windows.go

@@ -5,8 +5,6 @@
 package app
 
 import (
-	"golang.org/x/sys/windows"
-
 	"gioui.org/internal/egl"
 )
 
@@ -24,6 +22,18 @@ func init() {
 			if err != nil {
 				return nil, err
 			}
+			win, _, _ := w.HWND()
+			eglSurf := egl.NativeWindowType(win)
+			if err := ctx.CreateSurface(eglSurf); err != nil {
+				ctx.Release()
+				return nil, err
+			}
+			if err := ctx.MakeCurrent(); err != nil {
+				ctx.Release()
+				return nil, err
+			}
+			defer ctx.ReleaseCurrent()
+			ctx.EnableVSync(true)
 			return &glContext{win: w, Context: ctx}, nil
 		},
 	})
@@ -37,21 +47,6 @@ func (c *glContext) Release() {
 }
 
 func (c *glContext) Refresh() error {
-	c.Context.ReleaseSurface()
-	var (
-		win           windows.Handle
-		width, height int
-	)
-	win, width, height = c.win.HWND()
-	eglSurf := egl.NativeWindowType(win)
-	if err := c.Context.CreateSurface(eglSurf, width, height); err != nil {
-		return err
-	}
-	if err := c.Context.MakeCurrent(); err != nil {
-		return err
-	}
-	c.Context.EnableVSync(true)
-	c.Context.ReleaseCurrent()
 	return nil
 }
 

app/egl_x11.go

@@ -25,6 +25,18 @@ func init() {
 		if err != nil {
 			return nil, err
 		}
+		win, _, _ := w.window()
+		eglSurf := egl.NativeWindowType(uintptr(win))
+		if err := ctx.CreateSurface(eglSurf); err != nil {
+			ctx.Release()
+			return nil, err
+		}
+		if err := ctx.MakeCurrent(); err != nil {
+			ctx.Release()
+			return nil, err
+		}
+		defer ctx.ReleaseCurrent()
+		ctx.EnableVSync(true)
 		return &x11Context{win: w, Context: ctx}, nil
 	}
 }
@@ -37,17 +49,6 @@ func (c *x11Context) Release() {
 }
 
 func (c *x11Context) Refresh() error {
-	c.Context.ReleaseSurface()
-	win, width, height := c.win.window()
-	eglSurf := egl.NativeWindowType(uintptr(win))
-	if err := c.Context.CreateSurface(eglSurf, width, height); err != nil {
-		return err
-	}
-	if err := c.Context.MakeCurrent(); err != nil {
-		return err
-	}
-	c.Context.EnableVSync(true)
-	c.Context.ReleaseCurrent()
 	return nil
 }
 

app/gl_macos.go

@@ -8,7 +8,6 @@ package app
 import (
 	"errors"
 	"runtime"
-
 	"unsafe"
 
 	"gioui.org/gpu"

app/gl_macos.m

@@ -7,7 +7,7 @@
 #include <OpenGL/OpenGL.h>
 #include "_cgo_export.h"
 
-CALayer *gio_layerFactory(void) {
+CALayer *gio_layerFactory(BOOL presentWithTrans) {
 	@autoreleasepool {
 		return [CALayer layer];
 	}

app/ime.go

@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package app
+
+import (
+	"unicode"
+	"unicode/utf16"
+	"unicode/utf8"
+
+	"gioui.org/io/input"
+	"gioui.org/io/key"
+)
+
+type editorState struct {
+	input.EditorState
+	compose key.Range
+}
+
+func (e *editorState) Replace(r key.Range, text string) {
+	if r.Start > r.End {
+		r.Start, r.End = r.End, r.Start
+	}
+	runes := []rune(text)
+	newEnd := r.Start + len(runes)
+	adjust := func(pos int) int {
+		switch {
+		case newEnd < pos && pos <= r.End:
+			return newEnd
+		case r.End < pos:
+			diff := newEnd - r.End
+			return pos + diff
+		}
+		return pos
+	}
+	e.Selection.Start = adjust(e.Selection.Start)
+	e.Selection.End = adjust(e.Selection.End)
+	if e.compose.Start != -1 {
+		e.compose.Start = adjust(e.compose.Start)
+		e.compose.End = adjust(e.compose.End)
+	}
+	s := e.Snippet
+	if r.End < s.Start || r.Start > s.End {
+		// Discard snippet if it doesn't overlap with replacement.
+		s = key.Snippet{
+			Range: key.Range{
+				Start: r.Start,
+				End:   r.Start,
+			},
+		}
+	}
+	var newSnippet []rune
+	snippet := []rune(s.Text)
+	// Append first part of existing snippet.
+	if end := r.Start - s.Start; end > 0 {
+		newSnippet = append(newSnippet, snippet[:end]...)
+	}
+	// Append replacement.
+	newSnippet = append(newSnippet, runes...)
+	// Append last part of existing snippet.
+	if start := r.End; start < s.End {
+		newSnippet = append(newSnippet, snippet[start-s.Start:]...)
+	}
+	// Adjust snippet range to include replacement.
+	if r.Start < s.Start {
+		s.Start = r.Start
+	}
+	s.End = s.Start + len(newSnippet)
+	s.Text = string(newSnippet)
+	e.Snippet = s
+}
+
+// UTF16Index converts the given index in runes into an index in utf16 characters.
+func (e *editorState) UTF16Index(runes int) int {
+	if runes == -1 {
+		return -1
+	}
+	if runes < e.Snippet.Start {
+		// Assume runes before sippet are one UTF-16 character each.
+		return runes
+	}
+	chars := e.Snippet.Start
+	runes -= e.Snippet.Start
+	for _, r := range e.Snippet.Text {
+		if runes == 0 {
+			break
+		}
+		runes--
+		chars++
+		if r1, _ := utf16.EncodeRune(r); r1 != unicode.ReplacementChar {
+			chars++
+		}
+	}
+	// Assume runes after snippets are one UTF-16 character each.
+	return chars + runes
+}
+
+// RunesIndex converts the given index in utf16 characters to an index in runes.
+func (e *editorState) RunesIndex(chars int) int {
+	if chars == -1 {
+		return -1
+	}
+	if chars < e.Snippet.Start {
+		// Assume runes before offset are one UTF-16 character each.
+		return chars
+	}
+	runes := e.Snippet.Start
+	chars -= e.Snippet.Start
+	for _, r := range e.Snippet.Text {
+		if chars == 0 {
+			break
+		}
+		chars--
+		runes++
+		if r1, _ := utf16.EncodeRune(r); r1 != unicode.ReplacementChar {
+			chars--
+		}
+	}
+	// Assume runes after snippets are one UTF-16 character each.
+	return runes + chars
+}
+
+// areSnippetsConsistent reports whether the content of the old snippet is
+// consistent with the content of the new.
+func areSnippetsConsistent(old, new key.Snippet) bool {
+	// Compute the overlapping range.
+	r := old.Range
+	r.Start = max(r.Start, new.Start)
+	r.End = max(r.End, r.Start)
+	r.End = min(r.End, new.End)
+	return snippetSubstring(old, r) == snippetSubstring(new, r)
+}
+
+func snippetSubstring(s key.Snippet, r key.Range) string {
+	for r.Start > s.Start && r.Start < s.End {
+		_, n := utf8.DecodeRuneInString(s.Text)
+		s.Text = s.Text[n:]
+		s.Start++
+	}
+	for r.End < s.End && r.End > s.Start {
+		_, n := utf8.DecodeLastRuneInString(s.Text)
+		s.Text = s.Text[:len(s.Text)-n]
+		s.End--
+	}
+	return s.Text
+}

app/ime_test.go

@@ -6,13 +6,14 @@
 package app
 
 import (
+	"gioui.org/f32"
 	"testing"
 	"unicode/utf8"
 
 	"gioui.org/font"
 	"gioui.org/font/gofont"
+	"gioui.org/io/input"
 	"gioui.org/io/key"
-	"gioui.org/io/router"
 	"gioui.org/layout"
 	"gioui.org/op"
 	"gioui.org/text"
@@ -31,15 +32,16 @@ func FuzzIME(f *testing.F) {
 	f.Fuzz(func(t *testing.T, cmds []byte) {
 		cache := text.NewShaper(text.WithCollection(gofont.Collection()))
 		e := new(widget.Editor)
-		e.Focus()
 
-		var r router.Router
+		var r input.Router
-		gtx := layout.Context{Ops: new(op.Ops), Queue: &r}
+		gtx := layout.Context{Ops: new(op.Ops), Source: r.Source()}
+		gtx.Execute(key.FocusCmd{Tag: e})
 		// Layout once to register focus.
 		e.Layout(gtx, cache, font.Font{}, unit.Sp(10), op.CallOp{}, op.CallOp{})
 		r.Frame(gtx.Ops)
 
 		var state editorState
+		state.Selection.Transform = f32.AffineId()
 		const (
 			cmdReplace = iota
 			cmdSelect
@@ -139,6 +141,7 @@ func FuzzIME(f *testing.F) {
 
 func TestEditorIndices(t *testing.T) {
 	var s editorState
+	s.Selection.Transform = f32.AffineId()
 	const str = "Hello, 😀"
 	s.Snippet = key.Snippet{
 		Text: str,

app/internal/log/log.go

@@ -1,7 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-// Package points standard output, standard error and the standard
-// library package log to the platform logger.
-package log
-
-var appID = "gio"

app/internal/windows/windows.go

@@ -108,6 +108,74 @@ type MonitorInfo struct {
 	Flags    uint32
 }
 
+type POINTER_INPUT_TYPE int32
+
+const (
+	PT_POINTER  POINTER_INPUT_TYPE = 1
+	PT_TOUCH    POINTER_INPUT_TYPE = 2
+	PT_PEN      POINTER_INPUT_TYPE = 3
+	PT_MOUSE    POINTER_INPUT_TYPE = 4
+	PT_TOUCHPAD POINTER_INPUT_TYPE = 5
+)
+
+type POINTER_INFO_POINTER_FLAGS int32
+
+const (
+	POINTER_FLAG_NEW            POINTER_INFO_POINTER_FLAGS = 0x00000001
+	POINTER_FLAG_INRANGE        POINTER_INFO_POINTER_FLAGS = 0x00000002
+	POINTER_FLAG_INCONTACT      POINTER_INFO_POINTER_FLAGS = 0x00000004
+	POINTER_FLAG_FIRSTBUTTON    POINTER_INFO_POINTER_FLAGS = 0x00000010
+	POINTER_FLAG_SECONDBUTTON   POINTER_INFO_POINTER_FLAGS = 0x00000020
+	POINTER_FLAG_THIRDBUTTON    POINTER_INFO_POINTER_FLAGS = 0x00000040
+	POINTER_FLAG_FOURTHBUTTON   POINTER_INFO_POINTER_FLAGS = 0x00000080
+	POINTER_FLAG_FIFTHBUTTON    POINTER_INFO_POINTER_FLAGS = 0x00000100
+	POINTER_FLAG_PRIMARY        POINTER_INFO_POINTER_FLAGS = 0x00002000
+	POINTER_FLAG_CONFIDENCE     POINTER_INFO_POINTER_FLAGS = 0x00004000
+	POINTER_FLAG_CANCELED       POINTER_INFO_POINTER_FLAGS = 0x00008000
+	POINTER_FLAG_DOWN           POINTER_INFO_POINTER_FLAGS = 0x00010000
+	POINTER_FLAG_UPDATE         POINTER_INFO_POINTER_FLAGS = 0x00020000
+	POINTER_FLAG_UP             POINTER_INFO_POINTER_FLAGS = 0x00040000
+	POINTER_FLAG_WHEEL          POINTER_INFO_POINTER_FLAGS = 0x00080000
+	POINTER_FLAG_HWHEEL         POINTER_INFO_POINTER_FLAGS = 0x00100000
+	POINTER_FLAG_CAPTURECHANGED POINTER_INFO_POINTER_FLAGS = 0x00200000
+	POINTER_FLAG_HASTRANSFORM   POINTER_INFO_POINTER_FLAGS = 0x00400000
+)
+
+type POINTER_BUTTON_CHANGE_TYPE int32
+
+const (
+	POINTER_CHANGE_NONE              POINTER_BUTTON_CHANGE_TYPE = 0
+	POINTER_CHANGE_FIRSTBUTTON_DOWN  POINTER_BUTTON_CHANGE_TYPE = 1
+	POINTER_CHANGE_FIRSTBUTTON_UP    POINTER_BUTTON_CHANGE_TYPE = 2
+	POINTER_CHANGE_SECONDBUTTON_DOWN POINTER_BUTTON_CHANGE_TYPE = 3
+	POINTER_CHANGE_SECONDBUTTON_UP   POINTER_BUTTON_CHANGE_TYPE = 4
+	POINTER_CHANGE_THIRDBUTTON_DOWN  POINTER_BUTTON_CHANGE_TYPE = 5
+	POINTER_CHANGE_THIRDBUTTON_UP    POINTER_BUTTON_CHANGE_TYPE = 6
+	POINTER_CHANGE_FOURTHBUTTON_DOWN POINTER_BUTTON_CHANGE_TYPE = 7
+	POINTER_CHANGE_FOURTHBUTTON_UP   POINTER_BUTTON_CHANGE_TYPE = 8
+	POINTER_CHANGE_FIFTHBUTTON_DOWN  POINTER_BUTTON_CHANGE_TYPE = 9
+	POINTER_CHANGE_FIFTHBUTTON_UP    POINTER_BUTTON_CHANGE_TYPE = 10
+)
+
+type PointerInfo struct {
+	PointerType           POINTER_INPUT_TYPE
+	PointerId             uint32
+	FrameId               uint32
+	PointerFlags          POINTER_INFO_POINTER_FLAGS
+	SourceDevice          syscall.Handle
+	HwndTarget            syscall.Handle
+	PtPixelLocation       Point
+	PtHimetricLocation    Point
+	PtPixelLocationRaw    Point
+	PtHimetricLocationRaw Point
+	DwTime                uint32
+	HistoryCount          uint32
+	InputData             int32
+	DwKeyStates           uint32
+	PerformanceCount      uint64
+	ButtonChangeType      POINTER_BUTTON_CHANGE_TYPE
+}
+
 const (
 	TRUE = 1
 
@@ -244,44 +312,51 @@ const (
 
 	UNICODE_NOCHAR = 65535
 
-	WM_CANCELMODE           = 0x001F
+	WM_CANCELMODE            = 0x001F
-	WM_CHAR                 = 0x0102
+	WM_CHAR                  = 0x0102
-	WM_CLOSE                = 0x0010
+	WM_CLOSE                 = 0x0010
-	WM_CREATE               = 0x0001
+	WM_CREATE                = 0x0001
-	WM_DPICHANGED           = 0x02E0
+	WM_DPICHANGED            = 0x02E0
-	WM_DESTROY              = 0x0002
+	WM_DESTROY               = 0x0002
-	WM_ERASEBKGND           = 0x0014
+	WM_ERASEBKGND            = 0x0014
-	WM_GETMINMAXINFO        = 0x0024
+	WM_GETMINMAXINFO         = 0x0024
-	WM_IME_COMPOSITION      = 0x010F
+	WM_IME_COMPOSITION       = 0x010F
-	WM_IME_ENDCOMPOSITION   = 0x010E
+	WM_IME_ENDCOMPOSITION    = 0x010E
-	WM_IME_STARTCOMPOSITION = 0x010D
+	WM_IME_STARTCOMPOSITION  = 0x010D
-	WM_KEYDOWN              = 0x0100
+	WM_KEYDOWN               = 0x0100
-	WM_KEYUP                = 0x0101
+	WM_KEYUP                 = 0x0101
-	WM_KILLFOCUS            = 0x0008
+	WM_KILLFOCUS             = 0x0008
-	WM_LBUTTONDOWN          = 0x0201
+	WM_LBUTTONDOWN           = 0x0201
-	WM_LBUTTONUP            = 0x0202
+	WM_LBUTTONUP             = 0x0202
-	WM_MBUTTONDOWN          = 0x0207
+	WM_MBUTTONDOWN           = 0x0207
-	WM_MBUTTONUP            = 0x0208
+	WM_MBUTTONUP             = 0x0208
-	WM_MOUSEMOVE            = 0x0200
+	WM_MOUSEMOVE             = 0x0200
-	WM_MOUSEWHEEL           = 0x020A
+	WM_MOUSEWHEEL            = 0x020A
-	WM_MOUSEHWHEEL          = 0x020E
+	WM_MOUSEHWHEEL           = 0x020E
-	WM_NCACTIVATE           = 0x0086
+	WM_NCACTIVATE            = 0x0086
-	WM_NCHITTEST            = 0x0084
+	WM_NCHITTEST             = 0x0084
-	WM_NCCALCSIZE           = 0x0083
+	WM_NCCALCSIZE            = 0x0083
-	WM_PAINT                = 0x000F
+	WM_PAINT                 = 0x000F
-	WM_QUIT                 = 0x0012
+	WM_POINTERCAPTURECHANGED = 0x024C
-	WM_SETCURSOR            = 0x0020
+	WM_POINTERDOWN           = 0x0246
-	WM_SETFOCUS             = 0x0007
+	WM_POINTERUP             = 0x0247
-	WM_SHOWWINDOW           = 0x0018
+	WM_POINTERUPDATE         = 0x0245
-	WM_SIZE                 = 0x0005
+	WM_POINTERWHEEL          = 0x024E
-	WM_SYSKEYDOWN           = 0x0104
+	WM_POINTERHWHEEL         = 0x024F
-	WM_SYSKEYUP             = 0x0105
+	WM_QUIT                  = 0x0012
-	WM_RBUTTONDOWN          = 0x0204
+	WM_RBUTTONDOWN           = 0x0204
-	WM_RBUTTONUP            = 0x0205
+	WM_RBUTTONUP             = 0x0205
-	WM_TIMER                = 0x0113
+	WM_SETCURSOR             = 0x0020
-	WM_UNICHAR              = 0x0109
+	WM_SETFOCUS              = 0x0007
-	WM_USER                 = 0x0400
+	WM_SHOWWINDOW            = 0x0018
-	WM_WINDOWPOSCHANGED     = 0x0047
+	WM_SIZE                  = 0x0005
+	WM_STYLECHANGED          = 0x007D
+	WM_SYSKEYDOWN            = 0x0104
+	WM_SYSKEYUP              = 0x0105
+	WM_TIMER                 = 0x0113
+	WM_UNICHAR               = 0x0109
+	WM_USER                  = 0x0400
+	WM_WINDOWPOSCHANGED      = 0x0047
 
 	WS_CLIPCHILDREN     = 0x02000000
 	WS_CLIPSIBLINGS     = 0x04000000
@@ -345,6 +420,7 @@ var (
 	_DestroyWindow               = user32.NewProc("DestroyWindow")
 	_DispatchMessage             = user32.NewProc("DispatchMessageW")
 	_EmptyClipboard              = user32.NewProc("EmptyClipboard")
+	_EnableMouseInPointer        = user32.NewProc("EnableMouseInPointer")
 	_GetWindowRect               = user32.NewProc("GetWindowRect")
 	_GetClientRect               = user32.NewProc("GetClientRect")
 	_GetClipboardData            = user32.NewProc("GetClipboardData")
@@ -354,6 +430,7 @@ var (
 	_GetMessage                  = user32.NewProc("GetMessageW")
 	_GetMessageTime              = user32.NewProc("GetMessageTime")
 	_GetMonitorInfo              = user32.NewProc("GetMonitorInfoW")
+	_GetPointerInfo              = user32.NewProc("GetPointerInfo")
 	_GetSystemMetrics            = user32.NewProc("GetSystemMetrics")
 	_GetWindowLong               = user32.NewProc("GetWindowLongPtrW")
 	_GetWindowLong32             = user32.NewProc("GetWindowLongW")
@@ -371,6 +448,7 @@ var (
 	_PostQuitMessage             = user32.NewProc("PostQuitMessage")
 	_ReleaseCapture              = user32.NewProc("ReleaseCapture")
 	_RegisterClassExW            = user32.NewProc("RegisterClassExW")
+	_RegisterTouchWindow         = user32.NewProc("RegisterTouchWindow")
 	_ReleaseDC                   = user32.NewProc("ReleaseDC")
 	_ScreenToClient              = user32.NewProc("ScreenToClient")
 	_ShowWindow                  = user32.NewProc("ShowWindow")
@@ -444,6 +522,31 @@ func CreateWindowEx(dwExStyle uint32, lpClassName uint16, lpWindowName string, d
 	return syscall.Handle(hwnd), nil
 }
 
+func GetPointerInfo(pointerId uint32) (PointerInfo, error) {
+	var info PointerInfo
+	r1, _, err := _GetPointerInfo.Call(uintptr(pointerId), uintptr(unsafe.Pointer(&info)))
+	if r1 == 0 {
+		return PointerInfo{}, fmt.Errorf("GetPointerInfo failed: %v", err)
+	}
+	return info, nil
+}
+
+func RegisterTouchWindow(hwnd syscall.Handle, flags uint32) error {
+	r1, _, err := _RegisterTouchWindow.Call(uintptr(hwnd), uintptr(flags))
+	if r1 == 0 {
+		return fmt.Errorf("RegisterTouchWindow failed: %v", err)
+	}
+	return nil
+}
+
+func EnableMouseInPointer(enable uint) error {
+	r1, _, err := _EnableMouseInPointer.Call(uintptr(enable))
+	if r1 == 0 {
+		return fmt.Errorf("EnableMouseInPointer failed: %v", err)
+	}
+	return nil
+}
+
 func DefWindowProc(hwnd syscall.Handle, msg uint32, wparam, lparam uintptr) uintptr {
 	r, _, _ := _DefWindowProc.Call(uintptr(hwnd), uintptr(msg), wparam, lparam)
 	return r

app/internal/xkb/xkb_unix.go

@@ -238,17 +238,17 @@ func (x *Context) UpdateMask(depressed, latched, locked, depressedGroup, latched
 		C.xkb_layout_index_t(depressedGroup), C.xkb_layout_index_t(latchedGroup), C.xkb_layout_index_t(lockedGroup))
 }
 
-func convertKeysym(s C.xkb_keysym_t) (string, bool) {
+func convertKeysym(s C.xkb_keysym_t) (key.Name, bool) {
 	if 'a' <= s && s <= 'z' {
-		return string(rune(s - 'a' + 'A')), true
+		return key.Name(rune(s - 'a' + 'A')), true
 	}
 	if C.XKB_KEY_KP_0 <= s && s <= C.XKB_KEY_KP_9 {
-		return string(rune(s - C.XKB_KEY_KP_0 + '0')), true
+		return key.Name(rune(s - C.XKB_KEY_KP_0 + '0')), true
 	}
 	if ' ' < s && s <= '~' {
-		return string(rune(s)), true
+		return key.Name(rune(s)), true
 	}
-	var n string
+	var n key.Name
 	switch s {
 	case C.XKB_KEY_Escape:
 		n = key.NameEscape

app/log_android.go

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-package log
+package app
 
 /*
 #cgo LDFLAGS: -llog
@@ -22,7 +22,7 @@ import (
 // 1024 is the truncation limit from android/log.h, plus a \n.
 const logLineLimit = 1024
 
-var logTag = C.CString(appID)
+var logTag = C.CString(ID)
 
 func init() {
 	// Android's logcat already includes timestamps.

app/log_ios.go

@@ -3,7 +3,7 @@
 //go:build darwin && ios
 // +build darwin,ios
 
-package log
+package app
 
 /*
 #cgo CFLAGS: -Werror -fmodules -fobjc-arc -x objective-c

app/log_windows.go

@@ -1,17 +1,18 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-package log
+package app
 
 import (
 	"log"
-	"syscall"
 	"unsafe"
+
+	syscall "golang.org/x/sys/windows"
 )
 
 type logger struct{}
 
 var (
-	kernel32           = syscall.NewLazyDLL("kernel32")
+	kernel32           = syscall.NewLazySystemDLL("kernel32")
 	outputDebugStringW = kernel32.NewProc("OutputDebugStringW")
 	debugView          *logger
 )

app/metal_darwin.go

@@ -60,8 +60,9 @@ static void presentDrawable(CFTypeRef queueRef, CFTypeRef drawableRef) {
 		id<MTLDrawable> drawable = (__bridge id<MTLDrawable>)drawableRef;
 		id<MTLCommandQueue> queue = (__bridge id<MTLCommandQueue>)queueRef;
 		id<MTLCommandBuffer> cmdBuffer = [queue commandBuffer];
-		[cmdBuffer presentDrawable:drawable];
 		[cmdBuffer commit];
+		[cmdBuffer waitUntilScheduled];
+		[drawable present];
 	}
 }
 
@@ -95,7 +96,7 @@ func newMtlContext(w *window) (*mtlContext, error) {
 		return nil, errors.New("metal: CAMetalLayer construction failed")
 	}
 	queue := C.newCommandQueue(dev)
-	if layer == 0 {
+	if queue == 0 {
 		C.CFRelease(dev)
 		C.CFRelease(layer)
 		return nil, errors.New("metal: [MTLDevice newCommandQueue] failed")

app/metal_ios.go

@@ -21,7 +21,10 @@ Class gio_layerClass(void) {
 static CFTypeRef getMetalLayer(CFTypeRef viewRef) {
 	@autoreleasepool {
 		UIView *view = (__bridge UIView *)viewRef;
-		return CFBridgingRetain(view.layer);
+		CAMetalLayer *l = (CAMetalLayer *)view.layer;
+		l.needsDisplayOnBoundsChange = YES;
+		l.presentsWithTransaction = YES;
+		return CFBridgingRetain(l);
 	}
 }
 

app/metal_macos.go

@@ -12,9 +12,13 @@ package app
 #import <QuartzCore/CAMetalLayer.h>
 #include <CoreFoundation/CoreFoundation.h>
 
-CALayer *gio_layerFactory(void) {
+CALayer *gio_layerFactory(BOOL presentWithTrans) {
 	@autoreleasepool {
-		return [CAMetalLayer layer];
+		CAMetalLayer *l = [CAMetalLayer layer];
+		l.autoresizingMask = kCALayerHeightSizable|kCALayerWidthSizable;
+		l.needsDisplayOnBoundsChange = YES;
+		l.presentsWithTransaction = presentWithTrans;
+		return l;
 	}
 }
 

app/os.go

@@ -7,7 +7,9 @@ import (
 	"image"
 	"image/color"
 
+	"gioui.org/io/event"
 	"gioui.org/io/key"
+	"gioui.org/op"
 
 	"gioui.org/gpu"
 	"gioui.org/io/pointer"
@@ -43,6 +45,8 @@ type Config struct {
 	CustomRenderer bool
 	// Decorated reports whether window decorations are provided automatically.
 	Decorated bool
+	// Focused reports whether has the keyboard focus.
+	Focused bool
 	// decoHeight is the height of the fallback decoration for platforms such
 	// as Wayland that may need fallback client-side decorations.
 	decoHeight unit.Dp
@@ -131,8 +135,30 @@ func (o Orientation) String() string {
 	return ""
 }
 
+// eventLoop implements the functionality required for drivers where
+// window event loops must run on a separate thread.
+type eventLoop struct {
+	win *callbacks
+	// wakeup is the callback to wake up the event loop.
+	wakeup func()
+	// driverFuncs is a channel of functions to run the next
+	// time the window loop waits for events.
+	driverFuncs chan func()
+	// invalidates is notified when an invalidate is requested by the client.
+	invalidates chan struct{}
+	// immediateInvalidates is an optimistic invalidates that doesn't require a wakeup.
+	immediateInvalidates chan struct{}
+	// events is where the platform backend delivers events bound for the
+	// user program.
+	events   chan event.Event
+	frames   chan *op.Ops
+	frameAck chan struct{}
+	// delivering avoids re-entrant event delivery.
+	delivering bool
+}
+
 type frameEvent struct {
-	system.FrameEvent
+	FrameEvent
 
 	Sync bool
 }
@@ -147,9 +173,13 @@ type context interface {
 	Unlock()
 }
 
-// Driver is the interface for the platform implementation
+// driver is the interface for the platform implementation
 // of a window.
 type driver interface {
+	// Event blocks until an event is available and returns it.
+	Event() event.Event
+	// Invalidate requests a FrameEvent.
+	Invalidate()
 	// SetAnimating sets the animation flag. When the window is animating,
 	// FrameEvents are delivered as fast as the display can handle them.
 	SetAnimating(anim bool)
@@ -160,23 +190,27 @@ type driver interface {
 	// ReadClipboard requests the clipboard content.
 	ReadClipboard()
 	// WriteClipboard requests a clipboard write.
-	WriteClipboard(s string)
+	WriteClipboard(mime string, s []byte)
 	// Configure the window.
 	Configure([]Option)
 	// SetCursor updates the current cursor to name.
 	SetCursor(cursor pointer.Cursor)
-	// Wakeup wakes up the event loop and sends a WakeupEvent.
-	Wakeup()
 	// Perform actions on the window.
 	Perform(system.Action)
 	// EditorStateChanged notifies the driver that the editor state changed.
 	EditorStateChanged(old, new editorState)
+	// Run a function on the window thread.
+	Run(f func())
+	// Frame receives a frame.
+	Frame(frame *op.Ops)
+	// ProcessEvent processes an event.
+	ProcessEvent(e event.Event)
 }
 
 type windowRendezvous struct {
-	in   chan windowAndConfig
+	in      chan windowAndConfig
-	out  chan windowAndConfig
+	out     chan windowAndConfig
-	errs chan error
+	windows chan struct{}
 }
 
 type windowAndConfig struct {
@@ -186,32 +220,137 @@ type windowAndConfig struct {
 
 func newWindowRendezvous() *windowRendezvous {
 	wr := &windowRendezvous{
-		in:   make(chan windowAndConfig),
+		in:      make(chan windowAndConfig),
-		out:  make(chan windowAndConfig),
+		out:     make(chan windowAndConfig),
-		errs: make(chan error),
+		windows: make(chan struct{}),
 	}
 	go func() {
-		var main windowAndConfig
+		in := wr.in
+		var window windowAndConfig
 		var out chan windowAndConfig
 		for {
 			select {
-			case w := <-wr.in:
+			case w := <-in:
-				var err error
+				window = w
-				if main.window != nil {
-					err = errors.New("multiple windows are not supported")
-				}
-				wr.errs <- err
-				main = w
 				out = wr.out
-			case out <- main:
+			case out <- window:
 			}
 		}
 	}()
 	return wr
 }
 
-func (wakeupEvent) ImplementsEvent() {}
+func newEventLoop(w *callbacks, wakeup func()) *eventLoop {
-func (ConfigEvent) ImplementsEvent() {}
+	return &eventLoop{
+		win:                  w,
+		wakeup:               wakeup,
+		events:               make(chan event.Event),
+		invalidates:          make(chan struct{}, 1),
+		immediateInvalidates: make(chan struct{}),
+		frames:               make(chan *op.Ops),
+		frameAck:             make(chan struct{}),
+		driverFuncs:          make(chan func(), 1),
+	}
+}
+
+// Frame receives a frame and waits for its processing. It is called by
+// the client goroutine.
+func (e *eventLoop) Frame(frame *op.Ops) {
+	e.frames <- frame
+	<-e.frameAck
+}
+
+// Event returns the next available event. It is called by the client
+// goroutine.
+func (e *eventLoop) Event() event.Event {
+	for {
+		evt := <-e.events
+		// Receiving a flushEvent indicates to the platform backend that
+		// all previous events have been processed by the user program.
+		if _, ok := evt.(flushEvent); ok {
+			continue
+		}
+		return evt
+	}
+}
+
+// Invalidate requests invalidation of the window. It is called by the client
+// goroutine.
+func (e *eventLoop) Invalidate() {
+	select {
+	case e.immediateInvalidates <- struct{}{}:
+		// The event loop was waiting, no need for a wakeup.
+	case e.invalidates <- struct{}{}:
+		// The event loop is sleeping, wake it up.
+		e.wakeup()
+	default:
+		// A redraw is pending.
+	}
+}
+
+// Run f in the window loop thread. It is called by the client goroutine.
+func (e *eventLoop) Run(f func()) {
+	e.driverFuncs <- f
+	e.wakeup()
+}
+
+// FlushEvents delivers pending events to the client.
+func (e *eventLoop) FlushEvents() {
+	if e.delivering {
+		return
+	}
+	e.delivering = true
+	defer func() { e.delivering = false }()
+	for {
+		evt, ok := e.win.nextEvent()
+		if !ok {
+			break
+		}
+		e.deliverEvent(evt)
+	}
+}
+
+func (e *eventLoop) deliverEvent(evt event.Event) {
+	var frames <-chan *op.Ops
+	for {
+		select {
+		case f := <-e.driverFuncs:
+			f()
+		case frame := <-frames:
+			// The client called FrameEvent.Frame.
+			frames = nil
+			e.win.ProcessFrame(frame, e.frameAck)
+		case e.events <- evt:
+			switch evt.(type) {
+			case flushEvent, DestroyEvent:
+				// DestroyEvents are not flushed.
+				return
+			case FrameEvent:
+				frames = e.frames
+			}
+			evt = theFlushEvent
+		case <-e.invalidates:
+			e.win.Invalidate()
+		case <-e.immediateInvalidates:
+			e.win.Invalidate()
+		}
+	}
+}
+
+func (e *eventLoop) Wakeup() {
+	for {
+		select {
+		case f := <-e.driverFuncs:
+			f()
+		case <-e.invalidates:
+			e.win.Invalidate()
+		case <-e.immediateInvalidates:
+			e.win.Invalidate()
+		default:
+			return
+		}
+	}
+}
 
 func walkActions(actions system.Action, do func(system.Action)) {
 	for a := system.Action(1); actions != 0; a <<= 1 {
@@ -221,3 +360,6 @@ func walkActions(actions system.Action, do func(system.Action)) {
 		}
 	}
 }
+
+func (wakeupEvent) ImplementsEvent() {}
+func (ConfigEvent) ImplementsEvent() {}

app/os_android.go

@@ -123,31 +123,36 @@ import (
 	"fmt"
 	"image"
 	"image/color"
+	"io"
 	"math"
 	"os"
 	"path/filepath"
 	"runtime"
 	"runtime/cgo"
 	"runtime/debug"
+	"strings"
 	"sync"
 	"time"
 	"unicode/utf16"
 	"unsafe"
 
 	"gioui.org/internal/f32color"
+	"gioui.org/op"
 
 	"gioui.org/f32"
-	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
+	"gioui.org/io/input"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
-	"gioui.org/io/router"
 	"gioui.org/io/semantic"
 	"gioui.org/io/system"
+	"gioui.org/io/transfer"
 	"gioui.org/unit"
 )
 
 type window struct {
 	callbacks *callbacks
+	loop      *eventLoop
 
 	view   C.jobject
 	handle cgo.Handle
@@ -156,18 +161,19 @@ type window struct {
 	fontScale float32
 	insets    pixelInsets
 
-	stage     system.Stage
+	visible   bool
 	started   bool
 	animating bool
 
-	win    *C.ANativeWindow
+	win       *C.ANativeWindow
-	config Config
+	config    Config
+	inputHint key.InputHint
 
 	semantic struct {
-		hoverID router.SemanticID
+		hoverID input.SemanticID
-		rootID  router.SemanticID
+		rootID  input.SemanticID
-		focusID router.SemanticID
+		focusID input.SemanticID
-		diffs   []router.SemanticID
+		diffs   []input.SemanticID
 	}
 }
 
@@ -199,9 +205,9 @@ type pixelInsets struct {
 	top, bottom, left, right int
 }
 
-// ViewEvent is sent whenever the Window's underlying Android view
+// AndroidViewEvent is sent whenever the Window's underlying Android view
 // changes.
-type ViewEvent struct {
+type AndroidViewEvent struct {
 	// View is a JNI global reference to the android.view.View
 	// instance backing the Window. The reference is valid until
 	// the next ViewEvent is received.
@@ -485,24 +491,30 @@ func Java_org_gioui_GioView_onCreateView(env *C.JNIEnv, class C.jclass, view C.j
 	})
 	view = C.jni_NewGlobalRef(env, view)
 	wopts := <-mainWindow.out
+	var cnf Config
 	w, ok := windows[wopts.window]
 	if !ok {
 		w = &window{
 			callbacks: wopts.window,
 		}
+		w.loop = newEventLoop(w.callbacks, w.wakeup)
+		w.callbacks.SetDriver(w)
+		cnf.apply(unit.Metric{}, wopts.options)
 		windows[wopts.window] = w
+	} else {
+		cnf = w.config
 	}
+	mainWindow.windows <- struct{}{}
 	if w.view != 0 {
 		w.detach(env)
 	}
 	w.view = view
+	w.visible = false
 	w.handle = cgo.NewHandle(w)
-	w.callbacks.SetDriver(w)
 	w.loadConfig(env, class)
-	w.Configure(wopts.options)
+	w.setConfig(env, cnf)
-	w.SetInputHint(key.HintAny)
+	w.SetInputHint(w.inputHint)
-	w.setStage(system.StagePaused)
+	w.processEvent(AndroidViewEvent{View: uintptr(view)})
-	w.callbacks.Event(ViewEvent{View: uintptr(view)})
 	return C.jlong(w.handle)
 }
 
@@ -516,7 +528,7 @@ func Java_org_gioui_GioView_onDestroyView(env *C.JNIEnv, class C.jclass, handle
 func Java_org_gioui_GioView_onStopView(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 	w := cgo.Handle(handle).Value().(*window)
 	w.started = false
-	w.setStage(system.StagePaused)
+	w.visible = false
 }
 
 //export Java_org_gioui_GioView_onStartView
@@ -532,7 +544,7 @@ func Java_org_gioui_GioView_onStartView(env *C.JNIEnv, class C.jclass, handle C.
 func Java_org_gioui_GioView_onSurfaceDestroyed(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 	w := cgo.Handle(handle).Value().(*window)
 	w.win = nil
-	w.setStage(system.StagePaused)
+	w.visible = false
 }
 
 //export Java_org_gioui_GioView_onSurfaceChanged
@@ -554,9 +566,7 @@ func Java_org_gioui_GioView_onLowMemory(env *C.JNIEnv, class C.jclass) {
 func Java_org_gioui_GioView_onConfigurationChanged(env *C.JNIEnv, class C.jclass, view C.jlong) {
 	w := cgo.Handle(view).Value().(*window)
 	w.loadConfig(env, class)
-	if w.stage >= system.StageInactive {
+	w.draw(env, true)
-		w.draw(env, true)
-	}
 }
 
 //export Java_org_gioui_GioView_onFrameCallback
@@ -565,19 +575,13 @@ func Java_org_gioui_GioView_onFrameCallback(env *C.JNIEnv, class C.jclass, view
 	if !exist {
 		return
 	}
-	if w.stage < system.StageInactive {
+	w.draw(env, false)
-		return
-	}
-	if w.animating {
-		w.draw(env, false)
-		callVoidMethod(env, w.view, gioView.postFrameCallback)
-	}
 }
 
 //export Java_org_gioui_GioView_onBack
 func Java_org_gioui_GioView_onBack(env *C.JNIEnv, class C.jclass, view C.jlong) C.jboolean {
 	w := cgo.Handle(view).Value().(*window)
-	if w.callbacks.Event(key.Event{Name: key.NameBack}) {
+	if w.processEvent(key.Event{Name: key.NameBack}) {
 		return C.JNI_TRUE
 	}
 	return C.JNI_FALSE
@@ -586,7 +590,8 @@ func Java_org_gioui_GioView_onBack(env *C.JNIEnv, class C.jclass, view C.jlong)
 //export Java_org_gioui_GioView_onFocusChange
 func Java_org_gioui_GioView_onFocusChange(env *C.JNIEnv, class C.jclass, view C.jlong, focus C.jboolean) {
 	w := cgo.Handle(view).Value().(*window)
-	w.callbacks.Event(key.FocusEvent{Focus: focus == C.JNI_TRUE})
+	w.config.Focused = focus == C.JNI_TRUE
+	w.processEvent(ConfigEvent{Config: w.config})
 }
 
 //export Java_org_gioui_GioView_onWindowInsets
@@ -598,9 +603,7 @@ func Java_org_gioui_GioView_onWindowInsets(env *C.JNIEnv, class C.jclass, view C
 		left:   int(left),
 		right:  int(right),
 	}
-	if w.stage >= system.StageInactive {
+	w.draw(env, true)
-		w.draw(env, true)
-	}
 }
 
 //export Java_org_gioui_GioView_initializeAccessibilityNodeInfo
@@ -661,7 +664,35 @@ func Java_org_gioui_GioView_onClearA11yFocus(env *C.JNIEnv, class C.jclass, view
 	}
 }
 
-func (w *window) initAccessibilityNodeInfo(env *C.JNIEnv, sem router.SemanticNode, off image.Point, info C.jobject) error {
+func (w *window) ProcessEvent(e event.Event) {
+	w.processEvent(e)
+}
+
+func (w *window) processEvent(e event.Event) bool {
+	if !w.callbacks.ProcessEvent(e) {
+		return false
+	}
+	w.loop.FlushEvents()
+	return true
+}
+
+func (w *window) Event() event.Event {
+	return w.loop.Event()
+}
+
+func (w *window) Invalidate() {
+	w.loop.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	w.loop.Run(f)
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.loop.Frame(frame)
+}
+
+func (w *window) initAccessibilityNodeInfo(env *C.JNIEnv, sem input.SemanticNode, off image.Point, info C.jobject) error {
 	for _, ch := range sem.Children {
 		err := callVoidMethod(env, info, android.accessibilityNodeInfo.addChild, jvalue(w.view), jvalue(w.virtualIDFor(ch.ID)))
 		if err != nil {
@@ -704,7 +735,7 @@ func (w *window) initAccessibilityNodeInfo(env *C.JNIEnv, sem router.SemanticNod
 			panic(err)
 		}
 	}
-	if d.Gestures&router.ClickGesture != 0 {
+	if d.Gestures&input.ClickGesture != 0 {
 		addAction(ACTION_CLICK)
 	}
 	clsName := android.strings.androidViewView
@@ -749,25 +780,23 @@ func (w *window) initAccessibilityNodeInfo(env *C.JNIEnv, sem router.SemanticNod
 	return nil
 }
 
-func (w *window) virtualIDFor(id router.SemanticID) C.jint {
+func (w *window) virtualIDFor(id input.SemanticID) C.jint {
-	// TODO: Android virtual IDs are 32-bit Java integers, but childID is a int64.
 	if id == w.semantic.rootID {
 		return HOST_VIEW_ID
 	}
 	return C.jint(id)
 }
 
-func (w *window) semIDFor(virtID C.jint) router.SemanticID {
+func (w *window) semIDFor(virtID C.jint) input.SemanticID {
 	if virtID == HOST_VIEW_ID {
 		return w.semantic.rootID
 	}
-	return router.SemanticID(virtID)
+	return input.SemanticID(virtID)
 }
 
 func (w *window) detach(env *C.JNIEnv) {
 	callVoidMethod(env, w.view, gioView.unregister)
-	w.callbacks.Event(ViewEvent{})
+	w.processEvent(AndroidViewEvent{})
-	w.callbacks.SetDriver(nil)
 	w.handle.Delete()
 	C.jni_DeleteGlobalRef(env, w.view)
 	w.view = 0
@@ -778,18 +807,10 @@ func (w *window) setVisible(env *C.JNIEnv) {
 	if width == 0 || height == 0 {
 		return
 	}
-	w.setStage(system.StageRunning)
+	w.visible = true
 	w.draw(env, true)
 }
 
-func (w *window) setStage(stage system.Stage) {
-	if stage == w.stage {
-		return
-	}
-	w.stage = stage
-	w.callbacks.Event(system.StageEvent{stage})
-}
-
 func (w *window) setVisual(visID int) error {
 	if C.ANativeWindow_setBuffersGeometry(w.win, 0, 0, C.int32_t(visID)) != 0 {
 		return errors.New("ANativeWindow_setBuffersGeometry failed")
@@ -826,10 +847,13 @@ func (w *window) SetAnimating(anim bool) {
 }
 
 func (w *window) draw(env *C.JNIEnv, sync bool) {
+	if !w.visible {
+		return
+	}
 	size := image.Pt(int(C.ANativeWindow_getWidth(w.win)), int(C.ANativeWindow_getHeight(w.win)))
 	if size != w.config.Size {
 		w.config.Size = size
-		w.callbacks.Event(ConfigEvent{Config: w.config})
+		w.processEvent(ConfigEvent{Config: w.config})
 	}
 	if size.X == 0 || size.Y == 0 {
 		return
@@ -837,14 +861,14 @@ func (w *window) draw(env *C.JNIEnv, sync bool) {
 	const inchPrDp = 1.0 / 160
 	ppdp := float32(w.dpi) * inchPrDp
 	dppp := unit.Dp(1.0 / ppdp)
-	insets := system.Insets{
+	insets := Insets{
 		Top:    unit.Dp(w.insets.top) * dppp,
 		Bottom: unit.Dp(w.insets.bottom) * dppp,
 		Left:   unit.Dp(w.insets.left) * dppp,
 		Right:  unit.Dp(w.insets.right) * dppp,
 	}
-	w.callbacks.Event(frameEvent{
+	w.processEvent(frameEvent{
-		FrameEvent: system.FrameEvent{
+		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   w.config.Size,
 			Insets: insets,
@@ -855,6 +879,9 @@ func (w *window) draw(env *C.JNIEnv, sync bool) {
 		},
 		Sync: sync,
 	})
+	if w.animating {
+		callVoidMethod(env, w.view, gioView.postFrameCallback)
+	}
 	a11yActive, err := callBooleanMethod(env, w.view, gioView.isA11yActive)
 	if err != nil {
 		panic(err)
@@ -898,8 +925,8 @@ func runInJVM(jvm *C.JavaVM, f func(env *C.JNIEnv)) {
 	f(env)
 }
 
-func convertKeyCode(code C.jint) (string, bool) {
+func convertKeyCode(code C.jint) (key.Name, bool) {
-	var n string
+	var n key.Name
 	switch code {
 	case C.AKEYCODE_FORWARD_DEL:
 		n = key.NameDeleteForward
@@ -943,7 +970,7 @@ func Java_org_gioui_GioView_onKeyEvent(env *C.JNIEnv, class C.jclass, handle C.j
 		if pressed == C.JNI_TRUE {
 			state = key.Press
 		}
-		w.callbacks.Event(key.Event{Name: n, State: state})
+		w.processEvent(key.Event{Name: n, State: state})
 	}
 	if pressed == C.JNI_TRUE && r != 0 && r != '\n' { // Checking for "\n" to prevent duplication with key.NameEnter (gio#224).
 		w.callbacks.EditorInsert(string(rune(r)))
@@ -993,7 +1020,7 @@ func Java_org_gioui_GioView_onTouchEvent(env *C.JNIEnv, class C.jclass, handle C
 	default:
 		return
 	}
-	w.callbacks.Event(pointer.Event{
+	w.processEvent(pointer.Event{
 		Kind:      kind,
 		Source:    src,
 		Buttons:   btns,
@@ -1145,6 +1172,8 @@ func (w *window) ShowTextInput(show bool) {
 }
 
 func (w *window) SetInputHint(mode key.InputHint) {
+	w.inputHint = mode
+
 	// Constants defined at https://developer.android.com/reference/android/text/InputType.
 	const (
 		TYPE_NULL = 0
@@ -1291,14 +1320,14 @@ func findClass(env *C.JNIEnv, name string) C.jclass {
 func osMain() {
 }
 
-func newWindow(window *callbacks, options []Option) error {
+func newWindow(window *callbacks, options []Option) {
 	mainWindow.in <- windowAndConfig{window, options}
-	return <-mainWindow.errs
+	<-mainWindow.windows
 }
 
-func (w *window) WriteClipboard(s string) {
+func (w *window) WriteClipboard(mime string, s []byte) {
 	runInJVM(javaVM(), func(env *C.JNIEnv) {
-		jstr := javaString(env, s)
+		jstr := javaString(env, string(s))
 		callStaticVoidMethod(env, android.gioCls, android.mwriteClipboard,
 			jvalue(android.appCtx), jvalue(jstr))
 	})
@@ -1312,47 +1341,56 @@ func (w *window) ReadClipboard() {
 			return
 		}
 		content := goString(env, C.jstring(c))
-		w.callbacks.Event(clipboard.Event{Text: content})
+		w.processEvent(transfer.DataEvent{
+			Type: "application/text",
+			Open: func() io.ReadCloser {
+				return io.NopCloser(strings.NewReader(content))
+			},
+		})
 	})
 }
 
 func (w *window) Configure(options []Option) {
+	cnf := w.config
+	cnf.apply(unit.Metric{}, options)
 	runInJVM(javaVM(), func(env *C.JNIEnv) {
-		prev := w.config
+		w.setConfig(env, cnf)
-		cnf := w.config
-		cnf.apply(unit.Metric{}, options)
-		// Decorations are never disabled.
-		cnf.Decorated = true
-
-		if prev.Orientation != cnf.Orientation {
-			w.config.Orientation = cnf.Orientation
-			setOrientation(env, w.view, cnf.Orientation)
-		}
-		if prev.NavigationColor != cnf.NavigationColor {
-			w.config.NavigationColor = cnf.NavigationColor
-			setNavigationColor(env, w.view, cnf.NavigationColor)
-		}
-		if prev.StatusColor != cnf.StatusColor {
-			w.config.StatusColor = cnf.StatusColor
-			setStatusColor(env, w.view, cnf.StatusColor)
-		}
-		if prev.Mode != cnf.Mode {
-			switch cnf.Mode {
-			case Fullscreen:
-				callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_TRUE)
-				w.config.Mode = Fullscreen
-			case Windowed:
-				callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_FALSE)
-				w.config.Mode = Windowed
-			}
-		}
-		if cnf.Decorated != prev.Decorated {
-			w.config.Decorated = cnf.Decorated
-		}
-		w.callbacks.Event(ConfigEvent{Config: w.config})
 	})
 }
 
+func (w *window) setConfig(env *C.JNIEnv, cnf Config) {
+	prev := w.config
+	// Decorations are never disabled.
+	cnf.Decorated = true
+
+	if prev.Orientation != cnf.Orientation {
+		w.config.Orientation = cnf.Orientation
+		setOrientation(env, w.view, cnf.Orientation)
+	}
+	if prev.NavigationColor != cnf.NavigationColor {
+		w.config.NavigationColor = cnf.NavigationColor
+		setNavigationColor(env, w.view, cnf.NavigationColor)
+	}
+	if prev.StatusColor != cnf.StatusColor {
+		w.config.StatusColor = cnf.StatusColor
+		setStatusColor(env, w.view, cnf.StatusColor)
+	}
+	if prev.Mode != cnf.Mode {
+		switch cnf.Mode {
+		case Fullscreen:
+			callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_TRUE)
+			w.config.Mode = Fullscreen
+		case Windowed:
+			callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_FALSE)
+			w.config.Mode = Windowed
+		}
+	}
+	if cnf.Decorated != prev.Decorated {
+		w.config.Decorated = cnf.Decorated
+	}
+	w.processEvent(ConfigEvent{Config: w.config})
+}
+
 func (w *window) Perform(system.Action) {}
 
 func (w *window) SetCursor(cursor pointer.Cursor) {
@@ -1361,9 +1399,10 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 	})
 }
 
-func (w *window) Wakeup() {
+func (w *window) wakeup() {
 	runOnMain(func(env *C.JNIEnv) {
-		w.callbacks.Event(wakeupEvent{})
+		w.loop.Wakeup()
+		w.loop.FlushEvents()
 	})
 }
 
@@ -1454,4 +1493,8 @@ func Java_org_gioui_Gio_scheduleMainFuncs(env *C.JNIEnv, cls C.jclass) {
 	}
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (AndroidViewEvent) implementsViewEvent() {}
+func (AndroidViewEvent) ImplementsEvent()     {}
+func (a AndroidViewEvent) Valid() bool {
+	return a != (AndroidViewEvent{})
+}

app/os_darwin.go

@@ -5,7 +5,7 @@ package app
 /*
 #include <Foundation/Foundation.h>
 
-__attribute__ ((visibility ("hidden"))) void gio_wakeupMainThread(void);
+__attribute__ ((visibility ("hidden"))) void gio_runOnMain(uintptr_t h);
 __attribute__ ((visibility ("hidden"))) CFTypeRef gio_createDisplayLink(void);
 __attribute__ ((visibility ("hidden"))) void gio_releaseDisplayLink(CFTypeRef dl);
 __attribute__ ((visibility ("hidden"))) int gio_startDisplayLink(CFTypeRef dl);
@@ -40,8 +40,10 @@ static CFTypeRef newNSString(unichar *chars, NSUInteger length) {
 }
 */
 import "C"
+
 import (
 	"errors"
+	"runtime/cgo"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -73,30 +75,25 @@ type displayLink struct {
 // displayLinks maps CFTypeRefs to *displayLinks.
 var displayLinks sync.Map
 
-var mainFuncs = make(chan func(), 1)
+func isMainThread() bool {
+	return bool(C.isMainThread())
+}
 
 // runOnMain runs the function on the main thread.
 func runOnMain(f func()) {
-	if C.isMainThread() {
+	if isMainThread() {
 		f()
 		return
 	}
-	go func() {
+	C.gio_runOnMain(C.uintptr_t(cgo.NewHandle(f)))
-		mainFuncs <- f
-		C.gio_wakeupMainThread()
-	}()
 }
 
-//export gio_dispatchMainFuncs
+//export gio_runFunc
-func gio_dispatchMainFuncs() {
+func gio_runFunc(h C.uintptr_t) {
-	for {
+	handle := cgo.Handle(h)
-		select {
+	defer handle.Delete()
-		case f := <-mainFuncs:
+	f := handle.Value().(func())
-			f()
+	f()
-		default:
-			return
-		}
-	}
 }
 
 // nsstringToString converts a NSString to a Go string.
@@ -260,8 +257,9 @@ func windowSetCursor(from, to pointer.Cursor) pointer.Cursor {
 	return to
 }
 
-func (w *window) Wakeup() {
+func (w *window) wakeup() {
 	runOnMain(func() {
-		w.w.Event(wakeupEvent{})
+		w.loop.Wakeup()
+		w.loop.FlushEvents()
 	})
 }

app/os_darwin.m

@@ -4,8 +4,8 @@
 
 #include "_cgo_export.h"
 
-void gio_wakeupMainThread(void) {
+void gio_runOnMain(uintptr_t h) {
 	dispatch_async(dispatch_get_main_queue(), ^{
-		gio_dispatchMainFuncs();
+		gio_runFunc(h);
 	});
 }

app/os_ios.go

@@ -12,6 +12,9 @@ package app
 #include <UIKit/UIKit.h>
 #include <stdint.h>
 
+__attribute__ ((visibility ("hidden"))) int gio_applicationMain(int argc, char *argv[]);
+__attribute__ ((visibility ("hidden"))) void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle);
+
 struct drawParams {
 	CGFloat dpi, sdpi;
 	CGFloat width, height;
@@ -19,6 +22,7 @@ struct drawParams {
 };
 
 static void writeClipboard(unichar *chars, NSUInteger length) {
+#if !TARGET_OS_TV
 	@autoreleasepool {
 		NSString *s = [NSString string];
 		if (length > 0) {
@@ -27,13 +31,18 @@ static void writeClipboard(unichar *chars, NSUInteger length) {
 		UIPasteboard *p = UIPasteboard.generalPasteboard;
 		p.string = s;
 	}
+#endif
 }
 
 static CFTypeRef readClipboard(void) {
+#if !TARGET_OS_TV
 	@autoreleasepool {
 		UIPasteboard *p = UIPasteboard.generalPasteboard;
 		return (__bridge_retained CFTypeRef)p.string;
 	}
+#else
+	return nil;
+#endif
 }
 
 static void showTextInput(CFTypeRef viewRef) {
@@ -72,21 +81,27 @@ import "C"
 
 import (
 	"image"
+	"io"
+	"os"
 	"runtime"
+	"runtime/cgo"
 	"runtime/debug"
+	"strings"
 	"time"
 	"unicode/utf16"
 	"unsafe"
 
 	"gioui.org/f32"
-	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
+	"gioui.org/io/transfer"
+	"gioui.org/op"
 	"gioui.org/unit"
 )
 
-type ViewEvent struct {
+type UIKitViewEvent struct {
 	// ViewController is a CFTypeRef for the UIViewController backing a Window.
 	ViewController uintptr
 }
@@ -95,18 +110,17 @@ type window struct {
 	view        C.CFTypeRef
 	w           *callbacks
 	displayLink *displayLink
+	loop        *eventLoop
 
-	visible bool
+	hidden bool
-	cursor  pointer.Cursor
+	cursor pointer.Cursor
-	config  Config
+	config Config
 
 	pointerMap []C.CFTypeRef
 }
 
 var mainWindow = newWindowRendezvous()
 
-var views = make(map[C.CFTypeRef]*window)
-
 func init() {
 	// Darwin requires UI operations happen on the main thread only.
 	runtime.LockOSThread()
@@ -114,55 +128,59 @@ func init() {
 
 //export onCreate
 func onCreate(view, controller C.CFTypeRef) {
+	wopts := <-mainWindow.out
 	w := &window{
 		view: view,
+		w:    wopts.window,
 	}
+	w.loop = newEventLoop(w.w, w.wakeup)
+	w.w.SetDriver(w)
+	mainWindow.windows <- struct{}{}
 	dl, err := newDisplayLink(func() {
 		w.draw(false)
 	})
 	if err != nil {
-		panic(err)
+		w.w.ProcessEvent(DestroyEvent{Err: err})
+		return
 	}
 	w.displayLink = dl
-	wopts := <-mainWindow.out
+	C.gio_viewSetHandle(view, C.uintptr_t(cgo.NewHandle(w)))
-	w.w = wopts.window
-	w.w.SetDriver(w)
-	views[view] = w
 	w.Configure(wopts.options)
-	w.w.Event(system.StageEvent{Stage: system.StagePaused})
+	w.ProcessEvent(UIKitViewEvent{ViewController: uintptr(controller)})
-	w.w.Event(ViewEvent{ViewController: uintptr(controller)})
+}
+
+func viewFor(h C.uintptr_t) *window {
+	return cgo.Handle(h).Value().(*window)
 }
 
 //export gio_onDraw
-func gio_onDraw(view C.CFTypeRef) {
+func gio_onDraw(h C.uintptr_t) {
-	w := views[view]
+	w := viewFor(h)
 	w.draw(true)
 }
 
 func (w *window) draw(sync bool) {
+	if w.hidden {
+		return
+	}
 	params := C.viewDrawParams(w.view)
 	if params.width == 0 || params.height == 0 {
 		return
 	}
-	wasVisible := w.visible
-	w.visible = true
-	if !wasVisible {
-		w.w.Event(system.StageEvent{Stage: system.StageRunning})
-	}
 	const inchPrDp = 1.0 / 163
 	m := unit.Metric{
 		PxPerDp: float32(params.dpi) * inchPrDp,
 		PxPerSp: float32(params.sdpi) * inchPrDp,
 	}
 	dppp := unit.Dp(1. / m.PxPerDp)
-	w.w.Event(frameEvent{
+	w.ProcessEvent(frameEvent{
-		FrameEvent: system.FrameEvent{
+		FrameEvent: FrameEvent{
 			Now: time.Now(),
 			Size: image.Point{
 				X: int(params.width + .5),
 				Y: int(params.height + .5),
 			},
-			Insets: system.Insets{
+			Insets: Insets{
 				Top:    unit.Dp(params.top) * dppp,
 				Bottom: unit.Dp(params.bottom) * dppp,
 				Left:   unit.Dp(params.left) * dppp,
@@ -175,26 +193,34 @@ func (w *window) draw(sync bool) {
 }
 
 //export onStop
-func onStop(view C.CFTypeRef) {
+func onStop(h C.uintptr_t) {
-	w := views[view]
+	w := viewFor(h)
-	w.visible = false
+	w.hidden = true
-	w.w.Event(system.StageEvent{Stage: system.StagePaused})
+}
+
+//export onStart
+func onStart(h C.uintptr_t) {
+	w := viewFor(h)
+	w.hidden = false
+	w.draw(true)
 }
 
 //export onDestroy
-func onDestroy(view C.CFTypeRef) {
+func onDestroy(h C.uintptr_t) {
-	w := views[view]
+	w := viewFor(h)
-	delete(views, view)
+	w.ProcessEvent(UIKitViewEvent{})
-	w.w.Event(ViewEvent{})
+	w.ProcessEvent(DestroyEvent{})
-	w.w.Event(system.DestroyEvent{})
 	w.displayLink.Close()
+	w.displayLink = nil
+	cgo.Handle(h).Delete()
 	w.view = 0
 }
 
 //export onFocus
-func onFocus(view C.CFTypeRef, focus int) {
+func onFocus(h C.uintptr_t, focus int) {
-	w := views[view]
+	w := viewFor(h)
-	w.w.Event(key.FocusEvent{Focus: focus != 0})
+	w.config.Focused = focus != 0
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export onLowMemory
@@ -204,38 +230,38 @@ func onLowMemory() {
 }
 
 //export onUpArrow
-func onUpArrow(view C.CFTypeRef) {
+func onUpArrow(h C.uintptr_t) {
-	views[view].onKeyCommand(key.NameUpArrow)
+	viewFor(h).onKeyCommand(key.NameUpArrow)
 }
 
 //export onDownArrow
-func onDownArrow(view C.CFTypeRef) {
+func onDownArrow(h C.uintptr_t) {
-	views[view].onKeyCommand(key.NameDownArrow)
+	viewFor(h).onKeyCommand(key.NameDownArrow)
 }
 
 //export onLeftArrow
-func onLeftArrow(view C.CFTypeRef) {
+func onLeftArrow(h C.uintptr_t) {
-	views[view].onKeyCommand(key.NameLeftArrow)
+	viewFor(h).onKeyCommand(key.NameLeftArrow)
 }
 
 //export onRightArrow
-func onRightArrow(view C.CFTypeRef) {
+func onRightArrow(h C.uintptr_t) {
-	views[view].onKeyCommand(key.NameRightArrow)
+	viewFor(h).onKeyCommand(key.NameRightArrow)
 }
 
 //export onDeleteBackward
-func onDeleteBackward(view C.CFTypeRef) {
+func onDeleteBackward(h C.uintptr_t) {
-	views[view].onKeyCommand(key.NameDeleteBackward)
+	viewFor(h).onKeyCommand(key.NameDeleteBackward)
 }
 
 //export onText
-func onText(view, str C.CFTypeRef) {
+func onText(h C.uintptr_t, str C.CFTypeRef) {
-	w := views[view]
+	w := viewFor(h)
 	w.w.EditorInsert(nsstringToString(str))
 }
 
 //export onTouch
-func onTouch(last C.int, view, touchRef C.CFTypeRef, phase C.NSInteger, x, y C.CGFloat, ti C.double) {
+func onTouch(h C.uintptr_t, last C.int, touchRef C.CFTypeRef, phase C.NSInteger, x, y C.CGFloat, ti C.double) {
 	var kind pointer.Kind
 	switch phase {
 	case C.UITouchPhaseBegan:
@@ -249,10 +275,10 @@ func onTouch(last C.int, view, touchRef C.CFTypeRef, phase C.NSInteger, x, y C.C
 	default:
 		return
 	}
-	w := views[view]
+	w := viewFor(h)
 	t := time.Duration(float64(ti) * float64(time.Second))
 	p := f32.Point{X: float32(x), Y: float32(y)}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      kind,
 		Source:    pointer.Touch,
 		PointerID: w.lookupTouch(last != 0, touchRef),
@@ -265,11 +291,16 @@ func (w *window) ReadClipboard() {
 	cstr := C.readClipboard()
 	defer C.CFRelease(cstr)
 	content := nsstringToString(cstr)
-	w.w.Event(clipboard.Event{Text: content})
+	w.ProcessEvent(transfer.DataEvent{
+		Type: "application/text",
+		Open: func() io.ReadCloser {
+			return io.NopCloser(strings.NewReader(content))
+		},
+	})
 }
 
-func (w *window) WriteClipboard(s string) {
+func (w *window) WriteClipboard(mime string, s []byte) {
-	u16 := utf16.Encode([]rune(s))
+	u16 := utf16.Encode([]rune(string(s)))
 	var chars *C.unichar
 	if len(u16) > 0 {
 		chars = (*C.unichar)(unsafe.Pointer(&u16[0]))
@@ -280,7 +311,7 @@ func (w *window) WriteClipboard(s string) {
 func (w *window) Configure([]Option) {
 	// Decorations are never disabled.
 	w.config.Decorated = true
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *window) EditorStateChanged(old, new editorState) {}
@@ -288,10 +319,6 @@ func (w *window) EditorStateChanged(old, new editorState) {}
 func (w *window) Perform(system.Action) {}
 
 func (w *window) SetAnimating(anim bool) {
-	v := w.view
-	if v == 0 {
-		return
-	}
 	if anim {
 		w.displayLink.Start()
 	} else {
@@ -303,8 +330,8 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 	w.cursor = windowSetCursor(w.cursor, cursor)
 }
 
-func (w *window) onKeyCommand(name string) {
+func (w *window) onKeyCommand(name key.Name) {
-	w.w.Event(key.Event{
+	w.ProcessEvent(key.Event{
 		Name: name,
 	})
 }
@@ -343,17 +370,77 @@ func (w *window) ShowTextInput(show bool) {
 
 func (w *window) SetInputHint(_ key.InputHint) {}
 
-func newWindow(win *callbacks, options []Option) error {
+func (w *window) ProcessEvent(e event.Event) {
-	mainWindow.in <- windowAndConfig{win, options}
+	w.w.ProcessEvent(e)
-	return <-mainWindow.errs
+	w.loop.FlushEvents()
 }
 
+func (w *window) Event() event.Event {
+	return w.loop.Event()
+}
+
+func (w *window) Invalidate() {
+	w.loop.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	w.loop.Run(f)
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.loop.Frame(frame)
+}
+
+func newWindow(win *callbacks, options []Option) {
+	mainWindow.in <- windowAndConfig{win, options}
+	<-mainWindow.windows
+}
+
+var mainMode = mainModeUndefined
+
+const (
+	mainModeUndefined = iota
+	mainModeExe
+	mainModeLibrary
+)
+
 func osMain() {
+	if !isMainThread() {
+		panic("app.Main must be run on the main goroutine")
+	}
+	switch mainMode {
+	case mainModeUndefined:
+		mainMode = mainModeExe
+		var argv []*C.char
+		for _, arg := range os.Args {
+			a := C.CString(arg)
+			defer C.free(unsafe.Pointer(a))
+			argv = append(argv, a)
+		}
+		C.gio_applicationMain(C.int(len(argv)), unsafe.SliceData(argv))
+	case mainModeExe:
+		panic("app.Main may be called only once")
+	case mainModeLibrary:
+		// Do nothing, we're embedded as a library.
+	}
 }
 
 //export gio_runMain
 func gio_runMain() {
-	runMain()
+	if !isMainThread() {
+		panic("app.Main must be run on the main goroutine")
+	}
+	switch mainMode {
+	case mainModeUndefined:
+		mainMode = mainModeLibrary
+		runMain()
+	case mainModeExe:
+		// Do nothing, main has already been called.
+	}
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (UIKitViewEvent) implementsViewEvent() {}
+func (UIKitViewEvent) ImplementsEvent()     {}
+func (u UIKitViewEvent) Valid() bool {
+	return u != (UIKitViewEvent{})
+}

app/os_ios.m

@@ -11,6 +11,7 @@
 __attribute__ ((visibility ("hidden"))) Class gio_layerClass(void);
 
 @interface GioView: UIView <UIKeyInput>
+@property uintptr_t handle;
 @end
 
 @implementation GioViewController
@@ -25,12 +26,13 @@ CGFloat _keyboardHeight;
 	self.view.layoutMargins = UIEdgeInsetsMake(0, 0, 0, 0);
 	UIView *drawView = [[GioView alloc] initWithFrame:zeroFrame];
 	[self.view addSubview: drawView];
-#ifndef TARGET_OS_TV
+#if !TARGET_OS_TV
 	drawView.multipleTouchEnabled = YES;
 #endif
 	drawView.preservesSuperviewLayoutMargins = YES;
 	drawView.layoutMargins = UIEdgeInsetsMake(0, 0, 0, 0);
 	onCreate((__bridge CFTypeRef)drawView, (__bridge CFTypeRef)self);
+#if !TARGET_OS_TV
 	[[NSNotificationCenter defaultCenter] addObserver:self
 											 selector:@selector(keyboardWillChange:)
 												 name:UIKeyboardWillShowNotification
@@ -43,6 +45,7 @@ CGFloat _keyboardHeight;
 											 selector:@selector(keyboardWillHide:)
 												 name:UIKeyboardWillHideNotification
 											   object:nil];
+#endif
 	[[NSNotificationCenter defaultCenter] addObserver: self
 											 selector: @selector(applicationDidEnterBackground:)
 												 name: UIApplicationDidEnterBackgroundNotification
@@ -54,33 +57,33 @@ CGFloat _keyboardHeight;
 }
 
 - (void)applicationWillEnterForeground:(UIApplication *)application {
-	UIView *drawView = self.view.subviews[0];
+	GioView *view = (GioView *)self.view.subviews[0];
-	if (drawView != nil) {
+	if (view != nil) {
-		gio_onDraw((__bridge CFTypeRef)drawView);
+		onStart(view.handle);
 	}
 }
 
 - (void)applicationDidEnterBackground:(UIApplication *)application {
-	UIView *drawView = self.view.subviews[0];
+	GioView *view = (GioView *)self.view.subviews[0];
-	if (drawView != nil) {
+	if (view != nil) {
-		onStop((__bridge CFTypeRef)drawView);
+		onStop(view.handle);
 	}
 }
 
 - (void)viewDidDisappear:(BOOL)animated {
 	[super viewDidDisappear:animated];
-	CFTypeRef viewRef = (__bridge CFTypeRef)self.view.subviews[0];
+	GioView *view = (GioView *)self.view.subviews[0];
-	onDestroy(viewRef);
+	onDestroy(view.handle);
 }
 
 - (void)viewDidLayoutSubviews {
 	[super viewDidLayoutSubviews];
-	UIView *view = self.view.subviews[0];
+	GioView *view = (GioView *)self.view.subviews[0];
 	CGRect frame = self.view.bounds;
 	// Adjust view bounds to make room for the keyboard.
 	frame.size.height -= _keyboardHeight;
 	view.frame = frame;
-	gio_onDraw((__bridge CFTypeRef)view);
+	gio_onDraw(view.handle);
 }
 
 - (void)didReceiveMemoryWarning {
@@ -88,6 +91,7 @@ CGFloat _keyboardHeight;
 	[super didReceiveMemoryWarning];
 }
 
+#if !TARGET_OS_TV
 - (void)keyboardWillChange:(NSNotification *)note {
 	NSDictionary *userInfo = note.userInfo;
 	CGRect f = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
@@ -99,13 +103,13 @@ CGFloat _keyboardHeight;
 	_keyboardHeight = 0.0;
 	[self.view setNeedsLayout];
 }
+#endif
 @end
 
-static void handleTouches(int last, UIView *view, NSSet<UITouch *> *touches, UIEvent *event) {
+static void handleTouches(int last, GioView *view, NSSet<UITouch *> *touches, UIEvent *event) {
 	CGFloat scale = view.contentScaleFactor;
 	NSUInteger i = 0;
 	NSUInteger n = [touches count];
-	CFTypeRef viewRef = (__bridge CFTypeRef)view;
 	for (UITouch *touch in touches) {
 		CFTypeRef touchRef = (__bridge CFTypeRef)touch;
 		i++;
@@ -116,7 +120,7 @@ static void handleTouches(int last, UIView *view, NSSet<UITouch *> *touches, UIE
 			CGPoint loc = [coalescedTouch locationInView:view];
 			j++;
 			int lastTouch = last && i == n && j == m;
-			onTouch(lastTouch, viewRef, touchRef, touch.phase, loc.x*scale, loc.y*scale, [coalescedTouch timestamp]);
+			onTouch(view.handle, lastTouch, touchRef, touch.phase, loc.x*scale, loc.y*scale, [coalescedTouch timestamp]);
 		}
 	}
 }
@@ -151,13 +155,13 @@ NSArray<UIKeyCommand *> *_keyCommands;
 
 - (void)onWindowDidBecomeKey:(NSNotification *)note {
 	if (self.isFirstResponder) {
-		onFocus((__bridge CFTypeRef)self, YES);
+		onFocus(self.handle, YES);
 	}
 }
 
 - (void)onWindowDidResignKey:(NSNotification *)note {
 	if (self.isFirstResponder) {
-		onFocus((__bridge CFTypeRef)self, NO);
+		onFocus(self.handle, NO);
 	}
 }
 
@@ -178,7 +182,7 @@ NSArray<UIKeyCommand *> *_keyCommands;
 }
 
 - (void)insertText:(NSString *)text {
-	onText((__bridge CFTypeRef)self, (__bridge CFTypeRef)text);
+	onText(self.handle, (__bridge CFTypeRef)text);
 }
 
 - (BOOL)canBecomeFirstResponder {
@@ -190,23 +194,23 @@ NSArray<UIKeyCommand *> *_keyCommands;
 }
 
 - (void)deleteBackward {
-	onDeleteBackward((__bridge CFTypeRef)self);
+	onDeleteBackward(self.handle);
 }
 
 - (void)onUpArrow {
-	onUpArrow((__bridge CFTypeRef)self);
+	onUpArrow(self.handle);
 }
 
 - (void)onDownArrow {
-	onDownArrow((__bridge CFTypeRef)self);
+	onDownArrow(self.handle);
 }
 
 - (void)onLeftArrow {
-	onLeftArrow((__bridge CFTypeRef)self);
+	onLeftArrow(self.handle);
 }
 
 - (void)onRightArrow {
-	onRightArrow((__bridge CFTypeRef)self);
+	onRightArrow(self.handle);
 }
 
 - (NSArray<UIKeyCommand *> *)keyCommands {
@@ -271,3 +275,28 @@ void gio_showCursor() {
 void gio_setCursor(NSUInteger curID) {
 	// Not supported.
 }
+
+void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle) {
+	GioView *v = (__bridge GioView *)viewRef;
+	v.handle = handle;
+}
+
+@interface _gioAppDelegate : UIResponder <UIApplicationDelegate>
+@property (strong, nonatomic) UIWindow *window;
+@end
+
+@implementation _gioAppDelegate
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+	self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
+	GioViewController *controller = [[GioViewController alloc] initWithNibName:nil bundle:nil];
+	self.window.rootViewController = controller;
+	[self.window makeKeyAndVisible];
+	return YES;
+}
+@end
+
+int gio_applicationMain(int argc, char *argv[]) {
+	@autoreleasepool {
+		return UIApplicationMain(argc, argv, nil, NSStringFromClass([_gioAppDelegate class]));
+	}
+}

app/os_js.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"image"
 	"image/color"
+	"io"
 	"strings"
 	"syscall/js"
 	"time"
@@ -13,16 +14,18 @@ import (
 	"unicode/utf8"
 
 	"gioui.org/internal/f32color"
+	"gioui.org/op"
 
 	"gioui.org/f32"
-	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
+	"gioui.org/io/transfer"
 	"gioui.org/unit"
 )
 
-type ViewEvent struct {
+type JSViewEvent struct {
 	Element js.Value
 }
 
@@ -53,9 +56,6 @@ type window struct {
 	composing             bool
 	requestFocus          bool
 
-	chanAnimation chan struct{}
-	chanRedraw    chan struct{}
-
 	config    Config
 	inset     f32.Point
 	scale     float32
@@ -68,7 +68,7 @@ type window struct {
 	contextStatus contextStatus
 }
 
-func newWindow(win *callbacks, options []Option) error {
+func newWindow(win *callbacks, options []Option) {
 	doc := js.Global().Get("document")
 	cont := getContainer(doc)
 	cnv := createCanvas(doc)
@@ -83,7 +83,9 @@ func newWindow(win *callbacks, options []Option) error {
 		head:      doc.Get("head"),
 		clipboard: js.Global().Get("navigator").Get("clipboard"),
 		wakeups:   make(chan struct{}, 1),
+		w:         win,
 	}
+	w.w.SetDriver(w)
 	w.requestAnimationFrame = w.window.Get("requestAnimationFrame")
 	w.browserHistory = w.window.Get("history")
 	w.visualViewport = w.window.Get("visualViewport")
@@ -93,42 +95,28 @@ func newWindow(win *callbacks, options []Option) error {
 	if screen := w.window.Get("screen"); screen.Truthy() {
 		w.screenOrientation = screen.Get("orientation")
 	}
-	w.chanAnimation = make(chan struct{}, 1)
-	w.chanRedraw = make(chan struct{}, 1)
 	w.redraw = w.funcOf(func(this js.Value, args []js.Value) interface{} {
-		w.chanAnimation <- struct{}{}
+		w.draw(false)
 		return nil
 	})
 	w.clipboardCallback = w.funcOf(func(this js.Value, args []js.Value) interface{} {
 		content := args[0].String()
-		go win.Event(clipboard.Event{Text: content})
+		w.processEvent(transfer.DataEvent{
+			Type: "application/text",
+			Open: func() io.ReadCloser {
+				return io.NopCloser(strings.NewReader(content))
+			},
+		})
 		return nil
 	})
 	w.addEventListeners()
 	w.addHistory()
-	w.w = win
 
-	go func() {
+	w.Configure(options)
-		defer w.cleanup()
+	w.blur()
-		w.w.SetDriver(w)
+	w.processEvent(JSViewEvent{Element: cont})
-		w.Configure(options)
+	w.resize()
-		w.blur()
+	w.draw(true)
-		w.w.Event(ViewEvent{Element: cont})
-		w.w.Event(system.StageEvent{Stage: system.StageRunning})
-		w.resize()
-		w.draw(true)
-		for {
-			select {
-			case <-w.wakeups:
-				w.w.Event(wakeupEvent{})
-			case <-w.chanAnimation:
-				w.animCallback()
-			case <-w.chanRedraw:
-				w.draw(true)
-			}
-		}
-	}()
-	return nil
 }
 
 func getContainer(doc js.Value) js.Value {
@@ -188,12 +176,12 @@ func (w *window) addEventListeners() {
 		w.cnv.Set("width", 0)
 		w.cnv.Set("height", 0)
 		w.resize()
-		w.requestRedraw()
+		w.draw(true)
 		return nil
 	})
 	w.addEventListener(w.visualViewport, "resize", func(this js.Value, args []js.Value) interface{} {
 		w.resize()
-		w.requestRedraw()
+		w.draw(true)
 		return nil
 	})
 	w.addEventListener(w.window, "contextmenu", func(this js.Value, args []js.Value) interface{} {
@@ -201,22 +189,11 @@ func (w *window) addEventListeners() {
 		return nil
 	})
 	w.addEventListener(w.window, "popstate", func(this js.Value, args []js.Value) interface{} {
-		if w.w.Event(key.Event{Name: key.NameBack}) {
+		if w.processEvent(key.Event{Name: key.NameBack}) {
 			return w.browserHistory.Call("forward")
 		}
 		return w.browserHistory.Call("back")
 	})
-	w.addEventListener(w.document, "visibilitychange", func(this js.Value, args []js.Value) interface{} {
-		ev := system.StageEvent{}
-		switch w.document.Get("visibilityState").String() {
-		case "hidden", "prerender", "unloaded":
-			ev.Stage = system.StagePaused
-		default:
-			ev.Stage = system.StageRunning
-		}
-		w.w.Event(ev)
-		return nil
-	})
 	w.addEventListener(w.cnv, "mousemove", func(this js.Value, args []js.Value) interface{} {
 		w.pointerEvent(pointer.Move, 0, 0, args[0])
 		return nil
@@ -274,18 +251,20 @@ func (w *window) addEventListeners() {
 			w.touches[i] = js.Null()
 		}
 		w.touches = w.touches[:0]
-		w.w.Event(pointer.Event{
+		w.processEvent(pointer.Event{
 			Kind:   pointer.Cancel,
 			Source: pointer.Touch,
 		})
 		return nil
 	})
 	w.addEventListener(w.tarea, "focus", func(this js.Value, args []js.Value) interface{} {
-		w.w.Event(key.FocusEvent{Focus: true})
+		w.config.Focused = true
+		w.processEvent(ConfigEvent{Config: w.config})
 		return nil
 	})
 	w.addEventListener(w.tarea, "blur", func(this js.Value, args []js.Value) interface{} {
-		w.w.Event(key.FocusEvent{Focus: false})
+		w.config.Focused = false
+		w.processEvent(ConfigEvent{Config: w.config})
 		w.blur()
 		return nil
 	})
@@ -374,10 +353,50 @@ func (w *window) keyEvent(e js.Value, ks key.State) {
 			Modifiers: modifiersFor(e),
 			State:     ks,
 		}
-		w.w.Event(cmd)
+		w.processEvent(cmd)
 	}
 }
 
+func (w *window) ProcessEvent(e event.Event) {
+	w.processEvent(e)
+}
+
+func (w *window) processEvent(e event.Event) bool {
+	if !w.w.ProcessEvent(e) {
+		return false
+	}
+	select {
+	case w.wakeups <- struct{}{}:
+	default:
+	}
+	return true
+}
+
+func (w *window) Event() event.Event {
+	for {
+		evt, ok := w.w.nextEvent()
+		if ok {
+			if _, destroy := evt.(DestroyEvent); destroy {
+				w.cleanup()
+			}
+			return evt
+		}
+		<-w.wakeups
+	}
+}
+
+func (w *window) Invalidate() {
+	w.w.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	f()
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.w.ProcessFrame(frame, nil)
+}
+
 // modifiersFor returns the modifier set for a DOM MouseEvent or
 // KeyEvent.
 func modifiersFor(e js.Value) key.Modifiers {
@@ -425,7 +444,7 @@ func (w *window) touchEvent(kind pointer.Kind, e js.Value) {
 			X: float32(x) * scale,
 			Y: float32(y) * scale,
 		}
-		w.w.Event(pointer.Event{
+		w.processEvent(pointer.Event{
 			Kind:      kind,
 			Source:    pointer.Touch,
 			Position:  pos,
@@ -475,7 +494,7 @@ func (w *window) pointerEvent(kind pointer.Kind, dx, dy float32, e js.Value) {
 	if jbtns&4 != 0 {
 		btns |= pointer.ButtonTertiary
 	}
-	w.w.Event(pointer.Event{
+	w.processEvent(pointer.Event{
 		Kind:      kind,
 		Source:    pointer.Mouse,
 		Buttons:   btns,
@@ -502,17 +521,6 @@ func (w *window) funcOf(f func(this js.Value, args []js.Value) interface{}) js.F
 	return jsf
 }
 
-func (w *window) animCallback() {
-	anim := w.animating
-	w.animRequested = anim
-	if anim {
-		w.requestAnimationFrame.Invoke(w.redraw)
-	}
-	if anim {
-		w.draw(false)
-	}
-}
-
 func (w *window) EditorStateChanged(old, new editorState) {}
 
 func (w *window) SetAnimating(anim bool) {
@@ -533,14 +541,14 @@ func (w *window) ReadClipboard() {
 	w.clipboard.Call("readText", w.clipboard).Call("then", w.clipboardCallback)
 }
 
-func (w *window) WriteClipboard(s string) {
+func (w *window) WriteClipboard(mime string, s []byte) {
 	if w.clipboard.IsUndefined() {
 		return
 	}
 	if w.clipboard.Get("writeText").IsUndefined() {
 		return
 	}
-	w.clipboard.Call("writeText", s)
+	w.clipboard.Call("writeText", string(s))
 }
 
 func (w *window) Configure(options []Option) {
@@ -568,7 +576,7 @@ func (w *window) Configure(options []Option) {
 	if cnf.Decorated != prev.Decorated {
 		w.config.Decorated = cnf.Decorated
 	}
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.processEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *window) Perform(system.Action) {}
@@ -607,23 +615,14 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 	style.Set("cursor", webCursor[cursor])
 }
 
-func (w *window) Wakeup() {
-	select {
-	case w.wakeups <- struct{}{}:
-	default:
-	}
-}
-
 func (w *window) ShowTextInput(show bool) {
 	// Run in a goroutine to avoid a deadlock if the
 	// focus change result in an event.
-	go func() {
+	if show {
-		if show {
+		w.focus()
-			w.focus()
+	} else {
-		} else {
+		w.blur()
-			w.blur()
+	}
-		}
-	}()
 }
 
 func (w *window) SetInputHint(mode key.InputHint) {
@@ -640,7 +639,7 @@ func (w *window) resize() {
 	}
 	if size != w.config.Size {
 		w.config.Size = size
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.processEvent(ConfigEvent{Config: w.config})
 	}
 
 	if vx, vy := w.visualViewport.Get("width"), w.visualViewport.Get("height"); !vx.IsUndefined() && !vy.IsUndefined() {
@@ -660,13 +659,20 @@ func (w *window) draw(sync bool) {
 	if w.contextStatus == contextStatusLost {
 		return
 	}
+	anim := w.animating
+	w.animRequested = anim
+	if anim {
+		w.requestAnimationFrame.Invoke(w.redraw)
+	} else if !sync {
+		return
+	}
 	size, insets, metric := w.getConfig()
 	if metric == (unit.Metric{}) || size.X == 0 || size.Y == 0 {
 		return
 	}
 
-	w.w.Event(frameEvent{
+	w.processEvent(frameEvent{
-		FrameEvent: system.FrameEvent{
+		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   size,
 			Insets: insets,
@@ -676,10 +682,10 @@ func (w *window) draw(sync bool) {
 	})
 }
 
-func (w *window) getConfig() (image.Point, system.Insets, unit.Metric) {
+func (w *window) getConfig() (image.Point, Insets, unit.Metric) {
 	invscale := unit.Dp(1. / w.scale)
 	return image.Pt(w.config.Size.X, w.config.Size.Y),
-		system.Insets{
+		Insets{
 			Bottom: unit.Dp(w.inset.Y) * invscale,
 			Right:  unit.Dp(w.inset.X) * invscale,
 		}, unit.Metric{
@@ -735,19 +741,12 @@ func (w *window) navigationColor(c color.NRGBA) {
 	theme.Set("content", fmt.Sprintf("#%06X", []uint8{rgba.R, rgba.G, rgba.B}))
 }
 
-func (w *window) requestRedraw() {
-	select {
-	case w.chanRedraw <- struct{}{}:
-	default:
-	}
-}
-
 func osMain() {
 	select {}
 }
 
-func translateKey(k string) (string, bool) {
+func translateKey(k string) (key.Name, bool) {
-	var n string
+	var n key.Name
 
 	switch k {
 	case "ArrowUp":
@@ -814,11 +813,15 @@ func translateKey(k string) (string, bool) {
 		r, s := utf8.DecodeRuneInString(k)
 		// If there is exactly one printable character, return that.
 		if s == len(k) && unicode.IsPrint(r) {
-			return strings.ToUpper(k), true
+			return key.Name(strings.ToUpper(k)), true
 		}
 		return "", false
 	}
 	return n, true
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (JSViewEvent) implementsViewEvent() {}
+func (JSViewEvent) ImplementsEvent()     {}
+func (j JSViewEvent) Valid() bool {
+	return !(j.Element.IsNull() || j.Element.IsUndefined())
+}

app/os_macos.m

@@ -6,7 +6,7 @@
 
 #include "_cgo_export.h"
 
-__attribute__ ((visibility ("hidden"))) CALayer *gio_layerFactory(void);
+__attribute__ ((visibility ("hidden"))) CALayer *gio_layerFactory(BOOL presentWithTrans);
 
 @interface GioAppDelegate : NSObject<NSApplicationDelegate>
 @end
@@ -14,40 +14,55 @@ __attribute__ ((visibility ("hidden"))) CALayer *gio_layerFactory(void);
 @interface GioWindowDelegate : NSObject<NSWindowDelegate>
 @end
 
+@interface GioView : NSView <CALayerDelegate,NSTextInputClient>
+@property uintptr_t handle;
+@property BOOL presentWithTrans;
+@end
+
 @implementation GioWindowDelegate
 - (void)windowWillMiniaturize:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onHide((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onDraw(view.handle);
 }
 - (void)windowDidDeminiaturize:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onShow((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onDraw(view.handle);
 }
 - (void)windowWillEnterFullScreen:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onFullscreen((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onDraw(view.handle);
 }
 - (void)windowWillExitFullScreen:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onWindowed((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onDraw(view.handle);
 }
 - (void)windowDidChangeScreen:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
 	CGDirectDisplayID dispID = [[[window screen] deviceDescription][@"NSScreenNumber"] unsignedIntValue];
-	CFTypeRef view = (__bridge CFTypeRef)window.contentView;
+  GioView *view = (GioView *)window.contentView;
-	gio_onChangeScreen(view, dispID);
+	gio_onChangeScreen(view.handle, dispID);
 }
 - (void)windowDidBecomeKey:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onFocus((__bridge CFTypeRef)window.contentView, 1);
+	GioView *view = (GioView *)window.contentView;
+	if ([window firstResponder] == view) {
+		gio_onFocus(view.handle, 1);
+	}
 }
 - (void)windowDidResignKey:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onFocus((__bridge CFTypeRef)window.contentView, 0);
+	GioView *view = (GioView *)window.contentView;
+	if ([window firstResponder] == view) {
+		gio_onFocus(view.handle, 0);
+	}
 }
 @end
 
-static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFloat dy) {
+static void handleMouse(GioView *view, NSEvent *event, int typ, CGFloat dx, CGFloat dy) {
 	NSPoint p = [view convertPoint:[event locationInWindow] fromView:nil];
 	if (!event.hasPreciseScrollingDeltas) {
 		// dx and dy are in rows and columns.
@@ -56,12 +71,9 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 	}
 	// Origin is in the lower left corner. Convert to upper left.
 	CGFloat height = view.bounds.size.height;
-	gio_onMouse((__bridge CFTypeRef)view, (__bridge CFTypeRef)event, typ, event.buttonNumber, p.x, height - p.y, dx, dy, [event timestamp], [event modifierFlags]);
+	gio_onMouse(view.handle, (__bridge CFTypeRef)event, typ, event.buttonNumber, p.x, height - p.y, dx, dy, [event timestamp], [event modifierFlags]);
 }
 
-@interface GioView : NSView <CALayerDelegate,NSTextInputClient>
-@end
-
 @implementation GioView
 - (void)setFrameSize:(NSSize)newSize {
 	[super setFrameSize:newSize];
@@ -70,21 +82,19 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 // drawRect is called when OpenGL is used, displayLayer otherwise.
 // Don't know why.
 - (void)drawRect:(NSRect)r {
-	gio_onDraw((__bridge CFTypeRef)self);
+	gio_onDraw(self.handle);
 }
 - (void)displayLayer:(CALayer *)layer {
 	layer.contentsScale = self.window.backingScaleFactor;
-	gio_onDraw((__bridge CFTypeRef)self);
+	gio_onDraw(self.handle);
 }
 - (CALayer *)makeBackingLayer {
-	CALayer *layer = gio_layerFactory();
+	CALayer *layer = gio_layerFactory(self.presentWithTrans);
 	layer.delegate = self;
 	return layer;
 }
 - (void)viewDidMoveToWindow {
-	if (self.window == nil) {
+	gio_onAttached(self.handle, self.window != nil ? 1 : 0);
-		gio_onClose((__bridge CFTypeRef)self);
-	}
 }
 - (void)mouseDown:(NSEvent *)event {
 	handleMouse(self, event, MOUSE_DOWN, 0, 0);
@@ -122,34 +132,37 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 	handleMouse(self, event, MOUSE_SCROLL, dx, dy);
 }
 - (void)keyDown:(NSEvent *)event {
-	[self interpretKeyEvents:[NSArray arrayWithObject:event]];
 	NSString *keys = [event charactersIgnoringModifiers];
-	gio_onKeys((__bridge CFTypeRef)self, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], true);
+	gio_onKeys(self.handle, (__bridge CFTypeRef)event, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], true);
+}
+- (void)flagsChanged:(NSEvent *)event {
+	[self interpretKeyEvents:[NSArray arrayWithObject:event]];
+	gio_onFlagsChanged(self.handle, [event modifierFlags]);
 }
 - (void)keyUp:(NSEvent *)event {
 	NSString *keys = [event charactersIgnoringModifiers];
-	gio_onKeys((__bridge CFTypeRef)self, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], false);
+	gio_onKeys(self.handle, (__bridge CFTypeRef)event, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], false);
 }
 - (void)insertText:(id)string {
-	gio_onText((__bridge CFTypeRef)self, (__bridge CFTypeRef)string);
+	gio_onText(self.handle, (__bridge CFTypeRef)string);
 }
-- (void)doCommandBySelector:(SEL)sel {
+- (void)doCommandBySelector:(SEL)action {
-	// Don't pass commands up the responder chain.
+	if (!gio_onCommandBySelector(self.handle)) {
-	// They will end up in a beep.
+		[super doCommandBySelector:action];
+	}
 }
-
 - (BOOL)hasMarkedText {
-	int res = gio_hasMarkedText((__bridge CFTypeRef)self);
+	int res = gio_hasMarkedText(self.handle);
 	return res ? YES : NO;
 }
 - (NSRange)markedRange {
-	return gio_markedRange((__bridge CFTypeRef)self);
+	return gio_markedRange(self.handle);
 }
 - (NSRange)selectedRange {
-	return gio_selectedRange((__bridge CFTypeRef)self);
+	return gio_selectedRange(self.handle);
 }
 - (void)unmarkText {
-	gio_unmarkText((__bridge CFTypeRef)self);
+	gio_unmarkText(self.handle);
 }
 - (void)setMarkedText:(id)string
         selectedRange:(NSRange)selRange
@@ -161,14 +174,14 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 	} else {
 		str = string;
 	}
-	gio_setMarkedText((__bridge CFTypeRef)self, (__bridge CFTypeRef)str, selRange, replaceRange);
+	gio_setMarkedText(self.handle, (__bridge CFTypeRef)str, selRange, replaceRange);
 }
 - (NSArray<NSAttributedStringKey> *)validAttributesForMarkedText {
 	return nil;
 }
 - (NSAttributedString *)attributedSubstringForProposedRange:(NSRange)range
                                                 actualRange:(NSRangePointer)actualRange {
-	NSString *str = CFBridgingRelease(gio_substringForProposedRange((__bridge CFTypeRef)self, range, actualRange));
+	NSString *str = CFBridgingRelease(gio_substringForProposedRange(self.handle, range, actualRange));
 	return [[NSAttributedString alloc] initWithString:str attributes:nil];
 }
 - (void)insertText:(id)string
@@ -180,17 +193,34 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 	} else {
 		str = string;
 	}
-	gio_insertText((__bridge CFTypeRef)self, (__bridge CFTypeRef)str, replaceRange);
+	gio_insertText(self.handle, (__bridge CFTypeRef)str, replaceRange);
 }
 - (NSUInteger)characterIndexForPoint:(NSPoint)p {
-	return gio_characterIndexForPoint((__bridge CFTypeRef)self, p);
+	return gio_characterIndexForPoint(self.handle, p);
 }
 - (NSRect)firstRectForCharacterRange:(NSRange)rng
                          actualRange:(NSRangePointer)actual {
-    NSRect r = gio_firstRectForCharacterRange((__bridge CFTypeRef)self, rng, actual);
+    NSRect r = gio_firstRectForCharacterRange(self.handle, rng, actual);
     r = [self convertRect:r toView:nil];
     return [[self window] convertRectToScreen:r];
 }
+- (void)applicationWillUnhide:(NSNotification *)notification {
+	gio_onDraw(self.handle);
+}
+- (void)applicationDidHide:(NSNotification *)notification {
+	gio_onDraw(self.handle);
+}
+- (void)dealloc {
+	gio_onDestroy(self.handle);
+}
+- (BOOL) becomeFirstResponder {
+	gio_onFocus(self.handle, 1);
+	return [super becomeFirstResponder];
+ }
+- (BOOL) resignFirstResponder {
+	gio_onFocus(self.handle, 0);
+	return [super resignFirstResponder];
+}
 @end
 
 // Delegates are weakly referenced from their peers. Nothing
@@ -240,7 +270,7 @@ void gio_showCursor() {
 
 // some cursors are not public, this tries to use a private cursor
 // and uses fallback when the use of private cursor fails.
-void gio_trySetPrivateCursor(SEL cursorName, NSCursor* fallback) {
+static void trySetPrivateCursor(SEL cursorName, NSCursor* fallback) {
 	if ([NSCursor respondsToSelector:cursorName]) {
 		id object = [NSCursor performSelector:cursorName];
 		if ([object isKindOfClass:[NSCursor class]]) {
@@ -272,7 +302,7 @@ void gio_setCursor(NSUInteger curID) {
 				break;
 			case 6: // pointer.CursorAllScroll
 				// For some reason, using _moveCursor fails on Monterey.
-				// gio_trySetPrivateCursor(@selector(_moveCursor), NSCursor.arrowCursor);
+				// trySetPrivateCursor(@selector(_moveCursor), NSCursor.arrowCursor);
 				[NSCursor.arrowCursor set];
 				break;
 			case 7: // pointer.CursorColResize
@@ -282,33 +312,31 @@ void gio_setCursor(NSUInteger curID) {
 				[NSCursor.resizeUpDownCursor set];
 				break;
 			case 9: // pointer.CursorGrab
-				// [NSCursor.openHandCursor set];
+				[NSCursor.openHandCursor set];
-				gio_trySetPrivateCursor(@selector(openHandCursor), NSCursor.arrowCursor);
 				break;
 			case 10: // pointer.CursorGrabbing
-				// [NSCursor.closedHandCursor set];
+				[NSCursor.closedHandCursor set];
-				gio_trySetPrivateCursor(@selector(closedHandCursor), NSCursor.arrowCursor);
 				break;
 			case 11: // pointer.CursorNotAllowed
 				[NSCursor.operationNotAllowedCursor set];
 				break;
 			case 12: // pointer.CursorWait
-				gio_trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
+				trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
 				break;
 			case 13: // pointer.CursorProgress
-				gio_trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
+				trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
 				break;
 			case 14: // pointer.CursorNorthWestResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthWestCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthWestCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 15: // pointer.CursorNorthEastResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthEastCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthEastCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 16: // pointer.CursorSouthWestResize
-				gio_trySetPrivateCursor(@selector(_windowResizeSouthWestCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeSouthWestCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 17: // pointer.CursorSouthEastResize
-				gio_trySetPrivateCursor(@selector(_windowResizeSouthEastCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeSouthEastCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 18: // pointer.CursorNorthSouthResize
 				[NSCursor.resizeUpDownCursor set];
@@ -329,10 +357,10 @@ void gio_setCursor(NSUInteger curID) {
 				[NSCursor.resizeDownCursor set];
 				break;
 			case 24: // pointer.CursorNorthEastSouthWestResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthEastSouthWestCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthEastSouthWestCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 25: // pointer.CursorNorthWestSouthEastResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthWestSouthEastCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthWestSouthEastCursor), NSCursor.resizeUpDownCursor);
 				break;
 			default:
 				[NSCursor.arrowCursor set];
@@ -341,7 +369,7 @@ void gio_setCursor(NSUInteger curID) {
 	}
 }
 
-CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGFloat minWidth, CGFloat minHeight, CGFloat maxWidth, CGFloat maxHeight) {
+CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height) {
 	@autoreleasepool {
 		NSRect rect = NSMakeRect(0, 0, width, height);
 		NSUInteger styleMask = NSTitledWindowMask |
@@ -353,42 +381,45 @@ CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGF
 													   styleMask:styleMask
 														 backing:NSBackingStoreBuffered
 														   defer:NO];
-		if (minWidth > 0 || minHeight > 0) {
-			window.contentMinSize = NSMakeSize(minWidth, minHeight);
-		}
-		if (maxWidth > 0 || maxHeight > 0) {
-			window.contentMaxSize = NSMakeSize(maxWidth, maxHeight);
-		}
 		[window setAcceptsMouseMovedEvents:YES];
 		NSView *view = (__bridge NSView *)viewRef;
 		[window setContentView:view];
-		[window makeFirstResponder:view];
 		window.delegate = globalWindowDel;
 		return (__bridge_retained CFTypeRef)window;
 	}
 }
 
-CFTypeRef gio_createView(void) {
+CFTypeRef gio_createView(int presentWithTrans) {
 	@autoreleasepool {
 		NSRect frame = NSMakeRect(0, 0, 0, 0);
 		GioView* view = [[GioView alloc] initWithFrame:frame];
+		view.presentWithTrans = presentWithTrans ? YES : NO;
 		view.wantsLayer = YES;
 		view.layerContentsRedrawPolicy = NSViewLayerContentsRedrawDuringViewResize;
+
+		[[NSNotificationCenter defaultCenter] addObserver:view
+												 selector:@selector(applicationWillUnhide:)
+													 name:NSApplicationWillUnhideNotification
+												   object:nil];
+		[[NSNotificationCenter defaultCenter] addObserver:view
+												 selector:@selector(applicationDidHide:)
+													 name:NSApplicationDidHideNotification
+												   object:nil];
 		return CFBridgingRetain(view);
 	}
 }
 
+void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle) {
+	@autoreleasepool {
+		GioView *v = (__bridge GioView *)viewRef;
+		v.handle = handle;
+	}
+}
+
 @implementation GioAppDelegate
 - (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
 	[NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
 	[NSApp activateIgnoringOtherApps:YES];
-	gio_onFinishLaunching();
-}
-- (void)applicationDidHide:(NSNotification *)aNotification {
-	gio_onAppHide();
-}
-- (void)applicationWillUnhide:(NSNotification *)notification {
-	gio_onAppShow();
 }
 @end
 
@@ -419,3 +450,25 @@ void gio_main() {
 		[NSApp run];
 	}
 }
+
+@interface AppListener : NSObject
+@end
+
+static AppListener *appListener;
+
+@implementation AppListener
+- (void)launchFinished:(NSNotification *)notification {
+	appListener = nil;
+	gio_onFinishLaunching();
+}
+@end
+
+void gio_init() {
+	@autoreleasepool {
+		appListener = [[AppListener alloc] init];
+		[[NSNotificationCenter defaultCenter] addObserver:appListener
+												 selector:@selector(launchFinished:)
+													 name:NSApplicationDidFinishLaunchingNotification
+												   object:nil];
+	}
+}

app/os_unix.go

@@ -12,13 +12,6 @@ import (
 	"gioui.org/io/pointer"
 )
 
-// ViewEvent provides handles to the underlying window objects for the
-// current display protocol.
-type ViewEvent interface {
-	implementsViewEvent()
-	ImplementsEvent()
-}
-
 type X11ViewEvent struct {
 	// Display is a pointer to the X11 Display created by XOpenDisplay.
 	Display unsafe.Pointer
@@ -28,6 +21,9 @@ type X11ViewEvent struct {
 
 func (X11ViewEvent) implementsViewEvent() {}
 func (X11ViewEvent) ImplementsEvent()     {}
+func (x X11ViewEvent) Valid() bool {
+	return x != (X11ViewEvent{})
+}
 
 type WaylandViewEvent struct {
 	// Display is the *wl_display returned by wl_display_connect.
@@ -38,6 +34,9 @@ type WaylandViewEvent struct {
 
 func (WaylandViewEvent) implementsViewEvent() {}
 func (WaylandViewEvent) ImplementsEvent()     {}
+func (w WaylandViewEvent) Valid() bool {
+	return w != (WaylandViewEvent{})
+}
 
 func osMain() {
 	select {}
@@ -49,7 +48,7 @@ type windowDriver func(*callbacks, []Option) error
 // let each driver initialize these variables with their own version of createWindow.
 var wlDriver, x11Driver windowDriver
 
-func newWindow(window *callbacks, options []Option) error {
+func newWindow(window *callbacks, options []Option) {
 	var errFirst error
 	for _, d := range []windowDriver{wlDriver, x11Driver} {
 		if d == nil {
@@ -57,16 +56,16 @@ func newWindow(window *callbacks, options []Option) error {
 		}
 		err := d(window, options)
 		if err == nil {
-			return nil
+			return
 		}
 		if errFirst == nil {
 			errFirst = err
 		}
 	}
-	if errFirst != nil {
+	if errFirst == nil {
-		return errFirst
+		errFirst = errors.New("app: no window driver available")
 	}
-	return errors.New("app: no window driver available")
+	window.ProcessEvent(DestroyEvent{Err: errFirst})
 }
 
 // xCursor contains mapping from pointer.Cursor to XCursor.

app/os_wayland.go

@@ -15,6 +15,7 @@ import (
 	"math"
 	"os"
 	"os/exec"
+	"runtime"
 	"strconv"
 	"sync"
 	"time"
@@ -25,10 +26,12 @@ import (
 	"gioui.org/app/internal/xkb"
 	"gioui.org/f32"
 	"gioui.org/internal/fling"
-	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
+	"gioui.org/io/transfer"
+	"gioui.org/op"
 	"gioui.org/unit"
 )
 
@@ -97,7 +100,9 @@ type wlDisplay struct {
 		read, write int
 	}
 
-	repeat repeatState
+	repeat        repeatState
+	poller        poller
+	readClipClose chan struct{}
 }
 
 type wlSeat struct {
@@ -111,6 +116,8 @@ type wlSeat struct {
 
 	// The most recent input serial.
 	serial C.uint32_t
+	// The most recent pointer enter serial.
+	pointerSerial C.uint32_t
 
 	pointerFocus  *window
 	keyboardFocus *window
@@ -137,7 +144,7 @@ type repeatState struct {
 	delay time.Duration
 
 	key   uint32
-	win   *callbacks
+	win   *window
 	stopC chan struct{}
 
 	start time.Duration
@@ -149,7 +156,6 @@ type repeatState struct {
 type window struct {
 	w          *callbacks
 	disp       *wlDisplay
-	seat       *wlSeat
 	surf       *C.struct_wl_surface
 	wmSurf     *C.struct_xdg_surface
 	topLvl     *C.struct_xdg_toplevel
@@ -194,12 +200,10 @@ type window struct {
 		dir            f32.Point
 	}
 
-	stage             system.Stage
+	configured        bool
-	dead              bool
 	lastFrameCallback *C.struct_wl_callback
 
 	animating bool
-	redraw    bool
 	// The most recent configure serial waiting to be ack'ed.
 	serial C.uint32_t
 	scale  int
@@ -209,9 +213,11 @@ type window struct {
 	wsize        image.Point // window config size before going fullscreen or maximized
 	inCompositor bool        // window is moving or being resized
 
-	clipReads chan clipboard.Event
+	clipReads chan transfer.DataEvent
 
 	wakeups chan struct{}
+
+	closing bool
 }
 
 type poller struct {
@@ -260,25 +266,17 @@ func newWLWindow(callbacks *callbacks, options []Option) error {
 		return err
 	}
 	w.w = callbacks
-	go func() {
+	w.w.SetDriver(w)
-		defer d.destroy()
-		defer w.destroy()
 
-		w.w.SetDriver(w)
+	// Finish and commit setup from createNativeWindow.
+	w.Configure(options)
+	w.draw(true)
+	C.wl_surface_commit(w.surf)
 
-		// Finish and commit setup from createNativeWindow.
+	w.ProcessEvent(WaylandViewEvent{
-		w.Configure(options)
+		Display: unsafe.Pointer(w.display()),
-		C.wl_surface_commit(w.surf)
+		Surface: unsafe.Pointer(w.surf),
-
+	})
-		w.w.Event(WaylandViewEvent{
-			Display: unsafe.Pointer(w.display()),
-			Surface: unsafe.Pointer(w.surf),
-		})
-
-		err := w.loop()
-		w.w.Event(WaylandViewEvent{})
-		w.w.Event(system.DestroyEvent{Err: err})
-	}()
 	return nil
 }
 
@@ -354,7 +352,7 @@ func (d *wlDisplay) createNativeWindow(options []Option) (*window, error) {
 		ppdp:      ppdp,
 		ppsp:      ppdp,
 		wakeups:   make(chan struct{}, 1),
-		clipReads: make(chan clipboard.Event, 1),
+		clipReads: make(chan transfer.DataEvent, 1),
 	}
 	w.surf = C.wl_compositor_create_surface(d.compositor)
 	if w.surf == nil {
@@ -549,15 +547,15 @@ func gio_onSeatName(data unsafe.Pointer, seat *C.struct_wl_seat, name *C.char) {
 func gio_onXdgSurfaceConfigure(data unsafe.Pointer, wmSurf *C.struct_xdg_surface, serial C.uint32_t) {
 	w := callbackLoad(data).(*window)
 	w.serial = serial
-	w.redraw = true
 	C.xdg_surface_ack_configure(wmSurf, serial)
-	w.setStage(system.StageRunning)
+	w.configured = true
+	w.draw(true)
 }
 
 //export gio_onToplevelClose
 func gio_onToplevelClose(data unsafe.Pointer, topLvl *C.struct_xdg_toplevel) {
 	w := callbackLoad(data).(*window)
-	w.dead = true
+	w.closing = true
 }
 
 //export gio_onToplevelConfigure
@@ -586,8 +584,8 @@ func gio_onToplevelDecorationConfigure(data unsafe.Pointer, deco *C.struct_zxdg_
 		} else {
 			w.size.Y += int(w.config.decoHeight)
 		}
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
-		w.redraw = true
+		w.draw(true)
 	}
 }
 
@@ -645,7 +643,7 @@ func gio_onSurfaceEnter(data unsafe.Pointer, surf *C.struct_wl_surface, output *
 	if w.config.Mode == Minimized {
 		// Minimized window got brought back up: it is no longer so.
 		w.config.Mode = Windowed
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	}
 }
 
@@ -790,7 +788,7 @@ func gio_onTouchDown(data unsafe.Pointer, touch *C.struct_wl_touch, serial, t C.
 		X: fromFixed(x) * float32(w.scale),
 		Y: fromFixed(y) * float32(w.scale),
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Press,
 		Source:    pointer.Touch,
 		Position:  w.lastTouch,
@@ -806,7 +804,7 @@ func gio_onTouchUp(data unsafe.Pointer, touch *C.struct_wl_touch, serial, t C.ui
 	s.serial = serial
 	w := s.touchFoci[id]
 	delete(s.touchFoci, id)
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Release,
 		Source:    pointer.Touch,
 		Position:  w.lastTouch,
@@ -824,7 +822,7 @@ func gio_onTouchMotion(data unsafe.Pointer, touch *C.struct_wl_touch, t C.uint32
 		X: fromFixed(x) * float32(w.scale),
 		Y: fromFixed(y) * float32(w.scale),
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Move,
 		Position:  w.lastTouch,
 		Source:    pointer.Touch,
@@ -843,7 +841,7 @@ func gio_onTouchCancel(data unsafe.Pointer, touch *C.struct_wl_touch) {
 	s := callbackLoad(data).(*wlSeat)
 	for id, w := range s.touchFoci {
 		delete(s.touchFoci, id)
-		w.w.Event(pointer.Event{
+		w.ProcessEvent(pointer.Event{
 			Kind:   pointer.Cancel,
 			Source: pointer.Touch,
 		})
@@ -854,8 +852,8 @@ func gio_onTouchCancel(data unsafe.Pointer, touch *C.struct_wl_touch) {
 func gio_onPointerEnter(data unsafe.Pointer, pointer *C.struct_wl_pointer, serial C.uint32_t, surf *C.struct_wl_surface, x, y C.wl_fixed_t) {
 	s := callbackLoad(data).(*wlSeat)
 	s.serial = serial
+	s.pointerSerial = serial
 	w := callbackLoad(unsafe.Pointer(surf)).(*window)
-	w.seat = s
 	s.pointerFocus = w
 	w.setCursor(pointer, serial)
 	w.lastPos = f32.Point{X: fromFixed(x), Y: fromFixed(y)}
@@ -864,12 +862,12 @@ func gio_onPointerEnter(data unsafe.Pointer, pointer *C.struct_wl_pointer, seria
 //export gio_onPointerLeave
 func gio_onPointerLeave(data unsafe.Pointer, p *C.struct_wl_pointer, serial C.uint32_t, surf *C.struct_wl_surface) {
 	w := callbackLoad(unsafe.Pointer(surf)).(*window)
-	w.seat = nil
 	s := callbackLoad(data).(*wlSeat)
 	s.serial = serial
+	s.pointerFocus = nil
 	if w.inCompositor {
 		w.inCompositor = false
-		w.w.Event(pointer.Event{Kind: pointer.Cancel})
+		w.ProcessEvent(pointer.Event{Kind: pointer.Cancel})
 	}
 }
 
@@ -886,11 +884,13 @@ func gio_onPointerButton(data unsafe.Pointer, p *C.struct_wl_pointer, serial, t,
 	s := callbackLoad(data).(*wlSeat)
 	s.serial = serial
 	w := s.pointerFocus
-	// From linux-event-codes.h.
+	// From Linux: include/uapi/linux/input-event-codes.h
 	const (
 		BTN_LEFT   = 0x110
 		BTN_RIGHT  = 0x111
 		BTN_MIDDLE = 0x112
+		BTN_SIDE   = 0x113
+		BTN_EXTRA  = 0x114
 	)
 	var btn pointer.Buttons
 	switch wbtn {
@@ -900,6 +900,10 @@ func gio_onPointerButton(data unsafe.Pointer, p *C.struct_wl_pointer, serial, t,
 		btn = pointer.ButtonSecondary
 	case BTN_MIDDLE:
 		btn = pointer.ButtonTertiary
+	case BTN_SIDE:
+		btn = pointer.ButtonQuaternary
+	case BTN_EXTRA:
+		btn = pointer.ButtonQuinary
 	default:
 		return
 	}
@@ -930,7 +934,7 @@ func gio_onPointerButton(data unsafe.Pointer, p *C.struct_wl_pointer, serial, t,
 	}
 	w.flushScroll()
 	w.resetFling()
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      kind,
 		Source:    pointer.Mouse,
 		Buttons:   w.pointerBtns,
@@ -966,6 +970,9 @@ func gio_onPointerAxis(data unsafe.Pointer, p *C.struct_wl_pointer, t, axis C.ui
 func gio_onPointerFrame(data unsafe.Pointer, p *C.struct_wl_pointer) {
 	s := callbackLoad(data).(*wlSeat)
 	w := s.pointerFocus
+	if w == nil {
+		return
+	}
 	w.flushScroll()
 	w.flushFling()
 }
@@ -1018,23 +1025,34 @@ func gio_onPointerAxisDiscrete(data unsafe.Pointer, p *C.struct_wl_pointer, axis
 }
 
 func (w *window) ReadClipboard() {
+	if w.disp.readClipClose != nil {
+		return
+	}
+	w.disp.readClipClose = make(chan struct{})
 	r, err := w.disp.readClipboard()
-	// Send empty responses on unavailable clipboards or errors.
 	if r == nil || err != nil {
-		w.w.Event(clipboard.Event{})
 		return
 	}
 	// Don't let slow clipboard transfers block event loop.
 	go func() {
 		defer r.Close()
 		data, _ := io.ReadAll(r)
-		w.clipReads <- clipboard.Event{Text: string(data)}
+		e := transfer.DataEvent{
-		w.Wakeup()
+			Type: "application/text",
+			Open: func() io.ReadCloser {
+				return io.NopCloser(bytes.NewReader(data))
+			},
+		}
+		select {
+		case w.clipReads <- e:
+			w.disp.wakeup()
+		case <-w.disp.readClipClose:
+		}
 	}()
 }
 
-func (w *window) WriteClipboard(s string) {
+func (w *window) WriteClipboard(mime string, s []byte) {
-	w.disp.writeClipboard([]byte(s))
+	w.disp.writeClipboard(s)
 }
 
 func (w *window) Configure(options []Option) {
@@ -1092,8 +1110,7 @@ func (w *window) Configure(options []Option) {
 		w.config.MaxSize = cnf.MaxSize
 		w.setWindowConstraints()
 	}
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
-	w.redraw = true
 }
 
 func (w *window) setWindowConstraints() {
@@ -1130,22 +1147,23 @@ func (w *window) Perform(actions system.Action) {
 	walkActions(actions, func(action system.Action) {
 		switch action {
 		case system.ActionClose:
-			w.dead = true
+			w.closing = true
 		}
 	})
 }
 
 func (w *window) move(serial C.uint32_t) {
-	s := w.seat
+	s := w.disp.seat
-	if !w.inCompositor && s != nil {
+	if w.inCompositor || s.pointerFocus != w {
-		w.inCompositor = true
+		return
-		C.xdg_toplevel_move(w.topLvl, s.seat, serial)
 	}
+	w.inCompositor = true
+	C.xdg_toplevel_move(w.topLvl, s.seat, serial)
 }
 
 func (w *window) resize(serial, edge C.uint32_t) {
-	s := w.seat
+	s := w.disp.seat
-	if w.inCompositor || s == nil {
+	if w.inCompositor || s.pointerFocus != w {
 		return
 	}
 	w.inCompositor = true
@@ -1158,11 +1176,12 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 }
 
 func (w *window) updateCursor() {
-	ptr := w.disp.seat.pointer
+	s := w.disp.seat
-	if ptr == nil {
+	ptr := s.pointer
+	if ptr == nil || s.pointerFocus != w {
 		return
 	}
-	w.setCursor(ptr, w.serial)
+	w.setCursor(ptr, s.pointerSerial)
 }
 
 func (w *window) setCursor(pointer *C.struct_wl_pointer, serial C.uint32_t) {
@@ -1171,7 +1190,7 @@ func (w *window) setCursor(pointer *C.struct_wl_pointer, serial C.uint32_t) {
 		c = w.cursor.cursor
 	}
 	if c == nil {
-		C.wl_pointer_set_cursor(pointer, w.serial, nil, 0, 0)
+		C.wl_pointer_set_cursor(pointer, serial, nil, 0, 0)
 		return
 	}
 	// Get images[0].
@@ -1213,7 +1232,8 @@ func gio_onKeyboardEnter(data unsafe.Pointer, keyboard *C.struct_wl_keyboard, se
 	w := callbackLoad(unsafe.Pointer(surf)).(*window)
 	s.keyboardFocus = w
 	s.disp.repeat.Stop(0)
-	w.w.Event(key.FocusEvent{Focus: true})
+	w.config.Focused = true
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export gio_onKeyboardLeave
@@ -1222,7 +1242,8 @@ func gio_onKeyboardLeave(data unsafe.Pointer, keyboard *C.struct_wl_keyboard, se
 	s.serial = serial
 	s.disp.repeat.Stop(0)
 	w := s.keyboardFocus
-	w.w.Event(key.FocusEvent{Focus: false})
+	w.config.Focused = false
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export gio_onKeyboardKey
@@ -1240,7 +1261,7 @@ func gio_onKeyboardKey(data unsafe.Pointer, keyboard *C.struct_wl_keyboard, seri
 			// There's no support for IME yet.
 			w.w.EditorInsert(ee.Text)
 		} else {
-			w.w.Event(e)
+			w.ProcessEvent(e)
 		}
 	}
 	if state != C.WL_KEYBOARD_KEY_STATE_PRESSED {
@@ -1275,7 +1296,7 @@ func (r *repeatState) Start(w *window, keyCode uint32, t time.Duration) {
 	r.now = 0
 	r.stopC = stopC
 	r.key = keyCode
-	r.win = w.w
+	r.win = w
 	rate, delay := r.rate, r.delay
 	go func() {
 		timer := time.NewTimer(delay)
@@ -1333,9 +1354,9 @@ func (r *repeatState) Repeat(d *wlDisplay) {
 		for _, e := range d.xkb.DispatchKey(r.key, key.Press) {
 			if ee, ok := e.(key.EditEvent); ok {
 				// There's no support for IME yet.
-				r.win.EditorInsert(ee.Text)
+				r.win.w.EditorInsert(ee.Text)
 			} else {
-				r.win.Event(e)
+				r.win.ProcessEvent(e)
 			}
 		}
 		r.last += delay
@@ -1348,28 +1369,68 @@ func gio_onFrameDone(data unsafe.Pointer, callback *C.struct_wl_callback, t C.ui
 	w := callbackLoad(data).(*window)
 	if w.lastFrameCallback == callback {
 		w.lastFrameCallback = nil
+		w.draw(false)
 	}
 }
 
-func (w *window) loop() error {
+func (w *window) close(err error) {
-	var p poller
+	w.ProcessEvent(WaylandViewEvent{})
-	for {
+	w.ProcessEvent(DestroyEvent{Err: err})
-		if err := w.disp.dispatch(&p); err != nil {
+	w.destroy()
-			return err
+	w.disp.destroy()
-		}
+	w.disp = nil
-		select {
+}
-		case e := <-w.clipReads:
+
-			w.w.Event(e)
+func (w *window) dispatch() {
-		case <-w.wakeups:
+	if w.disp == nil {
-			w.w.Event(wakeupEvent{})
+		<-w.wakeups
-		default:
+		w.w.Invalidate()
-		}
+		return
-		if w.dead {
-			break
-		}
-		w.draw()
 	}
-	return nil
+	if err := w.disp.dispatch(); err != nil || w.closing {
+		w.close(err)
+		return
+	}
+	select {
+	case e := <-w.clipReads:
+		w.disp.readClipClose = nil
+		w.ProcessEvent(e)
+	case <-w.wakeups:
+		w.w.Invalidate()
+	default:
+	}
+}
+
+func (w *window) ProcessEvent(e event.Event) {
+	w.w.ProcessEvent(e)
+}
+
+func (w *window) Event() event.Event {
+	for {
+		evt, ok := w.w.nextEvent()
+		if !ok {
+			w.dispatch()
+			continue
+		}
+		return evt
+	}
+}
+
+func (w *window) Invalidate() {
+	select {
+	case w.wakeups <- struct{}{}:
+	default:
+		return
+	}
+	w.disp.wakeup()
+}
+
+func (w *window) Run(f func()) {
+	f()
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.w.ProcessFrame(frame, nil)
 }
 
 // bindDataDevice initializes the dataDev field if and only if both
@@ -1385,13 +1446,21 @@ func (d *wlDisplay) bindDataDevice() {
 	}
 }
 
-func (d *wlDisplay) dispatch(p *poller) error {
+func (d *wlDisplay) dispatch() error {
+	// wl_display_prepare_read records the current thread for
+	// use in wl_display_read_events or wl_display_cancel_events.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
 	dispfd := C.wl_display_get_fd(d.disp)
 	// Poll for events and notifications.
-	pollfds := append(p.pollfds[:0],
+	pollfds := append(d.poller.pollfds[:0],
 		syscall.PollFd{Fd: int32(dispfd), Events: syscall.POLLIN | syscall.POLLERR},
 		syscall.PollFd{Fd: int32(d.notify.read), Events: syscall.POLLIN | syscall.POLLERR},
 	)
+	for C.wl_display_prepare_read(d.disp) != 0 {
+		C.wl_display_dispatch_pending(d.disp)
+	}
 	dispFd := &pollfds[0]
 	if ret, err := C.wl_display_flush(d.disp); ret < 0 {
 		if err != syscall.EAGAIN {
@@ -1402,11 +1471,25 @@ func (d *wlDisplay) dispatch(p *poller) error {
 		dispFd.Events |= syscall.POLLOUT
 	}
 	if _, err := syscall.Poll(pollfds, -1); err != nil && err != syscall.EINTR {
+		C.wl_display_cancel_read(d.disp)
 		return fmt.Errorf("wayland: poll failed: %v", err)
 	}
+	if dispFd.Revents&(syscall.POLLERR|syscall.POLLHUP) != 0 {
+		C.wl_display_cancel_read(d.disp)
+		return errors.New("wayland: display file descriptor gone")
+	}
+	// Handle events.
+	if dispFd.Revents&syscall.POLLIN != 0 {
+		if ret, err := C.wl_display_read_events(d.disp); ret < 0 {
+			return fmt.Errorf("wayland: wl_display_read_events failed: %v", err)
+		}
+		C.wl_display_dispatch_pending(d.disp)
+	} else {
+		C.wl_display_cancel_read(d.disp)
+	}
 	// Clear notifications.
 	for {
-		_, err := syscall.Read(d.notify.read, p.buf[:])
+		_, err := syscall.Read(d.notify.read, d.poller.buf[:])
 		if err == syscall.EAGAIN {
 			break
 		}
@@ -1414,29 +1497,15 @@ func (d *wlDisplay) dispatch(p *poller) error {
 			return fmt.Errorf("wayland: read from notify pipe failed: %v", err)
 		}
 	}
-	// Handle events
-	switch {
-	case dispFd.Revents&syscall.POLLIN != 0:
-		if ret, err := C.wl_display_dispatch(d.disp); ret < 0 {
-			return fmt.Errorf("wayland: wl_display_dispatch failed: %v", err)
-		}
-	case dispFd.Revents&(syscall.POLLERR|syscall.POLLHUP) != 0:
-		return errors.New("wayland: display file descriptor gone")
-	}
 	d.repeat.Repeat(d)
 	return nil
 }
 
-func (w *window) Wakeup() {
-	select {
-	case w.wakeups <- struct{}{}:
-	default:
-	}
-	w.disp.wakeup()
-}
-
 func (w *window) SetAnimating(anim bool) {
 	w.animating = anim
+	if anim {
+		w.draw(false)
+	}
 }
 
 // Wakeup wakes up the event loop through the notification pipe.
@@ -1448,6 +1517,10 @@ func (d *wlDisplay) wakeup() {
 }
 
 func (w *window) destroy() {
+	if w.lastFrameCallback != nil {
+		C.wl_callback_destroy(w.lastFrameCallback)
+		w.lastFrameCallback = nil
+	}
 	if w.cursor.surf != nil {
 		C.wl_surface_destroy(w.cursor.surf)
 	}
@@ -1572,7 +1645,15 @@ func (w *window) flushScroll() {
 	if total == (f32.Point{}) {
 		return
 	}
-	w.w.Event(pointer.Event{
+	if w.scroll.steps == (image.Point{}) {
+		w.fling.xExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.X)
+		w.fling.yExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.Y)
+	}
+	// Zero scroll distance prior to calling ProcessEvent, otherwise we may recursively
+	// re-process the scroll distance.
+	w.scroll.dist = f32.Point{}
+	w.scroll.steps = image.Point{}
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Scroll,
 		Source:    pointer.Mouse,
 		Buttons:   w.pointerBtns,
@@ -1581,12 +1662,6 @@ func (w *window) flushScroll() {
 		Time:      w.scroll.time,
 		Modifiers: w.disp.xkb.Modifiers(),
 	})
-	if w.scroll.steps == (image.Point{}) {
-		w.fling.xExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.X)
-		w.fling.yExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.Y)
-	}
-	w.scroll.dist = f32.Point{}
-	w.scroll.steps = image.Point{}
 }
 
 func (w *window) onPointerMotion(x, y C.wl_fixed_t, t C.uint32_t) {
@@ -1595,7 +1670,7 @@ func (w *window) onPointerMotion(x, y C.wl_fixed_t, t C.uint32_t) {
 		X: fromFixed(x) * float32(w.scale),
 		Y: fromFixed(y) * float32(w.scale),
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Move,
 		Position:  w.lastPos,
 		Buttons:   w.pointerBtns,
@@ -1616,7 +1691,8 @@ func (w *window) systemGesture() (*C.struct_wl_cursor, C.uint32_t) {
 	if w.config.Mode != Windowed || w.config.Decorated {
 		return nil, 0
 	}
-	border := w.w.w.metric.Dp(3)
+	_, cfg := w.getConfig()
+	border := cfg.Dp(3)
 	x, y, size := int(w.lastPos.X), int(w.lastPos.Y), w.config.Size
 	north := y <= border
 	south := y >= size.Y-border
@@ -1670,13 +1746,10 @@ func (w *window) updateOutputs() {
 	if found && scale != w.scale {
 		w.scale = scale
 		C.wl_surface_set_buffer_scale(w.surf, C.int32_t(w.scale))
-		w.redraw = true
+		w.draw(true)
 	}
-	if !found {
+	if found {
-		w.setStage(system.StagePaused)
+		w.draw(true)
-	} else {
-		w.setStage(system.StageRunning)
-		w.redraw = true
 	}
 }
 
@@ -1688,7 +1761,10 @@ func (w *window) getConfig() (image.Point, unit.Metric) {
 	}
 }
 
-func (w *window) draw() {
+func (w *window) draw(sync bool) {
+	if !w.configured {
+		return
+	}
 	w.flushScroll()
 	size, cfg := w.getConfig()
 	if cfg == (unit.Metric{}) {
@@ -1696,11 +1772,9 @@ func (w *window) draw() {
 	}
 	if size != w.config.Size {
 		w.config.Size = size
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	}
 	anim := w.animating || w.fling.anim.Active()
-	sync := w.redraw
-	w.redraw = false
 	// Draw animation only when not waiting for frame callback.
 	redrawAnim := anim && w.lastFrameCallback == nil
 	if !redrawAnim && !sync {
@@ -1711,8 +1785,8 @@ func (w *window) draw() {
 		// Use the surface as listener data for gio_onFrameDone.
 		C.wl_callback_add_listener(w.lastFrameCallback, &C.gio_callback_listener, unsafe.Pointer(w.surf))
 	}
-	w.w.Event(frameEvent{
+	w.ProcessEvent(frameEvent{
-		FrameEvent: system.FrameEvent{
+		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   w.config.Size,
 			Metric: cfg,
@@ -1721,14 +1795,6 @@ func (w *window) draw() {
 	})
 }
 
-func (w *window) setStage(s system.Stage) {
-	if s == w.stage {
-		return
-	}
-	w.stage = s
-	w.w.Event(system.StageEvent{Stage: s})
-}
-
 func (w *window) display() *C.struct_wl_display {
 	return w.disp.disp
 }
@@ -1820,6 +1886,10 @@ func newWLDisplay() (*wlDisplay, error) {
 }
 
 func (d *wlDisplay) destroy() {
+	if d.readClipClose != nil {
+		close(d.readClipClose)
+		d.readClipClose = nil
+	}
 	if d.notify.write != 0 {
 		syscall.Close(d.notify.write)
 		d.notify.write = 0
@@ -1861,6 +1931,7 @@ func (d *wlDisplay) destroy() {
 	if d.disp != nil {
 		C.wl_display_disconnect(d.disp)
 		callbackDelete(unsafe.Pointer(d.disp))
+		d.disp = nil
 	}
 }
 

app/os_windows.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"image"
+	"io"
 	"runtime"
 	"sort"
 	"strings"
@@ -18,40 +19,39 @@ import (
 	syscall "golang.org/x/sys/windows"
 
 	"gioui.org/app/internal/windows"
+	"gioui.org/op"
 	"gioui.org/unit"
 	gowindows "golang.org/x/sys/windows"
 
 	"gioui.org/f32"
-	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
+	"gioui.org/io/transfer"
 )
 
-type ViewEvent struct {
+type Win32ViewEvent struct {
 	HWND uintptr
 }
 
 type window struct {
-	hwnd        syscall.Handle
+	hwnd syscall.Handle
-	hdc         syscall.Handle
+	hdc  syscall.Handle
-	w           *callbacks
+	w    *callbacks
-	stage       system.Stage
-	pointerBtns pointer.Buttons
 
 	// cursorIn tracks whether the cursor was inside the window according
 	// to the most recent WM_SETCURSOR.
 	cursorIn bool
 	cursor   syscall.Handle
 
-	// placement saves the previous window position when in full screen mode.
-	placement *windows.WindowPlacement
-
 	animating bool
-	focused   bool
 
 	borderSize image.Point
 	config     Config
+	// frameDims stores the last seen window frame width and height.
+	frameDims image.Point
+	loop      *eventLoop
 }
 
 const _WM_WAKEUP = windows.WM_USER + iota
@@ -84,36 +84,38 @@ func osMain() {
 	select {}
 }
 
-func newWindow(window *callbacks, options []Option) error {
+func newWindow(win *callbacks, options []Option) {
-	cerr := make(chan error)
+	done := make(chan struct{})
 	go func() {
 		// GetMessage and PeekMessage can filter on a window HWND, but
 		// then thread-specific messages such as WM_QUIT are ignored.
 		// Instead lock the thread so window messages arrive through
 		// unfiltered GetMessage calls.
 		runtime.LockOSThread()
-		w, err := createNativeWindow()
+
+		w := &window{
+			w: win,
+		}
+		w.loop = newEventLoop(w.w, w.wakeup)
+		w.w.SetDriver(w)
+		err := w.init()
+		done <- struct{}{}
 		if err != nil {
-			cerr <- err
+			w.ProcessEvent(DestroyEvent{Err: err})
 			return
 		}
-		cerr <- nil
 		winMap.Store(w.hwnd, w)
 		defer winMap.Delete(w.hwnd)
-		w.w = window
-		w.w.SetDriver(w)
-		w.w.Event(ViewEvent{HWND: uintptr(w.hwnd)})
 		w.Configure(options)
+		w.ProcessEvent(Win32ViewEvent{HWND: uintptr(w.hwnd)})
 		windows.SetForegroundWindow(w.hwnd)
 		windows.SetFocus(w.hwnd)
 		// Since the window class for the cursor is null,
 		// set it here to show the cursor.
 		w.SetCursor(pointer.CursorDefault)
-		if err := w.loop(); err != nil {
+		w.runLoop()
-			panic(err)
-		}
 	}()
-	return <-cerr
+	<-done
 }
 
 // initResources initializes the resources global.
@@ -148,13 +150,13 @@ func initResources() error {
 
 const dwExStyle = windows.WS_EX_APPWINDOW | windows.WS_EX_WINDOWEDGE
 
-func createNativeWindow() (*window, error) {
+func (w *window) init() error {
 	var resErr error
 	resources.once.Do(func() {
 		resErr = initResources()
 	})
 	if resErr != nil {
-		return nil, resErr
+		return resErr
 	}
 	const dwStyle = windows.WS_OVERLAPPEDWINDOW
 
@@ -170,33 +172,56 @@ func createNativeWindow() (*window, error) {
 		resources.handle,
 		0)
 	if err != nil {
-		return nil, err
+		return err
 	}
-	w := &window{
+	if err := windows.RegisterTouchWindow(hwnd, 0); err != nil {
-		hwnd: hwnd,
+		return err
+	}
+	if err := windows.EnableMouseInPointer(1); err != nil {
+		return err
 	}
 	w.hdc, err = windows.GetDC(hwnd)
 	if err != nil {
-		return nil, err
+		windows.DestroyWindow(hwnd)
+		return err
 	}
-	return w, nil
+	w.hwnd = hwnd
+	return nil
 }
 
-// update() handles changes done by the user, and updates the configuration.
+// update handles changes done by the user, and updates the configuration.
 // It reads the window style and size/position and updates w.config.
 // If anything has changed it emits a ConfigEvent to notify the application.
 func (w *window) update() {
-	cr := windows.GetClientRect(w.hwnd)
+	p := windows.GetWindowPlacement(w.hwnd)
-	w.config.Size = image.Point{
+	if !p.IsMinimized() {
-		X: int(cr.Right - cr.Left),
+		r := windows.GetWindowRect(w.hwnd)
-		Y: int(cr.Bottom - cr.Top),
+		cr := windows.GetClientRect(w.hwnd)
+		w.config.Size = image.Point{
+			X: int(cr.Right - cr.Left),
+			Y: int(cr.Bottom - cr.Top),
+		}
+		w.frameDims = image.Point{
+			X: int(r.Right - r.Left),
+			Y: int(r.Bottom - r.Top),
+		}.Sub(w.config.Size)
 	}
 
 	w.borderSize = image.Pt(
 		windows.GetSystemMetrics(windows.SM_CXSIZEFRAME),
 		windows.GetSystemMetrics(windows.SM_CYSIZEFRAME),
 	)
-	w.w.Event(ConfigEvent{Config: w.config})
+	style := windows.GetWindowLong(w.hwnd, windows.GWL_STYLE)
+	switch {
+	case p.IsMaximized() && style&windows.WS_OVERLAPPEDWINDOW != 0:
+		w.config.Mode = Maximized
+	case p.IsMaximized():
+		w.config.Mode = Fullscreen
+	default:
+		w.config.Mode = Windowed
+	}
+	w.ProcessEvent(ConfigEvent{Config: w.config})
+	w.draw(true)
 }
 
 func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr {
@@ -237,7 +262,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 				e.State = key.Release
 			}
 
-			w.w.Event(e)
+			w.ProcessEvent(e)
 
 			if (wParam == windows.VK_F10) && (msg == windows.WM_SYSKEYDOWN || msg == windows.WM_SYSKEYUP) {
 				// Reserve F10 for ourselves, and don't let it open the system menu. Other Windows programs
@@ -245,36 +270,42 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 				return 0
 			}
 		}
-	case windows.WM_LBUTTONDOWN:
+	case windows.WM_POINTERDOWN, windows.WM_POINTERUP, windows.WM_POINTERUPDATE, windows.WM_POINTERCAPTURECHANGED:
-		w.pointerButton(pointer.ButtonPrimary, true, lParam, getModifiers())
+		pid := getPointerIDwParam(wParam)
-	case windows.WM_LBUTTONUP:
+		pi, err := windows.GetPointerInfo(uint32(pid))
-		w.pointerButton(pointer.ButtonPrimary, false, lParam, getModifiers())
+		if err != nil {
-	case windows.WM_RBUTTONDOWN:
+			panic(err)
-		w.pointerButton(pointer.ButtonSecondary, true, lParam, getModifiers())
+		}
-	case windows.WM_RBUTTONUP:
+		switch msg {
-		w.pointerButton(pointer.ButtonSecondary, false, lParam, getModifiers())
+		case windows.WM_POINTERDOWN:
-	case windows.WM_MBUTTONDOWN:
+			windows.SetCapture(w.hwnd)
-		w.pointerButton(pointer.ButtonTertiary, true, lParam, getModifiers())
+		case windows.WM_POINTERUP:
-	case windows.WM_MBUTTONUP:
+			windows.ReleaseCapture()
-		w.pointerButton(pointer.ButtonTertiary, false, lParam, getModifiers())
+		}
+
+		kind := pointer.Move
+		switch pi.ButtonChangeType {
+		case windows.POINTER_CHANGE_FIRSTBUTTON_DOWN, windows.POINTER_CHANGE_SECONDBUTTON_DOWN, windows.POINTER_CHANGE_THIRDBUTTON_DOWN, windows.POINTER_CHANGE_FOURTHBUTTON_DOWN, windows.POINTER_CHANGE_FIFTHBUTTON_DOWN:
+			kind = pointer.Press
+		case windows.POINTER_CHANGE_FIRSTBUTTON_UP, windows.POINTER_CHANGE_SECONDBUTTON_UP, windows.POINTER_CHANGE_THIRDBUTTON_UP, windows.POINTER_CHANGE_FOURTHBUTTON_UP, windows.POINTER_CHANGE_FIFTHBUTTON_UP:
+			kind = pointer.Release
+		}
+
+		if (pi.PointerFlags&windows.POINTER_FLAG_CANCELED != 0) || (msg == windows.WM_POINTERCAPTURECHANGED) {
+			kind = pointer.Cancel
+		}
+
+		w.pointerUpdate(pi, pid, kind, lParam)
 	case windows.WM_CANCELMODE:
-		w.w.Event(pointer.Event{
+		w.ProcessEvent(pointer.Event{
 			Kind: pointer.Cancel,
 		})
 	case windows.WM_SETFOCUS:
-		w.focused = true
+		w.config.Focused = true
-		w.w.Event(key.FocusEvent{Focus: true})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	case windows.WM_KILLFOCUS:
-		w.focused = false
+		w.config.Focused = false
-		w.w.Event(key.FocusEvent{Focus: false})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
-	case windows.WM_NCACTIVATE:
-		if w.stage >= system.StageInactive {
-			if wParam == windows.TRUE {
-				w.setStage(system.StageRunning)
-			} else {
-				w.setStage(system.StageInactive)
-			}
-		}
 	case windows.WM_NCHITTEST:
 		if w.config.Decorated {
 			// Let the system handle it.
@@ -284,24 +315,14 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		np := windows.Point{X: int32(x), Y: int32(y)}
 		windows.ScreenToClient(w.hwnd, &np)
 		return w.hitTest(int(np.X), int(np.Y))
-	case windows.WM_MOUSEMOVE:
+	case windows.WM_POINTERWHEEL:
-		x, y := coordsFromlParam(lParam)
-		p := f32.Point{X: float32(x), Y: float32(y)}
-		w.w.Event(pointer.Event{
-			Kind:      pointer.Move,
-			Source:    pointer.Mouse,
-			Position:  p,
-			Buttons:   w.pointerBtns,
-			Time:      windows.GetMessageTime(),
-			Modifiers: getModifiers(),
-		})
-	case windows.WM_MOUSEWHEEL:
 		w.scrollEvent(wParam, lParam, false, getModifiers())
-	case windows.WM_MOUSEHWHEEL:
+	case windows.WM_POINTERHWHEEL:
 		w.scrollEvent(wParam, lParam, true, getModifiers())
 	case windows.WM_DESTROY:
-		w.w.Event(ViewEvent{})
+		w.ProcessEvent(Win32ViewEvent{})
-		w.w.Event(system.DestroyEvent{})
+		w.ProcessEvent(DestroyEvent{})
+		w.w = nil
 		if w.hdc != 0 {
 			windows.ReleaseDC(w.hdc)
 			w.hdc = 0
@@ -309,6 +330,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		// The system destroys the HWND for us.
 		w.hwnd = 0
 		windows.PostQuitMessage(0)
+		return 0
 	case windows.WM_NCCALCSIZE:
 		if w.config.Decorated {
 			// Let Windows handle decorations.
@@ -327,46 +349,37 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		// Adjust window position to avoid the extra padding in maximized
 		// state. See https://devblogs.microsoft.com/oldnewthing/20150304-00/?p=44543.
 		// Note that trying to do the adjustment in WM_GETMINMAXINFO is ignored by Windows.
-		szp := (*windows.NCCalcSizeParams)(unsafe.Pointer(uintptr(lParam)))
+		szp := (*windows.NCCalcSizeParams)(unsafe.Pointer(lParam))
 		mi := windows.GetMonitorInfo(w.hwnd)
 		szp.Rgrc[0] = mi.WorkArea
 		return 0
 	case windows.WM_PAINT:
 		w.draw(true)
+	case windows.WM_STYLECHANGED:
+		w.update()
+	case windows.WM_WINDOWPOSCHANGED:
+		w.update()
 	case windows.WM_SIZE:
 		w.update()
-		switch wParam {
-		case windows.SIZE_MINIMIZED:
-			w.config.Mode = Minimized
-			w.setStage(system.StagePaused)
-		case windows.SIZE_MAXIMIZED:
-			w.config.Mode = Maximized
-			w.setStage(system.StageRunning)
-		case windows.SIZE_RESTORED:
-			if w.config.Mode != Fullscreen {
-				w.config.Mode = Windowed
-			}
-			w.setStage(system.StageRunning)
-		}
 	case windows.WM_GETMINMAXINFO:
-		mm := (*windows.MinMaxInfo)(unsafe.Pointer(uintptr(lParam)))
+		mm := (*windows.MinMaxInfo)(unsafe.Pointer(lParam))
-		var bw, bh int32
+
+		var frameDims image.Point
 		if w.config.Decorated {
-			r := windows.GetWindowRect(w.hwnd)
+			frameDims = w.frameDims
-			cr := windows.GetClientRect(w.hwnd)
-			bw = r.Right - r.Left - (cr.Right - cr.Left)
-			bh = r.Bottom - r.Top - (cr.Bottom - cr.Top)
 		}
 		if p := w.config.MinSize; p.X > 0 || p.Y > 0 {
+			p = p.Add(frameDims)
 			mm.PtMinTrackSize = windows.Point{
-				X: int32(p.X) + bw,
+				X: int32(p.X),
-				Y: int32(p.Y) + bh,
+				Y: int32(p.Y),
 			}
 		}
 		if p := w.config.MaxSize; p.X > 0 || p.Y > 0 {
+			p = p.Add(frameDims)
 			mm.PtMaxTrackSize = windows.Point{
-				X: int32(p.X) + bw,
+				X: int32(p.X),
-				Y: int32(p.Y) + bh,
+				Y: int32(p.Y),
 			}
 		}
 		return 0
@@ -377,7 +390,8 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 			return windows.TRUE
 		}
 	case _WM_WAKEUP:
-		w.w.Event(wakeupEvent{})
+		w.loop.Wakeup()
+		w.loop.FlushEvents()
 	case windows.WM_IME_STARTCOMPOSITION:
 		imc := windows.ImmGetContext(w.hwnd)
 		if imc == 0 {
@@ -457,9 +471,6 @@ func getModifiers() key.Modifiers {
 // hitTest returns the non-client area hit by the point, needed to
 // process WM_NCHITTEST.
 func (w *window) hitTest(x, y int) uintptr {
-	if w.config.Mode == Fullscreen {
-		return windows.HTCLIENT
-	}
 	if w.config.Mode != Windowed {
 		// Only windowed mode should allow resizing.
 		return windows.HTCLIENT
@@ -496,34 +507,28 @@ func (w *window) hitTest(x, y int) uintptr {
 	return windows.HTCLIENT
 }
 
-func (w *window) pointerButton(btn pointer.Buttons, press bool, lParam uintptr, kmods key.Modifiers) {
+func (w *window) pointerUpdate(pi windows.PointerInfo, pid pointer.ID, kind pointer.Kind, lParam uintptr) {
-	if !w.focused {
+	if !w.config.Focused {
 		windows.SetFocus(w.hwnd)
 	}
 
-	var kind pointer.Kind
+	src := pointer.Touch
-	if press {
+	if pi.PointerType == windows.PT_MOUSE {
-		kind = pointer.Press
+		src = pointer.Mouse
-		if w.pointerBtns == 0 {
-			windows.SetCapture(w.hwnd)
-		}
-		w.pointerBtns |= btn
-	} else {
-		kind = pointer.Release
-		w.pointerBtns &^= btn
-		if w.pointerBtns == 0 {
-			windows.ReleaseCapture()
-		}
 	}
+
 	x, y := coordsFromlParam(lParam)
-	p := f32.Point{X: float32(x), Y: float32(y)}
+	np := windows.Point{X: int32(x), Y: int32(y)}
-	w.w.Event(pointer.Event{
+	windows.ScreenToClient(w.hwnd, &np)
+	p := f32.Point{X: float32(np.X), Y: float32(np.Y)}
+	w.ProcessEvent(pointer.Event{
 		Kind:      kind,
-		Source:    pointer.Mouse,
+		Source:    src,
 		Position:  p,
-		Buttons:   w.pointerBtns,
+		PointerID: pid,
+		Buttons:   getPointerButtons(pi),
 		Time:      windows.GetMessageTime(),
-		Modifiers: kmods,
+		Modifiers: getModifiers(),
 	})
 }
 
@@ -534,6 +539,12 @@ func coordsFromlParam(lParam uintptr) (int, int) {
 }
 
 func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.Modifiers) {
+	pid := getPointerIDwParam(wParam)
+	pi, err := windows.GetPointerInfo(uint32(pid))
+	if err != nil {
+		panic(err)
+	}
+
 	x, y := coordsFromlParam(lParam)
 	// The WM_MOUSEWHEEL coordinates are in screen coordinates, in contrast
 	// to other mouse events.
@@ -552,11 +563,11 @@ func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.
 			sp.Y = -dist
 		}
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Scroll,
 		Source:    pointer.Mouse,
 		Position:  p,
-		Buttons:   w.pointerBtns,
+		Buttons:   getPointerButtons(pi),
 		Scroll:    sp,
 		Modifiers: kmods,
 		Time:      windows.GetMessageTime(),
@@ -564,18 +575,19 @@ func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.
 }
 
 // Adapted from https://blogs.msdn.microsoft.com/oldnewthing/20060126-00/?p=32513/
-func (w *window) loop() error {
+func (w *window) runLoop() {
 	msg := new(windows.Msg)
 loop:
 	for {
 		anim := w.animating
-		if anim && !windows.PeekMessage(msg, 0, 0, 0, windows.PM_NOREMOVE) {
+		p := windows.GetWindowPlacement(w.hwnd)
+		if anim && !p.IsMinimized() && !windows.PeekMessage(msg, 0, 0, 0, windows.PM_NOREMOVE) {
 			w.draw(false)
 			continue
 		}
 		switch ret := windows.GetMessage(msg, 0, 0, 0); ret {
 		case -1:
-			return errors.New("GetMessage failed")
+			panic(errors.New("GetMessage failed"))
 		case 0:
 			// WM_QUIT received.
 			break loop
@@ -583,7 +595,6 @@ loop:
 		windows.TranslateMessage(msg)
 		windows.DispatchMessage(msg)
 	}
-	return nil
 }
 
 func (w *window) EditorStateChanged(old, new editorState) {
@@ -601,16 +612,30 @@ func (w *window) SetAnimating(anim bool) {
 	w.animating = anim
 }
 
-func (w *window) Wakeup() {
+func (w *window) ProcessEvent(e event.Event) {
-	if err := windows.PostMessage(w.hwnd, _WM_WAKEUP, 0, 0); err != nil {
+	w.w.ProcessEvent(e)
-		panic(err)
+	w.loop.FlushEvents()
-	}
 }
 
-func (w *window) setStage(s system.Stage) {
+func (w *window) Event() event.Event {
-	if s != w.stage {
+	return w.loop.Event()
-		w.stage = s
+}
-		w.w.Event(system.StageEvent{Stage: s})
+
+func (w *window) Invalidate() {
+	w.loop.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	w.loop.Run(f)
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.loop.Frame(frame)
+}
+
+func (w *window) wakeup() {
+	if err := windows.PostMessage(w.hwnd, _WM_WAKEUP, 0, 0); err != nil {
+		panic(err)
 	}
 }
 
@@ -620,8 +645,8 @@ func (w *window) draw(sync bool) {
 	}
 	dpi := windows.GetWindowDPI(w.hwnd)
 	cfg := configForDPI(dpi)
-	w.w.Event(frameEvent{
+	w.ProcessEvent(frameEvent{
-		FrameEvent: system.FrameEvent{
+		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   w.config.Size,
 			Metric: cfg,
@@ -667,15 +692,25 @@ func (w *window) readClipboard() error {
 	}
 	defer windows.GlobalUnlock(mem)
 	content := gowindows.UTF16PtrToString((*uint16)(unsafe.Pointer(ptr)))
-	w.w.Event(clipboard.Event{Text: content})
+	w.ProcessEvent(transfer.DataEvent{
+		Type: "application/text",
+		Open: func() io.ReadCloser {
+			return io.NopCloser(strings.NewReader(content))
+		},
+	})
 	return nil
 }
 
 func (w *window) Configure(options []Option) {
 	dpi := windows.GetSystemDPI()
 	metric := configForDPI(dpi)
-	w.config.apply(metric, options)
+	cnf := w.config
-	windows.SetWindowText(w.hwnd, w.config.Title)
+	cnf.apply(metric, options)
+	w.config.Title = cnf.Title
+	w.config.Decorated = cnf.Decorated
+	w.config.MinSize = cnf.MinSize
+	w.config.MaxSize = cnf.MaxSize
+	windows.SetWindowText(w.hwnd, cnf.Title)
 
 	style := windows.GetWindowLong(w.hwnd, windows.GWL_STYLE)
 	var showMode int32
@@ -683,7 +718,7 @@ func (w *window) Configure(options []Option) {
 	swpStyle := uintptr(windows.SWP_NOZORDER | windows.SWP_FRAMECHANGED)
 	winStyle := uintptr(windows.WS_OVERLAPPEDWINDOW)
 	style &^= winStyle
-	switch w.config.Mode {
+	switch cnf.Mode {
 	case Minimized:
 		style |= winStyle
 		swpStyle |= windows.SWP_NOMOVE | windows.SWP_NOSIZE
@@ -698,13 +733,13 @@ func (w *window) Configure(options []Option) {
 		style |= winStyle
 		showMode = windows.SW_SHOWNORMAL
 		// Get target for client area size.
-		width = int32(w.config.Size.X)
+		width = int32(cnf.Size.X)
-		height = int32(w.config.Size.Y)
+		height = int32(cnf.Size.Y)
 		// Get the current window size and position.
 		wr := windows.GetWindowRect(w.hwnd)
 		x = wr.Left
 		y = wr.Top
-		if w.config.Decorated {
+		if cnf.Decorated {
 			// Compute client size and position. Note that the client size is
 			// equal to the window size when we are in control of decorations.
 			r := windows.Rect{
@@ -714,28 +749,31 @@ func (w *window) Configure(options []Option) {
 			windows.AdjustWindowRectEx(&r, uint32(style), 0, dwExStyle)
 			width = r.Right - r.Left
 			height = r.Bottom - r.Top
-		}
+		} else {
-		if !w.config.Decorated {
 			// Enable drop shadows when we draw decorations.
 			windows.DwmExtendFrameIntoClientArea(w.hwnd, windows.Margins{-1, -1, -1, -1})
 		}
 
 	case Fullscreen:
-		mi := windows.GetMonitorInfo(w.hwnd)
+		swpStyle |= windows.SWP_NOMOVE | windows.SWP_NOSIZE
-		x, y = mi.Monitor.Left, mi.Monitor.Top
+		showMode = windows.SW_SHOWMAXIMIZED
-		width = mi.Monitor.Right - mi.Monitor.Left
-		height = mi.Monitor.Bottom - mi.Monitor.Top
-		showMode = windows.SW_SHOW
 	}
-	windows.SetWindowLong(w.hwnd, windows.GWL_STYLE, style)
-	windows.SetWindowPos(w.hwnd, 0, x, y, width, height, swpStyle)
-	windows.ShowWindow(w.hwnd, showMode)
 
-	w.update()
+	// Disable window resizing if MinSize and MaxSize are equal.
+	if cnf.MaxSize != (image.Point{}) && cnf.MinSize == cnf.MaxSize {
+		style &^= windows.WS_MAXIMIZEBOX
+		style &^= windows.WS_THICKFRAME
+	}
+
+	// Note: these invocation all trigger the windows callback method which may process a pending system.ActionCenter
+	// action, so SetWindowPos should come first so as to not "overwrite" system.ActionCenter.
+	windows.SetWindowPos(w.hwnd, 0, x, y, width, height, swpStyle)
+	windows.SetWindowLong(w.hwnd, windows.GWL_STYLE, style)
+	windows.ShowWindow(w.hwnd, showMode)
 }
 
-func (w *window) WriteClipboard(s string) {
+func (w *window) WriteClipboard(mime string, s []byte) {
-	w.writeClipboard(s)
+	w.writeClipboard(string(s))
 }
 
 func (w *window) writeClipboard(s string) error {
@@ -863,11 +901,11 @@ func (w *window) raise() {
 		windows.SWP_NOMOVE|windows.SWP_NOSIZE|windows.SWP_SHOWWINDOW)
 }
 
-func convertKeyCode(code uintptr) (string, bool) {
+func convertKeyCode(code uintptr) (key.Name, bool) {
 	if '0' <= code && code <= '9' || 'A' <= code && code <= 'Z' {
-		return string(rune(code)), true
+		return key.Name(rune(code)), true
 	}
-	var r string
+	var r key.Name
 
 	switch code {
 	case windows.VK_ESCAPE:
@@ -967,4 +1005,50 @@ func configForDPI(dpi int) unit.Metric {
 	}
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (Win32ViewEvent) implementsViewEvent() {}
+func (Win32ViewEvent) ImplementsEvent()     {}
+func (w Win32ViewEvent) Valid() bool {
+	return w != (Win32ViewEvent{})
+}
+
+// LOWORD (minwindef.h)
+func loWord(val uint32) uint16 {
+	return uint16(val & 0xFFFF)
+}
+
+// GET_POINTERID_WPARAM (winuser.h)
+func getPointerIDwParam(wParam uintptr) pointer.ID {
+	return pointer.ID(loWord(uint32(wParam)))
+}
+
+func getPointerButtons(pi windows.PointerInfo) pointer.Buttons {
+	var btns pointer.Buttons
+
+	if pi.PointerFlags&windows.POINTER_FLAG_FIRSTBUTTON != 0 {
+		btns |= pointer.ButtonPrimary
+	} else {
+		btns &^= pointer.ButtonPrimary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_SECONDBUTTON != 0 {
+		btns |= pointer.ButtonSecondary
+	} else {
+		btns &^= pointer.ButtonSecondary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_THIRDBUTTON != 0 {
+		btns |= pointer.ButtonTertiary
+	} else {
+		btns &^= pointer.ButtonTertiary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_FOURTHBUTTON != 0 {
+		btns |= pointer.ButtonQuaternary
+	} else {
+		btns &^= pointer.ButtonQuaternary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_FIFTHBUTTON != 0 {
+		btns |= pointer.ButtonQuinary
+	} else {
+		btns &^= pointer.ButtonQuinary
+	}
+
+	return btns
+}

app/os_x11.go

@@ -26,20 +26,25 @@ package app
 
 */
 import "C"
+
 import (
 	"errors"
 	"fmt"
 	"image"
+	"io"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 	"unsafe"
 
 	"gioui.org/f32"
-	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
+	"gioui.org/io/transfer"
+	"gioui.org/op"
 	"gioui.org/unit"
 
 	syscall "golang.org/x/sys/unix"
@@ -91,12 +96,10 @@ type x11Window struct {
 		// _NET_WM_STATE_MAXIMIZED_VERT
 		wmStateMaximizedVert C.Atom
 	}
-	stage  system.Stage
 	metric unit.Metric
 	notify struct {
 		read, write int
 	}
-	dead bool
 
 	animating bool
 
@@ -109,6 +112,8 @@ type x11Window struct {
 	config Config
 
 	wakeups chan struct{}
+	handler x11EventHandler
+	buf     [100]byte
 }
 
 var (
@@ -151,8 +156,8 @@ func (w *x11Window) ReadClipboard() {
 	C.XConvertSelection(w.x, w.atoms.clipboard, w.atoms.utf8string, w.atoms.clipboardContent, w.xw, C.CurrentTime)
 }
 
-func (w *x11Window) WriteClipboard(s string) {
+func (w *x11Window) WriteClipboard(mime string, s []byte) {
-	w.clipboard.content = []byte(s)
+	w.clipboard.content = s
 	C.XSetSelectionOwner(w.x, w.atoms.clipboard, w.xw, C.CurrentTime)
 	C.XSetSelectionOwner(w.x, w.atoms.primary, w.xw, C.CurrentTime)
 }
@@ -232,7 +237,7 @@ func (w *x11Window) Configure(options []Option) {
 	if cnf.Decorated != prev.Decorated {
 		w.config.Decorated = cnf.Decorated
 	}
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *x11Window) setTitle(prev, cnf Config) {
@@ -375,7 +380,36 @@ func (w *x11Window) sendWMStateEvent(action C.long, atom1, atom2 C.ulong) {
 
 var x11OneByte = make([]byte, 1)
 
-func (w *x11Window) Wakeup() {
+func (w *x11Window) ProcessEvent(e event.Event) {
+	w.w.ProcessEvent(e)
+}
+
+func (w *x11Window) shutdown(err error) {
+	w.ProcessEvent(X11ViewEvent{})
+	w.ProcessEvent(DestroyEvent{Err: err})
+	w.destroy()
+}
+
+func (w *x11Window) Event() event.Event {
+	for {
+		evt, ok := w.w.nextEvent()
+		if !ok {
+			w.dispatch()
+			continue
+		}
+		return evt
+	}
+}
+
+func (w *x11Window) Run(f func()) {
+	f()
+}
+
+func (w *x11Window) Frame(frame *op.Ops) {
+	w.w.ProcessFrame(frame, nil)
+}
+
+func (w *x11Window) Invalidate() {
 	select {
 	case w.wakeups <- struct{}{}:
 	default:
@@ -393,16 +427,20 @@ func (w *x11Window) window() (C.Window, int, int) {
 	return w.xw, w.config.Size.X, w.config.Size.Y
 }
 
-func (w *x11Window) setStage(s system.Stage) {
+func (w *x11Window) dispatch() {
-	if s == w.stage {
+	if w.x == nil {
+		// Only Invalidate can wake us up.
+		<-w.wakeups
+		w.w.Invalidate()
 		return
 	}
-	w.stage = s
-	w.w.Event(system.StageEvent{Stage: s})
-}
 
-func (w *x11Window) loop() {
+	select {
-	h := x11EventHandler{w: w, xev: new(C.XEvent), text: make([]byte, 4)}
+	case <-w.wakeups:
+		w.w.Invalidate()
+	default:
+	}
+
 	xfd := C.XConnectionNumber(w.x)
 
 	// Poll for events and notifications.
@@ -412,61 +450,55 @@ func (w *x11Window) loop() {
 	}
 	xEvents := &pollfds[0].Revents
 	// Plenty of room for a backlog of notifications.
-	buf := make([]byte, 100)
 
-loop:
+	var syn, anim bool
-	for !w.dead {
+	// Check for pending draw events before checking animation or blocking.
-		var syn, anim bool
+	// This fixes an issue on Xephyr where on startup XPending() > 0 but
-		// Check for pending draw events before checking animation or blocking.
+	// poll will still block. This also prevents no-op calls to poll.
-		// This fixes an issue on Xephyr where on startup XPending() > 0 but
+	syn = w.handler.handleEvents()
-		// poll will still block. This also prevents no-op calls to poll.
+	if w.x == nil {
-		if syn = h.handleEvents(); !syn {
+		// handleEvents received a close request and destroyed the window.
-			anim = w.animating
+		return
-			if !anim {
+	}
-				// Clear poll events.
+	if !syn {
-				*xEvents = 0
+		anim = w.animating
-				// Wait for X event or gio notification.
+		if !anim {
-				if _, err := syscall.Poll(pollfds, -1); err != nil && err != syscall.EINTR {
+			// Clear poll events.
-					panic(fmt.Errorf("x11 loop: poll failed: %w", err))
+			*xEvents = 0
-				}
+			// Wait for X event or gio notification.
-				switch {
+			if _, err := syscall.Poll(pollfds, -1); err != nil && err != syscall.EINTR {
-				case *xEvents&syscall.POLLIN != 0:
+				panic(fmt.Errorf("x11 loop: poll failed: %w", err))
-					syn = h.handleEvents()
+			}
-					if w.dead {
+			switch {
-						break loop
+			case *xEvents&syscall.POLLIN != 0:
-					}
+				syn = w.handler.handleEvents()
-				case *xEvents&(syscall.POLLERR|syscall.POLLHUP) != 0:
+				if w.x == nil {
-					break loop
+					return
 				}
+			case *xEvents&(syscall.POLLERR|syscall.POLLHUP) != 0:
 			}
 		}
-		// Clear notifications.
+	}
-		for {
+	// Clear notifications.
-			_, err := syscall.Read(w.notify.read, buf)
+	for {
-			if err == syscall.EAGAIN {
+		_, err := syscall.Read(w.notify.read, w.buf[:])
-				break
+		if err == syscall.EAGAIN {
-			}
+			break
-			if err != nil {
-				panic(fmt.Errorf("x11 loop: read from notify pipe failed: %w", err))
-			}
 		}
-		select {
+		if err != nil {
-		case <-w.wakeups:
+			panic(fmt.Errorf("x11 loop: read from notify pipe failed: %w", err))
-			w.w.Event(wakeupEvent{})
-		default:
-		}
-
-		if (anim || syn) && w.config.Size.X != 0 && w.config.Size.Y != 0 {
-			w.w.Event(frameEvent{
-				FrameEvent: system.FrameEvent{
-					Now:    time.Now(),
-					Size:   w.config.Size,
-					Metric: w.metric,
-				},
-				Sync: syn,
-			})
 		}
 	}
+	if (anim || syn) && w.config.Size.X != 0 && w.config.Size.Y != 0 {
+		w.ProcessEvent(frameEvent{
+			FrameEvent: FrameEvent{
+				Now:    time.Now(),
+				Size:   w.config.Size,
+				Metric: w.metric,
+			},
+			Sync: syn,
+		})
+	}
 }
 
 func (w *x11Window) destroy() {
@@ -484,6 +516,7 @@ func (w *x11Window) destroy() {
 	}
 	C.XDestroyWindow(w.x, w.xw)
 	C.XCloseDisplay(w.x)
+	w.x = nil
 }
 
 // atom is a wrapper around XInternAtom. Callers should cache the result
@@ -541,7 +574,7 @@ func (h *x11EventHandler) handleEvents() bool {
 					// There's no support for IME yet.
 					w.w.EditorInsert(ee.Text)
 				} else {
-					w.w.Event(e)
+					w.ProcessEvent(e)
 				}
 			}
 		case C.ButtonPress, C.ButtonRelease:
@@ -603,10 +636,10 @@ func (h *x11EventHandler) handleEvents() bool {
 				w.pointerBtns &^= btn
 			}
 			ev.Buttons = w.pointerBtns
-			w.w.Event(ev)
+			w.ProcessEvent(ev)
 		case C.MotionNotify:
 			mevt := (*C.XMotionEvent)(unsafe.Pointer(xev))
-			w.w.Event(pointer.Event{
+			w.ProcessEvent(pointer.Event{
 				Kind:    pointer.Move,
 				Source:  pointer.Mouse,
 				Buttons: w.pointerBtns,
@@ -621,14 +654,16 @@ func (h *x11EventHandler) handleEvents() bool {
 			// redraw only on the last expose event
 			redraw = (*C.XExposeEvent)(unsafe.Pointer(xev)).count == 0
 		case C.FocusIn:
-			w.w.Event(key.FocusEvent{Focus: true})
+			w.config.Focused = true
+			w.ProcessEvent(ConfigEvent{Config: w.config})
 		case C.FocusOut:
-			w.w.Event(key.FocusEvent{Focus: false})
+			w.config.Focused = false
+			w.ProcessEvent(ConfigEvent{Config: w.config})
 		case C.ConfigureNotify: // window configuration change
 			cevt := (*C.XConfigureEvent)(unsafe.Pointer(xev))
 			if sz := image.Pt(int(cevt.width), int(cevt.height)); sz != w.config.Size {
 				w.config.Size = sz
-				w.w.Event(ConfigEvent{Config: w.config})
+				w.ProcessEvent(ConfigEvent{Config: w.config})
 			}
 			// redraw will be done by a later expose event
 		case C.SelectionNotify:
@@ -650,7 +685,12 @@ func (h *x11EventHandler) handleEvents() bool {
 				break
 			}
 			str := C.GoStringN((*C.char)(unsafe.Pointer(text.value)), C.int(text.nitems))
-			w.w.Event(clipboard.Event{Text: str})
+			w.ProcessEvent(transfer.DataEvent{
+				Type: "application/text",
+				Open: func() io.ReadCloser {
+					return io.NopCloser(strings.NewReader(str))
+				},
+			})
 		case C.SelectionRequest:
 			cevt := (*C.XSelectionRequestEvent)(unsafe.Pointer(xev))
 			if (cevt.selection != w.atoms.clipboard && cevt.selection != w.atoms.primary) || cevt.property == C.None {
@@ -704,7 +744,7 @@ func (h *x11EventHandler) handleEvents() bool {
 			cevt := (*C.XClientMessageEvent)(unsafe.Pointer(xev))
 			switch *(*C.long)(unsafe.Pointer(&cevt.data)) {
 			case C.long(w.atoms.evDelWindow):
-				w.dead = true
+				w.shutdown(nil)
 				return false
 			}
 		}
@@ -712,9 +752,7 @@ func (h *x11EventHandler) handleEvents() bool {
 	return redraw
 }
 
-var (
+var x11Threads sync.Once
-	x11Threads sync.Once
-)
 
 func init() {
 	x11Driver = newX11Window
@@ -786,8 +824,10 @@ func newX11Window(gioWin *callbacks, options []Option) error {
 		wakeups:      make(chan struct{}, 1),
 		config:       Config{Size: cnf.Size},
 	}
+	w.handler = x11EventHandler{w: w, xev: new(C.XEvent), text: make([]byte, 4)}
 	w.notify.read = pipe[0]
 	w.notify.write = pipe[1]
+	w.w.SetDriver(w)
 
 	if err := w.updateXkbKeymap(); err != nil {
 		w.destroy()
@@ -823,19 +863,10 @@ func newX11Window(gioWin *callbacks, options []Option) error {
 	// extensions
 	C.XSetWMProtocols(dpy, win, &w.atoms.evDelWindow, 1)
 
-	go func() {
+	// make the window visible on the screen
-		w.w.SetDriver(w)
+	C.XMapWindow(dpy, win)
-
+	w.Configure(options)
-		// make the window visible on the screen
+	w.ProcessEvent(X11ViewEvent{Display: unsafe.Pointer(dpy), Window: uintptr(win)})
-		C.XMapWindow(dpy, win)
-		w.Configure(options)
-		w.w.Event(X11ViewEvent{Display: unsafe.Pointer(dpy), Window: uintptr(win)})
-		w.setStage(system.StageRunning)
-		w.loop()
-		w.w.Event(X11ViewEvent{})
-		w.w.Event(system.DestroyEvent{Err: nil})
-		w.destroy()
-	}()
 	return nil
 }
 

app/system.go

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package app
+
+// DestroyEvent is the last event sent through
+// a window event channel.
+type DestroyEvent struct {
+	// Err is nil for normal window closures. If a
+	// window is prematurely closed, Err is the cause.
+	Err error
+}
+
+func (DestroyEvent) ImplementsEvent() {}

app/vulkan.go

@@ -175,7 +175,7 @@ func (c *vkContext) refresh(surf vk.Surface, width, height int) error {
 	if err != nil {
 		return err
 	}
-	minExt, maxExt := caps.MinExtent(), caps.MaxExtent()
+	minExt, maxExt := vk.SurfaceCapabilitiesMinExtent(caps), vk.SurfaceCapabilitiesMaxExtent(caps)
 	if width < minExt.X || maxExt.X < width || height < minExt.Y || maxExt.Y < height {
 		return errOutOfDate
 	}

f32/affine.go

@@ -30,6 +30,15 @@ func NewAffine2D(sx, hx, ox, hy, sy, oy float32) Affine2D {
 	}
 }
 
+// AffineId returns an identity transformation matrix that represents no transformation
+// when applied.
+func AffineId() Affine2D {
+	return NewAffine2D(
+		1, 0, 0,
+		0, 1, 0,
+	)
+}
+
 // Offset the transformation.
 func (a Affine2D) Offset(offset Point) Affine2D {
 	return Affine2D{
@@ -114,7 +123,7 @@ func (a Affine2D) Elems() (sx, hx, ox, hy, sy, oy float32) {
 
 // Split a transform into two parts, one which is pure offset and the
 // other representing the scaling, shearing and rotation part.
-func (a *Affine2D) Split() (srs Affine2D, offset Point) {
+func (a Affine2D) Split() (srs Affine2D, offset Point) {
 	return Affine2D{
 		a: a.a, b: a.b, c: 0,
 		d: a.d, e: a.e, f: 0,

f32/affine_test.go

@@ -27,11 +27,11 @@ func TestTransformOffset(t *testing.T) {
 	p := Point{X: 1, Y: 2}
 	o := Point{X: 2, Y: -3}
 
-	r := Affine2D{}.Offset(o).Transform(p)
+	r := AffineId().Offset(o).Transform(p)
 	if !eq(r, Pt(3, -1)) {
 		t.Errorf("offset transformation mismatch: have %v, want {3 -1}", r)
 	}
-	i := Affine2D{}.Offset(o).Invert().Transform(r)
+	i := AffineId().Offset(o).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("offset transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -51,6 +51,9 @@ func TestString(t *testing.T) {
 		}, {
 			in:  NewAffine2D(29.142342, 31.4123412, 37.53152, 43.51324213, 47.123412, 53.14312342),
 			exp: "[[29.1423 31.4123 37.5315] [43.5132 47.1234 53.1431]]",
+		}, {
+			in:  AffineId(),
+			exp: "[[1 0 0] [0 1 0]]",
 		},
 	}
 	for _, test := range tests {
@@ -64,11 +67,11 @@ func TestTransformScale(t *testing.T) {
 	p := Point{X: 1, Y: 2}
 	s := Point{X: -1, Y: 2}
 
-	r := Affine2D{}.Scale(Point{}, s).Transform(p)
+	r := AffineId().Scale(Point{}, s).Transform(p)
 	if !eq(r, Pt(-1, 4)) {
 		t.Errorf("scale transformation mismatch: have %v, want {-1 4}", r)
 	}
-	i := Affine2D{}.Scale(Point{}, s).Invert().Transform(r)
+	i := AffineId().Scale(Point{}, s).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("scale transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -78,11 +81,11 @@ func TestTransformRotate(t *testing.T) {
 	p := Point{X: 1, Y: 0}
 	a := float32(math.Pi / 2)
 
-	r := Affine2D{}.Rotate(Point{}, a).Transform(p)
+	r := AffineId().Rotate(Point{}, a).Transform(p)
 	if !eq(r, Pt(0, 1)) {
 		t.Errorf("rotate transformation mismatch: have %v, want {0 1}", r)
 	}
-	i := Affine2D{}.Rotate(Point{}, a).Invert().Transform(r)
+	i := AffineId().Rotate(Point{}, a).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("rotate transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -91,11 +94,11 @@ func TestTransformRotate(t *testing.T) {
 func TestTransformShear(t *testing.T) {
 	p := Point{X: 1, Y: 1}
 
-	r := Affine2D{}.Shear(Point{}, math.Pi/4, 0).Transform(p)
+	r := AffineId().Shear(Point{}, math.Pi/4, 0).Transform(p)
 	if !eq(r, Pt(2, 1)) {
 		t.Errorf("shear transformation mismatch: have %v, want {2 1}", r)
 	}
-	i := Affine2D{}.Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
+	i := AffineId().Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("shear transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -107,11 +110,11 @@ func TestTransformMultiply(t *testing.T) {
 	s := Point{X: -1, Y: 2}
 	a := float32(-math.Pi / 2)
 
-	r := Affine2D{}.Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Transform(p)
+	r := AffineId().Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Transform(p)
 	if !eq(r, Pt(1, 3)) {
 		t.Errorf("complex transformation mismatch: have %v, want {1 3}", r)
 	}
-	i := Affine2D{}.Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
+	i := AffineId().Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("complex transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -163,7 +166,7 @@ func TestPrimes(t *testing.T) {
 func TestTransformScaleAround(t *testing.T) {
 	p := Pt(-1, -1)
 	target := Pt(-6, -13)
-	pt := Affine2D{}.Scale(Pt(4, 5), Pt(2, 3)).Transform(p)
+	pt := AffineId().Scale(Pt(4, 5), Pt(2, 3)).Transform(p)
 	if !eq(pt, target) {
 		t.Log(pt, "!=", target)
 		t.Error("Scale not as expected")
@@ -172,7 +175,7 @@ func TestTransformScaleAround(t *testing.T) {
 
 func TestTransformRotateAround(t *testing.T) {
 	p := Pt(-1, -1)
-	pt := Affine2D{}.Rotate(Pt(1, 1), -math.Pi/2).Transform(p)
+	pt := AffineId().Rotate(Pt(1, 1), -math.Pi/2).Transform(p)
 	target := Pt(-1, 3)
 	if !eq(pt, target) {
 		t.Log(pt, "!=", target)
@@ -181,12 +184,12 @@ func TestTransformRotateAround(t *testing.T) {
 }
 
 func TestMulOrder(t *testing.T) {
-	A := Affine2D{}.Offset(Pt(100, 100))
+	A := AffineId().Offset(Pt(100, 100))
-	B := Affine2D{}.Scale(Point{}, Pt(2, 2))
+	B := AffineId().Scale(Point{}, Pt(2, 2))
 	_ = A
 	_ = B
 
-	T1 := Affine2D{}.Offset(Pt(100, 100)).Scale(Point{}, Pt(2, 2))
+	T1 := AffineId().Offset(Pt(100, 100)).Scale(Point{}, Pt(2, 2))
 	T2 := B.Mul(A)
 
 	if T1 != T2 {
@@ -199,9 +202,9 @@ func TestMulOrder(t *testing.T) {
 func BenchmarkTransformOffset(b *testing.B) {
 	p := Point{X: 1, Y: 2}
 	o := Point{X: 0.5, Y: 0.5}
-	aff := Affine2D{}.Offset(o)
+	aff := AffineId().Offset(o)
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		p = aff.Transform(p)
 	}
 	_ = p
@@ -210,8 +213,8 @@ func BenchmarkTransformOffset(b *testing.B) {
 func BenchmarkTransformScale(b *testing.B) {
 	p := Point{X: 1, Y: 2}
 	s := Point{X: 0.5, Y: 0.5}
-	aff := Affine2D{}.Scale(Point{}, s)
+	aff := AffineId().Scale(Point{}, s)
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		p = aff.Transform(p)
 	}
 	_ = p
@@ -220,36 +223,163 @@ func BenchmarkTransformScale(b *testing.B) {
 func BenchmarkTransformRotate(b *testing.B) {
 	p := Point{X: 1, Y: 2}
 	a := float32(math.Pi / 2)
-	aff := Affine2D{}.Rotate(Point{}, a)
+	aff := AffineId().Rotate(Point{}, a)
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		p = aff.Transform(p)
 	}
 	_ = p
 }
 
 func BenchmarkTransformTranslateMultiply(b *testing.B) {
-	a := Affine2D{}.Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5})
+	t := AffineId().Offset(Point{X: 0.5, Y: 0.5})
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		a = a.Mul(t)
 	}
 }
 
 func BenchmarkTransformScaleMultiply(b *testing.B) {
-	a := Affine2D{}.Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5}).Scale(Point{}, Point{X: 0.4, Y: -0.5})
+	t := AffineId().Offset(Point{X: 0.5, Y: 0.5}).Scale(Point{}, Point{X: 0.4, Y: -0.5})
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		a = a.Mul(t)
 	}
 }
 
 func BenchmarkTransformMultiply(b *testing.B) {
-	a := Affine2D{}.Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5}).Rotate(Point{}, math.Pi/7)
+	t := AffineId().Offset(Point{X: 0.5, Y: 0.5}).Rotate(Point{}, math.Pi/7)
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		a = a.Mul(t)
 	}
 }
+
+func TestNewAffine2D(t *testing.T) {
+	tests := []struct {
+		sx, hx, ox, hy, sy, oy float32
+		expected               Affine2D
+	}{
+		{1, 0, 0, 0, 1, 0, AffineId()},
+		{2, 0, 5, 0, 3, 7, Affine2D{a: 1, b: 0, c: 5, d: 0, e: 2, f: 7}},
+		{-1, 2, 3, 4, -5, 6, Affine2D{a: -2, b: 2, c: 3, d: 4, e: -6, f: 6}},
+	}
+
+	for i, test := range tests {
+		got := NewAffine2D(test.sx, test.hx, test.ox, test.hy, test.sy, test.oy)
+		if !eqaff(got, test.expected) {
+			t.Errorf(
+				"Test %d: NewAffine2D(%v, %v, %v, %v, %v, %v) = %v, want %v",
+				i, test.sx, test.hx, test.ox, test.hy, test.sy, test.oy, got, test.expected,
+			)
+		}
+	}
+}
+
+func TestAffineId(t *testing.T) {
+	id := AffineId()
+
+	testPoints := []Point{
+		{0, 0},
+		{1, 0},
+		{0, 1},
+		{-1, -1},
+		{10, 20},
+	}
+
+	for _, p := range testPoints {
+		transformed := id.Transform(p)
+		if !eq(transformed, p) {
+			t.Errorf("Identity transform changed point: %v -> %v", p, transformed)
+		}
+	}
+}
+
+func TestElems(t *testing.T) {
+	tests := []struct {
+		aff                    Affine2D
+		sx, hx, ox, hy, sy, oy float32
+	}{
+		{AffineId(), 1, 0, 0, 0, 1, 0},
+		{Affine2D{a: 1, b: 2, c: 3, d: 4, e: 5, f: 6}, 2, 2, 3, 4, 6, 6},
+		{NewAffine2D(7, 8, 9, 10, 11, 12), 7, 8, 9, 10, 11, 12},
+	}
+
+	for i, test := range tests {
+		sx, hx, ox, hy, sy, oy := test.aff.Elems()
+		if sx != test.sx || hx != test.hx || ox != test.ox ||
+			hy != test.hy || sy != test.sy || oy != test.oy {
+			t.Errorf(
+				"Test %d: %v.Elems() = (%v, %v, %v, %v, %v, %v), want (%v, %v, %v, %v, %v, %v)",
+				i, test.aff, sx, hx, ox, hy, sy, oy, test.sx, test.hx, test.ox, test.hy, test.sy, test.oy,
+			)
+		}
+	}
+}
+
+func TestSplit(t *testing.T) {
+	tests := []struct {
+		aff            Affine2D
+		expectedSRS    Affine2D
+		expectedOffset Point
+	}{
+		{
+			AffineId(),
+			AffineId(),
+			Point{0, 0},
+		},
+		{
+			Affine2D{a: 1, b: 2, c: 3, d: 4, e: 5, f: 6},
+			Affine2D{a: 1, b: 2, c: 0, d: 4, e: 5, f: 0},
+			Point{3, 6},
+		},
+		{
+			NewAffine2D(2, 0, 10, 0, 3, 20),
+			NewAffine2D(2, 0, 0, 0, 3, 0),
+			Point{10, 20},
+		},
+	}
+
+	for i, test := range tests {
+		srs, offset := test.aff.Split()
+		if !eqaff(srs, test.expectedSRS) || !eq(offset, test.expectedOffset) {
+			t.Errorf(
+				"Test %d: %v.Split() = (%v, %v), want (%v, %v)",
+				i, test.aff, srs, offset, test.expectedSRS, test.expectedOffset,
+			)
+		}
+	}
+}
+
+func TestShear(t *testing.T) {
+	p := Pt(2, 3)
+	origin := Pt(1, 1)
+
+	shearX := AffineId().Shear(origin, math.Pi/4, 0)
+	resultX := shearX.Transform(p)
+	expectedX := Pt(4, 3)
+
+	if !eq(resultX, expectedX) {
+		t.Errorf("Shear around origin in X: got %v, want %v", resultX, expectedX)
+	}
+
+	inverseX := shearX.Invert().Transform(resultX)
+	if !eq(inverseX, p) {
+		t.Errorf("Inverse shear X: got %v, want %v", inverseX, p)
+	}
+
+	shearY := AffineId().Shear(origin, 0, math.Pi/4)
+	resultY := shearY.Transform(p)
+	expectedY := Pt(2, 4)
+
+	if !eq(resultY, expectedY) {
+		t.Errorf("Shear around origin in Y: got %v, want %v", resultY, expectedY)
+	}
+
+	inverseY := shearY.Invert().Transform(resultY)
+	if !eq(inverseY, p) {
+		t.Errorf("Inverse shear Y: got %v, want %v", inverseY, p)
+	}
+}

flake.lock

@@ -1,86 +1,58 @@
 {
   "nodes": {
-    "android": {
-      "inputs": {
-        "devshell": "devshell",
-        "flake-utils": "flake-utils",
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1659298920,
-        "narHash": "sha256-LgRMge8BZUG15EN43iDJOlnEMX1dvRprB7SaoNqgibU=",
-        "owner": "tadfisher",
-        "repo": "android-nixpkgs",
-        "rev": "d4f20a3cd4ce961bb23b48447457f6810d69ae5e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "tadfisher",
-        "repo": "android-nixpkgs",
-        "type": "github"
-      }
-    },
-    "devshell": {
-      "inputs": {
-        "flake-utils": [
-          "android",
-          "nixpkgs"
-        ],
-        "nixpkgs": [
-          "android",
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1658746384,
-        "narHash": "sha256-CCJcoMOcXyZFrV1ag4XMTpAPjLWb4Anbv+ktXFI1ry0=",
-        "owner": "numtide",
-        "repo": "devshell",
-        "rev": "0ffc7937bb5e8141af03d462b468bd071eb18e1b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "devshell",
-        "type": "github"
-      }
-    },
-    "flake-utils": {
-      "locked": {
-        "lastModified": 1656928814,
-        "narHash": "sha256-RIFfgBuKz6Hp89yRr7+NR5tzIAbn52h8vT6vXkYjZoM=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "7e2a3b3dfd9af950a856d66b0a7d01e3c18aa249",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1659305579,
+        "lastModified": 1747953325,
-        "narHash": "sha256-SFeQTmh7hc9Y2fSkooHaoS8mDfPa04sfmUCtQ8MA6Pg=",
+        "narHash": "sha256-y2ZtlIlNTuVJUZCqzZAhIw5rrKP4DOSklev6c8PyCkQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "5857574d45925585baffde730369414319228a84",
+        "rev": "55d1f923c480dadce40f5231feb472e81b0bab48",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
+        "ref": "nixos-25.05",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
-        "android": "android",
+        "nixpkgs": "nixpkgs",
-        "nixpkgs": "nixpkgs"
+        "utils": "utils"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
       }
     }
   },

flake.nix

@@ -3,42 +3,38 @@
   description = "Gio build environment";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
-    android.url = "github:tadfisher/android-nixpkgs";
+    utils.url = "github:numtide/flake-utils";
-    android.inputs.nixpkgs.follows = "nixpkgs";
   };
 
-  outputs = { self, nixpkgs, android }:
+  outputs = { self, nixpkgs, utils }:
-    let
+    utils.lib.eachDefaultSystem (system:
-      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-darwin" ];
+      let
-      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f system);
+        pkgs = import nixpkgs {
-    in
+          inherit system;
-    {
+
-      devShells = forAllSystems
+          # allow unfree Android packages.
-        (system:
+          config.allowUnfree = true;
-          let
+          # accept the Android SDK license.
-            pkgs = import nixpkgs {
+          config.android_sdk.accept_license = true; 
-              inherit system;
+        };
+      in {
+        devShells = let
+          android-sdk = let
+            androidComposition = pkgs.androidenv.composeAndroidPackages {
+              platformVersions = [ "latest" ];
+              abiVersions = [ "armeabi-v7a" "arm64-v8a" ];
+               # Omit the deprecated tools package.
+              toolsVersion = null;
+              includeNDK = true;
             };
-            android-sdk = android.sdk.${system} (sdkPkgs: with sdkPkgs;
+          in androidComposition.androidsdk;
-              [
+        in {
-                build-tools-31-0-0
+          default = with pkgs;
-                cmdline-tools-latest
+            mkShell (rec {
-                platform-tools
+              ANDROID_HOME = "${android-sdk}/libexec/android-sdk";
-                platforms-android-31
+              packages = [ android-sdk jdk clang ]
-                ndk-bundle
+                ++ (if stdenv.isLinux then [
-              ]);
-          in
-          {
-            default = with pkgs; mkShell
-              ({
-                ANDROID_SDK_ROOT = "${android-sdk}/share/android-sdk";
-                JAVA_HOME = jdk8.home;
-                packages = [
-                  android-sdk
-                  jdk8
-                  clang
-                ] ++ (if stdenv.isLinux then [
                   vulkan-headers
                   libxkbcommon
                   wayland
@@ -46,18 +42,13 @@
                   xorg.libXcursor
                   xorg.libXfixes
                   libGL
-                  pkgconfig
+                  pkg-config
-                ] else if stdenv.isDarwin then [
+                ] else
-                  darwin.apple_sdk_11_0.frameworks.Foundation
+                  [ ]);
-                  darwin.apple_sdk_11_0.frameworks.Metal
+            } // (if stdenv.isLinux then {
-                  darwin.apple_sdk_11_0.frameworks.QuartzCore
+              LD_LIBRARY_PATH = "${vulkan-loader}/lib";
-                  darwin.apple_sdk_11_0.frameworks.AppKit
+            } else
-                  darwin.apple_sdk_11_0.MacOSX-SDK
+              { }));
-                ] else [ ]);
+        };
-              } // (if stdenv.isLinux then {
+      });
-                LD_LIBRARY_PATH = "${vulkan-loader}/lib";
-              } else { }));
-          }
-        );
-    };
 }

font/font.go

@@ -34,7 +34,7 @@ type Font struct {
 // Face is an opaque handle to a typeface. The concrete implementation depends
 // upon the kind of font and shaper in use.
 type Face interface {
-	Face() font.Face
+	Face() *font.Face
 }
 
 // Typeface identifies a list of font families to attempt to use for displaying

font/opentype/opentype.go

@@ -16,23 +16,21 @@ import (
 	_ "image/png"
 
 	giofont "gioui.org/font"
-	"github.com/go-text/typesetting/font"
+	fontapi "github.com/go-text/typesetting/font"
-	fontapi "github.com/go-text/typesetting/opentype/api/font"
+	"github.com/go-text/typesetting/font/opentype"
-	"github.com/go-text/typesetting/opentype/api/metadata"
-	"github.com/go-text/typesetting/opentype/loader"
 )
 
 // Face is a thread-safe representation of a loaded font. For efficiency, applications
 // should construct a face for any given font file once, reusing it across different
 // text shapers.
 type Face struct {
-	face font.Font
+	face *fontapi.Font
 	font giofont.Font
 }
 
 // Parse constructs a Face from source bytes.
 func Parse(src []byte) (Face, error) {
-	ld, err := loader.NewLoader(bytes.NewReader(src))
+	ld, err := opentype.NewLoader(bytes.NewReader(src))
 	if err != nil {
 		return Face{}, err
 	}
@@ -49,11 +47,11 @@ func Parse(src []byte) (Face, error) {
 // ParseCollection parse an Opentype font file, with support for collections.
 // Single font files are supported, returning a slice with length 1.
 // The returned fonts are automatically wrapped in a text.FontFace with
-// inferred font metadata.
+// inferred font font.
 // BUG(whereswaldon): the only Variant that can be detected automatically is
 // "Mono".
 func ParseCollection(src []byte) ([]giofont.FontFace, error) {
-	lds, err := loader.NewLoaders(bytes.NewReader(src))
+	lds, err := opentype.NewLoaders(bytes.NewReader(src))
 	if err != nil {
 		return nil, err
 	}
@@ -76,7 +74,7 @@ func ParseCollection(src []byte) ([]giofont.FontFace, error) {
 	return out, nil
 }
 
-func DescriptionToFont(md metadata.Description) giofont.Font {
+func DescriptionToFont(md fontapi.Description) giofont.Font {
 	return giofont.Font{
 		Typeface: giofont.Typeface(md.Family),
 		Style:    gioStyle(md.Aspect.Style),
@@ -84,30 +82,30 @@ func DescriptionToFont(md metadata.Description) giofont.Font {
 	}
 }
 
-func FontToDescription(font giofont.Font) metadata.Description {
+func FontToDescription(font giofont.Font) fontapi.Description {
-	return metadata.Description{
+	return fontapi.Description{
 		Family: string(font.Typeface),
-		Aspect: metadata.Aspect{
+		Aspect: fontapi.Aspect{
 			Style:  mdStyle(font.Style),
 			Weight: mdWeight(font.Weight),
 		},
 	}
 }
 
-// parseLoader parses the contents of the loader into a face and its metadata.
+// parseLoader parses the contents of the loader into a face and its font.
-func parseLoader(ld *loader.Loader) (font.Font, giofont.Font, error) {
+func parseLoader(ld *opentype.Loader) (*fontapi.Font, giofont.Font, error) {
 	ft, err := fontapi.NewFont(ld)
 	if err != nil {
 		return nil, giofont.Font{}, err
 	}
-	data := DescriptionToFont(metadata.Metadata(ld))
+	data := DescriptionToFont(ft.Describe())
 	return ft, data, nil
 }
 
 // Face returns a thread-unsafe wrapper for this Face suitable for use by a single shaper.
 // Face many be invoked any number of times and is safe so long as each return value is
 // only used by one goroutine.
-func (f Face) Face() font.Face {
+func (f Face) Face() *fontapi.Face {
 	return &fontapi.Face{Font: f.face}
 }
 
@@ -119,74 +117,74 @@ func (f Face) Font() giofont.Font {
 	return f.font
 }
 
-func gioStyle(s metadata.Style) giofont.Style {
+func gioStyle(s fontapi.Style) giofont.Style {
 	switch s {
-	case metadata.StyleItalic:
+	case fontapi.StyleItalic:
 		return giofont.Italic
-	case metadata.StyleNormal:
+	case fontapi.StyleNormal:
 		fallthrough
 	default:
 		return giofont.Regular
 	}
 }
 
-func mdStyle(g giofont.Style) metadata.Style {
+func mdStyle(g giofont.Style) fontapi.Style {
 	switch g {
 	case giofont.Italic:
-		return metadata.StyleItalic
+		return fontapi.StyleItalic
 	case giofont.Regular:
 		fallthrough
 	default:
-		return metadata.StyleNormal
+		return fontapi.StyleNormal
 	}
 }
 
-func gioWeight(w metadata.Weight) giofont.Weight {
+func gioWeight(w fontapi.Weight) giofont.Weight {
 	switch w {
-	case metadata.WeightThin:
+	case fontapi.WeightThin:
 		return giofont.Thin
-	case metadata.WeightExtraLight:
+	case fontapi.WeightExtraLight:
 		return giofont.ExtraLight
-	case metadata.WeightLight:
+	case fontapi.WeightLight:
 		return giofont.Light
-	case metadata.WeightNormal:
+	case fontapi.WeightNormal:
 		return giofont.Normal
-	case metadata.WeightMedium:
+	case fontapi.WeightMedium:
 		return giofont.Medium
-	case metadata.WeightSemibold:
+	case fontapi.WeightSemibold:
 		return giofont.SemiBold
-	case metadata.WeightBold:
+	case fontapi.WeightBold:
 		return giofont.Bold
-	case metadata.WeightExtraBold:
+	case fontapi.WeightExtraBold:
 		return giofont.ExtraBold
-	case metadata.WeightBlack:
+	case fontapi.WeightBlack:
 		return giofont.Black
 	default:
 		return giofont.Normal
 	}
 }
 
-func mdWeight(g giofont.Weight) metadata.Weight {
+func mdWeight(g giofont.Weight) fontapi.Weight {
 	switch g {
 	case giofont.Thin:
-		return metadata.WeightThin
+		return fontapi.WeightThin
 	case giofont.ExtraLight:
-		return metadata.WeightExtraLight
+		return fontapi.WeightExtraLight
 	case giofont.Light:
-		return metadata.WeightLight
+		return fontapi.WeightLight
 	case giofont.Normal:
-		return metadata.WeightNormal
+		return fontapi.WeightNormal
 	case giofont.Medium:
-		return metadata.WeightMedium
+		return fontapi.WeightMedium
 	case giofont.SemiBold:
-		return metadata.WeightSemibold
+		return fontapi.WeightSemibold
 	case giofont.Bold:
-		return metadata.WeightBold
+		return fontapi.WeightBold
 	case giofont.ExtraBold:
-		return metadata.WeightExtraBold
+		return fontapi.WeightExtraBold
 	case giofont.Black:
-		return metadata.WeightBlack
+		return fontapi.WeightBlack
 	default:
-		return metadata.WeightNormal
+		return fontapi.WeightNormal
 	}
 }

gesture/gesture.go

@@ -18,6 +18,7 @@ import (
 	"gioui.org/f32"
 	"gioui.org/internal/fling"
 	"gioui.org/io/event"
+	"gioui.org/io/input"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/op"
@@ -37,15 +38,19 @@ type Hover struct {
 
 // Add the gesture to detect hovering over the current pointer area.
 func (h *Hover) Add(ops *op.Ops) {
-	pointer.InputOp{
+	event.Op(ops, h)
-		Tag:   h,
-		Kinds: pointer.Enter | pointer.Leave,
-	}.Add(ops)
 }
 
 // Update state and report whether a pointer is inside the area.
-func (h *Hover) Update(q event.Queue) bool {
+func (h *Hover) Update(q input.Source) bool {
-	for _, ev := range q.Events(h) {
+	for {
+		ev, ok := q.Event(pointer.Filter{
+			Target: h,
+			Kinds:  pointer.Enter | pointer.Leave | pointer.Cancel,
+		})
+		if !ok {
+			break
+		}
 		e, ok := ev.(pointer.Event)
 		if !ok {
 			continue
@@ -107,7 +112,6 @@ type Drag struct {
 	pressed  bool
 	pid      pointer.ID
 	start    f32.Point
-	grab     bool
 }
 
 // Scroll detects scroll gestures and reduces them to
@@ -115,11 +119,9 @@ type Drag struct {
 // movements as well as drag and fling touch gestures.
 type Scroll struct {
 	dragging  bool
-	axis      Axis
 	estimator fling.Extrapolation
 	flinger   fling.Animation
 	pid       pointer.ID
-	grab      bool
 	last      int
 	// Leftover scroll.
 	scroll float32
@@ -161,10 +163,7 @@ const touchSlop = unit.Dp(3)
 
 // Add the handler to the operation list to receive click events.
 func (c *Click) Add(ops *op.Ops) {
-	pointer.InputOp{
+	event.Op(ops, c)
-		Tag:   c,
-		Kinds: pointer.Press | pointer.Release | pointer.Enter | pointer.Leave,
-	}.Add(ops)
 }
 
 // Hovered returns whether a pointer is inside the area.
@@ -177,10 +176,16 @@ func (c *Click) Pressed() bool {
 	return c.pressed
 }
 
-// Update state and return the click events.
+// Update state and return the next click events, if any.
-func (c *Click) Update(q event.Queue) []ClickEvent {
+func (c *Click) Update(q input.Source) (ClickEvent, bool) {
-	var events []ClickEvent
+	for {
-	for _, evt := range q.Events(c) {
+		evt, ok := q.Event(pointer.Filter{
+			Target: c,
+			Kinds:  pointer.Press | pointer.Release | pointer.Enter | pointer.Leave | pointer.Cancel,
+		})
+		if !ok {
+			break
+		}
 		e, ok := evt.(pointer.Event)
 		if !ok {
 			continue
@@ -192,9 +197,15 @@ func (c *Click) Update(q event.Queue) []ClickEvent {
 			}
 			c.pressed = false
 			if !c.entered || c.hovered {
-				events = append(events, ClickEvent{Kind: KindClick, Position: e.Position.Round(), Source: e.Source, Modifiers: e.Modifiers, NumClicks: c.clicks})
+				return ClickEvent{
+					Kind:      KindClick,
+					Position:  e.Position.Round(),
+					Source:    e.Source,
+					Modifiers: e.Modifiers,
+					NumClicks: c.clicks,
+				}, true
 			} else {
-				events = append(events, ClickEvent{Kind: KindCancel})
+				return ClickEvent{Kind: KindCancel}, true
 			}
 		case pointer.Cancel:
 			wasPressed := c.pressed
@@ -202,7 +213,7 @@ func (c *Click) Update(q event.Queue) []ClickEvent {
 			c.hovered = false
 			c.entered = false
 			if wasPressed {
-				events = append(events, ClickEvent{Kind: KindCancel})
+				return ClickEvent{Kind: KindCancel}, true
 			}
 		case pointer.Press:
 			if c.pressed {
@@ -224,7 +235,7 @@ func (c *Click) Update(q event.Queue) []ClickEvent {
 				c.clicks = 1
 			}
 			c.clickedAt = e.Time
-			events = append(events, ClickEvent{Kind: KindPress, Position: e.Position.Round(), Source: e.Source, Modifiers: e.Modifiers, NumClicks: c.clicks})
+			return ClickEvent{Kind: KindPress, Position: e.Position.Round(), Source: e.Source, Modifiers: e.Modifiers, NumClicks: c.clicks}, true
 		case pointer.Leave:
 			if !c.pressed {
 				c.pid = e.PointerID
@@ -242,25 +253,16 @@ func (c *Click) Update(q event.Queue) []ClickEvent {
 			}
 		}
 	}
-	return events
+	return ClickEvent{}, false
 }
 
 func (ClickEvent) ImplementsEvent() {}
 
 // Add the handler to the operation list to receive scroll events.
 // The bounds variable refers to the scrolling boundaries
-// as defined in io/pointer.InputOp.
+// as defined in [pointer.Filter].
-func (s *Scroll) Add(ops *op.Ops, bounds image.Rectangle) {
+func (s *Scroll) Add(ops *op.Ops) {
-	oph := pointer.InputOp{
+	event.Op(ops, s)
-		Tag:          s,
-		Grab:         s.grab,
-		Kinds:        pointer.Press | pointer.Drag | pointer.Release | pointer.Scroll,
-		ScrollBounds: bounds,
-	}
-	oph.Add(ops)
-	if s.flinger.Active() {
-		op.InvalidateOp{}.Add(ops)
-	}
 }
 
 // Stop any remaining fling movement.
@@ -269,13 +271,19 @@ func (s *Scroll) Stop() {
 }
 
 // Update state and report the scroll distance along axis.
-func (s *Scroll) Update(cfg unit.Metric, q event.Queue, t time.Time, axis Axis) int {
+func (s *Scroll) Update(cfg unit.Metric, q input.Source, t time.Time, axis Axis, scrollx, scrolly pointer.ScrollRange) int {
-	if s.axis != axis {
-		s.axis = axis
-		return 0
-	}
 	total := 0
-	for _, evt := range q.Events(s) {
+	f := pointer.Filter{
+		Target:  s,
+		Kinds:   pointer.Press | pointer.Drag | pointer.Release | pointer.Scroll | pointer.Cancel,
+		ScrollX: scrollx,
+		ScrollY: scrolly,
+	}
+	for {
+		evt, ok := q.Event(f)
+		if !ok {
+			break
+		}
 		e, ok := evt.(pointer.Event)
 		if !ok {
 			continue
@@ -292,7 +300,7 @@ func (s *Scroll) Update(cfg unit.Metric, q event.Queue, t time.Time, axis Axis)
 			}
 			s.Stop()
 			s.estimator = fling.Extrapolation{}
-			v := s.val(e.Position)
+			v := s.val(axis, e.Position)
 			s.last = int(math.Round(float64(v)))
 			s.estimator.Sample(e.Time, v)
 			s.dragging = true
@@ -308,13 +316,14 @@ func (s *Scroll) Update(cfg unit.Metric, q event.Queue, t time.Time, axis Axis)
 			fallthrough
 		case pointer.Cancel:
 			s.dragging = false
-			s.grab = false
 		case pointer.Scroll:
-			switch s.axis {
+			switch axis {
 			case Horizontal:
 				s.scroll += e.Scroll.X
 			case Vertical:
 				s.scroll += e.Scroll.Y
+			case Both:
+				s.scroll += e.Scroll.X + e.Scroll.Y
 			}
 			iscroll := int(s.scroll)
 			s.scroll -= float32(iscroll)
@@ -323,14 +332,14 @@ func (s *Scroll) Update(cfg unit.Metric, q event.Queue, t time.Time, axis Axis)
 			if !s.dragging || s.pid != e.PointerID {
 				continue
 			}
-			val := s.val(e.Position)
+			val := s.val(axis, e.Position)
 			s.estimator.Sample(e.Time, val)
 			v := int(math.Round(float64(val)))
 			dist := s.last - v
 			if e.Priority < pointer.Grabbed {
 				slop := cfg.Dp(touchSlop)
 				if dist := dist; dist >= slop || -slop >= dist {
-					s.grab = true
+					q.Execute(pointer.GrabCmd{Tag: s, ID: e.PointerID})
 				}
 			} else {
 				s.last = v
@@ -339,14 +348,22 @@ func (s *Scroll) Update(cfg unit.Metric, q event.Queue, t time.Time, axis Axis)
 		}
 	}
 	total += s.flinger.Tick(t)
+	if s.flinger.Active() {
+		q.Execute(op.InvalidateCmd{})
+	}
 	return total
 }
 
-func (s *Scroll) val(p f32.Point) float32 {
+func (s *Scroll) val(axis Axis, p f32.Point) float32 {
-	if s.axis == Horizontal {
+	switch axis {
+	case Horizontal:
 		return p.X
-	} else {
+	case Vertical:
 		return p.Y
+	case Both:
+		return p.X + p.Y
+	default:
+		return 0
 	}
 }
 
@@ -364,18 +381,20 @@ func (s *Scroll) State() ScrollState {
 
 // Add the handler to the operation list to receive drag events.
 func (d *Drag) Add(ops *op.Ops) {
-	pointer.InputOp{
+	event.Op(ops, d)
-		Tag:   d,
-		Grab:  d.grab,
-		Kinds: pointer.Press | pointer.Drag | pointer.Release,
-	}.Add(ops)
 }
 
-// Update state and return the drag events.
+// Update state and return the next drag event, if any.
-func (d *Drag) Update(cfg unit.Metric, q event.Queue, axis Axis) []pointer.Event {
+func (d *Drag) Update(cfg unit.Metric, q input.Source, axis Axis) (pointer.Event, bool) {
-	var events []pointer.Event
+	for {
-	for _, e := range q.Events(d) {
+		ev, ok := q.Event(pointer.Filter{
-		e, ok := e.(pointer.Event)
+			Target: d,
+			Kinds:  pointer.Press | pointer.Drag | pointer.Release | pointer.Cancel,
+		})
+		if !ok {
+			break
+		}
+		e, ok := ev.(pointer.Event)
 		if !ok {
 			continue
 		}
@@ -408,7 +427,7 @@ func (d *Drag) Update(cfg unit.Metric, q event.Queue, axis Axis) []pointer.Event
 				diff := e.Position.Sub(d.start)
 				slop := cfg.Dp(touchSlop)
 				if diff.X*diff.X+diff.Y*diff.Y > float32(slop*slop) {
-					d.grab = true
+					q.Execute(pointer.GrabCmd{Tag: d, ID: e.PointerID})
 				}
 			}
 		case pointer.Release, pointer.Cancel:
@@ -417,13 +436,12 @@ func (d *Drag) Update(cfg unit.Metric, q event.Queue, axis Axis) []pointer.Event
 				continue
 			}
 			d.dragging = false
-			d.grab = false
 		}
 
-		events = append(events, e)
+		return e, true
 	}
 
-	return events
+	return pointer.Event{}, false
 }
 
 // Dragging reports whether it is currently in use.
@@ -446,13 +464,13 @@ func (a Axis) String() string {
 func (ct ClickKind) String() string {
 	switch ct {
 	case KindPress:
-		return "TypePress"
+		return "KindPress"
 	case KindClick:
-		return "TypeClick"
+		return "KindClick"
 	case KindCancel:
-		return "TypeCancel"
+		return "KindCancel"
 	default:
-		panic("invalid ClickType")
+		panic("invalid ClickKind")
 	}
 }
 

gesture/gesture_test.go

@@ -9,8 +9,8 @@ import (
 
 	"gioui.org/f32"
 	"gioui.org/io/event"
+	"gioui.org/io/input"
 	"gioui.org/io/pointer"
-	"gioui.org/io/router"
 	"gioui.org/op"
 	"gioui.org/op/clip"
 )
@@ -22,20 +22,21 @@ func TestHover(t *testing.T) {
 	stack := clip.Rect(rect).Push(ops)
 	h.Add(ops)
 	stack.Pop()
-	r := new(router.Router)
+	r := new(input.Router)
+	h.Update(r.Source())
 	r.Frame(ops)
 
 	r.Queue(
 		pointer.Event{Kind: pointer.Move, Position: f32.Pt(30, 30)},
 	)
-	if !h.Update(r) {
+	if !h.Update(r.Source()) {
 		t.Fatal("expected hovered")
 	}
 
 	r.Queue(
 		pointer.Event{Kind: pointer.Move, Position: f32.Pt(50, 50)},
 	)
-	if h.Update(r) {
+	if h.Update(r.Source()) {
 		t.Fatal("expected not hovered")
 	}
 }
@@ -71,12 +72,21 @@ func TestMouseClicks(t *testing.T) {
 			var ops op.Ops
 			click.Add(&ops)
 
-			var r router.Router
+			var r input.Router
+			click.Update(r.Source())
 			r.Frame(&ops)
 			r.Queue(tc.events...)
 
-			events := click.Update(&r)
+			var clicks []ClickEvent
-			clicks := filterMouseClicks(events)
+			for {
+				ev, ok := click.Update(r.Source())
+				if !ok {
+					break
+				}
+				if ev.Kind == KindClick {
+					clicks = append(clicks, ev)
+				}
+			}
 			if got, want := len(clicks), len(tc.clicks); got != want {
 				t.Fatalf("got %d mouse clicks, expected %d", got, want)
 			}
@@ -106,13 +116,3 @@ func mouseClickEvents(times ...time.Duration) []event.Event {
 	}
 	return events
 }
-
-func filterMouseClicks(events []ClickEvent) []ClickEvent {
-	var clicks []ClickEvent
-	for _, ev := range events {
-		if ev.Kind == KindClick {
-			clicks = append(clicks, ev)
-		}
-	}
-	return clicks
-}

go.mod

@@ -1,16 +1,14 @@
 module gioui.org
 
-go 1.19
+go 1.23.8
 
 require (
 	eliasnaur.com/font v0.0.0-20230308162249-dd43949cb42d
-	gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2
 	gioui.org/shader v1.0.8
-	github.com/go-text/typesetting v0.0.0-20230803102845-24e03d8b5372
+	github.com/go-text/typesetting v0.3.0
-	golang.org/x/exp v0.0.0-20221012211006-4de253d81b95
+	golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0
-	golang.org/x/exp/shiny v0.0.0-20220827204233-334a2380cb91
+	golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0
-	golang.org/x/image v0.5.0
+	golang.org/x/image v0.26.0
-	golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64
+	golang.org/x/sys v0.33.0
+	golang.org/x/text v0.24.0
 )
-
-require golang.org/x/text v0.7.0

go.sum

@@ -1,43 +1,19 @@
 eliasnaur.com/font v0.0.0-20230308162249-dd43949cb42d h1:ARo7NCVvN2NdhLlJE9xAbKweuI9L6UgfTbYb0YwPacY=
 eliasnaur.com/font v0.0.0-20230308162249-dd43949cb42d/go.mod h1:OYVuxibdk9OSLX8vAqydtRPP87PyTFcT9uH3MlEGBQA=
 gioui.org/cpu v0.0.0-20210808092351-bfe733dd3334/go.mod h1:A8M0Cn5o+vY5LTMlnRoK3O5kG+rH0kWfJjeKd9QpBmQ=
-gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2 h1:AGDDxsJE1RpcXTAxPG2B4jrwVUJGFDjINIPi1jtO6pc=
-gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2/go.mod h1:A8M0Cn5o+vY5LTMlnRoK3O5kG+rH0kWfJjeKd9QpBmQ=
 gioui.org/shader v1.0.8 h1:6ks0o/A+b0ne7RzEqRZK5f4Gboz2CfG+mVliciy6+qA=
 gioui.org/shader v1.0.8/go.mod h1:mWdiME581d/kV7/iEhLmUgUK5iZ09XR5XpduXzbePVM=
-github.com/go-text/typesetting v0.0.0-20230803102845-24e03d8b5372 h1:FQivqchis6bE2/9uF70M2gmmLpe82esEm2QadL0TEJo=
+github.com/go-text/typesetting v0.3.0 h1:OWCgYpp8njoxSRpwrdd1bQOxdjOXDj9Rqart9ML4iF4=
-github.com/go-text/typesetting v0.0.0-20230803102845-24e03d8b5372/go.mod h1:evDBbvNR/KaVFZ2ZlDSOWWXIUKq0wCOEtzLxRM8SG3k=
+github.com/go-text/typesetting v0.3.0/go.mod h1:qjZLkhRgOEYMhU9eHBr3AR4sfnGJvOXNLt8yRAySFuY=
-github.com/go-text/typesetting-utils v0.0.0-20230616150549-2a7df14b6a22 h1:LBQTFxP2MfsyEDqSKmUBZaDuDHN1vpqDyOZjcqS7MYI=
+github.com/go-text/typesetting-utils v0.0.0-20241103174707-87a29e9e6066 h1:qCuYC+94v2xrb1PoS4NIDe7DGYtLnU2wWiQe9a1B1c0=
-github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
+github.com/go-text/typesetting-utils v0.0.0-20241103174707-87a29e9e6066/go.mod h1:DDxDdQEnB70R8owOx3LVpEFvpMK9eeH1o2r0yZhFI9o=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0 h1:R84qjqJb5nVJMxqWYb3np9L5ZsaDtB+a39EqjV0JSUM=
-golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0/go.mod h1:S9Xr4PYopiDyqSyp5NjCrhFrqg6A5zA2E/iPHPhqnS8=
-golang.org/x/exp v0.0.0-20221012211006-4de253d81b95 h1:sBdrWpxhGDdTAYNqbgBLAR+ULAPPhfgncLr1X0lyWtg=
+golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0 h1:tMSqXTK+AQdW3LpCbfatHSRPHeW6+2WuxaVQuHftn80=
-golang.org/x/exp v0.0.0-20221012211006-4de253d81b95/go.mod h1:cyybsKvd6eL0RnXn6p/Grxp8F5bW7iYuBgsNCOHpMYE=
+golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0/go.mod h1:ygj7T6vSGhhm/9yTpOQQNvuAUFziTH7RUiH74EoE2C8=
-golang.org/x/exp/shiny v0.0.0-20220827204233-334a2380cb91 h1:ryT6Nf0R83ZgD8WnFFdfI8wCeyqgdXWN4+CkFVNPAT0=
+golang.org/x/image v0.26.0 h1:4XjIFEZWQmCZi6Wv8BoxsDhRU3RVnLX04dToTDAEPlY=
-golang.org/x/exp/shiny v0.0.0-20220827204233-334a2380cb91/go.mod h1:VjAR7z0ngyATZTELrBSkxOOHhhlnVUxDye4mcjx5h/8=
+golang.org/x/image v0.26.0/go.mod h1:lcxbMFAovzpnJxzXS3nyL83K27tmqtKzIJpctK8YO5c=
-golang.org/x/image v0.5.0 h1:5JMiNunQeQw++mMOz48/ISeNu3Iweh/JaZU8ZLqHRrI=
+golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
-golang.org/x/image v0.5.0/go.mod h1:FVC7BI/5Ym8R25iw5OLsgshdUBbT1h5jZTpA+mvAdZ4=
+golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/text v0.24.0 h1:dd5Bzh4yt5KYA8f9CJHCP4FB4D51c2c6JvN37xJJkJ0=
-golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/text v0.24.0/go.mod h1:L8rBsPeo2pSS+xqN0d5u2ikmjtmoJbDBT1b7nHvFCdU=
-golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64 h1:UiNENfZ8gDvpiWw7IpOMQ27spWmThO1RwwdQVbJahJM=
-golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.7.0 h1:4BRB4x83lYWy72KwLD/qYDuTu7q9PjSagHvijDw7cLo=
-golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

gpu/caches.go

@@ -4,12 +4,16 @@ package gpu
 
 import (
 	"fmt"
-
+	"image"
-	"gioui.org/internal/f32"
 )
 
-type resourceCache struct {
+type textureCacheKey struct {
-	res map[interface{}]resourceCacheValue
+	filter byte
+	handle any
+}
+
+type textureCache struct {
+	res map[textureCacheKey]resourceCacheValue
 }
 
 type resourceCacheValue struct {
@@ -31,19 +35,19 @@ type opCache struct {
 type opCacheValue struct {
 	data pathData
 
-	bounds f32.Rectangle
+	bounds image.Rectangle
 	// the fields below are handled by opCache
 	key  opKey
 	keep bool
 }
 
-func newResourceCache() *resourceCache {
+func newTextureCache() *textureCache {
-	return &resourceCache{
+	return &textureCache{
-		res: make(map[interface{}]resourceCacheValue),
+		res: make(map[textureCacheKey]resourceCacheValue),
 	}
 }
 
-func (r *resourceCache) get(key interface{}) (resource, bool) {
+func (r *textureCache) get(key textureCacheKey) (resource, bool) {
 	v, exists := r.res[key]
 	if !exists {
 		return nil, false
@@ -55,17 +59,17 @@ func (r *resourceCache) get(key interface{}) (resource, bool) {
 	return v.resource, exists
 }
 
-func (r *resourceCache) put(key interface{}, val resource) {
+func (r *textureCache) put(key textureCacheKey, val resource) {
 	v, exists := r.res[key]
 	if exists && v.used {
-		panic(fmt.Errorf("key exists, %p", key))
+		panic(fmt.Errorf("key exists, %v", key))
 	}
 	v.used = true
 	v.resource = val
 	r.res[key] = v
 }
 
-func (r *resourceCache) frame() {
+func (r *textureCache) frame() {
 	for k, v := range r.res {
 		if v.used {
 			v.used = false
@@ -77,7 +81,7 @@ func (r *resourceCache) frame() {
 	}
 }
 
-func (r *resourceCache) release() {
+func (r *textureCache) release() {
 	for _, v := range r.res {
 		v.resource.release()
 	}

gpu/caches_test.go

@@ -1,24 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-package gpu
-
-import "testing"
-
-func BenchmarkResourceCache(b *testing.B) {
-	offset := 0
-	const N = 100
-
-	cache := newResourceCache()
-	for i := 0; i < b.N; i++ {
-		// half are the same and half updated
-		for k := 0; k < N; k++ {
-			cache.put(offset+k, nullResource{})
-		}
-		cache.frame()
-		offset += N / 2
-	}
-}
-
-type nullResource struct{}
-
-func (nullResource) release() {}

gpu/clip.go

@@ -19,10 +19,10 @@ type quadSplitter struct {
 
 func encodeQuadTo(data []byte, meta uint32, from, ctrl, to f32.Point) {
 	// inlined code:
-	//   encodeVertex(data, meta, -1, 1, from, ctrl, to)
+	//   encodeVertex(data, meta, 1, -1, from, ctrl, to)
 	//   encodeVertex(data[vertStride:], meta, 1, 1, from, ctrl, to)
 	//   encodeVertex(data[vertStride*2:], meta, -1, -1, from, ctrl, to)
-	//   encodeVertex(data[vertStride*3:], meta, 1, -1, from, ctrl, to)
+	//   encodeVertex(data[vertStride*3:], meta, -1, 1, from, ctrl, to)
 	// this code needs to stay in sync with `vertex.encode`.
 
 	bo := binary.LittleEndian
@@ -48,10 +48,10 @@ func encodeQuadTo(data []byte, meta uint32, from, ctrl, to f32.Point) {
 }
 
 const (
-	nwCorner = 1*0.25 + 0*0.5
+	nwCorner = 1*0.5 + 0*0.25
-	neCorner = 1*0.25 + 1*0.5
+	neCorner = 1*0.5 + 1*0.25
-	swCorner = 0*0.25 + 0*0.5
+	swCorner = 0*0.5 + 0*0.25
-	seCorner = 0*0.25 + 1*0.5
+	seCorner = 0*0.5 + 1*0.25
 )
 
 func encodeVertex(data []byte, meta uint32, cornerx, cornery int16, from, ctrl, to f32.Point) {

gpu/clip_test.go

@@ -10,7 +10,7 @@ import (
 
 func BenchmarkEncodeQuadTo(b *testing.B) {
 	var data [vertStride * 4]byte
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		v := float32(i)
 		encodeQuadTo(data[:], 123,
 			f32.Point{X: v, Y: v},

gpu/cpu.go

@@ -1,129 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-package gpu
-
-import (
-	"unsafe"
-
-	"gioui.org/cpu"
-)
-
-// This file contains code specific to running compute shaders on the CPU.
-
-// dispatcher dispatches CPU compute programs across multiple goroutines.
-type dispatcher struct {
-	// done is notified when a worker completes its work slice.
-	done chan struct{}
-	// work receives work slice indices. It is closed when the dispatcher is released.
-	work chan work
-	// dispatch receives compute jobs, which is then split among workers.
-	dispatch chan dispatch
-	// sync receives notification when a Sync completes.
-	sync chan struct{}
-}
-
-type work struct {
-	ctx   *cpu.DispatchContext
-	index int
-}
-
-type dispatch struct {
-	_type   jobType
-	program *cpu.ProgramInfo
-	descSet unsafe.Pointer
-	x, y, z int
-}
-
-type jobType uint8
-
-const (
-	jobDispatch jobType = iota
-	jobBarrier
-	jobSync
-)
-
-func newDispatcher(workers int) *dispatcher {
-	d := &dispatcher{
-		work: make(chan work, workers),
-		done: make(chan struct{}, workers),
-		// Leave some room to avoid blocking calls to Dispatch.
-		dispatch: make(chan dispatch, 20),
-		sync:     make(chan struct{}),
-	}
-	for i := 0; i < workers; i++ {
-		go d.worker()
-	}
-	go d.dispatcher()
-	return d
-}
-
-func (d *dispatcher) dispatcher() {
-	defer close(d.work)
-	var free []*cpu.DispatchContext
-	defer func() {
-		for _, ctx := range free {
-			ctx.Free()
-		}
-	}()
-	var used []*cpu.DispatchContext
-	for job := range d.dispatch {
-		switch job._type {
-		case jobDispatch:
-			if len(free) == 0 {
-				free = append(free, cpu.NewDispatchContext())
-			}
-			ctx := free[len(free)-1]
-			free = free[:len(free)-1]
-			used = append(used, ctx)
-			ctx.Prepare(cap(d.work), job.program, job.descSet, job.x, job.y, job.z)
-			for i := 0; i < cap(d.work); i++ {
-				d.work <- work{
-					ctx:   ctx,
-					index: i,
-				}
-			}
-		case jobBarrier:
-			// Wait for all outstanding dispatches to complete.
-			for i := 0; i < len(used)*cap(d.work); i++ {
-				<-d.done
-			}
-			free = append(free, used...)
-			used = used[:0]
-		case jobSync:
-			d.sync <- struct{}{}
-		}
-	}
-}
-
-func (d *dispatcher) worker() {
-	thread := cpu.NewThreadContext()
-	defer thread.Free()
-	for w := range d.work {
-		w.ctx.Dispatch(w.index, thread)
-		d.done <- struct{}{}
-	}
-}
-
-func (d *dispatcher) Barrier() {
-	d.dispatch <- dispatch{_type: jobBarrier}
-}
-
-func (d *dispatcher) Sync() {
-	d.dispatch <- dispatch{_type: jobSync}
-	<-d.sync
-}
-
-func (d *dispatcher) Dispatch(program *cpu.ProgramInfo, descSet unsafe.Pointer, x, y, z int) {
-	d.dispatch <- dispatch{
-		_type:   jobDispatch,
-		program: program,
-		descSet: descSet,
-		x:       x,
-		y:       y,
-		z:       z,
-	}
-}
-
-func (d *dispatcher) Stop() {
-	close(d.dispatch)
-}

gpu/gpu.go

@@ -9,12 +9,13 @@ package gpu
 
 import (
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"image"
 	"image/color"
 	"math"
-	"os"
 	"reflect"
+	"slices"
 	"time"
 	"unsafe"
 
@@ -44,14 +45,10 @@ type GPU interface {
 	Clear(color color.NRGBA)
 	// Frame draws the graphics operations from op into a viewport of target.
 	Frame(frame *op.Ops, target RenderTarget, viewport image.Point) error
-	// Profile returns the last available profiling information. Profiling
-	// information is requested when Frame sees an io/profile.Op, and the result
-	// is available through Profile at some later time.
-	Profile() string
 }
 
 type gpu struct {
-	cache *resourceCache
+	cache *textureCache
 
 	profile                                string
 	timers                                 *timers
@@ -73,7 +70,6 @@ type renderer struct {
 }
 
 type drawOps struct {
-	profile      bool
 	reader       ops.Reader
 	states       []f32.Affine2D
 	transStack   []f32.Affine2D
@@ -122,17 +118,17 @@ type drawState struct {
 }
 
 type pathOp struct {
-	off f32.Point
+	off image.Point
 	// rect tracks whether the clip stack can be represented by a
 	// pixel-aligned rectangle.
 	rect bool
 	// clip is the union of all
 	// later clip rectangles.
 	clip   image.Rectangle
-	bounds f32.Rectangle
+	bounds image.Rectangle
 	// intersect is the intersection of bounds and all
 	// previous clip bounds.
-	intersect f32.Rectangle
+	intersect image.Rectangle
 	pathKey   opKey
 	path      bool
 	pathVerts []byte
@@ -194,7 +190,7 @@ const (
 // imageOpData is the shadow of paint.ImageOp.
 type imageOpData struct {
 	src    *image.RGBA
-	handle interface{}
+	handle any
 	filter byte
 }
 
@@ -205,7 +201,7 @@ type linearGradientOpData struct {
 	color2 color.NRGBA
 }
 
-func decodeImageOp(data []byte, refs []interface{}) imageOpData {
+func decodeImageOp(data []byte, refs []any) imageOpData {
 	handle := refs[1]
 	if handle == nil {
 		return imageOpData{}
@@ -266,7 +262,7 @@ type texture struct {
 type blitter struct {
 	ctx                    driver.Device
 	viewport               image.Point
-	pipelines              [3]*pipeline
+	pipelines              [2][3]*pipeline
 	colUniforms            *blitColUniforms
 	texUniforms            *blitTexUniforms
 	linearGradientUniforms *blitLinearGradientUniforms
@@ -348,18 +344,17 @@ func New(api API) (GPU, error) {
 func NewWithDevice(d driver.Device) (GPU, error) {
 	d.BeginFrame(nil, false, image.Point{})
 	defer d.EndFrame()
-	forceCompute := os.Getenv("GIORENDERER") == "forcecompute"
 	feats := d.Caps().Features
 	switch {
-	case !forceCompute && feats.Has(driver.FeatureFloatRenderTargets) && feats.Has(driver.FeatureSRGB):
+	case feats.Has(driver.FeatureFloatRenderTargets) && feats.Has(driver.FeatureSRGB):
 		return newGPU(d)
 	}
-	return newCompute(d)
+	return nil, errors.New("no available GPU driver")
 }
 
 func newGPU(ctx driver.Device) (*gpu, error) {
 	g := &gpu{
-		cache: newResourceCache(),
+		cache: newTextureCache(),
 	}
 	g.drawOps.pathCache = newOpCache()
 	if err := g.init(ctx); err != nil {
@@ -399,7 +394,7 @@ func (g *gpu) collect(viewport image.Point, frameOps *op.Ops) {
 	g.renderer.pather.viewport = viewport
 	g.drawOps.reset(viewport)
 	g.drawOps.collect(frameOps, viewport)
-	if g.drawOps.profile && g.timers == nil && g.ctx.Caps().Features.Has(driver.FeatureTimers) {
+	if false && g.timers == nil && g.ctx.Caps().Features.Has(driver.FeatureTimers) {
 		g.frameStart = time.Now()
 		g.timers = newTimers(g.ctx)
 		g.stencilTimer = g.timers.newTimer()
@@ -425,9 +420,9 @@ func (g *gpu) frame(target RenderTarget) error {
 	g.stencilTimer.end()
 	g.coverTimer.begin()
 	g.renderer.uploadImages(g.cache, g.drawOps.imageOps)
-	g.renderer.prepareDrawOps(g.cache, g.drawOps.imageOps)
+	g.renderer.prepareDrawOps(g.drawOps.imageOps)
 	g.drawOps.layers = g.renderer.packLayers(g.drawOps.layers)
-	g.renderer.drawLayers(g.cache, g.drawOps.layers, g.drawOps.imageOps)
+	g.renderer.drawLayers(g.drawOps.layers, g.drawOps.imageOps)
 	d := driver.LoadDesc{
 		ClearColor: g.drawOps.clearColor,
 	}
@@ -437,14 +432,14 @@ func (g *gpu) frame(target RenderTarget) error {
 	}
 	g.ctx.BeginRenderPass(defFBO, d)
 	g.ctx.Viewport(0, 0, viewport.X, viewport.Y)
-	g.renderer.drawOps(g.cache, false, image.Point{}, g.renderer.blitter.viewport, g.drawOps.imageOps)
+	g.renderer.drawOps(false, image.Point{}, g.renderer.blitter.viewport, g.drawOps.imageOps)
 	g.coverTimer.end()
 	g.ctx.EndRenderPass()
 	g.cleanupTimer.begin()
 	g.cache.frame()
 	g.drawOps.pathCache.frame()
 	g.cleanupTimer.end()
-	if g.drawOps.profile && g.timers.ready() {
+	if false && g.timers.ready() {
 		st, covt, cleant := g.stencilTimer.Elapsed, g.coverTimer.Elapsed, g.cleanupTimer.Elapsed
 		ft := st + covt + cleant
 		q := 100 * time.Microsecond
@@ -460,12 +455,8 @@ func (g *gpu) Profile() string {
 	return g.profile
 }
 
-func (r *renderer) texHandle(cache *resourceCache, data imageOpData) driver.Texture {
+func (r *renderer) texHandle(cache *textureCache, data imageOpData) driver.Texture {
-	type cachekey struct {
+	key := textureCacheKey{
-		filter byte
-		handle any
-	}
-	key := cachekey{
 		filter: data.filter,
 		handle: data.handle,
 	}
@@ -557,7 +548,7 @@ func newBlitter(ctx driver.Device) *blitter {
 	b.texUniforms = new(blitTexUniforms)
 	b.linearGradientUniforms = new(blitLinearGradientUniforms)
 	pipelines, err := createColorPrograms(ctx, gio.Shader_blit_vert, gio.Shader_blit_frag,
-		[3]interface{}{b.colUniforms, b.linearGradientUniforms, b.texUniforms},
+		[3]any{b.colUniforms, b.linearGradientUniforms, b.texUniforms},
 	)
 	if err != nil {
 		panic(err)
@@ -569,12 +560,24 @@ func newBlitter(ctx driver.Device) *blitter {
 func (b *blitter) release() {
 	b.quadVerts.Release()
 	for _, p := range b.pipelines {
-		p.Release()
+		for _, p := range p {
+			p.Release()
+		}
 	}
 }
 
-func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.Sources, uniforms [3]interface{}) ([3]*pipeline, error) {
+func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.Sources, uniforms [3]any) (pipelines [2][3]*pipeline, err error) {
-	var pipelines [3]*pipeline
+	defer func() {
+		if err != nil {
+			for _, p := range pipelines {
+				for _, p := range p {
+					if p != nil {
+						p.Release()
+					}
+				}
+			}
+		}
+	}()
 	blend := driver.BlendDesc{
 		Enable:    true,
 		SrcFactor: driver.BlendFactorOne,
@@ -592,86 +595,76 @@ func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.
 		return pipelines, err
 	}
 	defer vsh.Release()
-	{
+	for i, format := range []driver.TextureFormat{driver.TextureFormatOutput, driver.TextureFormatSRGBA} {
-		fsh, err := b.NewFragmentShader(fsSrc[materialTexture])
+		{
-		if err != nil {
+			fsh, err := b.NewFragmentShader(fsSrc[materialTexture])
-			return pipelines, err
+			if err != nil {
+				return pipelines, err
+			}
+			defer fsh.Release()
+			pipe, err := b.NewPipeline(driver.PipelineDesc{
+				VertexShader:   vsh,
+				FragmentShader: fsh,
+				BlendDesc:      blend,
+				VertexLayout:   layout,
+				PixelFormat:    format,
+				Topology:       driver.TopologyTriangleStrip,
+			})
+			if err != nil {
+				return pipelines, err
+			}
+			var vertBuffer *uniformBuffer
+			if u := uniforms[materialTexture]; u != nil {
+				vertBuffer = newUniformBuffer(b, u)
+			}
+			pipelines[i][materialTexture] = &pipeline{pipe, vertBuffer}
 		}
-		defer fsh.Release()
+		{
-		pipe, err := b.NewPipeline(driver.PipelineDesc{
+			var vertBuffer *uniformBuffer
-			VertexShader:   vsh,
+			fsh, err := b.NewFragmentShader(fsSrc[materialColor])
-			FragmentShader: fsh,
+			if err != nil {
-			BlendDesc:      blend,
+				return pipelines, err
-			VertexLayout:   layout,
+			}
-			PixelFormat:    driver.TextureFormatOutput,
+			defer fsh.Release()
-			Topology:       driver.TopologyTriangleStrip,
+			pipe, err := b.NewPipeline(driver.PipelineDesc{
-		})
+				VertexShader:   vsh,
-		if err != nil {
+				FragmentShader: fsh,
-			return pipelines, err
+				BlendDesc:      blend,
+				VertexLayout:   layout,
+				PixelFormat:    format,
+				Topology:       driver.TopologyTriangleStrip,
+			})
+			if err != nil {
+				return pipelines, err
+			}
+			if u := uniforms[materialColor]; u != nil {
+				vertBuffer = newUniformBuffer(b, u)
+			}
+			pipelines[i][materialColor] = &pipeline{pipe, vertBuffer}
 		}
-		var vertBuffer *uniformBuffer
+		{
-		if u := uniforms[materialTexture]; u != nil {
+			var vertBuffer *uniformBuffer
-			vertBuffer = newUniformBuffer(b, u)
+			fsh, err := b.NewFragmentShader(fsSrc[materialLinearGradient])
+			if err != nil {
+				return pipelines, err
+			}
+			defer fsh.Release()
+			pipe, err := b.NewPipeline(driver.PipelineDesc{
+				VertexShader:   vsh,
+				FragmentShader: fsh,
+				BlendDesc:      blend,
+				VertexLayout:   layout,
+				PixelFormat:    format,
+				Topology:       driver.TopologyTriangleStrip,
+			})
+			if err != nil {
+				return pipelines, err
+			}
+			if u := uniforms[materialLinearGradient]; u != nil {
+				vertBuffer = newUniformBuffer(b, u)
+			}
+			pipelines[i][materialLinearGradient] = &pipeline{pipe, vertBuffer}
 		}
-		pipelines[materialTexture] = &pipeline{pipe, vertBuffer}
-	}
-	{
-		var vertBuffer *uniformBuffer
-		fsh, err := b.NewFragmentShader(fsSrc[materialColor])
-		if err != nil {
-			pipelines[materialTexture].Release()
-			return pipelines, err
-		}
-		defer fsh.Release()
-		pipe, err := b.NewPipeline(driver.PipelineDesc{
-			VertexShader:   vsh,
-			FragmentShader: fsh,
-			BlendDesc:      blend,
-			VertexLayout:   layout,
-			PixelFormat:    driver.TextureFormatOutput,
-			Topology:       driver.TopologyTriangleStrip,
-		})
-		if err != nil {
-			pipelines[materialTexture].Release()
-			return pipelines, err
-		}
-		if u := uniforms[materialColor]; u != nil {
-			vertBuffer = newUniformBuffer(b, u)
-		}
-		pipelines[materialColor] = &pipeline{pipe, vertBuffer}
-	}
-	{
-		var vertBuffer *uniformBuffer
-		fsh, err := b.NewFragmentShader(fsSrc[materialLinearGradient])
-		if err != nil {
-			pipelines[materialTexture].Release()
-			pipelines[materialColor].Release()
-			return pipelines, err
-		}
-		defer fsh.Release()
-		pipe, err := b.NewPipeline(driver.PipelineDesc{
-			VertexShader:   vsh,
-			FragmentShader: fsh,
-			BlendDesc:      blend,
-			VertexLayout:   layout,
-			PixelFormat:    driver.TextureFormatOutput,
-			Topology:       driver.TopologyTriangleStrip,
-		})
-		if err != nil {
-			pipelines[materialTexture].Release()
-			pipelines[materialColor].Release()
-			return pipelines, err
-		}
-		if u := uniforms[materialLinearGradient]; u != nil {
-			vertBuffer = newUniformBuffer(b, u)
-		}
-		pipelines[materialLinearGradient] = &pipeline{pipe, vertBuffer}
-	}
-	if err != nil {
-		for _, p := range pipelines {
-			p.Release()
-		}
-		return pipelines, err
 	}
 	return pipelines, nil
 }
@@ -830,7 +823,7 @@ func (r *renderer) packLayers(layers []opacityLayer) []opacityLayer {
 			layers[l.parent].clip = b.Union(l.clip)
 		}
 		if l.clip.Empty() {
-			layers = append(layers[:i], layers[i+1:]...)
+			layers = slices.Delete(layers, i, i+1)
 		}
 	}
 	// Pack layers.
@@ -853,7 +846,7 @@ func (r *renderer) packLayers(layers []opacityLayer) []opacityLayer {
 	return layers
 }
 
-func (r *renderer) drawLayers(cache *resourceCache, layers []opacityLayer, ops []imageOp) {
+func (r *renderer) drawLayers(layers []opacityLayer, ops []imageOp) {
 	if len(r.layers.sizes) == 0 {
 		return
 	}
@@ -874,12 +867,12 @@ func (r *renderer) drawLayers(cache *resourceCache, layers []opacityLayer, ops [
 			Min: l.place.Pos,
 			Max: l.place.Pos.Add(l.clip.Size()),
 		}
-		r.ctx.Viewport(v.Min.X, v.Min.Y, v.Max.X, v.Max.Y)
+		r.ctx.Viewport(v.Min.X, v.Min.Y, v.Dx(), v.Dy())
 		f := r.layerFBOs.fbos[fbo]
-		r.drawOps(cache, true, l.clip.Min.Mul(-1), l.clip.Size(), ops[l.opStart:l.opEnd])
+		r.drawOps(true, l.clip.Min.Mul(-1), l.clip.Size(), ops[l.opStart:l.opEnd])
 		sr := f32.FRect(v)
 		uvScale, uvOffset := texSpaceTransform(sr, f.size)
-		uvTrans := f32.Affine2D{}.Scale(f32.Point{}, uvScale).Offset(uvOffset)
+		uvTrans := f32.AffineId().Scale(f32.Point{}, uvScale).Offset(uvOffset)
 		// Replace layer ops with one textured op.
 		ops[l.opStart] = imageOp{
 			clip: l.clip,
@@ -899,7 +892,6 @@ func (r *renderer) drawLayers(cache *resourceCache, layers []opacityLayer, ops [
 }
 
 func (d *drawOps) reset(viewport image.Point) {
-	d.profile = false
 	d.viewport = viewport
 	d.imageOps = d.imageOps[:0]
 	d.pathOps = d.pathOps[:0]
@@ -910,16 +902,14 @@ func (d *drawOps) reset(viewport image.Point) {
 	d.opacityStack = d.opacityStack[:0]
 }
 
-func (d *drawOps) collect(root *op.Ops, viewport image.Point) {
+func (d *drawOps) collect(root *op.Ops, viewportSize image.Point) {
-	viewf := f32.Rectangle{
+	viewport := image.Rectangle{Max: viewportSize}
-		Max: f32.Point{X: float32(viewport.X), Y: float32(viewport.Y)},
-	}
 	var ops *ops.Ops
 	if root != nil {
 		ops = &root.Internal
 	}
 	d.reader.Reset(ops)
-	d.collectOps(&d.reader, viewf)
+	d.collectOps(&d.reader, viewport)
 }
 
 func (d *drawOps) buildPaths(ctx driver.Device) {
@@ -940,7 +930,7 @@ func (d *drawOps) newPathOp() *pathOp {
 	return &d.pathOpCache[len(d.pathOpCache)-1]
 }
 
-func (d *drawOps) addClipPath(state *drawState, aux []byte, auxKey opKey, bounds f32.Rectangle, off f32.Point, push bool) {
+func (d *drawOps) addClipPath(state *drawState, aux []byte, auxKey opKey, bounds image.Rectangle, off image.Point) {
 	npath := d.newPathOp()
 	*npath = pathOp{
 		parent:    state.cpath,
@@ -965,7 +955,9 @@ func (d *drawOps) addClipPath(state *drawState, aux []byte, auxKey opKey, bounds
 
 func (d *drawOps) save(id int, state f32.Affine2D) {
 	if extra := id - len(d.states) + 1; extra > 0 {
-		d.states = append(d.states, make([]f32.Affine2D, extra)...)
+		for range extra {
+			d.states = append(d.states, f32.AffineId())
+		}
 	}
 	d.states[id] = state
 }
@@ -979,13 +971,14 @@ func (k opKey) SetTransform(t f32.Affine2D) opKey {
 	return k
 }
 
-func (d *drawOps) collectOps(r *ops.Reader, viewport f32.Rectangle) {
+func (d *drawOps) collectOps(r *ops.Reader, viewport image.Rectangle) {
-	var (
+	var quads quadsOp
-		quads quadsOp
+	state := drawState{
-		state drawState
+		t: f32.AffineId(),
-	)
+	}
 	reset := func() {
 		state = drawState{
+			t:     f32.AffineId(),
 			color: color.NRGBA{A: 0xff},
 		}
 	}
@@ -993,8 +986,6 @@ func (d *drawOps) collectOps(r *ops.Reader, viewport f32.Rectangle) {
 loop:
 	for encOp, ok := r.Decode(); ok; encOp, ok = r.Decode() {
 		switch ops.OpType(encOp.Data[0]) {
-		case ops.TypeProfile:
-			d.profile = true
 		case ops.TypeTransform:
 			dop, push := ops.DecodeTransform(encOp.Data)
 			if push {
@@ -1042,8 +1033,8 @@ loop:
 			var op ops.ClipOp
 			op.Decode(encOp.Data)
 			quads.key.outline = op.Outline
-			bounds := f32.FRect(op.Bounds)
+			bounds := op.Bounds
-			trans, off := state.t.Split()
+			trans, off := transformOffset(state.t)
 			if len(quads.aux) > 0 {
 				// There is a clipping path, build the gpu data and update the
 				// cache key such that it will be equal only if the transform is the
@@ -1054,11 +1045,11 @@ loop:
 					// Why is this not used for the offset shapes?
 					bounds = v.bounds
 				} else {
-					var pathData []byte
+					newPathData, newBounds := d.buildVerts(
-					pathData, bounds = d.buildVerts(
 						quads.aux, trans, quads.key.outline, quads.key.strokeWidth,
 					)
-					quads.aux = pathData
+					quads.aux = newPathData
+					bounds = newBounds.Round()
 					// add it to the cache, without GPU data, so the transform can be
 					// reused.
 					d.pathCache.put(quads.key, opCacheValue{bounds: bounds})
@@ -1066,8 +1057,9 @@ loop:
 			} else {
 				quads.aux, bounds, _ = d.boundsForTransformedRect(bounds, trans)
 				quads.key = opKey{Key: encOp.Key}
+				quads.key = quads.key.SetTransform(trans)
 			}
-			d.addClipPath(&state, quads.aux, quads.key, bounds, off, true)
+			d.addClipPath(&state, quads.aux, quads.key, bounds, off)
 			quads = quadsOp{}
 		case ops.TypePopClip:
 			state.cpath = state.cpath.parent
@@ -1089,21 +1081,21 @@ loop:
 			// Transform (if needed) the painting rectangle and if so generate a clip path,
 			// for those cases also compute a partialTrans that maps texture coordinates between
 			// the new bounding rectangle and the transformed original paint rectangle.
-			t, off := state.t.Split()
+			t, off := transformOffset(state.t)
 			// Fill the clip area, unless the material is a (bounded) image.
 			// TODO: Find a tighter bound.
-			inf := float32(1e6)
+			inf := int(1e6)
-			dst := f32.Rect(-inf, -inf, inf, inf)
+			dst := image.Rect(-inf, -inf, inf, inf)
 			if state.matType == materialTexture {
 				sz := state.image.src.Rect.Size()
-				dst = f32.Rectangle{Max: layout.FPt(sz)}
+				dst = image.Rectangle{Max: sz}
 			}
 			clipData, bnd, partialTrans := d.boundsForTransformedRect(dst, t)
-			cl := viewport.Intersect(bnd.Add(off))
+			bounds := viewport.Intersect(bnd.Add(off))
 			if state.cpath != nil {
-				cl = state.cpath.intersect.Intersect(cl)
+				bounds = state.cpath.intersect.Intersect(bounds)
 			}
-			if cl.Empty() {
+			if bounds.Empty() {
 				continue
 			}
 
@@ -1111,11 +1103,10 @@ loop:
 				// The paint operation is sheared or rotated, add a clip path representing
 				// this transformed rectangle.
 				k := opKey{Key: encOp.Key}
-				k.SetTransform(t) // TODO: This call has no effect.
+				k = k.SetTransform(t)
-				d.addClipPath(&state, clipData, k, bnd, off, false)
+				d.addClipPath(&state, clipData, k, bnd, off)
 			}
 
-			bounds := cl.Round()
 			mat := state.materialFor(bnd, off, partialTrans, bounds)
 
 			rect := state.cpath == nil || state.cpath.rect
@@ -1169,9 +1160,10 @@ func expandPathOp(p *pathOp, clip image.Rectangle) {
 	}
 }
 
-func (d *drawState) materialFor(rect f32.Rectangle, off f32.Point, partTrans f32.Affine2D, clip image.Rectangle) material {
+func (d *drawState) materialFor(rect image.Rectangle, off image.Point, partTrans f32.Affine2D, clip image.Rectangle) material {
 	m := material{
 		opacity: 1.,
+		uvTrans: f32.AffineId(),
 	}
 	switch d.matType {
 	case materialColor:
@@ -1188,7 +1180,7 @@ func (d *drawState) materialFor(rect f32.Rectangle, off f32.Point, partTrans f32
 		m.uvTrans = partTrans.Mul(gradientSpaceTransform(clip, off, d.stop1, d.stop2))
 	case materialTexture:
 		m.material = materialTexture
-		dr := rect.Add(off).Round()
+		dr := rect.Add(off)
 		sz := d.image.src.Bounds().Size()
 		sr := f32.Rectangle{
 			Max: f32.Point{
@@ -1205,13 +1197,13 @@ func (d *drawState) materialFor(rect f32.Rectangle, off f32.Point, partTrans f32
 		sr.Min.Y += float32(clip.Min.Y-dr.Min.Y) * sdy / dy
 		sr.Max.Y -= float32(dr.Max.Y-clip.Max.Y) * sdy / dy
 		uvScale, uvOffset := texSpaceTransform(sr, sz)
-		m.uvTrans = partTrans.Mul(f32.Affine2D{}.Scale(f32.Point{}, uvScale).Offset(uvOffset))
+		m.uvTrans = partTrans.Mul(f32.AffineId().Scale(f32.Point{}, uvScale).Offset(uvOffset))
 		m.data = d.image
 	}
 	return m
 }
 
-func (r *renderer) uploadImages(cache *resourceCache, ops []imageOp) {
+func (r *renderer) uploadImages(cache *textureCache, ops []imageOp) {
 	for i := range ops {
 		img := &ops[i]
 		m := img.material
@@ -1221,7 +1213,7 @@ func (r *renderer) uploadImages(cache *resourceCache, ops []imageOp) {
 	}
 }
 
-func (r *renderer) prepareDrawOps(cache *resourceCache, ops []imageOp) {
+func (r *renderer) prepareDrawOps(ops []imageOp) {
 	for _, img := range ops {
 		m := img.material
 		switch m.material {
@@ -1242,7 +1234,7 @@ func (r *renderer) prepareDrawOps(cache *resourceCache, ops []imageOp) {
 	}
 }
 
-func (r *renderer) drawOps(cache *resourceCache, isFBO bool, opOff image.Point, viewport image.Point, ops []imageOp) {
+func (r *renderer) drawOps(isFBO bool, opOff, viewport image.Point, ops []imageOp) {
 	var coverTex driver.Texture
 	for i := 0; i < len(ops); i++ {
 		img := ops[i]
@@ -1256,9 +1248,13 @@ func (r *renderer) drawOps(cache *resourceCache, isFBO bool, opOff image.Point,
 
 		scale, off := clipSpaceTransform(drc, viewport)
 		var fbo FBO
+		fboIdx := 0
+		if isFBO {
+			fboIdx = 1
+		}
 		switch img.clipType {
 		case clipTypeNone:
-			p := r.blitter.pipelines[m.material]
+			p := r.blitter.pipelines[fboIdx][m.material]
 			r.ctx.BindPipeline(p.pipeline)
 			r.ctx.BindVertexBuffer(r.blitter.quadVerts, 0)
 			r.blitter.blit(m.material, isFBO, m.color, m.color1, m.color2, scale, off, m.opacity, m.uvTrans)
@@ -1277,7 +1273,7 @@ func (r *renderer) drawOps(cache *resourceCache, isFBO bool, opOff image.Point,
 			Max: img.place.Pos.Add(drc.Size()),
 		}
 		coverScale, coverOff := texSpaceTransform(f32.FRect(uv), fbo.size)
-		p := r.pather.coverer.pipelines[m.material]
+		p := r.pather.coverer.pipelines[fboIdx][m.material]
 		r.ctx.BindPipeline(p.pipeline)
 		r.ctx.BindVertexBuffer(r.blitter.quadVerts, 0)
 		r.pather.cover(m.material, isFBO, m.color, m.color1, m.color2, scale, off, m.uvTrans, coverScale, coverOff)
@@ -1285,7 +1281,11 @@ func (r *renderer) drawOps(cache *resourceCache, isFBO bool, opOff image.Point,
 }
 
 func (b *blitter) blit(mat materialType, fbo bool, col f32color.RGBA, col1, col2 f32color.RGBA, scale, off f32.Point, opacity float32, uvTrans f32.Affine2D) {
-	p := b.pipelines[mat]
+	fboIdx := 0
+	if fbo {
+		fboIdx = 1
+	}
+	p := b.pipelines[fboIdx][mat]
 	b.ctx.BindPipeline(p.pipeline)
 	var uniforms *blitUniforms
 	switch mat {
@@ -1318,7 +1318,7 @@ func (b *blitter) blit(mat materialType, fbo bool, col f32color.RGBA, col1, col2
 
 // newUniformBuffer creates a new GPU uniform buffer backed by the
 // structure uniformBlock points to.
-func newUniformBuffer(b driver.Device, uniformBlock interface{}) *uniformBuffer {
+func newUniformBuffer(b driver.Device, uniformBlock any) *uniformBuffer {
 	ref := reflect.ValueOf(uniformBlock)
 	// Determine the size of the uniforms structure, *uniforms.
 	size := ref.Elem().Type().Size()
@@ -1365,19 +1365,19 @@ func texSpaceTransform(r f32.Rectangle, bounds image.Point) (f32.Point, f32.Poin
 }
 
 // gradientSpaceTransform transforms stop1 and stop2 to [(0,0), (1,1)].
-func gradientSpaceTransform(clip image.Rectangle, off f32.Point, stop1, stop2 f32.Point) f32.Affine2D {
+func gradientSpaceTransform(clip image.Rectangle, off image.Point, stop1, stop2 f32.Point) f32.Affine2D {
 	d := stop2.Sub(stop1)
 	l := float32(math.Sqrt(float64(d.X*d.X + d.Y*d.Y)))
 	a := float32(math.Atan2(float64(-d.Y), float64(d.X)))
 
 	// TODO: optimize
 	zp := f32.Point{}
-	return f32.Affine2D{}.
+	return f32.AffineId().
-		Scale(zp, layout.FPt(clip.Size())).            // scale to pixel space
+		Scale(zp, layout.FPt(clip.Size())).                     // scale to pixel space
-		Offset(zp.Sub(off).Add(layout.FPt(clip.Min))). // offset to clip space
+		Offset(zp.Sub(f32.FPt(off)).Add(layout.FPt(clip.Min))). // offset to clip space
-		Offset(zp.Sub(stop1)).                         // offset to first stop point
+		Offset(zp.Sub(stop1)).                                  // offset to first stop point
-		Rotate(zp, a).                                 // rotate to align gradient
+		Rotate(zp, a).                                          // rotate to align gradient
-		Scale(zp, f32.Pt(1/l, 1/l))                    // scale gradient to right size
+		Scale(zp, f32.Pt(1/l, 1/l))                             // scale gradient to right size
 }
 
 // clipSpaceTransform returns the scale and offset that transforms the given
@@ -1486,7 +1486,7 @@ func (d *drawOps) buildVerts(pathData []byte, tr f32.Affine2D, outline bool, str
 // as needed and feeds them to the supplied splitter.
 func decodeToOutlineQuads(qs *quadSplitter, tr f32.Affine2D, pathData []byte) {
 	for len(pathData) >= scene.CommandSize+4 {
-		qs.contour = bo.Uint32(pathData)
+		qs.contour = binary.LittleEndian.Uint32(pathData)
 		cmd := ops.DecodeCommand(pathData[4:])
 		switch cmd.Op() {
 		case scene.OpLine:
@@ -1521,37 +1521,38 @@ func decodeToOutlineQuads(qs *quadSplitter, tr f32.Affine2D, pathData []byte) {
 }
 
 // create GPU vertices for transformed r, find the bounds and establish texture transform.
-func (d *drawOps) boundsForTransformedRect(r f32.Rectangle, tr f32.Affine2D) (aux []byte, bnd f32.Rectangle, ptr f32.Affine2D) {
+func (d *drawOps) boundsForTransformedRect(r image.Rectangle, tr f32.Affine2D) (aux []byte, bnd image.Rectangle, ptr f32.Affine2D) {
-	if isPureOffset(tr) {
+	ptr = f32.AffineId()
-		// fast-path to allow blitting of pure rectangles
+	if tr == f32.AffineId() {
-		_, _, ox, _, _, oy := tr.Elems()
+		// fast-path to allow blitting of pure rectangles.
-		off := f32.Pt(ox, oy)
+		bnd = r
-		bnd.Min = r.Min.Add(off)
-		bnd.Max = r.Max.Add(off)
 		return
 	}
 
 	// transform all corners, find new bounds
 	corners := [4]f32.Point{
-		tr.Transform(r.Min), tr.Transform(f32.Pt(r.Max.X, r.Min.Y)),
+		tr.Transform(f32.FPt(r.Min)), tr.Transform(f32.Pt(float32(r.Max.X), float32(r.Min.Y))),
-		tr.Transform(r.Max), tr.Transform(f32.Pt(r.Min.X, r.Max.Y)),
+		tr.Transform(f32.FPt(r.Max)), tr.Transform(f32.Pt(float32(r.Min.X), float32(r.Max.Y))),
+	}
+	fBounds := f32.Rectangle{
+		Min: f32.Pt(math.MaxFloat32, math.MaxFloat32),
+		Max: f32.Pt(-math.MaxFloat32, -math.MaxFloat32),
 	}
-	bnd.Min = f32.Pt(math.MaxFloat32, math.MaxFloat32)
-	bnd.Max = f32.Pt(-math.MaxFloat32, -math.MaxFloat32)
 	for _, c := range corners {
-		if c.X < bnd.Min.X {
+		if c.X < fBounds.Min.X {
-			bnd.Min.X = c.X
+			fBounds.Min.X = c.X
 		}
-		if c.Y < bnd.Min.Y {
+		if c.Y < fBounds.Min.Y {
-			bnd.Min.Y = c.Y
+			fBounds.Min.Y = c.Y
 		}
-		if c.X > bnd.Max.X {
+		if c.X > fBounds.Max.X {
-			bnd.Max.X = c.X
+			fBounds.Max.X = c.X
 		}
-		if c.Y > bnd.Max.Y {
+		if c.Y > fBounds.Max.Y {
-			bnd.Max.Y = c.Y
+			fBounds.Max.Y = c.Y
 		}
 	}
+	bnd = fBounds.Round()
 
 	// build the GPU vertices
 	l := len(d.vertCache)
@@ -1565,19 +1566,38 @@ func (d *drawOps) boundsForTransformedRect(r f32.Rectangle, tr f32.Affine2D) (au
 
 	// establish the transform mapping from bounds rectangle to transformed corners
 	var P1, P2, P3 f32.Point
-	P1.X = (corners[1].X - bnd.Min.X) / (bnd.Max.X - bnd.Min.X)
+	P1.X = (corners[1].X - fBounds.Min.X) / (fBounds.Max.X - fBounds.Min.X)
-	P1.Y = (corners[1].Y - bnd.Min.Y) / (bnd.Max.Y - bnd.Min.Y)
+	P1.Y = (corners[1].Y - fBounds.Min.Y) / (fBounds.Max.Y - fBounds.Min.Y)
-	P2.X = (corners[2].X - bnd.Min.X) / (bnd.Max.X - bnd.Min.X)
+	P2.X = (corners[2].X - fBounds.Min.X) / (fBounds.Max.X - fBounds.Min.X)
-	P2.Y = (corners[2].Y - bnd.Min.Y) / (bnd.Max.Y - bnd.Min.Y)
+	P2.Y = (corners[2].Y - fBounds.Min.Y) / (fBounds.Max.Y - fBounds.Min.Y)
-	P3.X = (corners[3].X - bnd.Min.X) / (bnd.Max.X - bnd.Min.X)
+	P3.X = (corners[3].X - fBounds.Min.X) / (fBounds.Max.X - fBounds.Min.X)
-	P3.Y = (corners[3].Y - bnd.Min.Y) / (bnd.Max.Y - bnd.Min.Y)
+	P3.Y = (corners[3].Y - fBounds.Min.Y) / (fBounds.Max.Y - fBounds.Min.Y)
 	sx, sy := P2.X-P3.X, P2.Y-P3.Y
 	ptr = f32.NewAffine2D(sx, P2.X-P1.X, P1.X-sx, sy, P2.Y-P1.Y, P1.Y-sy).Invert()
 
-	return
+	return aux, bnd, ptr
 }
 
-func isPureOffset(t f32.Affine2D) bool {
+// transformOffset a transform into two parts, one which is pure integer offset
-	a, b, _, d, e, _ := t.Elems()
+// and the other representing the scaling, shearing and rotation and fractional
-	return a == 1 && b == 0 && d == 0 && e == 1
+// offset.
+func transformOffset(t f32.Affine2D) (f32.Affine2D, image.Point) {
+	sx, hx, ox, hy, sy, oy := t.Elems()
+	iox, fox := math.Modf(float64(ox))
+	ioy, foy := math.Modf(float64(oy))
+	ft := f32.NewAffine2D(sx, hx, float32(fox), hy, sy, float32(foy))
+	ip := image.Pt(int(iox), int(ioy))
+	return ft, ip
+}
+
+func newShaders(ctx driver.Device, vsrc, fsrc shader.Sources) (vert driver.VertexShader, frag driver.FragmentShader, err error) {
+	vert, err = ctx.NewVertexShader(vsrc)
+	if err != nil {
+		return
+	}
+	frag, err = ctx.NewFragmentShader(fsrc)
+	if err != nil {
+		vert.Release()
+	}
+	return
 }

gpu/headless/driver_test.go

@@ -21,8 +21,10 @@ import (
 
 var dumpImages = flag.Bool("saveimages", false, "save test images")
 
-var clearCol = color.NRGBA{A: 0xff, R: 0xde, G: 0xad, B: 0xbe}
+var (
-var clearColExpect = f32color.NRGBAToRGBA(clearCol)
+	clearCol       = color.NRGBA{A: 0xff, R: 0xde, G: 0xad, B: 0xbe}
+	clearColExpect = f32color.NRGBAToRGBA(clearCol)
+)
 
 func TestFramebufferClear(t *testing.T) {
 	b := newDriver(t)
@@ -202,5 +204,5 @@ func saveImage(file string, img image.Image) error {
 	if err := png.Encode(&buf, img); err != nil {
 		return err
 	}
-	return os.WriteFile(file, buf.Bytes(), 0666)
+	return os.WriteFile(file, buf.Bytes(), 0o666)
 }

gpu/internal/d3d11/d3d11_windows.go

@@ -152,9 +152,7 @@ func newDirect3D11Device(api driver.Direct3D11) (driver.Device, error) {
 }
 
 func (b *Backend) BeginFrame(target driver.RenderTarget, clear bool, viewport image.Point) driver.Texture {
-	var (
+	var renderTarget *d3d11.RenderTargetView
-		renderTarget *d3d11.RenderTargetView
-	)
 	if target != nil {
 		switch t := target.(type) {
 		case driver.Direct3D11RenderTarget:
@@ -229,10 +227,7 @@ func (b *Backend) NewTexture(format driver.TextureFormat, width, height int, min
 		// Flags required by ID3D11DeviceContext::GenerateMips.
 		bindFlags |= d3d11.BIND_SHADER_RESOURCE | d3d11.BIND_RENDER_TARGET
 		miscFlags |= d3d11.RESOURCE_MISC_GENERATE_MIPS
-		dim := width
+		dim := max(height, width)
-		if height > dim {
-			dim = height
-		}
 		log2 := 32 - bits.LeadingZeros32(uint32(dim)) - 1
 		nmipmaps = log2 + 1
 	}
@@ -802,7 +797,7 @@ func (t *Texture) ReadPixels(src image.Rectangle, pixels []byte, stride int) err
 	mapSize := dstPitch * h
 	data := sliceOf(resMap.PData, mapSize)
 	width := w * 4
-	for r := 0; r < h; r++ {
+	for r := range h {
 		pixels := pixels[r*srcPitch:]
 		copy(pixels[:width], data[r*dstPitch:])
 	}

gpu/internal/driver/driver.go

@@ -96,8 +96,10 @@ type BlendFactor uint8
 
 type Topology uint8
 
-type TextureFilter uint8
+type (
-type TextureFormat uint8
+	TextureFilter uint8
+	TextureFormat uint8
+)
 
 type BufferBinding uint8
 
@@ -217,7 +219,7 @@ func flipImageY(stride, height int, pixels []byte) {
 	// Flip image in y-direction. OpenGL's origin is in the lower
 	// left corner.
 	row := make([]uint8, stride)
-	for y := 0; y < height/2; y++ {
+	for y := range height / 2 {
 		y1 := height - y - 1
 		dest := y1 * stride
 		src := y * stride

gpu/internal/opengl/opengl.go

@@ -8,6 +8,7 @@ import (
 	"image"
 	"math/bits"
 	"runtime"
+	"slices"
 	"strings"
 	"time"
 	"unsafe"
@@ -717,10 +718,7 @@ func (b *Backend) NewTexture(format driver.TextureFormat, width, height int, min
 	if mipmap {
 		nmipmaps := 1
 		if mipmap {
-			dim := width
+			dim := max(height, width)
-			if height > dim {
-				dim = height
-			}
 			log2 := 32 - bits.LeadingZeros32(uint32(dim)) - 1
 			nmipmaps = log2 + 1
 		}
@@ -1132,7 +1130,7 @@ func (b *Backend) setupVertexArrays() {
 		enabled[inp.Location] = true
 		b.glstate.vertexAttribPointer(b.funcs, buf.obj, inp.Location, l.Size, gltyp, false, p.layout.Stride, buf.offset+l.Offset)
 	}
-	for i := 0; i < max; i++ {
+	for i := range max {
 		b.glstate.setVertexAttribArray(b.funcs, i, enabled[i])
 	}
 }
@@ -1175,7 +1173,7 @@ func (t *texture) ReadPixels(src image.Rectangle, pixels []byte, stride int) err
 	} else {
 		tmp := make([]byte, w*h*4)
 		t.backend.funcs.ReadPixels(src.Min.X, src.Min.Y, w, h, gl.RGBA, gl.UNSIGNED_BYTE, tmp)
-		for y := 0; y < h; y++ {
+		for y := range h {
 			copy(pixels[y*stride:], tmp[y*w*4:])
 		}
 	}
@@ -1357,12 +1355,7 @@ func alphaTripleFor(ver [2]int) textureTriple {
 }
 
 func hasExtension(exts []string, ext string) bool {
-	for _, e := range exts {
+	return slices.Contains(exts, ext)
-		if ext == e {
-			return true
-		}
-	}
-	return false
 }
 
 func firstBufferType(typ driver.BufferBinding) gl.Enum {

gpu/internal/rendertest/bench_test.go

@@ -66,8 +66,8 @@ func BenchmarkDrawUICached(b *testing.B) {
 	defer w.Release()
 	drawCore(gtx, th)
 	w.Frame(gtx.Ops)
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		w.Frame(gtx.Ops)
 	}
 	finishBenchmark(b, w)
@@ -83,12 +83,12 @@ func BenchmarkDrawUI(b *testing.B) {
 	drawCore(gtx, th)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		resetOps(gtx)
 
 		off := float32(math.Mod(float64(i)/10, 10))
-		t := op.Affine(f32.Affine2D{}.Offset(f32.Pt(off, off))).Push(gtx.Ops)
+		t := op.Affine(f32.AffineId().Offset(f32.Pt(off, off))).Push(gtx.Ops)
 
 		drawCore(gtx, th)
 
@@ -105,12 +105,12 @@ func BenchmarkDrawUITransformed(b *testing.B) {
 	drawCore(gtx, th)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		resetOps(gtx)
 
 		angle := float32(math.Mod(float64(i)/1000, 0.05))
-		a := f32.Affine2D{}.Shear(f32.Point{}, angle, angle).Rotate(f32.Point{}, angle)
+		a := f32.AffineId().Shear(f32.Point{}, angle, angle).Rotate(f32.Point{}, angle)
 		t := op.Affine(a).Push(gtx.Ops)
 
 		drawCore(gtx, th)
@@ -130,8 +130,8 @@ func Benchmark1000Circles(b *testing.B) {
 	draw1000Circles(gtx)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		resetOps(gtx)
 		draw1000Circles(gtx)
 		w.Frame(gtx.Ops)
@@ -147,8 +147,8 @@ func Benchmark1000CirclesInstanced(b *testing.B) {
 	draw1000CirclesInstanced(gtx)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		resetOps(gtx)
 		draw1000CirclesInstanced(gtx)
 		w.Frame(gtx.Ops)
@@ -158,9 +158,9 @@ func Benchmark1000CirclesInstanced(b *testing.B) {
 
 func draw1000Circles(gtx layout.Context) {
 	ops := gtx.Ops
-	for x := 0; x < 100; x++ {
+	for x := range 100 {
 		op.Offset(image.Pt(x*10, 0)).Add(ops)
-		for y := 0; y < 10; y++ {
+		for y := range 10 {
 			paint.FillShape(ops,
 				color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
 				clip.RRect{Rect: image.Rect(0, 0, 10, 10), NE: 5, SE: 5, SW: 5, NW: 5}.Op(ops),
@@ -179,9 +179,9 @@ func draw1000CirclesInstanced(gtx layout.Context) {
 	cl.Pop()
 	c := r.Stop()
 
-	for x := 0; x < 100; x++ {
+	for x := range 100 {
 		op.Offset(image.Pt(x*10, 0)).Add(ops)
-		for y := 0; y < 10; y++ {
+		for y := range 10 {
 			paint.ColorOp{Color: color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120}}.Add(ops)
 			c.Add(ops)
 			op.Offset(image.Pt(0, 100)).Add(ops)
@@ -204,9 +204,9 @@ func drawIndividualShapes(gtx layout.Context, th *material.Theme) chan op.CallOp
 	go func() {
 		ops := &op1
 		c := op.Record(ops)
-		for x := 0; x < 9; x++ {
+		for x := range 9 {
 			op.Offset(image.Pt(x*50, 0)).Add(ops)
-			for y := 0; y < 9; y++ {
+			for y := range 9 {
 				paint.FillShape(ops,
 					color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
 					clip.RRect{Rect: image.Rect(0, 0, 25, 25), NE: 10, SE: 10, SW: 10, NW: 10}.Op(ops),
@@ -233,8 +233,8 @@ func drawShapeInstances(gtx layout.Context, th *material.Theme) chan op.CallOp {
 
 		squares.Add(ops)
 		rad := float32(0)
-		for x := 0; x < 20; x++ {
+		for x := range 20 {
-			for y := 0; y < 20; y++ {
+			for y := range 20 {
 				t := op.Offset(image.Pt(x*50+25, y*50+25)).Push(ops)
 				c.Add(ops)
 				t.Pop()
@@ -253,7 +253,7 @@ func drawText(gtx layout.Context, th *material.Theme) chan op.CallOp {
 		c := op.Record(ops)
 
 		txt := material.H6(th, "")
-		for x := 0; x < 40; x++ {
+		for x := range 40 {
 			txt.Text = textRows[x]
 			t := op.Offset(image.Pt(0, 24*x)).Push(ops)
 			gtx.Ops = ops

gpu/internal/rendertest/clip_test.go

@@ -40,6 +40,25 @@ func TestPaintClippedRect(t *testing.T) {
 	})
 }
 
+func TestPaintClippedRectOffset(t *testing.T) {
+	run(t, func(o *op.Ops) {
+		defer op.Affine(f32.AffineId().Offset(f32.Pt(0.5, 0.5))).Push(o).Pop()
+		defer clip.RRect{Rect: image.Rect(25, 25, 60, 60)}.Push(o).Pop()
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
+	}, func(r result) {
+		r.expect(0, 0, transparent)
+		r.expect(24, 35, transparent)
+		r.expect(24, 24, transparent)
+		r.expect(25, 25, color.RGBA{R: 137, A: 64})
+		r.expect(25, 35, color.RGBA{R: 187, A: 128})
+		r.expect(35, 25, color.RGBA{R: 187, A: 128})
+		r.expect(50, 50, color.RGBA{R: 137, A: 64})
+		r.expect(51, 51, transparent)
+		r.expect(50, 0, transparent)
+		r.expect(10, 50, transparent)
+	})
+}
+
 func TestPaintClippedCircle(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		const r = 10
@@ -132,8 +151,7 @@ func TestTexturedStrokeClipped(t *testing.T) {
 		defer clip.RRect{Rect: image.Rect(-30, -30, 60, 60)}.Push(o).Pop()
 		defer op.Offset(image.Pt(-10, -10)).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func TestTexturedStroke(t *testing.T) {
@@ -146,8 +164,7 @@ func TestTexturedStroke(t *testing.T) {
 		}.Op().Push(o).Pop()
 		defer op.Offset(image.Pt(-10, -10)).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func TestPaintClippedTexture(t *testing.T) {
@@ -178,7 +195,6 @@ func TestStrokedPathZeroWidth(t *testing.T) {
 			paint.Fill(o, red)
 			cl.Pop()
 		}
-
 	}, func(r result) {
 		r.expect(0, 0, transparent)
 		r.expect(10, 50, colornames.Black)
@@ -252,8 +268,7 @@ func TestPathReuse(t *testing.T) {
 		stroke := clip.Stroke{Path: spec, Width: 3}.Op().Push(o)
 		paint.Fill(o, color.NRGBA{B: 0xFF, A: 0xFF})
 		stroke.Pop()
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func TestPathInterleave(t *testing.T) {
@@ -290,6 +305,22 @@ func TestStrokedRect(t *testing.T) {
 				Width: 5,
 			}.Op(),
 		)
-	}, func(r result) {
+	}, nil)
-	})
+}
+
+func TestInstancedRects(t *testing.T) {
+	run(t, func(o *op.Ops) {
+		macro := op.Record(o)
+		clip := clip.Rect{Max: image.Pt(20, 20)}.Push(o)
+		paint.ColorOp{Color: color.NRGBA{R: 0x80, A: 0xFF}}.Add(o)
+		paint.PaintOp{}.Add(o)
+		clip.Pop()
+		c := macro.Stop()
+
+		for range 2 {
+			op.Affine(f32.AffineId().Rotate(f32.Pt(0, 0), .2)).Add(o)
+			c.Add(o)
+			op.Offset(image.Pt(20, 20)).Add(o)
+		}
+	}, nil)
 }

gpu/internal/rendertest/render_test.go

@@ -24,7 +24,6 @@ func TestTransformMacro(t *testing.T) {
 	c := constSqPath()
 
 	run(t, func(o *op.Ops) {
-
 		// render the first Stacked item
 		m1 := op.Record(o)
 		dr := image.Rect(0, 0, 128, 50)
@@ -88,10 +87,10 @@ func TestNoClipFromPaint(t *testing.T) {
 	// ensure that a paint operation does not pollute the state
 	// by leaving any clip paths in place.
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Rotate(f32.Pt(20, 20), math.Pi/4)
+		a := f32.AffineId().Rotate(f32.Pt(20, 20), math.Pi/4)
 		defer op.Affine(a).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(10, 10, 30, 30)).Op())
-		a = f32.Affine2D{}.Rotate(f32.Pt(20, 20), -math.Pi/4)
+		a = f32.AffineId().Rotate(f32.Pt(20, 20), -math.Pi/4)
 		defer op.Affine(a).Push(o).Pop()
 
 		paint.FillShape(o, black, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
@@ -110,7 +109,7 @@ func TestDeferredPaint(t *testing.T) {
 		paint.PaintOp{}.Add(o)
 		cl.Pop()
 
-		t := op.Affine(f32.Affine2D{}.Offset(f32.Pt(20, 20))).Push(o)
+		t := op.Affine(f32.AffineId().Offset(f32.Pt(20, 20))).Push(o)
 		m := op.Record(o)
 		cl2 := clip.Rect(image.Rect(0, 0, 80, 80)).Op().Push(o)
 		paint.ColorOp{Color: color.NRGBA{A: 0x60, R: 0xff, G: 0xff}}.Add(o)
@@ -120,12 +119,11 @@ func TestDeferredPaint(t *testing.T) {
 		op.Defer(o, paintMacro)
 		t.Pop()
 
-		defer op.Affine(f32.Affine2D{}.Offset(f32.Pt(10, 10))).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Offset(f32.Pt(10, 10))).Push(o).Pop()
 		defer clip.Rect(image.Rect(0, 0, 80, 80)).Op().Push(o).Pop()
 		paint.ColorOp{Color: color.NRGBA{A: 0x60, B: 0xff}}.Add(o)
 		paint.PaintOp{}.Add(o)
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func constSqPath() clip.Op {
@@ -143,8 +141,10 @@ func constSqPath() clip.Op {
 
 func constSqCirc() clip.Op {
 	innerOps := new(op.Ops)
-	return clip.RRect{Rect: image.Rect(0, 0, 40, 40),
+	return clip.RRect{
-		NW: 20, NE: 20, SW: 20, SE: 20}.Op(innerOps)
+		Rect: image.Rect(0, 0, 40, 40),
+		NW:   20, NE: 20, SW: 20, SE: 20,
+	}.Op(innerOps)
 }
 
 func drawChild(ops *op.Ops, text clip.Op) op.CallOp {
@@ -260,7 +260,7 @@ func TestLinearGradient(t *testing.T) {
 				Color2: g.To,
 			}.Add(ops)
 			cl := clip.RRect{Rect: gr.Round()}.Push(ops)
-			t1 := op.Affine(f32.Affine2D{}.Offset(pixelAligned.Min)).Push(ops)
+			t1 := op.Affine(f32.AffineId().Offset(pixelAligned.Min)).Push(ops)
 			t2 := scale(pixelAligned.Dx()/128, 1).Push(ops)
 			paint.PaintOp{}.Add(ops)
 			t2.Pop()
@@ -323,7 +323,7 @@ func TestLinearGradientAngled(t *testing.T) {
 		cl = clip.Rect(image.Rect(0, 64, 64, 128)).Push(ops)
 		paint.PaintOp{}.Add(ops)
 		cl.Pop()
-	}, func(r result) {})
+	}, nil)
 }
 
 func TestZeroImage(t *testing.T) {
@@ -363,7 +363,7 @@ func TestImageRGBA_ScaleLinear(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		w := newWindow(t, 128, 128)
 		defer clip.Rect{Max: image.Pt(128, 128)}.Push(o).Pop()
-		op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
+		op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
 
 		im := image.NewRGBA(image.Rect(0, 0, 2, 2))
 		im.Set(0, 0, colornames.Red)
@@ -397,7 +397,7 @@ func TestImageRGBA_ScaleLinear(t *testing.T) {
 func TestImageRGBA_ScaleNearest(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		w := newWindow(t, 128, 128)
-		op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
+		op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
 
 		im := image.NewRGBA(image.Rect(0, 0, 2, 2))
 		im.Set(0, 0, colornames.Red)
@@ -483,17 +483,16 @@ func TestGapsInPath(t *testing.T) {
 func TestOpacity(t *testing.T) {
 	run(t, func(ops *op.Ops) {
 		opc1 := paint.PushOpacity(ops, .3)
-		// Fill screen to exercize the glClear optimization.
+		// Fill screen to exercise the glClear optimization.
 		paint.FillShape(ops, color.NRGBA{R: 255, A: 255}, clip.Rect{Max: image.Pt(1024, 1024)}.Op())
 		opc2 := paint.PushOpacity(ops, .6)
 		paint.FillShape(ops, color.NRGBA{G: 255, A: 255}, clip.Rect{Min: image.Pt(20, 10), Max: image.Pt(64, 128)}.Op())
 		opc2.Pop()
 		opc1.Pop()
 		opc3 := paint.PushOpacity(ops, .6)
-		paint.FillShape(ops, color.NRGBA{G: 255, A: 255}, clip.Rect{Min: image.Pt(50+20, 10), Max: image.Pt(50+64, 128)}.Op())
+		paint.FillShape(ops, color.NRGBA{B: 255, A: 255}, clip.Ellipse(image.Rectangle{Min: image.Pt(20+20, 10), Max: image.Pt(50+64, 128)}).Op(ops))
 		opc3.Pop()
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 // lerp calculates linear interpolation with color b and p.

gpu/internal/rendertest/transform_test.go

@@ -29,7 +29,7 @@ func TestPaintOffset(t *testing.T) {
 
 func TestPaintRotate(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Rotate(f32.Pt(40, 40), -math.Pi/8)
+		a := f32.AffineId().Rotate(f32.Pt(40, 40), -math.Pi/8)
 		defer op.Affine(a).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(20, 20, 60, 60)).Op())
 	}, func(r result) {
@@ -42,7 +42,7 @@ func TestPaintRotate(t *testing.T) {
 
 func TestPaintShear(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Shear(f32.Point{}, math.Pi/4, 0)
+		a := f32.AffineId().Shear(f32.Point{}, math.Pi/4, 0)
 		defer op.Affine(a).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 40, 40)).Op())
 	}, func(r result) {
@@ -79,7 +79,7 @@ func TestClipOffset(t *testing.T) {
 
 func TestClipScale(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(2, 2)).Offset(f32.Pt(10, 10))
+		a := f32.AffineId().Scale(f32.Point{}, f32.Pt(2, 2)).Offset(f32.Pt(10, 10))
 		defer op.Affine(a).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(10, 10, 20, 20)}.Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 1000, 1000)).Op())
@@ -93,7 +93,7 @@ func TestClipScale(t *testing.T) {
 
 func TestClipRotate(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		defer op.Affine(f32.Affine2D{}.Rotate(f32.Pt(40, 40), -math.Pi/4)).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Rotate(f32.Pt(40, 40), -math.Pi/4)).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(30, 30, 50, 50)}.Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 40, 100, 100)).Op())
 	}, func(r result) {
@@ -121,7 +121,7 @@ func TestOffsetScaleTexture(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		defer op.Offset(image.Pt(15, 15)).Push(o).Pop()
 		squares.Add(o)
-		defer op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(2, 1))).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(2, 1))).Push(o).Pop()
 		defer scale(50.0/512, 50.0/512).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
 	}, func(r result) {
@@ -133,7 +133,7 @@ func TestOffsetScaleTexture(t *testing.T) {
 func TestRotateTexture(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		squares.Add(o)
-		a := f32.Affine2D{}.Offset(f32.Pt(30, 30)).Rotate(f32.Pt(40, 40), math.Pi/4)
+		a := f32.AffineId().Offset(f32.Pt(30, 30)).Rotate(f32.Pt(40, 40), math.Pi/4)
 		defer op.Affine(a).Push(o).Pop()
 		defer scale(20.0/512, 20.0/512).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
@@ -146,10 +146,10 @@ func TestRotateTexture(t *testing.T) {
 func TestRotateClipTexture(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		squares.Add(o)
-		a := f32.Affine2D{}.Rotate(f32.Pt(40, 40), math.Pi/8)
+		a := f32.AffineId().Rotate(f32.Pt(40, 40), math.Pi/8)
 		defer op.Affine(a).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(30, 30, 50, 50)}.Push(o).Pop()
-		defer op.Affine(f32.Affine2D{}.Offset(f32.Pt(10, 10))).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Offset(f32.Pt(10, 10))).Push(o).Pop()
 		defer scale(60.0/512, 60.0/512).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
 	}, func(r result) {
@@ -168,7 +168,7 @@ func TestComplicatedTransform(t *testing.T) {
 
 		defer clip.RRect{Rect: image.Rect(0, 0, 100, 100), SE: 50, SW: 50, NW: 50, NE: 50}.Push(o).Pop()
 
-		a := f32.Affine2D{}.Shear(f32.Point{}, math.Pi/4, 0)
+		a := f32.AffineId().Shear(f32.Point{}, math.Pi/4, 0)
 		defer op.Affine(a).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(0, 0, 50, 40)}.Push(o).Pop()
 
@@ -182,13 +182,13 @@ func TestComplicatedTransform(t *testing.T) {
 func TestTransformOrder(t *testing.T) {
 	// check the ordering of operations bot in affine and in gpu stack.
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Offset(f32.Pt(64, 64))
+		a := f32.AffineId().Offset(f32.Pt(64, 64))
 		defer op.Affine(a).Push(o).Pop()
 
-		b := f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(8, 8))
+		b := f32.AffineId().Scale(f32.Point{}, f32.Pt(8, 8))
 		defer op.Affine(b).Push(o).Pop()
 
-		c := f32.Affine2D{}.Offset(f32.Pt(-10, -10)).Scale(f32.Point{}, f32.Pt(0.5, 0.5))
+		c := f32.AffineId().Offset(f32.Pt(-10, -10)).Scale(f32.Point{}, f32.Pt(0.5, 0.5))
 		defer op.Affine(c).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 20, 20)).Op())
 	}, func(r result) {

gpu/internal/rendertest/util_test.go

@@ -49,8 +49,8 @@ func buildSquares(size int) paint.ImageOp {
 	sub := size / 4
 	im := image.NewNRGBA(image.Rect(0, 0, size, size))
 	c1, c2 := image.NewUniform(colornames.Green), image.NewUniform(colornames.Blue)
-	for r := 0; r < 4; r++ {
+	for r := range 4 {
-		for c := 0; c < 4; c++ {
+		for c := range 4 {
 			c1, c2 = c2, c1
 			draw.Draw(im, image.Rect(r*sub, c*sub, r*sub+sub, c*sub+sub), c1, image.Point{}, draw.Over)
 		}
@@ -78,7 +78,7 @@ func run(t *testing.T, f func(o *op.Ops), c func(r result)) {
 	var img *image.RGBA
 	var err error
 	ops := new(op.Ops)
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		ops.Reset()
 		img, err = drawImage(t, 128, ops, f)
 		if err != nil {
@@ -90,7 +90,9 @@ func run(t *testing.T, f func(o *op.Ops), c func(r result)) {
 			name := fmt.Sprintf("%s-%d-bad.png", t.Name(), i)
 			saveImage(t, name, img)
 		}
-		c(result{t: t, img: img})
+		if c != nil {
+			c(result{t: t, img: img})
+		}
 	}
 }
 
@@ -151,7 +153,7 @@ func verifyRef(t *testing.T, img *image.RGBA, frame int) (ok bool) {
 	}
 	path = filepath.Join("refs", path+".png")
 	if *dumpImages {
-		if err := os.MkdirAll(filepath.Dir(path), 0766); err != nil {
+		if err := os.MkdirAll(filepath.Dir(path), 0o766); err != nil {
 			if !os.IsExist(err) {
 				t.Error(err)
 				return
@@ -285,7 +287,7 @@ func saveImage(t testing.TB, file string, img *image.RGBA) {
 		t.Error(err)
 		return
 	}
-	if err := os.WriteFile(file, buf.Bytes(), 0666); err != nil {
+	if err := os.WriteFile(file, buf.Bytes(), 0o666); err != nil {
 		t.Error(err)
 		return
 	}
@@ -300,5 +302,5 @@ func newWindow(t testing.TB, width, height int) *headless.Window {
 }
 
 func scale(sx, sy float32) op.TransformOp {
-	return op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(sx, sy)))
+	return op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(sx, sy)))
 }

gpu/internal/vulkan/vulkan.go

@@ -862,8 +862,8 @@ func (b *Backend) BindUniforms(buffer driver.Buffer) {
 	buf := buffer.(*Buffer)
 	cmdBuf := b.currentCmdBuf()
 	for _, s := range b.pipe.pushRanges {
-		off := s.Offset()
+		off := vk.PushConstantRangeOffset(s)
-		vk.CmdPushConstants(cmdBuf, b.pipe.desc.layout, s.StageFlags(), off, buf.store[off:off+s.Size()])
+		vk.CmdPushConstants(cmdBuf, b.pipe.desc.layout, vk.PushConstantRangeStageFlags(s), off, buf.store[off:off+vk.PushConstantRangeSize(s)])
 	}
 }
 

gpu/pack_test.go

@@ -10,10 +10,10 @@ import (
 func BenchmarkPacker(b *testing.B) {
 	var p packer
 	p.maxDims = image.Point{X: 4096, Y: 4096}
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		p.clear()
 		p.newPage()
-		for k := 0; k < 500; k++ {
+		for k := range 500 {
 			_, ok := p.tryAdd(xy(k))
 			if !ok {
 				b.Fatal("add failed", i, k, xy(k))

gpu/path.go

@@ -30,7 +30,7 @@ type pather struct {
 
 type coverer struct {
 	ctx                    driver.Device
-	pipelines              [3]*pipeline
+	pipelines              [2][3]*pipeline
 	texUniforms            *coverTexUniforms
 	colUniforms            *coverColUniforms
 	linearGradientUniforms *coverLinearGradientUniforms
@@ -150,7 +150,7 @@ func newCoverer(ctx driver.Device) *coverer {
 	c.texUniforms = new(coverTexUniforms)
 	c.linearGradientUniforms = new(coverLinearGradientUniforms)
 	pipelines, err := createColorPrograms(ctx, gio.Shader_cover_vert, gio.Shader_cover_frag,
-		[3]interface{}{c.colUniforms, c.linearGradientUniforms, c.texUniforms},
+		[3]any{c.colUniforms, c.linearGradientUniforms, c.texUniforms},
 	)
 	if err != nil {
 		panic(err)
@@ -162,7 +162,7 @@ func newCoverer(ctx driver.Device) *coverer {
 func newStenciler(ctx driver.Device) *stenciler {
 	// Allocate a suitably large index buffer for drawing paths.
 	indices := make([]uint16, pathBatchSize*6)
-	for i := 0; i < pathBatchSize; i++ {
+	for i := range pathBatchSize {
 		i := uint16(i)
 		indices[i*6+0] = i*4 + 0
 		indices[i*6+1] = i*4 + 1
@@ -309,7 +309,9 @@ func (p *pather) release() {
 
 func (c *coverer) release() {
 	for _, p := range c.pipelines {
-		p.Release()
+		for _, p := range p {
+			p.Release()
+		}
 	}
 }
 
@@ -332,7 +334,7 @@ func (p *pather) begin(sizes []image.Point) {
 	p.stenciler.begin(sizes)
 }
 
-func (p *pather) stencilPath(bounds image.Rectangle, offset f32.Point, uv image.Point, data pathData) {
+func (p *pather) stencilPath(bounds image.Rectangle, offset image.Point, uv image.Point, data pathData) {
 	p.stenciler.stencilPath(bounds, offset, uv, data)
 }
 
@@ -351,14 +353,14 @@ func (s *stenciler) begin(sizes []image.Point) {
 	s.fbos.resize(s.ctx, driver.TextureFormatFloat, sizes)
 }
 
-func (s *stenciler) stencilPath(bounds image.Rectangle, offset f32.Point, uv image.Point, data pathData) {
+func (s *stenciler) stencilPath(bounds image.Rectangle, offset image.Point, uv image.Point, data pathData) {
 	s.ctx.Viewport(uv.X, uv.Y, bounds.Dx(), bounds.Dy())
 	// Transform UI coordinates to OpenGL coordinates.
 	texSize := f32.Point{X: float32(bounds.Dx()), Y: float32(bounds.Dy())}
 	scale := f32.Point{X: 2 / texSize.X, Y: 2 / texSize.Y}
 	orig := f32.Point{X: -1 - float32(bounds.Min.X)*2/texSize.X, Y: -1 - float32(bounds.Min.Y)*2/texSize.Y}
 	s.pipeline.uniforms.transform = [4]float32{scale.X, scale.Y, orig.X, orig.Y}
-	s.pipeline.uniforms.pathOffset = [2]float32{offset.X, offset.Y}
+	s.pipeline.uniforms.pathOffset = [2]float32{float32(offset.X), float32(offset.Y)}
 	s.pipeline.pipeline.UploadUniforms(s.ctx)
 	// Draw in batches that fit in uint16 indices.
 	start := 0
@@ -405,7 +407,11 @@ func (c *coverer) cover(mat materialType, isFBO bool, col f32color.RGBA, col1, c
 	}
 	uniforms.transform = [4]float32{scale.X, scale.Y, off.X, off.Y}
 	uniforms.uvCoverTransform = [4]float32{coverScale.X, coverScale.Y, coverOff.X, coverOff.Y}
-	c.pipelines[mat].UploadUniforms(c.ctx)
+	fboIdx := 0
+	if isFBO {
+		fboIdx = 1
+	}
+	c.pipelines[fboIdx][mat].UploadUniforms(c.ctx)
 	c.ctx.DrawArrays(0, 4)
 }
 

internal/byteslice/byteslice.go

@@ -10,7 +10,7 @@ import (
 )
 
 // Struct returns a byte slice view of a struct.
-func Struct(s interface{}) []byte {
+func Struct(s any) []byte {
 	v := reflect.ValueOf(s)
 	sz := int(v.Elem().Type().Size())
 	return unsafe.Slice((*byte)(unsafe.Pointer(v.Pointer())), sz)
@@ -27,7 +27,7 @@ func Uint32(s []uint32) []byte {
 }
 
 // Slice returns a byte slice view of a slice.
-func Slice(s interface{}) []byte {
+func Slice(s any) []byte {
 	v := reflect.ValueOf(s)
 	first := v.Index(0)
 	sz := int(first.Type().Size())

internal/egl/egl.go

@@ -9,16 +9,16 @@ import (
 	"errors"
 	"fmt"
 	"runtime"
+	"slices"
 	"strings"
 
 	"gioui.org/gpu"
 )
 
 type Context struct {
-	disp          _EGLDisplay
+	disp    _EGLDisplay
-	eglCtx        *eglContext
+	eglCtx  *eglContext
-	eglSurf       _EGLSurface
+	eglSurf _EGLSurface
-	width, height int
 }
 
 type eglContext struct {
@@ -121,11 +121,9 @@ func (c *Context) VisualID() int {
 	return c.eglCtx.visualID
 }
 
-func (c *Context) CreateSurface(win NativeWindowType, width, height int) error {
+func (c *Context) CreateSurface(win NativeWindowType) error {
 	eglSurf, err := createSurface(c.disp, c.eglCtx, win)
 	c.eglSurf = eglSurf
-	c.width = width
-	c.height = height
 	return err
 }
 
@@ -157,12 +155,7 @@ func (c *Context) EnableVSync(enable bool) {
 }
 
 func hasExtension(exts []string, ext string) bool {
-	for _, e := range exts {
+	return slices.Contains(exts, ext)
-		if ext == e {
-			return true
-		}
-	}
-	return false
 }
 
 func createContext(disp _EGLDisplay) (*eglContext, error) {

internal/egl/egl_windows.go

@@ -9,8 +9,6 @@ import (
 	"unsafe"
 
 	syscall "golang.org/x/sys/windows"
-
-	"gioui.org/internal/gl"
 )
 
 type (
@@ -24,23 +22,23 @@ type (
 )
 
 var (
-	libEGL                  = syscall.NewLazyDLL("libEGL.dll")
+	libEGL                  = syscall.DLL{}
-	_eglChooseConfig        = libEGL.NewProc("eglChooseConfig")
+	_eglChooseConfig        *syscall.Proc
-	_eglCreateContext       = libEGL.NewProc("eglCreateContext")
+	_eglCreateContext       *syscall.Proc
-	_eglCreateWindowSurface = libEGL.NewProc("eglCreateWindowSurface")
+	_eglCreateWindowSurface *syscall.Proc
-	_eglDestroyContext      = libEGL.NewProc("eglDestroyContext")
+	_eglDestroyContext      *syscall.Proc
-	_eglDestroySurface      = libEGL.NewProc("eglDestroySurface")
+	_eglDestroySurface      *syscall.Proc
-	_eglGetConfigAttrib     = libEGL.NewProc("eglGetConfigAttrib")
+	_eglGetConfigAttrib     *syscall.Proc
-	_eglGetDisplay          = libEGL.NewProc("eglGetDisplay")
+	_eglGetDisplay          *syscall.Proc
-	_eglGetError            = libEGL.NewProc("eglGetError")
+	_eglGetError            *syscall.Proc
-	_eglInitialize          = libEGL.NewProc("eglInitialize")
+	_eglInitialize          *syscall.Proc
-	_eglMakeCurrent         = libEGL.NewProc("eglMakeCurrent")
+	_eglMakeCurrent         *syscall.Proc
-	_eglReleaseThread       = libEGL.NewProc("eglReleaseThread")
+	_eglReleaseThread       *syscall.Proc
-	_eglSwapInterval        = libEGL.NewProc("eglSwapInterval")
+	_eglSwapInterval        *syscall.Proc
-	_eglSwapBuffers         = libEGL.NewProc("eglSwapBuffers")
+	_eglSwapBuffers         *syscall.Proc
-	_eglTerminate           = libEGL.NewProc("eglTerminate")
+	_eglTerminate           *syscall.Proc
-	_eglQueryString         = libEGL.NewProc("eglQueryString")
+	_eglQueryString         *syscall.Proc
-	_eglWaitClient          = libEGL.NewProc("eglWaitClient")
+	_eglWaitClient          *syscall.Proc
 )
 
 var loadOnce sync.Once
@@ -54,21 +52,45 @@ func loadEGL() error {
 }
 
 func loadDLLs() error {
-	if err := loadDLL(libEGL, "libEGL.dll"); err != nil {
+	if err := loadDLL(&libEGL, "libEGL.dll"); err != nil {
 		return err
 	}
-	if err := loadDLL(gl.LibGLESv2, "libGLESv2.dll"); err != nil {
+
-		return err
+	procs := map[string]**syscall.Proc{
+		"eglChooseConfig":        &_eglChooseConfig,
+		"eglCreateContext":       &_eglCreateContext,
+		"eglCreateWindowSurface": &_eglCreateWindowSurface,
+		"eglDestroyContext":      &_eglDestroyContext,
+		"eglDestroySurface":      &_eglDestroySurface,
+		"eglGetConfigAttrib":     &_eglGetConfigAttrib,
+		"eglGetDisplay":          &_eglGetDisplay,
+		"eglGetError":            &_eglGetError,
+		"eglInitialize":          &_eglInitialize,
+		"eglMakeCurrent":         &_eglMakeCurrent,
+		"eglReleaseThread":       &_eglReleaseThread,
+		"eglSwapInterval":        &_eglSwapInterval,
+		"eglSwapBuffers":         &_eglSwapBuffers,
+		"eglTerminate":           &_eglTerminate,
+		"eglQueryString":         &_eglQueryString,
+		"eglWaitClient":          &_eglWaitClient,
 	}
-	// d3dcompiler_47.dll is needed internally for shader compilation to function.
+	for name, proc := range procs {
-	return loadDLL(syscall.NewLazyDLL("d3dcompiler_47.dll"), "d3dcompiler_47.dll")
+		p, err := libEGL.FindProc(name)
+		if err != nil {
+			return fmt.Errorf("failed to locate %s in %s: %w", name, libEGL.Name, err)
+		}
+		*proc = p
+	}
+	return nil
 }
 
-func loadDLL(dll *syscall.LazyDLL, name string) error {
+func loadDLL(dll *syscall.DLL, name string) error {
-	err := dll.Load()
+	handle, err := syscall.LoadLibraryEx(name, 0, syscall.LOAD_LIBRARY_SEARCH_DEFAULT_DIRS)
 	if err != nil {
 		return fmt.Errorf("egl: failed to load %s: %v", name, err)
 	}
+	dll.Handle = handle
+	dll.Name = name
 	return nil
 }
 
@@ -164,6 +186,6 @@ func eglWaitClient() bool {
 
 // issue34474KeepAlive calls runtime.KeepAlive as a
 // workaround for golang.org/issue/34474.
-func issue34474KeepAlive(v interface{}) {
+func issue34474KeepAlive(v any) {
 	runtime.KeepAlive(v)
 }

internal/f32/f32.go

@@ -19,6 +19,8 @@ type Affine2D = f32.Affine2D
 
 var NewAffine2D = f32.NewAffine2D
 
+var AffineId = f32.AffineId
+
 // A Rectangle contains the points (X, Y) where Min.X <= X < Max.X,
 // Min.Y <= Y < Max.Y.
 type Rectangle struct {

internal/f32color/f32colorgen/main.go

@@ -16,7 +16,7 @@ func main() {
 	flag.Parse()
 
 	var b bytes.Buffer
-	printf := func(content string, args ...interface{}) {
+	printf := func(content string, args ...any) {
 		fmt.Fprintf(&b, content, args...)
 	}
 
@@ -42,7 +42,7 @@ func main() {
 		panic(err)
 	}
 
-	err = os.WriteFile(*out, data, 0755)
+	err = os.WriteFile(*out, data, 0o755)
 	if err != nil {
 		panic(err)
 	}

internal/f32color/rgba_test.go

@@ -41,17 +41,17 @@ var sink RGBA
 
 func BenchmarkLinearFromSRGB(b *testing.B) {
 	b.Run("opaque", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
+		for i := 0; b.Loop(); i++ {
 			sink = LinearFromSRGB(color.NRGBA{R: byte(i), G: byte(i >> 8), B: byte(i >> 16), A: 0xFF})
 		}
 	})
 	b.Run("translucent", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
+		for i := 0; b.Loop(); i++ {
 			sink = LinearFromSRGB(color.NRGBA{R: byte(i), G: byte(i >> 8), B: byte(i >> 16), A: 0x50})
 		}
 	})
 	b.Run("transparent", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
+		for i := 0; b.Loop(); i++ {
 			sink = LinearFromSRGB(color.NRGBA{R: byte(i), G: byte(i >> 8), B: byte(i >> 16), A: 0x00})
 		}
 	})

internal/fling/extrapolation.go

@@ -90,7 +90,7 @@ func (e *Extrapolation) Estimate() Estimate {
 	first := e.get(0)
 	t := first.t
 	// Walk backwards collecting samples.
-	for i := 0; i < len(e.samples); i++ {
+	for i := range e.samples {
 		p := e.get(-i)
 		age := first.t - p.t
 		if age >= maxAge || t-p.t >= maxSampleGap {
@@ -172,9 +172,9 @@ func decomposeQR(A *matrix) (*matrix, *matrix, bool) {
 	// https://en.wikipedia.org/wiki/Gram%E2%80%93Schmidt_process
 	Q := newMatrix(A.rows, A.cols)  // Column-major.
 	Rt := newMatrix(A.rows, A.rows) // R transposed, row-major.
-	for i := 0; i < Q.rows; i++ {
+	for i := range Q.rows {
 		// Copy A column.
-		for j := 0; j < Q.cols; j++ {
+		for j := range Q.cols {
 			Q.set(i, j, A.get(i, j))
 		}
 		// Subtract projections. Note that int the projection
@@ -184,9 +184,9 @@ func decomposeQR(A *matrix) (*matrix, *matrix, bool) {
 		// the normalized column e replaces u, where <e, e> = 1:
 		//
 		// proje a = <e, a>/<e, e> e = <e, a> e
-		for j := 0; j < i; j++ {
+		for j := range i {
 			d := dot(Q.col(j), Q.col(i))
-			for k := 0; k < Q.cols; k++ {
+			for k := range Q.cols {
 				Q.set(i, k, Q.get(i, k)-d*Q.get(j, k))
 			}
 		}
@@ -197,7 +197,7 @@ func decomposeQR(A *matrix) (*matrix, *matrix, bool) {
 			return nil, nil, false
 		}
 		invNorm := 1 / n
-		for j := 0; j < Q.cols; j++ {
+		for j := range Q.cols {
 			Q.set(i, j, Q.get(i, j)*invNorm)
 		}
 		// Update Rt.
@@ -261,8 +261,8 @@ func (m *matrix) approxEqual(m2 *matrix) bool {
 		return false
 	}
 	const epsilon = 0.00001
-	for row := 0; row < m.rows; row++ {
+	for row := range m.rows {
-		for col := 0; col < m.cols; col++ {
+		for col := range m.cols {
 			d := m2.get(row, col) - m.get(row, col)
 			if d < -epsilon || d > epsilon {
 				return false
@@ -278,8 +278,8 @@ func (m *matrix) transpose() *matrix {
 		cols: m.rows,
 		data: make([]float32, len(m.data)),
 	}
-	for i := 0; i < m.rows; i++ {
+	for i := range m.rows {
-		for j := 0; j < m.cols; j++ {
+		for j := range m.cols {
 			t.set(j, i, m.get(i, j))
 		}
 	}
@@ -295,10 +295,10 @@ func (m *matrix) mul(m2 *matrix) *matrix {
 		cols: m2.cols,
 		data: make([]float32, m.rows*m2.cols),
 	}
-	for i := 0; i < mm.rows; i++ {
+	for i := range mm.rows {
-		for j := 0; j < mm.cols; j++ {
+		for j := range mm.cols {
 			var v float32
-			for k := 0; k < m.rows; k++ {
+			for k := range m.rows {
 				v += m.get(k, j) * m2.get(i, k)
 			}
 			mm.set(i, j, v)
@@ -309,8 +309,8 @@ func (m *matrix) mul(m2 *matrix) *matrix {
 
 func (m *matrix) String() string {
 	var b strings.Builder
-	for i := 0; i < m.rows; i++ {
+	for i := range m.rows {
-		for j := 0; j < m.cols; j++ {
+		for j := range m.cols {
 			v := m.get(i, j)
 			b.WriteString(strconv.FormatFloat(float64(v), 'g', -1, 32))
 			b.WriteString(", ")

internal/gl/gl_js.go

@@ -247,9 +247,11 @@ func (f *Functions) getExtension(name string) js.Value {
 func (f *Functions) ActiveTexture(t Enum) {
 	f._activeTexture.Invoke(int(t))
 }
+
 func (f *Functions) AttachShader(p Program, s Shader) {
 	f._attachShader.Invoke(js.Value(p), js.Value(s))
 }
+
 func (f *Functions) BeginQuery(target Enum, query Query) {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		f._beginQuery.Invoke(int(target), js.Value(query))
@@ -257,36 +259,47 @@ func (f *Functions) BeginQuery(target Enum, query Query) {
 		f.EXT_disjoint_timer_query.Call("beginQueryEXT", int(target), js.Value(query))
 	}
 }
+
 func (f *Functions) BindAttribLocation(p Program, a Attrib, name string) {
 	f._bindAttribLocation.Invoke(js.Value(p), int(a), name)
 }
+
 func (f *Functions) BindBuffer(target Enum, b Buffer) {
 	f._bindBuffer.Invoke(int(target), js.Value(b))
 }
+
 func (f *Functions) BindBufferBase(target Enum, index int, b Buffer) {
 	f._bindBufferBase.Invoke(int(target), index, js.Value(b))
 }
+
 func (f *Functions) BindFramebuffer(target Enum, fb Framebuffer) {
 	f._bindFramebuffer.Invoke(int(target), js.Value(fb))
 }
+
 func (f *Functions) BindRenderbuffer(target Enum, rb Renderbuffer) {
 	f._bindRenderbuffer.Invoke(int(target), js.Value(rb))
 }
+
 func (f *Functions) BindTexture(target Enum, t Texture) {
 	f._bindTexture.Invoke(int(target), js.Value(t))
 }
+
 func (f *Functions) BindImageTexture(unit int, t Texture, level int, layered bool, layer int, access, format Enum) {
 	panic("not implemented")
 }
+
 func (f *Functions) BindVertexArray(a VertexArray) {
 	panic("not supported")
 }
+
 func (f *Functions) BlendEquation(mode Enum) {
 	f._blendEquation.Invoke(int(mode))
 }
+
 func (f *Functions) BlendFuncSeparate(srcRGB, dstRGB, srcA, dstA Enum) {
 	f._blendFunc.Invoke(int(srcRGB), int(dstRGB), int(srcA), int(dstA))
 }
+
 func (f *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 	if data == nil {
 		f._bufferData.Invoke(int(target), size, int(usage))
@@ -297,9 +310,11 @@ func (f *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 		f._bufferData.Invoke(int(target), f.byteArrayOf(data), int(usage))
 	}
 }
+
 func (f *Functions) BufferSubData(target Enum, offset int, src []byte) {
 	f._bufferSubData.Invoke(int(target), offset, f.byteArrayOf(src))
 }
+
 func (f *Functions) CheckFramebufferStatus(target Enum) Enum {
 	status := Enum(f._checkFramebufferStatus.Invoke(int(target)).Int())
 	if status != FRAMEBUFFER_COMPLETE && f.Ctx.Call("isContextLost").Bool() {
@@ -308,54 +323,71 @@ func (f *Functions) CheckFramebufferStatus(target Enum) Enum {
 	}
 	return status
 }
+
 func (f *Functions) Clear(mask Enum) {
 	f._clear.Invoke(int(mask))
 }
+
 func (f *Functions) ClearColor(red, green, blue, alpha float32) {
 	f._clearColor.Invoke(red, green, blue, alpha)
 }
+
 func (f *Functions) ClearDepthf(d float32) {
 	f._clearDepth.Invoke(d)
 }
+
 func (f *Functions) CompileShader(s Shader) {
 	f._compileShader.Invoke(js.Value(s))
 }
+
 func (f *Functions) CopyTexSubImage2D(target Enum, level, xoffset, yoffset, x, y, width, height int) {
 	f._copyTexSubImage2D.Invoke(int(target), level, xoffset, yoffset, x, y, width, height)
 }
+
 func (f *Functions) CreateBuffer() Buffer {
 	return Buffer(f._createBuffer.Invoke())
 }
+
 func (f *Functions) CreateFramebuffer() Framebuffer {
 	return Framebuffer(f._createFramebuffer.Invoke())
 }
+
 func (f *Functions) CreateProgram() Program {
 	return Program(f._createProgram.Invoke())
 }
+
 func (f *Functions) CreateQuery() Query {
 	return Query(f._createQuery.Invoke())
 }
+
 func (f *Functions) CreateRenderbuffer() Renderbuffer {
 	return Renderbuffer(f._createRenderbuffer.Invoke())
 }
+
 func (f *Functions) CreateShader(ty Enum) Shader {
 	return Shader(f._createShader.Invoke(int(ty)))
 }
+
 func (f *Functions) CreateTexture() Texture {
 	return Texture(f._createTexture.Invoke())
 }
+
 func (f *Functions) CreateVertexArray() VertexArray {
 	panic("not supported")
 }
+
 func (f *Functions) DeleteBuffer(v Buffer) {
 	f._deleteBuffer.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteFramebuffer(v Framebuffer) {
 	f._deleteFramebuffer.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteProgram(p Program) {
 	f._deleteProgram.Invoke(js.Value(p))
 }
+
 func (f *Functions) DeleteQuery(query Query) {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		f._deleteQuery.Invoke(js.Value(query))
@@ -363,45 +395,59 @@ func (f *Functions) DeleteQuery(query Query) {
 		f.EXT_disjoint_timer_query.Call("deleteQueryEXT", js.Value(query))
 	}
 }
+
 func (f *Functions) DeleteShader(s Shader) {
 	f._deleteShader.Invoke(js.Value(s))
 }
+
 func (f *Functions) DeleteRenderbuffer(v Renderbuffer) {
 	f._deleteRenderbuffer.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteTexture(v Texture) {
 	f._deleteTexture.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteVertexArray(a VertexArray) {
 	panic("not implemented")
 }
+
 func (f *Functions) DepthFunc(fn Enum) {
 	f._depthFunc.Invoke(int(fn))
 }
+
 func (f *Functions) DepthMask(mask bool) {
 	f._depthMask.Invoke(mask)
 }
+
 func (f *Functions) DisableVertexAttribArray(a Attrib) {
 	f._disableVertexAttribArray.Invoke(int(a))
 }
+
 func (f *Functions) Disable(cap Enum) {
 	f._disable.Invoke(int(cap))
 }
+
 func (f *Functions) DrawArrays(mode Enum, first, count int) {
 	f._drawArrays.Invoke(int(mode), first, count)
 }
+
 func (f *Functions) DrawElements(mode Enum, count int, ty Enum, offset int) {
 	f._drawElements.Invoke(int(mode), count, int(ty), offset)
 }
+
 func (f *Functions) DispatchCompute(x, y, z int) {
 	panic("not implemented")
 }
+
 func (f *Functions) Enable(cap Enum) {
 	f._enable.Invoke(int(cap))
 }
+
 func (f *Functions) EnableVertexAttribArray(a Attrib) {
 	f._enableVertexAttribArray.Invoke(int(a))
 }
+
 func (f *Functions) EndQuery(target Enum) {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		f._endQuery.Invoke(int(target))
@@ -409,28 +455,36 @@ func (f *Functions) EndQuery(target Enum) {
 		f.EXT_disjoint_timer_query.Call("endQueryEXT", int(target))
 	}
 }
+
 func (f *Functions) Finish() {
 	f._finish.Invoke()
 }
+
 func (f *Functions) Flush() {
 	f._flush.Invoke()
 }
+
 func (f *Functions) FramebufferRenderbuffer(target, attachment, renderbuffertarget Enum, renderbuffer Renderbuffer) {
 	f._framebufferRenderbuffer.Invoke(int(target), int(attachment), int(renderbuffertarget), js.Value(renderbuffer))
 }
+
 func (f *Functions) FramebufferTexture2D(target, attachment, texTarget Enum, t Texture, level int) {
 	f._framebufferTexture2D.Invoke(int(target), int(attachment), int(texTarget), js.Value(t), level)
 }
+
 func (f *Functions) GenerateMipmap(target Enum) {
 	f._generateMipmap.Invoke(int(target))
 }
+
 func (f *Functions) GetError() Enum {
 	// Avoid slow getError calls. See gio#179.
 	return 0
 }
+
 func (f *Functions) GetRenderbufferParameteri(target, pname Enum) int {
 	return paramVal(f._getRenderbufferParameteri.Invoke(int(pname)))
 }
+
 func (f *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname Enum) int {
 	if !f.isWebGL2 && pname == FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING {
 		// FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING is only available on WebGL 2
@@ -438,6 +492,7 @@ func (f *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname
 	}
 	return paramVal(f._getFramebufferAttachmentParameter.Invoke(int(target), int(attachment), int(pname)))
 }
+
 func (f *Functions) GetBinding(pname Enum) Object {
 	obj := f._getParameter.Invoke(int(pname))
 	if !obj.Truthy() {
@@ -445,6 +500,7 @@ func (f *Functions) GetBinding(pname Enum) Object {
 	}
 	return Object(obj)
 }
+
 func (f *Functions) GetBindingi(pname Enum, idx int) Object {
 	obj := f._getIndexedParameter.Invoke(int(pname), idx)
 	if !obj.Truthy() {
@@ -452,6 +508,7 @@ func (f *Functions) GetBindingi(pname Enum, idx int) Object {
 	}
 	return Object(obj)
 }
+
 func (f *Functions) GetInteger(pname Enum) int {
 	if !f.isWebGL2 {
 		switch pname {
@@ -461,9 +518,11 @@ func (f *Functions) GetInteger(pname Enum) int {
 	}
 	return paramVal(f._getParameter.Invoke(int(pname)))
 }
+
 func (f *Functions) GetFloat(pname Enum) float32 {
 	return float32(f._getParameter.Invoke(int(pname)).Float())
 }
+
 func (f *Functions) GetInteger4(pname Enum) [4]int {
 	arr := f._getParameter.Invoke(int(pname))
 	var res [4]int
@@ -472,6 +531,7 @@ func (f *Functions) GetInteger4(pname Enum) [4]int {
 	}
 	return res
 }
+
 func (f *Functions) GetFloat4(pname Enum) [4]float32 {
 	arr := f._getParameter.Invoke(int(pname))
 	var res [4]float32
@@ -480,12 +540,15 @@ func (f *Functions) GetFloat4(pname Enum) [4]float32 {
 	}
 	return res
 }
+
 func (f *Functions) GetProgrami(p Program, pname Enum) int {
 	return paramVal(f._getProgramParameter.Invoke(js.Value(p), int(pname)))
 }
+
 func (f *Functions) GetProgramInfoLog(p Program) string {
 	return f._getProgramInfoLog.Invoke(js.Value(p)).String()
 }
+
 func (f *Functions) GetQueryObjectuiv(query Query, pname Enum) uint {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		return uint(paramVal(f._getQueryParameter.Invoke(js.Value(query), int(pname))))
@@ -493,12 +556,15 @@ func (f *Functions) GetQueryObjectuiv(query Query, pname Enum) uint {
 		return uint(paramVal(f.EXT_disjoint_timer_query.Call("getQueryObjectEXT", js.Value(query), int(pname))))
 	}
 }
+
 func (f *Functions) GetShaderi(s Shader, pname Enum) int {
 	return paramVal(f._getShaderParameter.Invoke(js.Value(s), int(pname)))
 }
+
 func (f *Functions) GetShaderInfoLog(s Shader) string {
 	return f._getShaderInfoLog.Invoke(js.Value(s)).String()
 }
+
 func (f *Functions) GetString(pname Enum) string {
 	switch pname {
 	case EXTENSIONS:
@@ -512,15 +578,19 @@ func (f *Functions) GetString(pname Enum) string {
 		return f._getParameter.Invoke(int(pname)).String()
 	}
 }
+
 func (f *Functions) GetUniformBlockIndex(p Program, name string) uint {
 	return uint(paramVal(f._getUniformBlockIndex.Invoke(js.Value(p), name)))
 }
+
 func (f *Functions) GetUniformLocation(p Program, name string) Uniform {
 	return Uniform(f._getUniformLocation.Invoke(js.Value(p), name))
 }
+
 func (f *Functions) GetVertexAttrib(index int, pname Enum) int {
 	return paramVal(f._getVertexAttrib.Invoke(index, int(pname)))
 }
+
 func (f *Functions) GetVertexAttribBinding(index int, pname Enum) Object {
 	obj := f._getVertexAttrib.Invoke(index, int(pname))
 	if !obj.Truthy() {
@@ -528,9 +598,11 @@ func (f *Functions) GetVertexAttribBinding(index int, pname Enum) Object {
 	}
 	return Object(obj)
 }
+
 func (f *Functions) GetVertexAttribPointer(index int, pname Enum) uintptr {
 	return uintptr(f._getVertexAttribOffset.Invoke(index, int(pname)).Int())
 }
+
 func (f *Functions) InvalidateFramebuffer(target, attachment Enum) {
 	fn := f.Ctx.Get("invalidateFramebuffer")
 	if !fn.IsUndefined() {
@@ -541,74 +613,97 @@ func (f *Functions) InvalidateFramebuffer(target, attachment Enum) {
 		f._invalidateFramebuffer.Invoke(int(target), f.int32Buf)
 	}
 }
+
 func (f *Functions) IsEnabled(cap Enum) bool {
 	return f._isEnabled.Invoke(int(cap)).Truthy()
 }
+
 func (f *Functions) LinkProgram(p Program) {
 	f._linkProgram.Invoke(js.Value(p))
 }
+
 func (f *Functions) PixelStorei(pname Enum, param int) {
 	f._pixelStorei.Invoke(int(pname), param)
 }
+
 func (f *Functions) MemoryBarrier(barriers Enum) {
 	panic("not implemented")
 }
+
 func (f *Functions) MapBufferRange(target Enum, offset, length int, access Enum) []byte {
 	panic("not implemented")
 }
+
 func (f *Functions) RenderbufferStorage(target, internalformat Enum, width, height int) {
 	f._renderbufferStorage.Invoke(int(target), int(internalformat), width, height)
 }
+
 func (f *Functions) ReadPixels(x, y, width, height int, format, ty Enum, data []byte) {
 	ba := f.byteArrayOf(data)
 	f._readPixels.Invoke(x, y, width, height, int(format), int(ty), ba)
 	js.CopyBytesToGo(data, ba)
 }
+
 func (f *Functions) Scissor(x, y, width, height int32) {
 	f._scissor.Invoke(x, y, width, height)
 }
+
 func (f *Functions) ShaderSource(s Shader, src string) {
 	f._shaderSource.Invoke(js.Value(s), src)
 }
+
 func (f *Functions) TexImage2D(target Enum, level int, internalFormat Enum, width, height int, format, ty Enum) {
 	f._texImage2D.Invoke(int(target), int(level), int(internalFormat), int(width), int(height), 0, int(format), int(ty), nil)
 }
+
 func (f *Functions) TexStorage2D(target Enum, levels int, internalFormat Enum, width, height int) {
 	f._texStorage2D.Invoke(int(target), levels, int(internalFormat), width, height)
 }
+
 func (f *Functions) TexSubImage2D(target Enum, level int, x, y, width, height int, format, ty Enum, data []byte) {
 	f._texSubImage2D.Invoke(int(target), level, x, y, width, height, int(format), int(ty), f.byteArrayOf(data))
 }
+
 func (f *Functions) TexParameteri(target, pname Enum, param int) {
 	f._texParameteri.Invoke(int(target), int(pname), int(param))
 }
+
 func (f *Functions) UniformBlockBinding(p Program, uniformBlockIndex uint, uniformBlockBinding uint) {
 	f._uniformBlockBinding.Invoke(js.Value(p), int(uniformBlockIndex), int(uniformBlockBinding))
 }
+
 func (f *Functions) Uniform1f(dst Uniform, v float32) {
 	f._uniform1f.Invoke(js.Value(dst), v)
 }
+
 func (f *Functions) Uniform1i(dst Uniform, v int) {
 	f._uniform1i.Invoke(js.Value(dst), v)
 }
+
 func (f *Functions) Uniform2f(dst Uniform, v0, v1 float32) {
 	f._uniform2f.Invoke(js.Value(dst), v0, v1)
 }
+
 func (f *Functions) Uniform3f(dst Uniform, v0, v1, v2 float32) {
 	f._uniform3f.Invoke(js.Value(dst), v0, v1, v2)
 }
+
 func (f *Functions) Uniform4f(dst Uniform, v0, v1, v2, v3 float32) {
 	f._uniform4f.Invoke(js.Value(dst), v0, v1, v2, v3)
 }
+
 func (f *Functions) UseProgram(p Program) {
 	f._useProgram.Invoke(js.Value(p))
 }
+
 func (f *Functions) UnmapBuffer(target Enum) bool {
 	panic("not implemented")
 }
+
 func (f *Functions) VertexAttribPointer(dst Attrib, size int, ty Enum, normalized bool, stride, offset int) {
 	f._vertexAttribPointer.Invoke(int(dst), size, int(ty), normalized, stride, offset)
 }
+
 func (f *Functions) Viewport(x, y, width, height int) {
 	f._viewport.Invoke(x, y, width, height)
 }

internal/gl/gl_unix.go

@@ -665,7 +665,7 @@ func (f *Functions) load(forceES bool) error {
 	case runtime.GOOS == "android":
 		libNames = []string{"libGLESv2.so", "libGLESv3.so"}
 	default:
-		libNames = []string{"libGLESv2.so.2"}
+		libNames = []string{"libGLESv2.so.2", "libGLESv2.so.3.0"}
 	}
 	for _, lib := range libNames {
 		if h := dlopen(lib); h != nil {

internal/gl/gl_windows.go

@@ -3,103 +3,217 @@
 package gl
 
 import (
+	"fmt"
 	"math"
 	"runtime"
+	"sync"
 	"syscall"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
 )
 
+func loadGLESv2Procs() error {
+	dllName := "libGLESv2.dll"
+	handle, err := windows.LoadLibraryEx(dllName, 0, windows.LOAD_LIBRARY_SEARCH_DEFAULT_DIRS)
+	if err != nil {
+		return fmt.Errorf("gl: failed to load %s: %v", dllName, err)
+	}
+	gles := windows.DLL{Handle: handle, Name: dllName}
+	// d3dcompiler_47.dll is needed internally for shader compilation to function.
+	dllName = "d3dcompiler_47.dll"
+	_, err = windows.LoadLibraryEx(dllName, 0, windows.LOAD_LIBRARY_SEARCH_DEFAULT_DIRS)
+	if err != nil {
+		return fmt.Errorf("gl: failed to load %s: %v", dllName, err)
+	}
+	procs := map[string]**windows.Proc{
+		"glActiveTexture":                       &_glActiveTexture,
+		"glAttachShader":                        &_glAttachShader,
+		"glBeginQuery":                          &_glBeginQuery,
+		"glBindAttribLocation":                  &_glBindAttribLocation,
+		"glBindBuffer":                          &_glBindBuffer,
+		"glBindBufferBase":                      &_glBindBufferBase,
+		"glBindFramebuffer":                     &_glBindFramebuffer,
+		"glBindRenderbuffer":                    &_glBindRenderbuffer,
+		"glBindTexture":                         &_glBindTexture,
+		"glBindVertexArray":                     &_glBindVertexArray,
+		"glBlendEquation":                       &_glBlendEquation,
+		"glBlendFuncSeparate":                   &_glBlendFuncSeparate,
+		"glBufferData":                          &_glBufferData,
+		"glBufferSubData":                       &_glBufferSubData,
+		"glCheckFramebufferStatus":              &_glCheckFramebufferStatus,
+		"glClear":                               &_glClear,
+		"glClearColor":                          &_glClearColor,
+		"glClearDepthf":                         &_glClearDepthf,
+		"glDeleteQueries":                       &_glDeleteQueries,
+		"glDeleteVertexArrays":                  &_glDeleteVertexArrays,
+		"glCompileShader":                       &_glCompileShader,
+		"glCopyTexSubImage2D":                   &_glCopyTexSubImage2D,
+		"glGenerateMipmap":                      &_glGenerateMipmap,
+		"glGenBuffers":                          &_glGenBuffers,
+		"glGenFramebuffers":                     &_glGenFramebuffers,
+		"glGenVertexArrays":                     &_glGenVertexArrays,
+		"glGetUniformBlockIndex":                &_glGetUniformBlockIndex,
+		"glCreateProgram":                       &_glCreateProgram,
+		"glGenRenderbuffers":                    &_glGenRenderbuffers,
+		"glCreateShader":                        &_glCreateShader,
+		"glGenTextures":                         &_glGenTextures,
+		"glDeleteBuffers":                       &_glDeleteBuffers,
+		"glDeleteFramebuffers":                  &_glDeleteFramebuffers,
+		"glDeleteProgram":                       &_glDeleteProgram,
+		"glDeleteShader":                        &_glDeleteShader,
+		"glDeleteRenderbuffers":                 &_glDeleteRenderbuffers,
+		"glDeleteTextures":                      &_glDeleteTextures,
+		"glDepthFunc":                           &_glDepthFunc,
+		"glDepthMask":                           &_glDepthMask,
+		"glDisableVertexAttribArray":            &_glDisableVertexAttribArray,
+		"glDisable":                             &_glDisable,
+		"glDrawArrays":                          &_glDrawArrays,
+		"glDrawElements":                        &_glDrawElements,
+		"glEnable":                              &_glEnable,
+		"glEnableVertexAttribArray":             &_glEnableVertexAttribArray,
+		"glEndQuery":                            &_glEndQuery,
+		"glFinish":                              &_glFinish,
+		"glFlush":                               &_glFlush,
+		"glFramebufferRenderbuffer":             &_glFramebufferRenderbuffer,
+		"glFramebufferTexture2D":                &_glFramebufferTexture2D,
+		"glGenQueries":                          &_glGenQueries,
+		"glGetError":                            &_glGetError,
+		"glGetRenderbufferParameteriv":          &_glGetRenderbufferParameteriv,
+		"glGetFloatv":                           &_glGetFloatv,
+		"glGetFramebufferAttachmentParameteriv": &_glGetFramebufferAttachmentParameteriv,
+		"glGetIntegerv":                         &_glGetIntegerv,
+		"glGetIntegeri_v":                       &_glGetIntegeri_v,
+		"glGetProgramiv":                        &_glGetProgramiv,
+		"glGetProgramInfoLog":                   &_glGetProgramInfoLog,
+		"glGetQueryObjectuiv":                   &_glGetQueryObjectuiv,
+		"glGetShaderiv":                         &_glGetShaderiv,
+		"glGetShaderInfoLog":                    &_glGetShaderInfoLog,
+		"glGetString":                           &_glGetString,
+		"glGetUniformLocation":                  &_glGetUniformLocation,
+		"glGetVertexAttribiv":                   &_glGetVertexAttribiv,
+		"glGetVertexAttribPointerv":             &_glGetVertexAttribPointerv,
+		"glInvalidateFramebuffer":               &_glInvalidateFramebuffer,
+		"glIsEnabled":                           &_glIsEnabled,
+		"glLinkProgram":                         &_glLinkProgram,
+		"glPixelStorei":                         &_glPixelStorei,
+		"glReadPixels":                          &_glReadPixels,
+		"glRenderbufferStorage":                 &_glRenderbufferStorage,
+		"glScissor":                             &_glScissor,
+		"glShaderSource":                        &_glShaderSource,
+		"glTexImage2D":                          &_glTexImage2D,
+		"glTexStorage2D":                        &_glTexStorage2D,
+		"glTexSubImage2D":                       &_glTexSubImage2D,
+		"glTexParameteri":                       &_glTexParameteri,
+		"glUniformBlockBinding":                 &_glUniformBlockBinding,
+		"glUniform1f":                           &_glUniform1f,
+		"glUniform1i":                           &_glUniform1i,
+		"glUniform2f":                           &_glUniform2f,
+		"glUniform3f":                           &_glUniform3f,
+		"glUniform4f":                           &_glUniform4f,
+		"glUseProgram":                          &_glUseProgram,
+		"glVertexAttribPointer":                 &_glVertexAttribPointer,
+		"glViewport":                            &_glViewport,
+	}
+	for name, proc := range procs {
+		p, err := gles.FindProc(name)
+		if err != nil {
+			return fmt.Errorf("failed to locate %s in %s: %w", name, gles.Name, err)
+		}
+		*proc = p
+	}
+	return nil
+}
+
 var (
-	LibGLESv2                              = windows.NewLazyDLL("libGLESv2.dll")
+	glInitOnce                             sync.Once
-	_glActiveTexture                       = LibGLESv2.NewProc("glActiveTexture")
+	_glActiveTexture                       *windows.Proc
-	_glAttachShader                        = LibGLESv2.NewProc("glAttachShader")
+	_glAttachShader                        *windows.Proc
-	_glBeginQuery                          = LibGLESv2.NewProc("glBeginQuery")
+	_glBeginQuery                          *windows.Proc
-	_glBindAttribLocation                  = LibGLESv2.NewProc("glBindAttribLocation")
+	_glBindAttribLocation                  *windows.Proc
-	_glBindBuffer                          = LibGLESv2.NewProc("glBindBuffer")
+	_glBindBuffer                          *windows.Proc
-	_glBindBufferBase                      = LibGLESv2.NewProc("glBindBufferBase")
+	_glBindBufferBase                      *windows.Proc
-	_glBindFramebuffer                     = LibGLESv2.NewProc("glBindFramebuffer")
+	_glBindFramebuffer                     *windows.Proc
-	_glBindRenderbuffer                    = LibGLESv2.NewProc("glBindRenderbuffer")
+	_glBindRenderbuffer                    *windows.Proc
-	_glBindTexture                         = LibGLESv2.NewProc("glBindTexture")
+	_glBindTexture                         *windows.Proc
-	_glBindVertexArray                     = LibGLESv2.NewProc("glBindVertexArray")
+	_glBindVertexArray                     *windows.Proc
-	_glBlendEquation                       = LibGLESv2.NewProc("glBlendEquation")
+	_glBlendEquation                       *windows.Proc
-	_glBlendFuncSeparate                   = LibGLESv2.NewProc("glBlendFuncSeparate")
+	_glBlendFuncSeparate                   *windows.Proc
-	_glBufferData                          = LibGLESv2.NewProc("glBufferData")
+	_glBufferData                          *windows.Proc
-	_glBufferSubData                       = LibGLESv2.NewProc("glBufferSubData")
+	_glBufferSubData                       *windows.Proc
-	_glCheckFramebufferStatus              = LibGLESv2.NewProc("glCheckFramebufferStatus")
+	_glCheckFramebufferStatus              *windows.Proc
-	_glClear                               = LibGLESv2.NewProc("glClear")
+	_glClear                               *windows.Proc
-	_glClearColor                          = LibGLESv2.NewProc("glClearColor")
+	_glClearColor                          *windows.Proc
-	_glClearDepthf                         = LibGLESv2.NewProc("glClearDepthf")
+	_glClearDepthf                         *windows.Proc
-	_glDeleteQueries                       = LibGLESv2.NewProc("glDeleteQueries")
+	_glDeleteQueries                       *windows.Proc
-	_glDeleteVertexArrays                  = LibGLESv2.NewProc("glDeleteVertexArrays")
+	_glDeleteVertexArrays                  *windows.Proc
-	_glCompileShader                       = LibGLESv2.NewProc("glCompileShader")
+	_glCompileShader                       *windows.Proc
-	_glCopyTexSubImage2D                   = LibGLESv2.NewProc("glCopyTexSubImage2D")
+	_glCopyTexSubImage2D                   *windows.Proc
-	_glGenerateMipmap                      = LibGLESv2.NewProc("glGenerateMipmap")
+	_glGenerateMipmap                      *windows.Proc
-	_glGenBuffers                          = LibGLESv2.NewProc("glGenBuffers")
+	_glGenBuffers                          *windows.Proc
-	_glGenFramebuffers                     = LibGLESv2.NewProc("glGenFramebuffers")
+	_glGenFramebuffers                     *windows.Proc
-	_glGenVertexArrays                     = LibGLESv2.NewProc("glGenVertexArrays")
+	_glGenVertexArrays                     *windows.Proc
-	_glGetUniformBlockIndex                = LibGLESv2.NewProc("glGetUniformBlockIndex")
+	_glGetUniformBlockIndex                *windows.Proc
-	_glCreateProgram                       = LibGLESv2.NewProc("glCreateProgram")
+	_glCreateProgram                       *windows.Proc
-	_glGenRenderbuffers                    = LibGLESv2.NewProc("glGenRenderbuffers")
+	_glGenRenderbuffers                    *windows.Proc
-	_glCreateShader                        = LibGLESv2.NewProc("glCreateShader")
+	_glCreateShader                        *windows.Proc
-	_glGenTextures                         = LibGLESv2.NewProc("glGenTextures")
+	_glGenTextures                         *windows.Proc
-	_glDeleteBuffers                       = LibGLESv2.NewProc("glDeleteBuffers")
+	_glDeleteBuffers                       *windows.Proc
-	_glDeleteFramebuffers                  = LibGLESv2.NewProc("glDeleteFramebuffers")
+	_glDeleteFramebuffers                  *windows.Proc
-	_glDeleteProgram                       = LibGLESv2.NewProc("glDeleteProgram")
+	_glDeleteProgram                       *windows.Proc
-	_glDeleteShader                        = LibGLESv2.NewProc("glDeleteShader")
+	_glDeleteShader                        *windows.Proc
-	_glDeleteRenderbuffers                 = LibGLESv2.NewProc("glDeleteRenderbuffers")
+	_glDeleteRenderbuffers                 *windows.Proc
-	_glDeleteTextures                      = LibGLESv2.NewProc("glDeleteTextures")
+	_glDeleteTextures                      *windows.Proc
-	_glDepthFunc                           = LibGLESv2.NewProc("glDepthFunc")
+	_glDepthFunc                           *windows.Proc
-	_glDepthMask                           = LibGLESv2.NewProc("glDepthMask")
+	_glDepthMask                           *windows.Proc
-	_glDisableVertexAttribArray            = LibGLESv2.NewProc("glDisableVertexAttribArray")
+	_glDisableVertexAttribArray            *windows.Proc
-	_glDisable                             = LibGLESv2.NewProc("glDisable")
+	_glDisable                             *windows.Proc
-	_glDrawArrays                          = LibGLESv2.NewProc("glDrawArrays")
+	_glDrawArrays                          *windows.Proc
-	_glDrawElements                        = LibGLESv2.NewProc("glDrawElements")
+	_glDrawElements                        *windows.Proc
-	_glEnable                              = LibGLESv2.NewProc("glEnable")
+	_glEnable                              *windows.Proc
-	_glEnableVertexAttribArray             = LibGLESv2.NewProc("glEnableVertexAttribArray")
+	_glEnableVertexAttribArray             *windows.Proc
-	_glEndQuery                            = LibGLESv2.NewProc("glEndQuery")
+	_glEndQuery                            *windows.Proc
-	_glFinish                              = LibGLESv2.NewProc("glFinish")
+	_glFinish                              *windows.Proc
-	_glFlush                               = LibGLESv2.NewProc("glFlush")
+	_glFlush                               *windows.Proc
-	_glFramebufferRenderbuffer             = LibGLESv2.NewProc("glFramebufferRenderbuffer")
+	_glFramebufferRenderbuffer             *windows.Proc
-	_glFramebufferTexture2D                = LibGLESv2.NewProc("glFramebufferTexture2D")
+	_glFramebufferTexture2D                *windows.Proc
-	_glGenQueries                          = LibGLESv2.NewProc("glGenQueries")
+	_glGenQueries                          *windows.Proc
-	_glGetError                            = LibGLESv2.NewProc("glGetError")
+	_glGetError                            *windows.Proc
-	_glGetRenderbufferParameteriv          = LibGLESv2.NewProc("glGetRenderbufferParameteriv")
+	_glGetRenderbufferParameteriv          *windows.Proc
-	_glGetFloatv                           = LibGLESv2.NewProc("glGetFloatv")
+	_glGetFloatv                           *windows.Proc
-	_glGetFramebufferAttachmentParameteriv = LibGLESv2.NewProc("glGetFramebufferAttachmentParameteriv")
+	_glGetFramebufferAttachmentParameteriv *windows.Proc
-	_glGetIntegerv                         = LibGLESv2.NewProc("glGetIntegerv")
+	_glGetIntegerv                         *windows.Proc
-	_glGetIntegeri_v                       = LibGLESv2.NewProc("glGetIntegeri_v")
+	_glGetIntegeri_v                       *windows.Proc
-	_glGetProgramiv                        = LibGLESv2.NewProc("glGetProgramiv")
+	_glGetProgramiv                        *windows.Proc
-	_glGetProgramInfoLog                   = LibGLESv2.NewProc("glGetProgramInfoLog")
+	_glGetProgramInfoLog                   *windows.Proc
-	_glGetQueryObjectuiv                   = LibGLESv2.NewProc("glGetQueryObjectuiv")
+	_glGetQueryObjectuiv                   *windows.Proc
-	_glGetShaderiv                         = LibGLESv2.NewProc("glGetShaderiv")
+	_glGetShaderiv                         *windows.Proc
-	_glGetShaderInfoLog                    = LibGLESv2.NewProc("glGetShaderInfoLog")
+	_glGetShaderInfoLog                    *windows.Proc
-	_glGetString                           = LibGLESv2.NewProc("glGetString")
+	_glGetString                           *windows.Proc
-	_glGetUniformLocation                  = LibGLESv2.NewProc("glGetUniformLocation")
+	_glGetUniformLocation                  *windows.Proc
-	_glGetVertexAttribiv                   = LibGLESv2.NewProc("glGetVertexAttribiv")
+	_glGetVertexAttribiv                   *windows.Proc
-	_glGetVertexAttribPointerv             = LibGLESv2.NewProc("glGetVertexAttribPointerv")
+	_glGetVertexAttribPointerv             *windows.Proc
-	_glInvalidateFramebuffer               = LibGLESv2.NewProc("glInvalidateFramebuffer")
+	_glInvalidateFramebuffer               *windows.Proc
-	_glIsEnabled                           = LibGLESv2.NewProc("glIsEnabled")
+	_glIsEnabled                           *windows.Proc
-	_glLinkProgram                         = LibGLESv2.NewProc("glLinkProgram")
+	_glLinkProgram                         *windows.Proc
-	_glPixelStorei                         = LibGLESv2.NewProc("glPixelStorei")
+	_glPixelStorei                         *windows.Proc
-	_glReadPixels                          = LibGLESv2.NewProc("glReadPixels")
+	_glReadPixels                          *windows.Proc
-	_glRenderbufferStorage                 = LibGLESv2.NewProc("glRenderbufferStorage")
+	_glRenderbufferStorage                 *windows.Proc
-	_glScissor                             = LibGLESv2.NewProc("glScissor")
+	_glScissor                             *windows.Proc
-	_glShaderSource                        = LibGLESv2.NewProc("glShaderSource")
+	_glShaderSource                        *windows.Proc
-	_glTexImage2D                          = LibGLESv2.NewProc("glTexImage2D")
+	_glTexImage2D                          *windows.Proc
-	_glTexStorage2D                        = LibGLESv2.NewProc("glTexStorage2D")
+	_glTexStorage2D                        *windows.Proc
-	_glTexSubImage2D                       = LibGLESv2.NewProc("glTexSubImage2D")
+	_glTexSubImage2D                       *windows.Proc
-	_glTexParameteri                       = LibGLESv2.NewProc("glTexParameteri")
+	_glTexParameteri                       *windows.Proc
-	_glUniformBlockBinding                 = LibGLESv2.NewProc("glUniformBlockBinding")
+	_glUniformBlockBinding                 *windows.Proc
-	_glUniform1f                           = LibGLESv2.NewProc("glUniform1f")
+	_glUniform1f                           *windows.Proc
-	_glUniform1i                           = LibGLESv2.NewProc("glUniform1i")
+	_glUniform1i                           *windows.Proc
-	_glUniform2f                           = LibGLESv2.NewProc("glUniform2f")
+	_glUniform2f                           *windows.Proc
-	_glUniform3f                           = LibGLESv2.NewProc("glUniform3f")
+	_glUniform3f                           *windows.Proc
-	_glUniform4f                           = LibGLESv2.NewProc("glUniform4f")
+	_glUniform4f                           *windows.Proc
-	_glUseProgram                          = LibGLESv2.NewProc("glUseProgram")
+	_glUseProgram                          *windows.Proc
-	_glVertexAttribPointer                 = LibGLESv2.NewProc("glVertexAttribPointer")
+	_glVertexAttribPointer                 *windows.Proc
-	_glViewport                            = LibGLESv2.NewProc("glViewport")
+	_glViewport                            *windows.Proc
 )
 
 type Functions struct {
@@ -109,57 +223,74 @@ type Functions struct {
 	uintptrs [100]uintptr
 }
 
-type Context interface{}
+type Context any
 
 func NewFunctions(ctx Context, forceES bool) (*Functions, error) {
 	if ctx != nil {
 		panic("non-nil context")
 	}
-	return new(Functions), nil
+	var err error
+	glInitOnce.Do(func() {
+		err = loadGLESv2Procs()
+	})
+	return new(Functions), err
 }
 
 func (c *Functions) ActiveTexture(t Enum) {
 	syscall.Syscall(_glActiveTexture.Addr(), 1, uintptr(t), 0, 0)
 }
+
 func (c *Functions) AttachShader(p Program, s Shader) {
 	syscall.Syscall(_glAttachShader.Addr(), 2, uintptr(p.V), uintptr(s.V), 0)
 }
+
 func (f *Functions) BeginQuery(target Enum, query Query) {
 	syscall.Syscall(_glBeginQuery.Addr(), 2, uintptr(target), uintptr(query.V), 0)
 }
+
 func (c *Functions) BindAttribLocation(p Program, a Attrib, name string) {
 	cname := cString(name)
 	c0 := &cname[0]
 	syscall.Syscall(_glBindAttribLocation.Addr(), 3, uintptr(p.V), uintptr(a), uintptr(unsafe.Pointer(c0)))
 	issue34474KeepAlive(c)
 }
+
 func (c *Functions) BindBuffer(target Enum, b Buffer) {
 	syscall.Syscall(_glBindBuffer.Addr(), 2, uintptr(target), uintptr(b.V), 0)
 }
+
 func (c *Functions) BindBufferBase(target Enum, index int, b Buffer) {
 	syscall.Syscall(_glBindBufferBase.Addr(), 3, uintptr(target), uintptr(index), uintptr(b.V))
 }
+
 func (c *Functions) BindFramebuffer(target Enum, fb Framebuffer) {
 	syscall.Syscall(_glBindFramebuffer.Addr(), 2, uintptr(target), uintptr(fb.V), 0)
 }
+
 func (c *Functions) BindRenderbuffer(target Enum, rb Renderbuffer) {
 	syscall.Syscall(_glBindRenderbuffer.Addr(), 2, uintptr(target), uintptr(rb.V), 0)
 }
+
 func (f *Functions) BindImageTexture(unit int, t Texture, level int, layered bool, layer int, access, format Enum) {
 	panic("not implemented")
 }
+
 func (c *Functions) BindTexture(target Enum, t Texture) {
 	syscall.Syscall(_glBindTexture.Addr(), 2, uintptr(target), uintptr(t.V), 0)
 }
+
 func (c *Functions) BindVertexArray(a VertexArray) {
 	syscall.Syscall(_glBindVertexArray.Addr(), 1, uintptr(a.V), 0, 0)
 }
+
 func (c *Functions) BlendEquation(mode Enum) {
 	syscall.Syscall(_glBlendEquation.Addr(), 1, uintptr(mode), 0, 0)
 }
+
 func (c *Functions) BlendFuncSeparate(srcRGB, dstRGB, srcA, dstA Enum) {
 	syscall.Syscall6(_glBlendFuncSeparate.Addr(), 4, uintptr(srcRGB), uintptr(dstRGB), uintptr(srcA), uintptr(dstA), 0, 0)
 }
+
 func (c *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 	var p unsafe.Pointer
 	if len(data) > 0 {
@@ -167,6 +298,7 @@ func (c *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 	}
 	syscall.Syscall6(_glBufferData.Addr(), 4, uintptr(target), uintptr(size), uintptr(p), uintptr(usage), 0, 0)
 }
+
 func (f *Functions) BufferSubData(target Enum, offset int, src []byte) {
 	if n := len(src); n > 0 {
 		s0 := &src[0]
@@ -174,93 +306,118 @@ func (f *Functions) BufferSubData(target Enum, offset int, src []byte) {
 		issue34474KeepAlive(s0)
 	}
 }
+
 func (c *Functions) CheckFramebufferStatus(target Enum) Enum {
 	s, _, _ := syscall.Syscall(_glCheckFramebufferStatus.Addr(), 1, uintptr(target), 0, 0)
 	return Enum(s)
 }
+
 func (c *Functions) Clear(mask Enum) {
 	syscall.Syscall(_glClear.Addr(), 1, uintptr(mask), 0, 0)
 }
+
 func (c *Functions) ClearColor(red, green, blue, alpha float32) {
 	syscall.Syscall6(_glClearColor.Addr(), 4, uintptr(math.Float32bits(red)), uintptr(math.Float32bits(green)), uintptr(math.Float32bits(blue)), uintptr(math.Float32bits(alpha)), 0, 0)
 }
+
 func (c *Functions) ClearDepthf(d float32) {
 	syscall.Syscall(_glClearDepthf.Addr(), 1, uintptr(math.Float32bits(d)), 0, 0)
 }
+
 func (c *Functions) CompileShader(s Shader) {
 	syscall.Syscall(_glCompileShader.Addr(), 1, uintptr(s.V), 0, 0)
 }
+
 func (f *Functions) CopyTexSubImage2D(target Enum, level, xoffset, yoffset, x, y, width, height int) {
 	syscall.Syscall9(_glCopyTexSubImage2D.Addr(), 8, uintptr(target), uintptr(level), uintptr(xoffset), uintptr(yoffset), uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0)
 }
+
 func (f *Functions) GenerateMipmap(target Enum) {
 	syscall.Syscall(_glGenerateMipmap.Addr(), 1, uintptr(target), 0, 0)
 }
+
 func (c *Functions) CreateBuffer() Buffer {
 	var buf uintptr
 	syscall.Syscall(_glGenBuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&buf)), 0)
 	return Buffer{uint(buf)}
 }
+
 func (c *Functions) CreateFramebuffer() Framebuffer {
 	var fb uintptr
 	syscall.Syscall(_glGenFramebuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&fb)), 0)
 	return Framebuffer{uint(fb)}
 }
+
 func (c *Functions) CreateProgram() Program {
 	p, _, _ := syscall.Syscall(_glCreateProgram.Addr(), 0, 0, 0, 0)
 	return Program{uint(p)}
 }
+
 func (f *Functions) CreateQuery() Query {
 	var q uintptr
 	syscall.Syscall(_glGenQueries.Addr(), 2, 1, uintptr(unsafe.Pointer(&q)), 0)
 	return Query{uint(q)}
 }
+
 func (c *Functions) CreateRenderbuffer() Renderbuffer {
 	var rb uintptr
 	syscall.Syscall(_glGenRenderbuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&rb)), 0)
 	return Renderbuffer{uint(rb)}
 }
+
 func (c *Functions) CreateShader(ty Enum) Shader {
 	s, _, _ := syscall.Syscall(_glCreateShader.Addr(), 1, uintptr(ty), 0, 0)
 	return Shader{uint(s)}
 }
+
 func (c *Functions) CreateTexture() Texture {
 	var t uintptr
 	syscall.Syscall(_glGenTextures.Addr(), 2, 1, uintptr(unsafe.Pointer(&t)), 0)
 	return Texture{uint(t)}
 }
+
 func (c *Functions) CreateVertexArray() VertexArray {
 	var t uintptr
 	syscall.Syscall(_glGenVertexArrays.Addr(), 2, 1, uintptr(unsafe.Pointer(&t)), 0)
 	return VertexArray{uint(t)}
 }
+
 func (c *Functions) DeleteBuffer(v Buffer) {
 	syscall.Syscall(_glDeleteBuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v)), 0)
 }
+
 func (c *Functions) DeleteFramebuffer(v Framebuffer) {
 	syscall.Syscall(_glDeleteFramebuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0)
 }
+
 func (c *Functions) DeleteProgram(p Program) {
 	syscall.Syscall(_glDeleteProgram.Addr(), 1, uintptr(p.V), 0, 0)
 }
+
 func (f *Functions) DeleteQuery(query Query) {
 	syscall.Syscall(_glDeleteQueries.Addr(), 2, 1, uintptr(unsafe.Pointer(&query.V)), 0)
 }
+
 func (c *Functions) DeleteShader(s Shader) {
 	syscall.Syscall(_glDeleteShader.Addr(), 1, uintptr(s.V), 0, 0)
 }
+
 func (c *Functions) DeleteRenderbuffer(v Renderbuffer) {
 	syscall.Syscall(_glDeleteRenderbuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0)
 }
+
 func (c *Functions) DeleteTexture(v Texture) {
 	syscall.Syscall(_glDeleteTextures.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0)
 }
+
 func (f *Functions) DeleteVertexArray(array VertexArray) {
 	syscall.Syscall(_glDeleteVertexArrays.Addr(), 2, 1, uintptr(unsafe.Pointer(&array.V)), 0)
 }
+
 func (c *Functions) DepthFunc(f Enum) {
 	syscall.Syscall(_glDepthFunc.Addr(), 1, uintptr(f), 0, 0)
 }
+
 func (c *Functions) DepthMask(mask bool) {
 	var m uintptr
 	if mask {
@@ -268,42 +425,55 @@ func (c *Functions) DepthMask(mask bool) {
 	}
 	syscall.Syscall(_glDepthMask.Addr(), 1, m, 0, 0)
 }
+
 func (c *Functions) DisableVertexAttribArray(a Attrib) {
 	syscall.Syscall(_glDisableVertexAttribArray.Addr(), 1, uintptr(a), 0, 0)
 }
+
 func (c *Functions) Disable(cap Enum) {
 	syscall.Syscall(_glDisable.Addr(), 1, uintptr(cap), 0, 0)
 }
+
 func (c *Functions) DrawArrays(mode Enum, first, count int) {
 	syscall.Syscall(_glDrawArrays.Addr(), 3, uintptr(mode), uintptr(first), uintptr(count))
 }
+
 func (c *Functions) DrawElements(mode Enum, count int, ty Enum, offset int) {
 	syscall.Syscall6(_glDrawElements.Addr(), 4, uintptr(mode), uintptr(count), uintptr(ty), uintptr(offset), 0, 0)
 }
+
 func (f *Functions) DispatchCompute(x, y, z int) {
 	panic("not implemented")
 }
+
 func (c *Functions) Enable(cap Enum) {
 	syscall.Syscall(_glEnable.Addr(), 1, uintptr(cap), 0, 0)
 }
+
 func (c *Functions) EnableVertexAttribArray(a Attrib) {
 	syscall.Syscall(_glEnableVertexAttribArray.Addr(), 1, uintptr(a), 0, 0)
 }
+
 func (f *Functions) EndQuery(target Enum) {
 	syscall.Syscall(_glEndQuery.Addr(), 1, uintptr(target), 0, 0)
 }
+
 func (c *Functions) Finish() {
 	syscall.Syscall(_glFinish.Addr(), 0, 0, 0, 0)
 }
+
 func (c *Functions) Flush() {
 	syscall.Syscall(_glFlush.Addr(), 0, 0, 0, 0)
 }
+
 func (c *Functions) FramebufferRenderbuffer(target, attachment, renderbuffertarget Enum, renderbuffer Renderbuffer) {
 	syscall.Syscall6(_glFramebufferRenderbuffer.Addr(), 4, uintptr(target), uintptr(attachment), uintptr(renderbuffertarget), uintptr(renderbuffer.V), 0, 0)
 }
+
 func (c *Functions) FramebufferTexture2D(target, attachment, texTarget Enum, t Texture, level int) {
 	syscall.Syscall6(_glFramebufferTexture2D.Addr(), 5, uintptr(target), uintptr(attachment), uintptr(texTarget), uintptr(t.V), uintptr(level), 0)
 }
+
 func (f *Functions) GetUniformBlockIndex(p Program, name string) uint {
 	cname := cString(name)
 	c0 := &cname[0]
@@ -311,24 +481,30 @@ func (f *Functions) GetUniformBlockIndex(p Program, name string) uint {
 	issue34474KeepAlive(c0)
 	return uint(u)
 }
+
 func (c *Functions) GetBinding(pname Enum) Object {
 	return Object{uint(c.GetInteger(pname))}
 }
+
 func (c *Functions) GetBindingi(pname Enum, idx int) Object {
 	return Object{uint(c.GetIntegeri(pname, idx))}
 }
+
 func (c *Functions) GetError() Enum {
 	e, _, _ := syscall.Syscall(_glGetError.Addr(), 0, 0, 0, 0)
 	return Enum(e)
 }
+
 func (c *Functions) GetRenderbufferParameteri(target, pname Enum) int {
 	syscall.Syscall(_glGetRenderbufferParameteriv.Addr(), 3, uintptr(target), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname Enum) int {
 	syscall.Syscall6(_glGetFramebufferAttachmentParameteriv.Addr(), 4, uintptr(target), uintptr(attachment), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0, 0)
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetInteger4(pname Enum) [4]int {
 	syscall.Syscall(_glGetIntegerv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0)
 	var r [4]int
@@ -337,52 +513,66 @@ func (c *Functions) GetInteger4(pname Enum) [4]int {
 	}
 	return r
 }
+
 func (c *Functions) GetInteger(pname Enum) int {
 	syscall.Syscall(_glGetIntegerv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0)
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetIntegeri(pname Enum, idx int) int {
 	syscall.Syscall(_glGetIntegeri_v.Addr(), 3, uintptr(pname), uintptr(idx), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetFloat(pname Enum) float32 {
 	syscall.Syscall(_glGetFloatv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.float32s[0])), 0)
 	return c.float32s[0]
 }
+
 func (c *Functions) GetFloat4(pname Enum) [4]float32 {
 	syscall.Syscall(_glGetFloatv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.float32s[0])), 0)
 	var r [4]float32
 	copy(r[:], c.float32s[:])
 	return r
 }
+
 func (c *Functions) GetProgrami(p Program, pname Enum) int {
 	syscall.Syscall(_glGetProgramiv.Addr(), 3, uintptr(p.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetProgramInfoLog(p Program) string {
 	n := c.GetProgrami(p, INFO_LOG_LENGTH)
+	if n == 0 {
+		return ""
+	}
 	buf := make([]byte, n)
 	syscall.Syscall6(_glGetProgramInfoLog.Addr(), 4, uintptr(p.V), uintptr(len(buf)), 0, uintptr(unsafe.Pointer(&buf[0])), 0, 0)
 	return string(buf)
 }
+
 func (c *Functions) GetQueryObjectuiv(query Query, pname Enum) uint {
 	syscall.Syscall(_glGetQueryObjectuiv.Addr(), 3, uintptr(query.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return uint(c.int32s[0])
 }
+
 func (c *Functions) GetShaderi(s Shader, pname Enum) int {
 	syscall.Syscall(_glGetShaderiv.Addr(), 3, uintptr(s.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetShaderInfoLog(s Shader) string {
 	n := c.GetShaderi(s, INFO_LOG_LENGTH)
 	buf := make([]byte, n)
 	syscall.Syscall6(_glGetShaderInfoLog.Addr(), 4, uintptr(s.V), uintptr(len(buf)), 0, uintptr(unsafe.Pointer(&buf[0])), 0, 0)
 	return string(buf)
 }
+
 func (c *Functions) GetString(pname Enum) string {
 	s, _, _ := syscall.Syscall(_glGetString.Addr(), 1, uintptr(pname), 0, 0)
 	return windows.BytePtrToString((*byte)(unsafe.Pointer(s)))
 }
+
 func (c *Functions) GetUniformLocation(p Program, name string) Uniform {
 	cname := cString(name)
 	c0 := &cname[0]
@@ -390,6 +580,7 @@ func (c *Functions) GetUniformLocation(p Program, name string) Uniform {
 	issue34474KeepAlive(c0)
 	return Uniform{int(u)}
 }
+
 func (c *Functions) GetVertexAttrib(index int, pname Enum) int {
 	syscall.Syscall(_glGetVertexAttribiv.Addr(), 3, uintptr(index), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
@@ -403,6 +594,7 @@ func (c *Functions) GetVertexAttribPointer(index int, pname Enum) uintptr {
 	syscall.Syscall(_glGetVertexAttribPointerv.Addr(), 3, uintptr(index), uintptr(pname), uintptr(unsafe.Pointer(&c.uintptrs[0])))
 	return c.uintptrs[0]
 }
+
 func (c *Functions) InvalidateFramebuffer(target, attachment Enum) {
 	addr := _glInvalidateFramebuffer.Addr()
 	if addr == 0 {
@@ -411,77 +603,99 @@ func (c *Functions) InvalidateFramebuffer(target, attachment Enum) {
 	}
 	syscall.Syscall(addr, 3, uintptr(target), 1, uintptr(unsafe.Pointer(&attachment)))
 }
+
 func (f *Functions) IsEnabled(cap Enum) bool {
 	u, _, _ := syscall.Syscall(_glIsEnabled.Addr(), 1, uintptr(cap), 0, 0)
 	return u == TRUE
 }
+
 func (c *Functions) LinkProgram(p Program) {
 	syscall.Syscall(_glLinkProgram.Addr(), 1, uintptr(p.V), 0, 0)
 }
+
 func (c *Functions) PixelStorei(pname Enum, param int) {
 	syscall.Syscall(_glPixelStorei.Addr(), 2, uintptr(pname), uintptr(param), 0)
 }
+
 func (f *Functions) MemoryBarrier(barriers Enum) {
 	panic("not implemented")
 }
+
 func (f *Functions) MapBufferRange(target Enum, offset, length int, access Enum) []byte {
 	panic("not implemented")
 }
+
 func (f *Functions) ReadPixels(x, y, width, height int, format, ty Enum, data []byte) {
 	d0 := &data[0]
 	syscall.Syscall9(_glReadPixels.Addr(), 7, uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(format), uintptr(ty), uintptr(unsafe.Pointer(d0)), 0, 0)
 	issue34474KeepAlive(d0)
 }
+
 func (c *Functions) RenderbufferStorage(target, internalformat Enum, width, height int) {
 	syscall.Syscall6(_glRenderbufferStorage.Addr(), 4, uintptr(target), uintptr(internalformat), uintptr(width), uintptr(height), 0, 0)
 }
+
 func (c *Functions) Scissor(x, y, width, height int32) {
 	syscall.Syscall6(_glScissor.Addr(), 4, uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0, 0)
 }
+
 func (c *Functions) ShaderSource(s Shader, src string) {
 	var n uintptr = uintptr(len(src))
 	psrc := &src
 	syscall.Syscall6(_glShaderSource.Addr(), 4, uintptr(s.V), 1, uintptr(unsafe.Pointer(psrc)), uintptr(unsafe.Pointer(&n)), 0, 0)
 	issue34474KeepAlive(psrc)
 }
+
 func (f *Functions) TexImage2D(target Enum, level int, internalFormat Enum, width int, height int, format Enum, ty Enum) {
 	syscall.Syscall9(_glTexImage2D.Addr(), 9, uintptr(target), uintptr(level), uintptr(internalFormat), uintptr(width), uintptr(height), 0, uintptr(format), uintptr(ty), 0)
 }
+
 func (f *Functions) TexStorage2D(target Enum, levels int, internalFormat Enum, width, height int) {
 	syscall.Syscall6(_glTexStorage2D.Addr(), 5, uintptr(target), uintptr(levels), uintptr(internalFormat), uintptr(width), uintptr(height), 0)
 }
+
 func (c *Functions) TexSubImage2D(target Enum, level int, x, y, width, height int, format, ty Enum, data []byte) {
 	d0 := &data[0]
 	syscall.Syscall9(_glTexSubImage2D.Addr(), 9, uintptr(target), uintptr(level), uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(format), uintptr(ty), uintptr(unsafe.Pointer(d0)))
 	issue34474KeepAlive(d0)
 }
+
 func (c *Functions) TexParameteri(target, pname Enum, param int) {
 	syscall.Syscall(_glTexParameteri.Addr(), 3, uintptr(target), uintptr(pname), uintptr(param))
 }
+
 func (f *Functions) UniformBlockBinding(p Program, uniformBlockIndex uint, uniformBlockBinding uint) {
 	syscall.Syscall(_glUniformBlockBinding.Addr(), 3, uintptr(p.V), uintptr(uniformBlockIndex), uintptr(uniformBlockBinding))
 }
+
 func (c *Functions) Uniform1f(dst Uniform, v float32) {
 	syscall.Syscall(_glUniform1f.Addr(), 2, uintptr(dst.V), uintptr(math.Float32bits(v)), 0)
 }
+
 func (c *Functions) Uniform1i(dst Uniform, v int) {
 	syscall.Syscall(_glUniform1i.Addr(), 2, uintptr(dst.V), uintptr(v), 0)
 }
+
 func (c *Functions) Uniform2f(dst Uniform, v0, v1 float32) {
 	syscall.Syscall(_glUniform2f.Addr(), 3, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)))
 }
+
 func (c *Functions) Uniform3f(dst Uniform, v0, v1, v2 float32) {
 	syscall.Syscall6(_glUniform3f.Addr(), 4, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)), uintptr(math.Float32bits(v2)), 0, 0)
 }
+
 func (c *Functions) Uniform4f(dst Uniform, v0, v1, v2, v3 float32) {
 	syscall.Syscall6(_glUniform4f.Addr(), 5, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)), uintptr(math.Float32bits(v2)), uintptr(math.Float32bits(v3)), 0)
 }
+
 func (c *Functions) UseProgram(p Program) {
 	syscall.Syscall(_glUseProgram.Addr(), 1, uintptr(p.V), 0, 0)
 }
+
 func (f *Functions) UnmapBuffer(target Enum) bool {
 	panic("not implemented")
 }
+
 func (c *Functions) VertexAttribPointer(dst Attrib, size int, ty Enum, normalized bool, stride, offset int) {
 	var norm uintptr
 	if normalized {
@@ -489,6 +703,7 @@ func (c *Functions) VertexAttribPointer(dst Attrib, size int, ty Enum, normalize
 	}
 	syscall.Syscall6(_glVertexAttribPointer.Addr(), 6, uintptr(dst), uintptr(size), uintptr(ty), norm, uintptr(stride), uintptr(offset))
 }
+
 func (c *Functions) Viewport(x, y, width, height int) {
 	syscall.Syscall6(_glViewport.Addr(), 4, uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0, 0)
 }
@@ -501,6 +716,6 @@ func cString(s string) []byte {
 
 // issue34474KeepAlive calls runtime.KeepAlive as a
 // workaround for golang.org/issue/34474.
-func issue34474KeepAlive(v interface{}) {
+func issue34474KeepAlive(v any) {
 	runtime.KeepAlive(v)
 }

internal/ops/ops.go

@@ -18,7 +18,7 @@ type Ops struct {
 	// data contains the serialized operations.
 	data []byte
 	// refs hold external references for operations.
-	refs []interface{}
+	refs []any
 	// stringRefs provides space for string references, pointers to which will
 	// be stored in refs. Storing a string directly in refs would cause a heap
 	// allocation, to store the string header in an interface value. The backing
@@ -55,28 +55,19 @@ const (
 	TypePopTransform
 	TypePushOpacity
 	TypePopOpacity
-	TypeInvalidate
 	TypeImage
 	TypePaint
 	TypeColor
 	TypeLinearGradient
 	TypePass
 	TypePopPass
-	TypePointerInput
+	TypeInput
-	TypeClipboardRead
+	TypeKeyInputHint
-	TypeClipboardWrite
-	TypeSource
-	TypeTarget
-	TypeOffer
-	TypeKeyInput
-	TypeKeyFocus
-	TypeKeySoftKeyboard
 	TypeSave
 	TypeLoad
 	TypeAux
 	TypeClip
 	TypePopClip
-	TypeProfile
 	TypeCursor
 	TypePath
 	TypeStroke
@@ -85,8 +76,6 @@ const (
 	TypeSemanticClass
 	TypeSemanticSelected
 	TypeSemanticEnabled
-	TypeSnippet
-	TypeSelection
 	TypeActionInput
 )
 
@@ -148,21 +137,13 @@ const (
 	TypeLinearGradientLen   = 1 + 8*2 + 4*2
 	TypePassLen             = 1
 	TypePopPassLen          = 1
-	TypePointerInputLen     = 1 + 1 + 1*2 + 2*4 + 2*4
+	TypeInputLen            = 1
-	TypeClipboardReadLen    = 1
+	TypeKeyInputHintLen     = 1 + 1
-	TypeClipboardWriteLen   = 1
-	TypeSourceLen           = 1
-	TypeTargetLen           = 1
-	TypeOfferLen            = 1
-	TypeKeyInputLen         = 1 + 1
-	TypeKeyFocusLen         = 1 + 1
-	TypeKeySoftKeyboardLen  = 1 + 1
 	TypeSaveLen             = 1 + 4
 	TypeLoadLen             = 1 + 4
 	TypeAuxLen              = 1
 	TypeClipLen             = 1 + 4*4 + 1 + 1
 	TypePopClipLen          = 1
-	TypeProfileLen          = 1
 	TypeCursorLen           = 2
 	TypePathLen             = 8 + 1
 	TypeStrokeLen           = 1 + 4
@@ -171,8 +152,6 @@ const (
 	TypeSemanticClassLen    = 2
 	TypeSemanticSelectedLen = 2
 	TypeSemanticEnabledLen  = 2
-	TypeSnippetLen          = 1 + 4 + 4
-	TypeSelectionLen        = 1 + 2*4 + 2*4 + 4 + 4
 	TypeActionInputLen      = 1 + 1
 )
 
@@ -277,7 +256,7 @@ func PopOp(o *Ops, kind StackKind, sid StackID, macroID uint32) {
 	o.stacks[kind].pop(sid)
 }
 
-func Write1(o *Ops, n int, ref1 interface{}) []byte {
+func Write1(o *Ops, n int, ref1 any) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.refs = append(o.refs, ref1)
 	return o.data[len(o.data)-n:]
@@ -290,20 +269,20 @@ func Write1String(o *Ops, n int, ref1 string) []byte {
 	return o.data[len(o.data)-n:]
 }
 
-func Write2(o *Ops, n int, ref1, ref2 interface{}) []byte {
+func Write2(o *Ops, n int, ref1, ref2 any) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.refs = append(o.refs, ref1, ref2)
 	return o.data[len(o.data)-n:]
 }
 
-func Write2String(o *Ops, n int, ref1 interface{}, ref2 string) []byte {
+func Write2String(o *Ops, n int, ref1 any, ref2 string) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.stringRefs = append(o.stringRefs, ref2)
 	o.refs = append(o.refs, ref1, &o.stringRefs[len(o.stringRefs)-1])
 	return o.data[len(o.data)-n:]
 }
 
-func Write3(o *Ops, n int, ref1, ref2, ref3 interface{}) []byte {
+func Write3(o *Ops, n int, ref1, ref2, ref3 any) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.refs = append(o.refs, ref1, ref2, ref3)
 	return o.data[len(o.data)-n:]
@@ -425,28 +404,19 @@ var opProps = [0x100]opProp{
 	TypePopTransform:     {Size: TypePopTransformLen, NumRefs: 0},
 	TypePushOpacity:      {Size: TypePushOpacityLen, NumRefs: 0},
 	TypePopOpacity:       {Size: TypePopOpacityLen, NumRefs: 0},
-	TypeInvalidate:       {Size: TypeRedrawLen, NumRefs: 0},
 	TypeImage:            {Size: TypeImageLen, NumRefs: 2},
 	TypePaint:            {Size: TypePaintLen, NumRefs: 0},
 	TypeColor:            {Size: TypeColorLen, NumRefs: 0},
 	TypeLinearGradient:   {Size: TypeLinearGradientLen, NumRefs: 0},
 	TypePass:             {Size: TypePassLen, NumRefs: 0},
 	TypePopPass:          {Size: TypePopPassLen, NumRefs: 0},
-	TypePointerInput:     {Size: TypePointerInputLen, NumRefs: 1},
+	TypeInput:            {Size: TypeInputLen, NumRefs: 1},
-	TypeClipboardRead:    {Size: TypeClipboardReadLen, NumRefs: 1},
+	TypeKeyInputHint:     {Size: TypeKeyInputHintLen, NumRefs: 1},
-	TypeClipboardWrite:   {Size: TypeClipboardWriteLen, NumRefs: 1},
-	TypeSource:           {Size: TypeSourceLen, NumRefs: 2},
-	TypeTarget:           {Size: TypeTargetLen, NumRefs: 2},
-	TypeOffer:            {Size: TypeOfferLen, NumRefs: 3},
-	TypeKeyInput:         {Size: TypeKeyInputLen, NumRefs: 2},
-	TypeKeyFocus:         {Size: TypeKeyFocusLen, NumRefs: 1},
-	TypeKeySoftKeyboard:  {Size: TypeKeySoftKeyboardLen, NumRefs: 0},
 	TypeSave:             {Size: TypeSaveLen, NumRefs: 0},
 	TypeLoad:             {Size: TypeLoadLen, NumRefs: 0},
 	TypeAux:              {Size: TypeAuxLen, NumRefs: 0},
 	TypeClip:             {Size: TypeClipLen, NumRefs: 0},
 	TypePopClip:          {Size: TypePopClipLen, NumRefs: 0},
-	TypeProfile:          {Size: TypeProfileLen, NumRefs: 1},
 	TypeCursor:           {Size: TypeCursorLen, NumRefs: 0},
 	TypePath:             {Size: TypePathLen, NumRefs: 0},
 	TypeStroke:           {Size: TypeStrokeLen, NumRefs: 0},
@@ -455,8 +425,6 @@ var opProps = [0x100]opProp{
 	TypeSemanticClass:    {Size: TypeSemanticClassLen, NumRefs: 0},
 	TypeSemanticSelected: {Size: TypeSemanticSelectedLen, NumRefs: 0},
 	TypeSemanticEnabled:  {Size: TypeSemanticEnabledLen, NumRefs: 0},
-	TypeSnippet:          {Size: TypeSnippetLen, NumRefs: 2},
-	TypeSelection:        {Size: TypeSelectionLen, NumRefs: 1},
 	TypeActionInput:      {Size: TypeActionInputLen, NumRefs: 0},
 }
 
@@ -489,8 +457,6 @@ func (t OpType) String() string {
 		return "PushOpacity"
 	case TypePopOpacity:
 		return "PopOpacity"
-	case TypeInvalidate:
-		return "Invalidate"
 	case TypeImage:
 		return "Image"
 	case TypePaint:
@@ -503,24 +469,10 @@ func (t OpType) String() string {
 		return "Pass"
 	case TypePopPass:
 		return "PopPass"
-	case TypePointerInput:
+	case TypeInput:
-		return "PointerInput"
+		return "Input"
-	case TypeClipboardRead:
+	case TypeKeyInputHint:
-		return "ClipboardRead"
+		return "KeyInputHint"
-	case TypeClipboardWrite:
-		return "ClipboardWrite"
-	case TypeSource:
-		return "Source"
-	case TypeTarget:
-		return "Target"
-	case TypeOffer:
-		return "Offer"
-	case TypeKeyInput:
-		return "KeyInput"
-	case TypeKeyFocus:
-		return "KeyFocus"
-	case TypeKeySoftKeyboard:
-		return "KeySoftKeyboard"
 	case TypeSave:
 		return "Save"
 	case TypeLoad:
@@ -531,8 +483,6 @@ func (t OpType) String() string {
 		return "Clip"
 	case TypePopClip:
 		return "PopClip"
-	case TypeProfile:
-		return "Profile"
 	case TypeCursor:
 		return "Cursor"
 	case TypePath:

internal/ops/reader.go

@@ -20,7 +20,7 @@ type Reader struct {
 type EncodedOp struct {
 	Key  Key
 	Data []byte
-	Refs []interface{}
+	Refs []any
 }
 
 // Key is a unique key for a given op.
@@ -175,7 +175,7 @@ func (op *opMacroDef) decode(data []byte) {
 	op.endpc.refs = bo.Uint32(data[5:])
 }
 
-func (m *macroOp) decode(data []byte, refs []interface{}) {
+func (m *macroOp) decode(data []byte, refs []any) {
 	if len(data) < TypeCallLen || len(refs) < 1 || OpType(data[0]) != TypeCall {
 		panic("invalid op")
 	}

internal/stroke/stroke.go

@@ -87,7 +87,7 @@ func (qs *StrokeQuads) lineTo(pt f32.Point) {
 func (qs *StrokeQuads) arc(f1, f2 f32.Point, angle float32) {
 	pen := qs.pen()
 	m, segments := ArcTransform(pen, f1.Add(pen), f2.Add(pen), angle)
-	for i := 0; i < segments; i++ {
+	for range segments {
 		p0 := qs.pen()
 		p1 := m.Transform(p0)
 		p2 := m.Transform(p1)
@@ -327,10 +327,26 @@ func strokePathNorm(p0, p1, p2 f32.Point, t, d float32) f32.Point {
 func rot90CW(p f32.Point) f32.Point { return f32.Pt(+p.Y, -p.X) }
 
 func normPt(p f32.Point, l float32) f32.Point {
+	if (p.X == 0 && p.Y == 0) || l == 0 {
+		return f32.Point{}
+	}
+	isVerticalUnit := p.X == 0 && (p.Y == l || p.Y == -l)
+	isHorizontalUnit := p.Y == 0 && (p.X == l || p.X == -l)
+	if isVerticalUnit || isHorizontalUnit {
+		if math.Signbit(float64(l)) {
+			return f32.Point{X: -p.X, Y: -p.Y}
+		} else {
+			return f32.Point{X: p.X, Y: p.Y}
+		}
+	}
 	d := math.Hypot(float64(p.X), float64(p.Y))
 	l64 := float64(l)
 	if math.Abs(d-l64) < 1e-10 {
-		return f32.Point{}
+		if math.Signbit(float64(l)) {
+			return f32.Point{X: -p.X, Y: -p.Y}
+		} else {
+			return f32.Point{X: p.X, Y: p.Y}
+		}
 	}
 	n := float32(l64 / d)
 	return f32.Point{X: p.X * n, Y: p.Y * n}
@@ -437,7 +453,6 @@ func flattenQuadBezier(qs StrokeQuads, p0, p1, p2 f32.Point, d, flatness float32
 }
 
 func (qs *StrokeQuads) addLine(p0, ctrl, p1 f32.Point, t, d float32) {
-
 	switch i := len(*qs); i {
 	case 0:
 		p0 = p0.Add(strokePathNorm(p0, ctrl, p1, 0, d))
@@ -470,7 +485,6 @@ func quadInterp(p, q f32.Point, t float32) f32.Point {
 // quadBezierSplit returns the pair of triplets (from,ctrl,to) Bézier curve,
 // split before (resp. after) the provided parametric t value.
 func quadBezierSplit(p0, p1, p2 f32.Point, t float32) (f32.Point, f32.Point, f32.Point, f32.Point, f32.Point, f32.Point) {
-
 	var (
 		b0 = p0
 		b1 = quadInterp(p0, p1, t)
@@ -574,12 +588,10 @@ func ArcTransform(p, f1, f2 f32.Point, angle float32) (transform f32.Affine2D, s
 		}
 	}
 
-	var (
+	θ := angle / float32(segments)
-		θ   = angle / float32(segments)
+	ref := f32.AffineId() // transform from absolute frame to ellipse-based one
-		ref f32.Affine2D // transform from absolute frame to ellipse-based one
+	rot := f32.AffineId() // rotation matrix for each segment
-		rot f32.Affine2D // rotation matrix for each segment
+	inv := f32.AffineId() // transform from ellipse-based frame to absolute one
-		inv f32.Affine2D // transform from ellipse-based frame to absolute one
-	)
 	center := f32.Point{
 		X: 0.5 * (f1.X + f2.X),
 		Y: 0.5 * (f1.Y + f2.Y),

internal/stroke/stroke_test.go

@@ -9,6 +9,111 @@ import (
 	"gioui.org/internal/f32"
 )
 
+func TestNormPt(t *testing.T) {
+	type scenario struct {
+		l           float32
+		ptIn, ptOut f32.Point
+	}
+
+	scenarios := []scenario{
+		// l!=0 && X=Y=0
+		{l: 10, ptIn: f32.Point{X: 0, Y: 0}, ptOut: f32.Point{X: 0, Y: 0}},
+		{l: -10, ptIn: f32.Point{X: 0, Y: 0}, ptOut: f32.Point{X: 0, Y: 0}},
+
+		// l>0 & X
+		{l: +20, ptIn: f32.Point{X: +30, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: +20, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: +10, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: -10, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: -20, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: -30, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+
+		// l<0 & X
+		{l: -20, ptIn: f32.Point{X: +30, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: +20, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: +10, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: -10, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: -20, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: -30, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+
+		// l>0 & Y
+		{l: +20, ptIn: f32.Point{X: 0, Y: +30}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: +20}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: +10}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: -10}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: -20}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: -30}, ptOut: f32.Point{X: 0, Y: -20}},
+
+		// l<0 & Y
+		{l: -20, ptIn: f32.Point{X: 0, Y: +30}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: +20}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: +10}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: -10}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: -20}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: -30}, ptOut: f32.Point{X: 0, Y: +20}},
+
+		// l>0 && X=Y
+		{l: +20, ptIn: f32.Point{X: +90, Y: +90}, ptOut: f32.Point{X: +14.142137, Y: +14.142137}},
+		{l: +20, ptIn: f32.Point{X: +30, Y: +30}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: +20, Y: +20}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: +10, Y: +10}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -10, Y: -10}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -20, Y: -20}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -30, Y: -30}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -90, Y: -90}, ptOut: f32.Point{X: -14.142137, Y: -14.142137}},
+
+		// l>0 && X=-Y
+		{l: +20, ptIn: f32.Point{X: +90, Y: -90}, ptOut: f32.Point{X: +14.142137, Y: -14.142137}},
+		{l: +20, ptIn: f32.Point{X: +30, Y: -30}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: +20, Y: -20}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: +10, Y: -10}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -10, Y: +10}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -20, Y: +20}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -30, Y: +30}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -90, Y: +90}, ptOut: f32.Point{X: -14.142137, Y: +14.142137}},
+
+		// l<0 && X=Y
+		{l: -20, ptIn: f32.Point{X: +90, Y: +90}, ptOut: f32.Point{X: -14.142137, Y: -14.142137}},
+		{l: -20, ptIn: f32.Point{X: +30, Y: +30}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: +20, Y: +20}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: +10, Y: +10}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -10, Y: -10}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -20, Y: -20}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -30, Y: -30}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -90, Y: -90}, ptOut: f32.Point{X: +14.142137, Y: +14.142137}},
+
+		// l<0 && X=-Y
+		{l: -20, ptIn: f32.Point{X: +90, Y: -90}, ptOut: f32.Point{X: -14.142137, Y: +14.142137}},
+		{l: -20, ptIn: f32.Point{X: +30, Y: -30}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: +20, Y: -20}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: +10, Y: -10}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -10, Y: +10}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -20, Y: +20}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -30, Y: +30}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -90, Y: +90}, ptOut: f32.Point{X: +14.142137, Y: -14.142137}},
+
+		// l!=0 && Hypot=l
+		{l: 5, ptIn: f32.Point{X: 3, Y: 4}, ptOut: f32.Point{X: 3, Y: 4}},
+		{l: 5, ptIn: f32.Point{X: 3, Y: -4}, ptOut: f32.Point{X: 3, Y: -4}},
+		{l: 5, ptIn: f32.Point{X: -3, Y: -4}, ptOut: f32.Point{X: -3, Y: -4}},
+		{l: 5, ptIn: f32.Point{X: -3, Y: 4}, ptOut: f32.Point{X: -3, Y: 4}},
+		{l: -5, ptIn: f32.Point{X: 3, Y: 4}, ptOut: f32.Point{X: -3, Y: -4}},
+		{l: -5, ptIn: f32.Point{X: 3, Y: -4}, ptOut: f32.Point{X: -3, Y: 4}},
+		{l: -5, ptIn: f32.Point{X: -3, Y: -4}, ptOut: f32.Point{X: 3, Y: 4}},
+		{l: -5, ptIn: f32.Point{X: -3, Y: 4}, ptOut: f32.Point{X: 3, Y: -4}},
+	}
+
+	for i, s := range scenarios {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			actual := normPt(s.ptIn, s.l)
+			if actual != s.ptOut {
+				t.Errorf("in: %v*%v, expected: %v, actual: %v", s.l, s.ptIn, s.ptOut, actual)
+			}
+		})
+
+	}
+}
+
 func BenchmarkSplitCubic(b *testing.B) {
 	type scenario struct {
 		segments               int
@@ -52,7 +157,7 @@ func BenchmarkSplitCubic(b *testing.B) {
 			from, ctrl0, ctrl1, to := s.from, s.ctrl0, s.ctrl1, s.to
 			quads := make([]QuadSegment, s.segments)
 			b.ResetTimer()
-			for i := 0; i < b.N; i++ {
+			for b.Loop() {
 				quads = SplitCubic(from, ctrl0, ctrl1, to, quads[:0])
 			}
 			if len(quads) != s.segments {

internal/vk/vulkan.go

@@ -385,6 +385,7 @@ static VkResult vkQueuePresentKHR(PFN_vkQueuePresentKHR f, VkQueue queue, const
 }
 */
 import "C"
+
 import (
 	"errors"
 	"fmt"
@@ -1167,7 +1168,6 @@ func CreateFramebuffer(d Device, rp RenderPass, view ImageView, width, height in
 		return nilFramebuffer, fmt.Errorf("vulkan: vkCreateFramebuffer: %w", err)
 	}
 	return fbo, nil
-
 }
 
 func DestroyFramebuffer(d Device, f Framebuffer) {
@@ -1893,27 +1893,27 @@ func BuildWriteDescriptorSetBuffer(set DescriptorSet, binding int, typ Descripto
 	}
 }
 
-func (r PushConstantRange) StageFlags() ShaderStageFlags {
+func PushConstantRangeStageFlags(r PushConstantRange) ShaderStageFlags {
 	return r.stageFlags
 }
 
-func (r PushConstantRange) Offset() int {
+func PushConstantRangeOffset(r PushConstantRange) int {
 	return int(r.offset)
 }
 
-func (r PushConstantRange) Size() int {
+func PushConstantRangeSize(r PushConstantRange) int {
 	return int(r.size)
 }
 
-func (p QueueFamilyProperties) Flags() QueueFlags {
+func QueueFamilyPropertiesFlags(p QueueFamilyProperties) QueueFlags {
 	return p.queueFlags
 }
 
-func (c SurfaceCapabilities) MinExtent() image.Point {
+func SurfaceCapabilitiesMinExtent(c SurfaceCapabilities) image.Point {
 	return image.Pt(int(c.minImageExtent.width), int(c.minImageExtent.height))
 }
 
-func (c SurfaceCapabilities) MaxExtent() image.Point {
+func SurfaceCapabilitiesMaxExtent(c SurfaceCapabilities) image.Point {
 	return image.Pt(int(c.maxImageExtent.width), int(c.maxImageExtent.height))
 }
 

internal/vk/vulkan_android.go

@@ -17,6 +17,7 @@ static VkResult vkCreateAndroidSurfaceKHR(PFN_vkCreateAndroidSurfaceKHR f, VkIns
 }
 */
 import "C"
+
 import (
 	"fmt"
 	"unsafe"

internal/vk/vulkan_wayland.go

@@ -19,6 +19,7 @@ static VkResult vkCreateWaylandSurfaceKHR(PFN_vkCreateWaylandSurfaceKHR f, VkIns
 }
 */
 import "C"
+
 import (
 	"fmt"
 	"unsafe"

internal/vk/vulkan_x11.go

@@ -17,6 +17,7 @@ static VkResult vkCreateXlibSurfaceKHR(PFN_vkCreateXlibSurfaceKHR f, VkInstance
 }
 */
 import "C"
+
 import (
 	"fmt"
 	"unsafe"

io/clipboard/clipboard.go

@@ -3,35 +3,22 @@
 package clipboard
 
 import (
-	"gioui.org/internal/ops"
+	"io"
+
 	"gioui.org/io/event"
-	"gioui.org/op"
 )
 
-// Event is generated when the clipboard content is requested.
+// WriteCmd copies Text to the clipboard.
-type Event struct {
+type WriteCmd struct {
-	Text string
+	Type string
+	Data io.ReadCloser
 }
 
-// ReadOp requests the text of the clipboard, delivered to
+// ReadCmd requests the text of the clipboard, delivered to
-// the current handler through an Event.
+// the handler through an [io/transfer.DataEvent].
-type ReadOp struct {
+type ReadCmd struct {
 	Tag event.Tag
 }
 
-// WriteOp copies Text to the clipboard.
+func (WriteCmd) ImplementsCommand() {}
-type WriteOp struct {
+func (ReadCmd) ImplementsCommand()  {}
-	Text string
-}
-
-func (h ReadOp) Add(o *op.Ops) {
-	data := ops.Write1(&o.Internal, ops.TypeClipboardReadLen, h.Tag)
-	data[0] = byte(ops.TypeClipboardRead)
-}
-
-func (h WriteOp) Add(o *op.Ops) {
-	data := ops.Write1String(&o.Internal, ops.TypeClipboardWriteLen, h.Text)
-	data[0] = byte(ops.TypeClipboardWrite)
-}
-
-func (Event) ImplementsEvent() {}

io/event/event.go

@@ -1,47 +1,33 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-/*
+// Package event contains types for event handling.
-Package event contains the types for event handling.
-
-The Queue interface is the protocol for receiving external events.
-
-For example:
-
-	var queue event.Queue = ...
-
-	for _, e := range queue.Events(h) {
-		switch e.(type) {
-			...
-		}
-	}
-
-In general, handlers must be declared before events become
-available. Other packages such as pointer and key provide
-the means for declaring handlers for specific event types.
-
-The following example declares a handler ready for key input:
-
-	import gioui.org/io/key
-
-	ops := new(op.Ops)
-	var h *Handler = ...
-	key.InputOp{Tag: h, Filter: ...}.Add(ops)
-*/
 package event
 
-// Queue maps an event handler key to the events
+import (
-// available to the handler.
+	"gioui.org/internal/ops"
-type Queue interface {
+	"gioui.org/op"
-	// Events returns the available events for an
+)
-	// event handler tag.
-	Events(t Tag) []Event
-}
 
 // Tag is the stable identifier for an event handler.
 // For a handler h, the tag is typically &h.
-type Tag interface{}
+type Tag any
 
 // Event is the marker interface for events.
 type Event interface {
 	ImplementsEvent()
 }
+
+// Filter represents a filter for [Event] types.
+type Filter interface {
+	ImplementsFilter()
+}
+
+// Op declares a tag for input routing at the current transformation
+// and clip area hierarchy. It panics if tag is nil.
+func Op(o *op.Ops, tag Tag) {
+	if tag == nil {
+		panic("Tag must be non-nil")
+	}
+	data := ops.Write1(&o.Internal, ops.TypeInputLen, tag)
+	data[0] = byte(ops.TypeInput)
+}

io/input/clipboard.go

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package input
+
+import (
+	"io"
+	"slices"
+
+	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
+)
+
+// clipboardState contains the state for clipboard event routing.
+type clipboardState struct {
+	receivers []event.Tag
+}
+
+type clipboardQueue struct {
+	// request avoid read clipboard every frame while waiting.
+	requested bool
+	mime      string
+	text      []byte
+}
+
+// WriteClipboard returns the most recent data to be copied
+// to the clipboard, if any.
+func (q *clipboardQueue) WriteClipboard() (mime string, content []byte, ok bool) {
+	if q.text == nil {
+		return "", nil, false
+	}
+	content = q.text
+	q.text = nil
+	return q.mime, content, true
+}
+
+// ClipboardRequested reports if any new handler is waiting
+// to read the clipboard.
+func (q *clipboardQueue) ClipboardRequested(state clipboardState) bool {
+	req := len(state.receivers) > 0 && q.requested
+	q.requested = false
+	return req
+}
+
+func (q *clipboardQueue) Push(state clipboardState, e event.Event) (clipboardState, []taggedEvent) {
+	var evts []taggedEvent
+	for _, r := range state.receivers {
+		evts = append(evts, taggedEvent{tag: r, event: e})
+	}
+	state.receivers = nil
+	return state, evts
+}
+
+func (q *clipboardQueue) ProcessWriteClipboard(req clipboard.WriteCmd) {
+	defer req.Data.Close()
+	content, err := io.ReadAll(req.Data)
+	if err != nil {
+		return
+	}
+	q.mime = req.Type
+	q.text = content
+}
+
+func (q *clipboardQueue) ProcessReadClipboard(state clipboardState, tag event.Tag) clipboardState {
+	if slices.Contains(state.receivers, tag) {
+		return state
+	}
+	n := len(state.receivers)
+	state.receivers = append(state.receivers[:n:n], tag)
+	q.requested = true
+	return state
+}

io/input/clipboard_test.go

@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package input
+
+import (
+	"io"
+	"strings"
+	"testing"
+
+	"gioui.org/io/clipboard"
+	"gioui.org/io/transfer"
+	"gioui.org/op"
+)
+
+func TestClipboardDuplicateEvent(t *testing.T) {
+	ops, r, handlers := new(op.Ops), new(Router), make([]int, 2)
+
+	// Both must receive the event once.
+	r.Source().Execute(clipboard.ReadCmd{Tag: &handlers[0]})
+	r.Source().Execute(clipboard.ReadCmd{Tag: &handlers[1]})
+
+	event := transfer.DataEvent{
+		Type: "application/text",
+		Open: func() io.ReadCloser {
+			return io.NopCloser(strings.NewReader("Test"))
+		},
+	}
+	r.Queue(event)
+	for i := range handlers {
+		f := transfer.TargetFilter{Target: &handlers[i], Type: "application/text"}
+		assertEventTypeSequence(t, events(r, -1, f), transfer.DataEvent{})
+	}
+	assertClipboardReadCmd(t, r, 0)
+
+	r.Source().Execute(clipboard.ReadCmd{Tag: &handlers[0]})
+
+	r.Frame(ops)
+	// No ClipboardEvent sent
+	assertClipboardReadCmd(t, r, 1)
+	for i := range handlers {
+		f := transfer.TargetFilter{Target: &handlers[i]}
+		assertEventTypeSequence(t, events(r, -1, f))
+	}
+}
+
+func TestQueueProcessReadClipboard(t *testing.T) {
+	ops, r, handler := new(op.Ops), new(Router), make([]int, 2)
+
+	// Request read
+	r.Source().Execute(clipboard.ReadCmd{Tag: &handler[0]})
+
+	assertClipboardReadCmd(t, r, 1)
+	ops.Reset()
+
+	for range 3 {
+		// No ReadCmd
+		// One receiver must still wait for response
+
+		r.Frame(ops)
+		assertClipboardReadDuplicated(t, r, 1)
+	}
+
+	// Send the clipboard event
+	event := transfer.DataEvent{
+		Type: "application/text",
+		Open: func() io.ReadCloser {
+			return io.NopCloser(strings.NewReader("Text 2"))
+		},
+	}
+	r.Queue(event)
+	assertEventTypeSequence(t, events(r, -1, transfer.TargetFilter{Target: &handler[0], Type: "application/text"}), transfer.DataEvent{})
+	assertClipboardReadCmd(t, r, 0)
+}
+
+func TestQueueProcessWriteClipboard(t *testing.T) {
+	r := new(Router)
+
+	const mime = "application/text"
+	r.Source().Execute(clipboard.WriteCmd{Type: mime, Data: io.NopCloser(strings.NewReader("Write 1"))})
+
+	assertClipboardWriteCmd(t, r, mime, "Write 1")
+	assertClipboardWriteCmd(t, r, "", "")
+
+	r.Source().Execute(clipboard.WriteCmd{Type: mime, Data: io.NopCloser(strings.NewReader("Write 2"))})
+
+	assertClipboardReadCmd(t, r, 0)
+	assertClipboardWriteCmd(t, r, mime, "Write 2")
+}
+
+func assertClipboardReadCmd(t *testing.T, router *Router, expected int) {
+	t.Helper()
+	if got := len(router.state().receivers); got != expected {
+		t.Errorf("unexpected %d receivers, got %d", expected, got)
+	}
+	if router.ClipboardRequested() != (expected > 0) {
+		t.Error("missing requests")
+	}
+}
+
+func assertClipboardReadDuplicated(t *testing.T, router *Router, expected int) {
+	t.Helper()
+	if len(router.state().receivers) != expected {
+		t.Error("receivers removed")
+	}
+	if router.ClipboardRequested() != false {
+		t.Error("duplicated requests")
+	}
+}
+
+func assertClipboardWriteCmd(t *testing.T, router *Router, mimeExp, expected string) {
+	t.Helper()
+	if (router.cqueue.text != nil) != (expected != "") {
+		t.Error("text not defined")
+	}
+	mime, text, ok := router.cqueue.WriteClipboard()
+	if ok != (expected != "") {
+		t.Error("duplicated requests")
+	}
+	if string(mime) != mimeExp {
+		t.Errorf("got MIME type %s, expected %s", mime, mimeExp)
+	}
+	if string(text) != expected {
+		t.Errorf("got text %s, expected %s", text, expected)
+	}
+}

io/input/doc.go

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+/*
+Package input implements input routing and tracking of interface
+state for a window.
+
+The [Source] is the interface between the window and the widgets
+of a user interface and is exposed by [gioui.org/app.FrameEvent]
+received from windows.
+
+The [Router] is used by [gioui.org/app.Window] to track window state and route
+events from the platform to event handlers. It is otherwise only
+useful for using Gio with external window implementations.
+*/
+package input

io/input/key.go

@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package input
+
+import (
+	"image"
+	"slices"
+	"sort"
+
+	"gioui.org/f32"
+	"gioui.org/io/event"
+	"gioui.org/io/key"
+)
+
+// EditorState represents the state of an editor needed by input handlers.
+type EditorState struct {
+	Selection struct {
+		Transform f32.Affine2D
+		key.Range
+		key.Caret
+	}
+	Snippet key.Snippet
+}
+
+type TextInputState uint8
+
+type keyQueue struct {
+	order    []event.Tag
+	dirOrder []dirFocusEntry
+	hint     key.InputHint
+}
+
+// keyState is the input state related to key events.
+type keyState struct {
+	focus   event.Tag
+	state   TextInputState
+	content EditorState
+}
+
+type keyHandler struct {
+	// visible will be true if the InputOp is present
+	// in the current frame.
+	visible bool
+	// reset tracks whether the handler has seen a
+	// focus reset.
+	reset        bool
+	hint         key.InputHint
+	orderPlusOne int
+	dirOrder     int
+	trans        f32.Affine2D
+}
+
+type keyFilter []key.Filter
+
+type dirFocusEntry struct {
+	tag    event.Tag
+	row    int
+	area   int
+	bounds image.Rectangle
+}
+
+const (
+	TextInputKeep TextInputState = iota
+	TextInputClose
+	TextInputOpen
+)
+
+func (k *keyHandler) inputHint(hint key.InputHint) {
+	k.hint = hint
+}
+
+// InputState returns the input state and returns a state
+// reset to [TextInputKeep].
+func (s keyState) InputState() (keyState, TextInputState) {
+	state := s.state
+	s.state = TextInputKeep
+	return s, state
+}
+
+// InputHint returns the input hint from the focused handler and whether it was
+// changed since the last call.
+func (q *keyQueue) InputHint(handlers map[event.Tag]*handler, state keyState) (key.InputHint, bool) {
+	focused, ok := handlers[state.focus]
+	if !ok {
+		return q.hint, false
+	}
+	old := q.hint
+	q.hint = focused.key.hint
+	return q.hint, old != q.hint
+}
+
+func (k *keyHandler) Reset() {
+	k.visible = false
+	k.orderPlusOne = 0
+	k.hint = key.HintAny
+}
+
+func (q *keyQueue) Reset() {
+	q.order = q.order[:0]
+	q.dirOrder = q.dirOrder[:0]
+}
+
+func (k *keyHandler) ResetEvent() (event.Event, bool) {
+	if k.reset {
+		return nil, false
+	}
+	k.reset = true
+	return key.FocusEvent{Focus: false}, true
+}
+
+func (q *keyQueue) Frame(handlers map[event.Tag]*handler, state keyState) keyState {
+	if state.focus != nil {
+		if h, ok := handlers[state.focus]; !ok || !h.filter.focusable || !h.key.visible {
+			// Remove focus from the handler that is no longer focusable.
+			state.focus = nil
+			state.state = TextInputClose
+		}
+	}
+	q.updateFocusLayout(handlers)
+	return state
+}
+
+// updateFocusLayout partitions input handlers handlers into rows
+// for directional focus moves.
+//
+// The approach is greedy: pick the topmost handler and create a row
+// containing it. Then, extend the handler bounds to a horizontal beam
+// and add to the row every handler whose center intersect it. Repeat
+// until no handlers remain.
+func (q *keyQueue) updateFocusLayout(handlers map[event.Tag]*handler) {
+	order := q.dirOrder
+	// Sort by ascending y position.
+	sort.SliceStable(order, func(i, j int) bool {
+		return order[i].bounds.Min.Y < order[j].bounds.Min.Y
+	})
+	row := 0
+	for len(order) > 0 {
+		h := &order[0]
+		h.row = row
+		bottom := h.bounds.Max.Y
+		end := 1
+		for ; end < len(order); end++ {
+			h := &order[end]
+			center := (h.bounds.Min.Y + h.bounds.Max.Y) / 2
+			if center > bottom {
+				break
+			}
+			h.row = row
+		}
+		// Sort row by ascending x position.
+		sort.SliceStable(order[:end], func(i, j int) bool {
+			return order[i].bounds.Min.X < order[j].bounds.Min.X
+		})
+		order = order[end:]
+		row++
+	}
+	for i, o := range q.dirOrder {
+		handlers[o.tag].key.dirOrder = i
+	}
+}
+
+// MoveFocus attempts to move the focus in the direction of dir.
+func (q *keyQueue) MoveFocus(handlers map[event.Tag]*handler, state keyState, dir key.FocusDirection) (keyState, []taggedEvent) {
+	if len(q.dirOrder) == 0 {
+		return state, nil
+	}
+	order := 0
+	if state.focus != nil {
+		order = handlers[state.focus].key.dirOrder
+	}
+	focus := q.dirOrder[order]
+	switch dir {
+	case key.FocusForward, key.FocusBackward:
+		if len(q.order) == 0 {
+			break
+		}
+		order := 0
+		if dir == key.FocusBackward {
+			order = -1
+		}
+		if state.focus != nil {
+			order = handlers[state.focus].key.orderPlusOne - 1
+			if dir == key.FocusForward {
+				order++
+			} else {
+				order--
+			}
+		}
+		order = (order + len(q.order)) % len(q.order)
+		return q.Focus(handlers, state, q.order[order])
+	case key.FocusRight, key.FocusLeft:
+		next := order
+		if state.focus != nil {
+			next = order + 1
+			if dir == key.FocusLeft {
+				next = order - 1
+			}
+		}
+		if 0 <= next && next < len(q.dirOrder) {
+			newFocus := q.dirOrder[next]
+			if newFocus.row == focus.row {
+				return q.Focus(handlers, state, newFocus.tag)
+			}
+		}
+	case key.FocusUp, key.FocusDown:
+		delta := +1
+		if dir == key.FocusUp {
+			delta = -1
+		}
+		nextRow := 0
+		if state.focus != nil {
+			nextRow = focus.row + delta
+		}
+		var closest event.Tag
+		dist := int(1e6)
+		center := (focus.bounds.Min.X + focus.bounds.Max.X) / 2
+	loop:
+		for 0 <= order && order < len(q.dirOrder) {
+			next := q.dirOrder[order]
+			switch next.row {
+			case nextRow:
+				nextCenter := (next.bounds.Min.X + next.bounds.Max.X) / 2
+				d := center - nextCenter
+				if d < 0 {
+					d = -d
+				}
+				if d > dist {
+					break loop
+				}
+				dist = d
+				closest = next.tag
+			case nextRow + delta:
+				break loop
+			}
+			order += delta
+		}
+		if closest != nil {
+			return q.Focus(handlers, state, closest)
+		}
+	}
+	return state, nil
+}
+
+func (q *keyQueue) BoundsFor(k *keyHandler) image.Rectangle {
+	order := k.dirOrder
+	return q.dirOrder[order].bounds
+}
+
+func (q *keyQueue) AreaFor(k *keyHandler) int {
+	order := k.dirOrder
+	return q.dirOrder[order].area
+}
+
+func (k *keyFilter) Matches(focus event.Tag, e key.Event, system bool) bool {
+	for _, f := range *k {
+		if keyFilterMatch(focus, f, e, system) {
+			return true
+		}
+	}
+	return false
+}
+
+func keyFilterMatch(focus event.Tag, f key.Filter, e key.Event, system bool) bool {
+	if f.Focus != nil && f.Focus != focus {
+		return false
+	}
+	if (f.Name != "" || system) && f.Name != e.Name {
+		return false
+	}
+	if e.Modifiers&f.Required != f.Required {
+		return false
+	}
+	if e.Modifiers&^(f.Required|f.Optional) != 0 {
+		return false
+	}
+	return true
+}
+
+func (q *keyQueue) Focus(handlers map[event.Tag]*handler, state keyState, focus event.Tag) (keyState, []taggedEvent) {
+	if focus == state.focus {
+		return state, nil
+	}
+	state.content = EditorState{}
+	state.content.Selection.Transform = f32.AffineId()
+	var evts []taggedEvent
+	if state.focus != nil {
+		evts = append(evts, taggedEvent{tag: state.focus, event: key.FocusEvent{Focus: false}})
+	}
+	state.focus = focus
+	if state.focus != nil {
+		evts = append(evts, taggedEvent{tag: state.focus, event: key.FocusEvent{Focus: true}})
+	}
+	if state.focus == nil || state.state == TextInputKeep {
+		state.state = TextInputClose
+	}
+	return state, evts
+}
+
+func (s keyState) softKeyboard(show bool) keyState {
+	if show {
+		s.state = TextInputOpen
+	} else {
+		s.state = TextInputClose
+	}
+	return s
+}
+
+func (k *keyFilter) Add(f key.Filter) {
+	if slices.Contains(*k, f) {
+		return
+	}
+	*k = append(*k, f)
+}
+
+func (k *keyFilter) Merge(k2 keyFilter) {
+	*k = append(*k, k2...)
+}
+
+func (q *keyQueue) inputOp(tag event.Tag, state *keyHandler, t f32.Affine2D, area int, bounds image.Rectangle) {
+	state.visible = true
+	if state.orderPlusOne == 0 {
+		state.orderPlusOne = len(q.order) + 1
+		q.order = append(q.order, tag)
+		q.dirOrder = append(q.dirOrder, dirFocusEntry{tag: tag, area: area, bounds: bounds})
+	}
+	state.trans = t
+}
+
+func (q *keyQueue) setSelection(state keyState, req key.SelectionCmd) keyState {
+	if req.Tag != state.focus {
+		return state
+	}
+	state.content.Selection.Range = req.Range
+	state.content.Selection.Caret = req.Caret
+	return state
+}
+
+func (q *keyQueue) editorState(handlers map[event.Tag]*handler, state keyState) EditorState {
+	s := state.content
+	if f := state.focus; f != nil {
+		s.Selection.Transform = handlers[f].key.trans
+	}
+	return s
+}
+
+func (q *keyQueue) setSnippet(state keyState, req key.SnippetCmd) keyState {
+	if req.Tag == state.focus {
+		state.content.Snippet = req.Snippet
+	}
+	return state
+}
+
+func (t TextInputState) String() string {
+	switch t {
+	case TextInputKeep:
+		return "Keep"
+	case TextInputClose:
+		return "Close"
+	case TextInputOpen:
+		return "Open"
+	default:
+		panic("unexpected value")
+	}
+}

io/input/key_test.go

@@ -0,0 +1,332 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package input
+
+import (
+	"image"
+	"testing"
+
+	"gioui.org/f32"
+	"gioui.org/io/event"
+	"gioui.org/io/key"
+	"gioui.org/io/pointer"
+	"gioui.org/op"
+	"gioui.org/op/clip"
+)
+
+func TestAllMatchKeyFilter(t *testing.T) {
+	r := new(Router)
+	r.Event(key.Filter{})
+	ke := key.Event{Name: "A"}
+	r.Queue(ke)
+	// Catch-all gets all non-system events.
+	assertEventSequence(t, events(r, -1, key.Filter{}), ke)
+
+	r = new(Router)
+	r.Event(key.Filter{Name: "A"})
+	r.Queue(SystemEvent{ke})
+	if _, handled := r.WakeupTime(); !handled {
+		t.Errorf("system event was unexpectedly ignored")
+	}
+	// Only specific filters match system events.
+	assertEventSequence(t, events(r, -1, key.Filter{Name: "A"}), ke)
+}
+
+func TestInputHint(t *testing.T) {
+	r := new(Router)
+	if hint, changed := r.TextInputHint(); hint != key.HintAny || changed {
+		t.Fatal("unexpected hint")
+	}
+	ops := new(op.Ops)
+	h := new(int)
+	key.InputHintOp{Tag: h, Hint: key.HintEmail}.Add(ops)
+	r.Frame(ops)
+	if hint, changed := r.TextInputHint(); hint != key.HintAny || changed {
+		t.Fatal("unexpected hint")
+	}
+	r.Source().Execute(key.FocusCmd{Tag: h})
+	if hint, changed := r.TextInputHint(); hint != key.HintEmail || !changed {
+		t.Fatal("unexpected hint")
+	}
+}
+
+func TestDeferred(t *testing.T) {
+	r := new(Router)
+	h := new(int)
+	f := []event.Filter{
+		key.FocusFilter{Target: h},
+		key.Filter{Name: "A"},
+	}
+	// Provoke deferring by exhausting events for h.
+	events(r, -1, f...)
+	r.Source().Execute(key.FocusCmd{Tag: h})
+	ke := key.Event{Name: "A"}
+	r.Queue(ke)
+	// All events are deferred at this point.
+	assertEventSequence(t, events(r, -1, f...))
+	r.Frame(new(op.Ops))
+	// But delivered after a frame.
+	assertEventSequence(t, events(r, -1, f...), key.FocusEvent{Focus: true}, ke)
+}
+
+func TestInputWakeup(t *testing.T) {
+	handler := new(int)
+	var ops op.Ops
+	// InputOps shouldn't trigger redraws.
+	event.Op(&ops, handler)
+
+	var r Router
+	// Reset events shouldn't either.
+	evts := events(&r, -1, key.FocusFilter{Target: new(int)}, key.Filter{Name: "A"})
+	assertEventSequence(t, evts, key.FocusEvent{Focus: false})
+	r.Frame(&ops)
+	if _, wake := r.WakeupTime(); wake {
+		t.Errorf("InputOp or the resetting FocusEvent triggered a wakeup")
+	}
+	// And neither does events that don't match anything.
+	r.Queue(key.SnippetEvent{})
+	if _, handled := r.WakeupTime(); handled {
+		t.Errorf("a not-matching event triggered a wakeup")
+	}
+	// However, events that does match should trigger wakeup.
+	r.Queue(key.Event{Name: "A"})
+	if _, handled := r.WakeupTime(); !handled {
+		t.Errorf("a key.Event didn't trigger redraw")
+	}
+}
+
+func TestKeyMultiples(t *testing.T) {
+	handlers := make([]int, 3)
+	r := new(Router)
+	r.Source().Execute(key.SoftKeyboardCmd{Show: true})
+	for i := range handlers {
+		assertEventSequence(t, events(r, 1, key.FocusFilter{Target: &handlers[i]}), key.FocusEvent{Focus: false})
+	}
+	r.Source().Execute(key.FocusCmd{Tag: &handlers[2]})
+	assertEventSequence(t, events(r, -1, key.FocusFilter{Target: &handlers[2]}), key.FocusEvent{Focus: true})
+	assertFocus(t, r, &handlers[2])
+
+	assertKeyboard(t, r, TextInputOpen)
+}
+
+func TestKeySoftKeyboardNoFocus(t *testing.T) {
+	r := new(Router)
+
+	// It's possible to open the keyboard
+	// without any active focus:
+	r.Source().Execute(key.SoftKeyboardCmd{Show: true})
+
+	assertFocus(t, r, nil)
+	assertKeyboard(t, r, TextInputOpen)
+}
+
+func TestKeyRemoveFocus(t *testing.T) {
+	handlers := make([]int, 2)
+	r := new(Router)
+
+	filters := func(h event.Tag) []event.Filter {
+		return []event.Filter{
+			key.FocusFilter{Target: h},
+			key.Filter{Focus: h, Name: key.NameTab, Required: key.ModShortcut},
+		}
+	}
+	var all []event.Filter
+	for i := range handlers {
+		all = append(all, filters(&handlers[i])...)
+	}
+	assertEventSequence(t, events(r, len(handlers), all...), key.FocusEvent{}, key.FocusEvent{})
+	r.Source().Execute(key.FocusCmd{Tag: &handlers[0]})
+	r.Source().Execute(key.SoftKeyboardCmd{Show: true})
+
+	evt := key.Event{Name: key.NameTab, Modifiers: key.ModShortcut, State: key.Press}
+	r.Queue(evt)
+
+	assertEventSequence(t, events(r, 2, filters(&handlers[0])...), key.FocusEvent{Focus: true}, evt)
+	assertFocus(t, r, &handlers[0])
+	assertKeyboard(t, r, TextInputOpen)
+
+	// Frame removes focus from tags that don't filter for focus events nor mentioned in an InputOp.
+	r.Source().Execute(key.FocusCmd{Tag: new(int)})
+	r.Frame(new(op.Ops))
+
+	assertEventSequence(t, events(r, -1, filters(&handlers[1])...))
+	assertFocus(t, r, nil)
+	assertKeyboard(t, r, TextInputClose)
+
+	// Set focus to InputOp which already
+	// exists in the previous frame:
+	r.Source().Execute(key.FocusCmd{Tag: &handlers[0]})
+	assertFocus(t, r, &handlers[0])
+}
+
+func TestKeyFocusedInvisible(t *testing.T) {
+	handlers := make([]int, 2)
+	ops := new(op.Ops)
+	r := new(Router)
+
+	for i := range handlers {
+		assertEventSequence(t, events(r, 1, key.FocusFilter{Target: &handlers[i]}), key.FocusEvent{Focus: false})
+	}
+
+	// Set new InputOp with focus:
+	r.Source().Execute(key.FocusCmd{Tag: &handlers[0]})
+	r.Source().Execute(key.SoftKeyboardCmd{Show: true})
+
+	assertEventSequence(t, events(r, 1, key.FocusFilter{Target: &handlers[0]}), key.FocusEvent{Focus: true})
+	assertFocus(t, r, &handlers[0])
+	assertKeyboard(t, r, TextInputOpen)
+
+	// Frame will clear the focus because the handler is not visible.
+	r.Frame(ops)
+
+	for i := range handlers {
+		assertEventSequence(t, events(r, -1, key.FocusFilter{Target: &handlers[i]}))
+	}
+	assertFocus(t, r, nil)
+	assertKeyboard(t, r, TextInputClose)
+
+	r.Frame(ops)
+	r.Frame(ops)
+
+	ops.Reset()
+
+	// Respawn the first element:
+	// It must receive one `Event{Focus: false}`.
+	event.Op(ops, &handlers[0])
+
+	assertEventSequence(t, events(r, -1, key.FocusFilter{Target: &handlers[0]}), key.FocusEvent{Focus: false})
+}
+
+func TestNoOps(t *testing.T) {
+	r := new(Router)
+	r.Frame(nil)
+}
+
+func TestDirectionalFocus(t *testing.T) {
+	ops := new(op.Ops)
+	r := new(Router)
+	handlers := []image.Rectangle{
+		image.Rect(10, 10, 50, 50),
+		image.Rect(50, 20, 100, 80),
+		image.Rect(20, 26, 60, 80),
+		image.Rect(10, 60, 50, 100),
+	}
+
+	for i, bounds := range handlers {
+		cl := clip.Rect(bounds).Push(ops)
+		event.Op(ops, &handlers[i])
+		cl.Pop()
+		events(r, -1, key.FocusFilter{Target: &handlers[i]})
+	}
+	r.Frame(ops)
+
+	r.MoveFocus(key.FocusLeft)
+	assertFocus(t, r, &handlers[0])
+	r.MoveFocus(key.FocusLeft)
+	assertFocus(t, r, &handlers[0])
+	r.MoveFocus(key.FocusRight)
+	assertFocus(t, r, &handlers[1])
+	r.MoveFocus(key.FocusRight)
+	assertFocus(t, r, &handlers[1])
+	r.MoveFocus(key.FocusDown)
+	assertFocus(t, r, &handlers[2])
+	r.MoveFocus(key.FocusDown)
+	assertFocus(t, r, &handlers[2])
+	r.MoveFocus(key.FocusLeft)
+	assertFocus(t, r, &handlers[3])
+	r.MoveFocus(key.FocusUp)
+	assertFocus(t, r, &handlers[0])
+
+	r.MoveFocus(key.FocusForward)
+	assertFocus(t, r, &handlers[1])
+	r.MoveFocus(key.FocusBackward)
+	assertFocus(t, r, &handlers[0])
+}
+
+func TestFocusScroll(t *testing.T) {
+	ops := new(op.Ops)
+	r := new(Router)
+	h := new(int)
+
+	filters := []event.Filter{
+		key.FocusFilter{Target: h},
+		pointer.Filter{
+			Target:  h,
+			Kinds:   pointer.Scroll,
+			ScrollX: pointer.ScrollRange{Min: -100, Max: +100},
+			ScrollY: pointer.ScrollRange{Min: -100, Max: +100},
+		},
+	}
+	events(r, -1, filters...)
+	parent := clip.Rect(image.Rect(1, 1, 14, 39)).Push(ops)
+	cl := clip.Rect(image.Rect(10, -20, 20, 30)).Push(ops)
+	event.Op(ops, h)
+	// Test that h is scrolled even if behind another handler.
+	event.Op(ops, new(int))
+	cl.Pop()
+	parent.Pop()
+	r.Frame(ops)
+
+	r.MoveFocus(key.FocusLeft)
+	r.RevealFocus(image.Rect(0, 0, 15, 40))
+	evts := events(r, -1, filters...)
+	assertScrollEvent(t, evts[len(evts)-1], f32.Pt(6, -9))
+}
+
+func TestFocusClick(t *testing.T) {
+	ops := new(op.Ops)
+	r := new(Router)
+	h := new(int)
+
+	filters := []event.Filter{
+		key.FocusFilter{Target: h},
+		pointer.Filter{
+			Target: h,
+			Kinds:  pointer.Press | pointer.Release | pointer.Cancel,
+		},
+	}
+	assertEventPointerTypeSequence(t, events(r, -1, filters...), pointer.Cancel)
+	cl := clip.Rect(image.Rect(0, 0, 10, 10)).Push(ops)
+	event.Op(ops, h)
+	cl.Pop()
+	r.Frame(ops)
+
+	r.MoveFocus(key.FocusLeft)
+	r.ClickFocus()
+
+	assertEventPointerTypeSequence(t, events(r, -1, filters...), pointer.Press, pointer.Release)
+}
+
+func TestNoFocus(t *testing.T) {
+	r := new(Router)
+	r.MoveFocus(key.FocusForward)
+}
+
+func TestKeyRouting(t *testing.T) {
+	r := new(Router)
+	h := new(int)
+	A, B := key.Event{Name: "A"}, key.Event{Name: "B"}
+	// Register filters.
+	events(r, -1, key.Filter{Name: "A"}, key.Filter{Name: "B"})
+	r.Frame(new(op.Ops))
+	r.Queue(A, B)
+	// The handler is not focused, so only B is delivered.
+	assertEventSequence(t, events(r, -1, key.Filter{Focus: h, Name: "A"}, key.Filter{Name: "B"}), B)
+	r.Source().Execute(key.FocusCmd{Tag: h})
+	// A is delivered to the focused handler.
+	assertEventSequence(t, events(r, -1, key.Filter{Focus: h, Name: "A"}, key.Filter{Name: "B"}), A)
+}
+
+func assertFocus(t *testing.T, router *Router, expected event.Tag) {
+	t.Helper()
+	if !router.Source().Focused(expected) {
+		t.Errorf("expected %v to be focused", expected)
+	}
+}
+
+func assertKeyboard(t *testing.T, router *Router, expected TextInputState) {
+	t.Helper()
+	if got := router.state().state; got != expected {
+		t.Errorf("expected %v keyboard, got %v", expected, got)
+	}
+}

io/input/pointer.go

@@ -1,16 +1,16 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-package router
+package input
 
 import (
 	"image"
 	"io"
+	"slices"
 
 	"gioui.org/f32"
 	f32internal "gioui.org/internal/f32"
 	"gioui.org/internal/ops"
 	"gioui.org/io/event"
-	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/semantic"
 	"gioui.org/io/system"
@@ -18,14 +18,8 @@ import (
 )
 
 type pointerQueue struct {
-	hitTree   []hitNode
+	hitTree []hitNode
-	areas     []areaNode
+	areas   []areaNode
-	cursor    pointer.Cursor
-	handlers  map[event.Tag]*pointerHandler
-	pointers  []pointerInfo
-	transfers []io.ReadCloser // pending data transfers
-
-	scratch []event.Tag
 
 	semantic struct {
 		idsAssigned bool
@@ -43,10 +37,15 @@ type hitNode struct {
 
 	// For handler nodes.
 	tag  event.Tag
-	ktag event.Tag
 	pass bool
 }
 
+// pointerState is the input state related to pointer events.
+type pointerState struct {
+	cursor   pointer.Cursor
+	pointers []pointerInfo
+}
+
 type pointerInfo struct {
 	id       pointer.ID
 	pressed  bool
@@ -63,17 +62,21 @@ type pointerInfo struct {
 }
 
 type pointerHandler struct {
-	area      int
+	// areaPlusOne is the index into the list of pointerQueue.areas, plus 1.
-	active    bool
+	areaPlusOne int
-	wantsGrab bool
+	// setup tracks whether the handler has received
-	types     pointer.Kind
+	// the pointer.Cancel event that resets its state.
+	setup bool
+}
+
+// pointerFilter represents the union of a set of pointer filters.
+type pointerFilter struct {
+	kinds pointer.Kind
 	// min and max horizontal/vertical scroll
-	scrollRange image.Rectangle
+	scrollX, scrollY pointer.ScrollRange
 
 	sourceMimes []string
 	targetMimes []string
-	offeredMime string
-	data        io.ReadCloser
 }
 
 type areaOp struct {
@@ -141,7 +144,9 @@ const (
 )
 
 func (c *pointerCollector) resetState() {
-	c.state = collectState{}
+	c.state = collectState{
+		t: f32.AffineId(),
+	}
 	c.nodeStack = c.nodeStack[:0]
 	// Pop every node except the root.
 	if len(c.q.hitTree) > 0 {
@@ -229,33 +234,18 @@ func (c *pointerCollector) addHitNode(n hitNode) {
 }
 
 // newHandler returns the current handler or a new one for tag.
-func (c *pointerCollector) newHandler(tag event.Tag, events *handlerEvents) *pointerHandler {
+func (c *pointerCollector) newHandler(tag event.Tag, state *pointerHandler) {
 	areaID := c.currentArea()
 	c.addHitNode(hitNode{
 		area: areaID,
 		tag:  tag,
 		pass: c.state.pass > 0,
 	})
-	h, ok := c.q.handlers[tag]
+	state.areaPlusOne = areaID + 1
-	if !ok {
-		h = new(pointerHandler)
-		c.q.handlers[tag] = h
-		// Cancel handlers on (each) first appearance, but don't
-		// trigger redraw.
-		events.AddNoRedraw(tag, pointer.Event{Kind: pointer.Cancel})
-	}
-	h.active = true
-	h.area = areaID
-	return h
 }
 
-func (c *pointerCollector) keyInputOp(op key.InputOp) {
+func (s *pointerHandler) Reset() {
-	areaID := c.currentArea()
+	s.areaPlusOne = 0
-	c.addHitNode(hitNode{
-		area: areaID,
-		ktag: op.Tag,
-		pass: true,
-	})
 }
 
 func (c *pointerCollector) actionInputOp(act system.Action) {
@@ -264,21 +254,108 @@ func (c *pointerCollector) actionInputOp(act system.Action) {
 	area.action = act
 }
 
-func (c *pointerCollector) inputOp(op pointer.InputOp, events *handlerEvents) {
+func (q *pointerQueue) grab(state pointerState, req pointer.GrabCmd) (pointerState, []taggedEvent) {
+	var evts []taggedEvent
+	for _, p := range state.pointers {
+		if !p.pressed || p.id != req.ID {
+			continue
+		}
+		// Verify that the grabber is among the handlers.
+		found := slices.Contains(p.handlers, req.Tag)
+		if !found {
+			continue
+		}
+		// Drop other handlers that lost their grab.
+		for i := len(p.handlers) - 1; i >= 0; i-- {
+			if tag := p.handlers[i]; tag != req.Tag {
+				evts = append(evts, taggedEvent{
+					tag:   tag,
+					event: pointer.Event{Kind: pointer.Cancel},
+				})
+				state = dropHandler(state, tag)
+			}
+		}
+		break
+	}
+	return state, evts
+}
+
+func (c *pointerCollector) inputOp(tag event.Tag, state *pointerHandler) {
 	areaID := c.currentArea()
 	area := &c.q.areas[areaID]
-	area.semantic.content.tag = op.Tag
+	area.semantic.content.tag = tag
-	if op.Kinds&(pointer.Press|pointer.Release) != 0 {
+	c.newHandler(tag, state)
-		area.semantic.content.gestures |= ClickGesture
+}
+
+func (p *pointerFilter) Add(f event.Filter) {
+	switch f := f.(type) {
+	case transfer.SourceFilter:
+		if slices.Contains(p.sourceMimes, f.Type) {
+			return
+		}
+		p.sourceMimes = append(p.sourceMimes, f.Type)
+	case transfer.TargetFilter:
+		if slices.Contains(p.targetMimes, f.Type) {
+			return
+		}
+		p.targetMimes = append(p.targetMimes, f.Type)
+	case pointer.Filter:
+		p.kinds = p.kinds | f.Kinds
+		p.scrollX = p.scrollX.Union(f.ScrollX)
+		p.scrollY = p.scrollY.Union(f.ScrollY)
 	}
-	if op.Kinds&pointer.Scroll != 0 {
+}
-		area.semantic.content.gestures |= ScrollGesture
+
+func (p *pointerFilter) Matches(e event.Event) bool {
+	switch e := e.(type) {
+	case pointer.Event:
+		return e.Kind&p.kinds == e.Kind
+	case transfer.CancelEvent, transfer.InitiateEvent:
+		return len(p.sourceMimes) > 0 || len(p.targetMimes) > 0
+	case transfer.RequestEvent:
+		if slices.Contains(p.sourceMimes, e.Type) {
+			return true
+		}
+	case transfer.DataEvent:
+		if slices.Contains(p.targetMimes, e.Type) {
+			return true
+		}
 	}
-	area.semantic.valid = area.semantic.content.gestures != 0
+	return false
-	h := c.newHandler(op.Tag, events)
+}
-	h.wantsGrab = h.wantsGrab || op.Grab
+
-	h.types = h.types | op.Kinds
+func (p *pointerFilter) Merge(p2 pointerFilter) {
-	h.scrollRange = op.ScrollBounds
+	p.kinds = p.kinds | p2.kinds
+	p.scrollX = p.scrollX.Union(p2.scrollX)
+	p.scrollY = p.scrollY.Union(p2.scrollY)
+	p.sourceMimes = append(p.sourceMimes, p2.sourceMimes...)
+	p.targetMimes = append(p.targetMimes, p2.targetMimes...)
+}
+
+// clampScroll splits a scroll distance in the remaining scroll and the
+// scroll accepted by the filter.
+func (p *pointerFilter) clampScroll(scroll f32.Point) (left, scrolled f32.Point) {
+	left.X, scrolled.X = clampSplit(scroll.X, p.scrollX.Min, p.scrollX.Max)
+	left.Y, scrolled.Y = clampSplit(scroll.Y, p.scrollY.Min, p.scrollY.Max)
+	return
+}
+
+func clampSplit(v float32, min, max int) (float32, float32) {
+	if m := float32(max); v > m {
+		return v - m, m
+	}
+	if m := float32(min); v < m {
+		return v - m, m
+	}
+	return 0, v
+}
+
+func (s *pointerHandler) ResetEvent() (event.Event, bool) {
+	if s.setup {
+		return nil, false
+	}
+	s.setup = true
+	return pointer.Event{Kind: pointer.Cancel}, true
 }
 
 func (c *pointerCollector) semanticLabel(lbl string) {
@@ -322,23 +399,28 @@ func (c *pointerCollector) cursor(cursor pointer.Cursor) {
 	area.cursor = cursor
 }
 
-func (c *pointerCollector) sourceOp(op transfer.SourceOp, events *handlerEvents) {
+func (q *pointerQueue) offerData(handlers map[event.Tag]*handler, state pointerState, req transfer.OfferCmd) (pointerState, []taggedEvent) {
-	h := c.newHandler(op.Tag, events)
+	var evts []taggedEvent
-	h.sourceMimes = append(h.sourceMimes, op.Type)
+	for i, p := range state.pointers {
+		if p.dataSource != req.Tag {
+			continue
+		}
+		if p.dataTarget != nil {
+			evts = append(evts, taggedEvent{tag: p.dataTarget, event: transfer.DataEvent{
+				Type: req.Type,
+				Open: func() io.ReadCloser {
+					return req.Data
+				},
+			}})
+		}
+		state.pointers = slices.Clone(state.pointers)
+		state.pointers[i], evts = q.deliverTransferCancelEvent(handlers, p, evts)
+		break
+	}
+	return state, evts
 }
 
-func (c *pointerCollector) targetOp(op transfer.TargetOp, events *handlerEvents) {
+func (c *pointerCollector) Reset() {
-	h := c.newHandler(op.Tag, events)
-	h.targetMimes = append(h.targetMimes, op.Type)
-}
-
-func (c *pointerCollector) offerOp(op transfer.OfferOp, events *handlerEvents) {
-	h := c.newHandler(op.Tag, events)
-	h.offeredMime = op.Type
-	h.data = op.Data
-}
-
-func (c *pointerCollector) reset() {
 	c.q.reset()
 	c.resetState()
 	c.ensureRoot()
@@ -493,20 +575,6 @@ func (q *pointerQueue) hitTest(pos f32.Point, onNode func(*hitNode) bool) pointe
 	return cursor
 }
 
-func (q *pointerQueue) opHit(pos f32.Point) ([]event.Tag, pointer.Cursor) {
-	hits := q.scratch[:0]
-	cursor := q.hitTest(pos, func(n *hitNode) bool {
-		if n.tag != nil {
-			if _, exists := q.handlers[n.tag]; exists {
-				hits = addHandler(hits, n.tag)
-			}
-		}
-		return true
-	})
-	q.scratch = hits[:0]
-	return hits, cursor
-}
-
 func (q *pointerQueue) invTransform(areaIdx int, p f32.Point) f32.Point {
 	if areaIdx == -1 {
 		return p
@@ -531,24 +599,13 @@ func (q *pointerQueue) hit(areaIdx int, p f32.Point) (bool, pointer.Cursor) {
 }
 
 func (q *pointerQueue) reset() {
-	if q.handlers == nil {
-		q.handlers = make(map[event.Tag]*pointerHandler)
-	}
-	for _, h := range q.handlers {
-		// Reset handler.
-		h.active = false
-		h.wantsGrab = false
-		h.types = 0
-		h.sourceMimes = h.sourceMimes[:0]
-		h.targetMimes = h.targetMimes[:0]
-	}
 	q.hitTree = q.hitTree[:0]
 	q.areas = q.areas[:0]
 	q.semantic.idsAssigned = false
 	for k, ids := range q.semantic.contentIDs {
 		for i := len(ids) - 1; i >= 0; i-- {
 			if !ids[i].used {
-				ids = append(ids[:i], ids[i+1:]...)
+				ids = slices.Delete(ids, i, i+1)
 			} else {
 				ids[i].used = false
 			}
@@ -559,80 +616,71 @@ func (q *pointerQueue) reset() {
 			delete(q.semantic.contentIDs, k)
 		}
 	}
-	for _, rc := range q.transfers {
-		if rc != nil {
-			rc.Close()
-		}
-	}
-	q.transfers = nil
 }
 
-func (q *pointerQueue) Frame(events *handlerEvents) {
+func (q *pointerQueue) Frame(handlers map[event.Tag]*handler, state pointerState) (pointerState, []taggedEvent) {
-	for k, h := range q.handlers {
+	for _, h := range handlers {
-		if !h.active {
+		if h.pointer.areaPlusOne != 0 {
-			q.dropHandler(nil, k)
+			area := &q.areas[h.pointer.areaPlusOne-1]
-			delete(q.handlers, k)
+			if h.filter.pointer.kinds&(pointer.Press|pointer.Release) != 0 {
-		}
+				area.semantic.content.gestures |= ClickGesture
-		if h.wantsGrab {
-			for _, p := range q.pointers {
-				if !p.pressed {
-					continue
-				}
-				for i, k2 := range p.handlers {
-					if k2 == k {
-						// Drop other handlers that lost their grab.
-						dropped := q.scratch[:0]
-						dropped = append(dropped, p.handlers[:i]...)
-						dropped = append(dropped, p.handlers[i+1:]...)
-						for _, tag := range dropped {
-							q.dropHandler(events, tag)
-						}
-						break
-					}
-				}
 			}
+			if h.filter.pointer.kinds&pointer.Scroll != 0 {
+				area.semantic.content.gestures |= ScrollGesture
+			}
+			area.semantic.valid = area.semantic.content.gestures != 0
 		}
 	}
-	for i := range q.pointers {
+	var evts []taggedEvent
-		p := &q.pointers[i]
+	for i, p := range state.pointers {
-		q.deliverEnterLeaveEvents(p, events, p.last)
+		changed := false
-		q.deliverTransferDataEvent(p, events)
+		p, evts, state.cursor, changed = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, p.last)
+		if changed {
+			state.pointers = slices.Clone(state.pointers)
+			state.pointers[i] = p
+		}
 	}
+	return state, evts
 }
 
-func (q *pointerQueue) dropHandler(events *handlerEvents, tag event.Tag) {
+func dropHandler(state pointerState, tag event.Tag) pointerState {
-	if events != nil {
+	pointers := state.pointers
-		events.Add(tag, pointer.Event{Kind: pointer.Cancel})
+	state.pointers = nil
-	}
+	for _, p := range pointers {
-	for i := range q.pointers {
+		handlers := p.handlers
-		p := &q.pointers[i]
+		p.handlers = nil
-		for i := len(p.handlers) - 1; i >= 0; i-- {
+		for _, h := range handlers {
-			if p.handlers[i] == tag {
+			if h != tag {
-				p.handlers = append(p.handlers[:i], p.handlers[i+1:]...)
+				p.handlers = append(p.handlers, h)
 			}
 		}
-		for i := len(p.entered) - 1; i >= 0; i-- {
+		entered := p.entered
-			if p.entered[i] == tag {
+		p.entered = nil
-				p.entered = append(p.entered[:i], p.entered[i+1:]...)
+		for _, h := range entered {
+			if h != tag {
+				p.entered = append(p.entered, h)
 			}
 		}
+		state.pointers = append(state.pointers, p)
 	}
+	return state
 }
 
 // pointerOf returns the pointerInfo index corresponding to the pointer in e.
-func (q *pointerQueue) pointerOf(e pointer.Event) int {
+func (s pointerState) pointerOf(e pointer.Event) (pointerState, int) {
-	for i, p := range q.pointers {
+	for i, p := range s.pointers {
 		if p.id == e.PointerID {
-			return i
+			return s, i
 		}
 	}
-	q.pointers = append(q.pointers, pointerInfo{id: e.PointerID})
+	n := len(s.pointers)
-	return len(q.pointers) - 1
+	s.pointers = append(s.pointers[:n:n], pointerInfo{id: e.PointerID})
+	return s, len(s.pointers) - 1
 }
 
 // Deliver is like Push, but delivers an event to a particular area.
-func (q *pointerQueue) Deliver(areaIdx int, e pointer.Event, events *handlerEvents) {
+func (q *pointerQueue) Deliver(handlers map[event.Tag]*handler, areaIdx int, e pointer.Event) []taggedEvent {
-	var sx, sy = e.Scroll.X, e.Scroll.Y
+	scroll := e.Scroll
 	idx := len(q.hitTree) - 1
 	// Locate first potential receiver.
 	for idx != -1 {
@@ -642,31 +690,28 @@ func (q *pointerQueue) Deliver(areaIdx int, e pointer.Event, events *handlerEven
 		}
 		idx--
 	}
+	var evts []taggedEvent
 	for idx != -1 {
 		n := &q.hitTree[idx]
 		idx = n.next
-		if n.tag == nil {
+		h, ok := handlers[n.tag]
-			continue
+		if !ok || !h.filter.pointer.Matches(e) {
-		}
-		h := q.handlers[n.tag]
-		if e.Kind&h.types == 0 {
 			continue
 		}
 		e := e
 		if e.Kind == pointer.Scroll {
-			if sx == 0 && sy == 0 {
+			if scroll == (f32.Point{}) {
 				break
 			}
-			// Distribute the scroll to the handler based on its ScrollRange.
+			scroll, e.Scroll = h.filter.pointer.clampScroll(scroll)
-			sx, e.Scroll.X = setScrollEvent(sx, h.scrollRange.Min.X, h.scrollRange.Max.X)
-			sy, e.Scroll.Y = setScrollEvent(sy, h.scrollRange.Min.Y, h.scrollRange.Max.Y)
 		}
-		e.Position = q.invTransform(h.area, e.Position)
+		e.Position = q.invTransform(h.pointer.areaPlusOne-1, e.Position)
-		events.Add(n.tag, e)
+		evts = append(evts, taggedEvent{tag: n.tag, event: e})
 		if e.Kind != pointer.Scroll {
 			break
 		}
 	}
+	return evts
 }
 
 // SemanticArea returns the sematic content for area, and its parent area.
@@ -682,106 +727,123 @@ func (q *pointerQueue) SemanticArea(areaIdx int) (semanticContent, int) {
 	return semanticContent{}, -1
 }
 
-func (q *pointerQueue) Push(e pointer.Event, events *handlerEvents) {
+func (q *pointerQueue) Push(handlers map[event.Tag]*handler, state pointerState, e pointer.Event) (pointerState, []taggedEvent) {
+	var evts []taggedEvent
 	if e.Kind == pointer.Cancel {
-		q.pointers = q.pointers[:0]
+		for k := range handlers {
-		for k := range q.handlers {
+			evts = append(evts, taggedEvent{
-			q.dropHandler(events, k)
+				event: pointer.Event{Kind: pointer.Cancel},
+				tag:   k,
+			})
 		}
-		return
+		state.pointers = nil
+		return state, evts
 	}
-	pidx := q.pointerOf(e)
+	state, pidx := state.pointerOf(e)
-	p := &q.pointers[pidx]
+	p := state.pointers[pidx]
-	p.last = e
 
 	switch e.Kind {
 	case pointer.Press:
-		q.deliverEnterLeaveEvents(p, events, e)
+		p, evts, state.cursor, _ = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, e)
 		p.pressed = true
-		q.deliverEvent(p, events, e)
+		evts = q.deliverEvent(handlers, p, evts, e)
 	case pointer.Move:
 		if p.pressed {
 			e.Kind = pointer.Drag
 		}
-		q.deliverEnterLeaveEvents(p, events, e)
+		p, evts, state.cursor, _ = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, e)
-		q.deliverEvent(p, events, e)
+		evts = q.deliverEvent(handlers, p, evts, e)
 		if p.pressed {
-			q.deliverDragEvent(p, events)
+			p, evts = q.deliverDragEvent(handlers, p, evts)
 		}
 	case pointer.Release:
-		q.deliverEvent(p, events, e)
+		evts = q.deliverEvent(handlers, p, evts, e)
 		p.pressed = false
-		q.deliverEnterLeaveEvents(p, events, e)
+		p, evts, state.cursor, _ = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, e)
-		q.deliverDropEvent(p, events)
+		p, evts = q.deliverDropEvent(handlers, p, evts)
 	case pointer.Scroll:
-		q.deliverEnterLeaveEvents(p, events, e)
+		p, evts, state.cursor, _ = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, e)
-		q.deliverEvent(p, events, e)
+		evts = q.deliverEvent(handlers, p, evts, e)
 	default:
 		panic("unsupported pointer event type")
 	}
 
+	p.last = e
+
 	if !p.pressed && len(p.entered) == 0 {
 		// No longer need to track pointer.
-		q.pointers = append(q.pointers[:pidx], q.pointers[pidx+1:]...)
+		state.pointers = slices.Concat(state.pointers[:pidx:pidx], state.pointers[pidx+1:])
+	} else {
+		state.pointers = slices.Clone(state.pointers)
+		state.pointers[pidx] = p
 	}
+	return state, evts
 }
 
-func (q *pointerQueue) deliverEvent(p *pointerInfo, events *handlerEvents, e pointer.Event) {
+func (q *pointerQueue) deliverEvent(handlers map[event.Tag]*handler, p pointerInfo, evts []taggedEvent, e pointer.Event) []taggedEvent {
-	foremost := true
 	if p.pressed && len(p.handlers) == 1 {
 		e.Priority = pointer.Grabbed
-		foremost = false
 	}
-	var sx, sy = e.Scroll.X, e.Scroll.Y
+	scroll := e.Scroll
 	for _, k := range p.handlers {
-		h := q.handlers[k]
+		h, ok := handlers[k]
-		if e.Kind == pointer.Scroll {
+		if !ok {
-			if sx == 0 && sy == 0 {
-				return
-			}
-			// Distribute the scroll to the handler based on its ScrollRange.
-			sx, e.Scroll.X = setScrollEvent(sx, h.scrollRange.Min.X, h.scrollRange.Max.X)
-			sy, e.Scroll.Y = setScrollEvent(sy, h.scrollRange.Min.Y, h.scrollRange.Max.Y)
-		}
-		if e.Kind&h.types == 0 {
 			continue
 		}
-		e := e
+		f := h.filter.pointer
-		if foremost {
+		if !f.Matches(e) {
-			foremost = false
+			continue
-			e.Priority = pointer.Foremost
 		}
-		e.Position = q.invTransform(h.area, e.Position)
+		if e.Kind == pointer.Scroll {
-		events.Add(k, e)
+			if scroll == (f32.Point{}) {
+				return evts
+			}
+			scroll, e.Scroll = f.clampScroll(scroll)
+		}
+		e := e
+		e.Position = q.invTransform(h.pointer.areaPlusOne-1, e.Position)
+		evts = append(evts, taggedEvent{event: e, tag: k})
 	}
+	return evts
 }
 
-func (q *pointerQueue) deliverEnterLeaveEvents(p *pointerInfo, events *handlerEvents, e pointer.Event) {
+func (q *pointerQueue) deliverEnterLeaveEvents(handlers map[event.Tag]*handler, cursor pointer.Cursor, p pointerInfo, evts []taggedEvent, e pointer.Event) (pointerInfo, []taggedEvent, pointer.Cursor, bool) {
+	changed := false
 	var hits []event.Tag
 	if e.Source != pointer.Mouse && !p.pressed && e.Kind != pointer.Press {
 		// Consider non-mouse pointers leaving when they're released.
 	} else {
-		hits, q.cursor = q.opHit(e.Position)
+		var transSrc *pointerFilter
-		if p.pressed {
+		if p.dataSource != nil {
-			// Filter out non-participating handlers,
+			transSrc = &handlers[p.dataSource].filter.pointer
-			// except potential transfer targets when a transfer has been initiated.
+		}
-			var hitsHaveTarget bool
+		cursor = q.hitTest(e.Position, func(n *hitNode) bool {
-			if p.dataSource != nil {
+			h, ok := handlers[n.tag]
-				transferSource := q.handlers[p.dataSource]
+			if !ok {
-				for _, hit := range hits {
+				return true
-					if _, ok := firstMimeMatch(transferSource, q.handlers[hit]); ok {
+			}
-						hitsHaveTarget = true
+			add := true
-						break
+			if p.pressed {
+				add = false
+				// Filter out non-participating handlers,
+				// except potential transfer targets when a transfer has been initiated.
+				if _, found := searchTag(p.handlers, n.tag); found {
+					add = true
+				}
+				if transSrc != nil {
+					if _, ok := firstMimeMatch(transSrc, &h.filter.pointer); ok {
+						add = true
 					}
 				}
 			}
-			for i := len(hits) - 1; i >= 0; i-- {
+			if add {
-				if _, found := searchTag(p.handlers, hits[i]); !found && !hitsHaveTarget {
+				hits = addHandler(hits, n.tag)
-					hits = append(hits[:i], hits[i+1:]...)
-				}
 			}
-		} else {
+			return true
-			p.handlers = append(p.handlers[:0], hits...)
+		})
+		if !p.pressed {
+			changed = true
+			p.handlers = hits
 		}
 	}
 	// Deliver Leave events.
@@ -789,111 +851,94 @@ func (q *pointerQueue) deliverEnterLeaveEvents(p *pointerInfo, events *handlerEv
 		if _, found := searchTag(hits, k); found {
 			continue
 		}
-		h := q.handlers[k]
+		h, ok := handlers[k]
+		if !ok {
+			continue
+		}
+		changed = true
+		e := e
 		e.Kind = pointer.Leave
 
-		if e.Kind&h.types != 0 {
+		if h.filter.pointer.Matches(e) {
-			e := e
+			e.Position = q.invTransform(h.pointer.areaPlusOne-1, e.Position)
-			e.Position = q.invTransform(h.area, e.Position)
+			evts = append(evts, taggedEvent{tag: k, event: e})
-			events.Add(k, e)
 		}
 	}
 	// Deliver Enter events.
 	for _, k := range hits {
-		h := q.handlers[k]
 		if _, found := searchTag(p.entered, k); found {
 			continue
 		}
+		h, ok := handlers[k]
+		if !ok {
+			continue
+		}
+		changed = true
+		e := e
 		e.Kind = pointer.Enter
 
-		if e.Kind&h.types != 0 {
+		if h.filter.pointer.Matches(e) {
-			e := e
+			e.Position = q.invTransform(h.pointer.areaPlusOne-1, e.Position)
-			e.Position = q.invTransform(h.area, e.Position)
+			evts = append(evts, taggedEvent{tag: k, event: e})
-			events.Add(k, e)
 		}
 	}
-	p.entered = append(p.entered[:0], hits...)
+	p.entered = hits
+	return p, evts, cursor, changed
 }
 
-func (q *pointerQueue) deliverDragEvent(p *pointerInfo, events *handlerEvents) {
+func (q *pointerQueue) deliverDragEvent(handlers map[event.Tag]*handler, p pointerInfo, evts []taggedEvent) (pointerInfo, []taggedEvent) {
 	if p.dataSource != nil {
-		return
+		return p, evts
 	}
 	// Identify the data source.
 	for _, k := range p.entered {
-		src := q.handlers[k]
+		src := &handlers[k].filter.pointer
 		if len(src.sourceMimes) == 0 {
 			continue
 		}
 		// One data source handler per pointer.
 		p.dataSource = k
 		// Notify all potential targets.
-		for k, tgt := range q.handlers {
+		for k, tgt := range handlers {
-			if _, ok := firstMimeMatch(src, tgt); ok {
+			if _, ok := firstMimeMatch(src, &tgt.filter.pointer); ok {
-				events.Add(k, transfer.InitiateEvent{})
+				evts = append(evts, taggedEvent{tag: k, event: transfer.InitiateEvent{}})
 			}
 		}
 		break
 	}
+	return p, evts
 }
 
-func (q *pointerQueue) deliverDropEvent(p *pointerInfo, events *handlerEvents) {
+func (q *pointerQueue) deliverDropEvent(handlers map[event.Tag]*handler, p pointerInfo, evts []taggedEvent) (pointerInfo, []taggedEvent) {
 	if p.dataSource == nil {
-		return
+		return p, evts
 	}
 	// Request data from the source.
-	src := q.handlers[p.dataSource]
+	src := &handlers[p.dataSource].filter.pointer
 	for _, k := range p.entered {
-		h := q.handlers[k]
+		h := handlers[k]
-		if m, ok := firstMimeMatch(src, h); ok {
+		if m, ok := firstMimeMatch(src, &h.filter.pointer); ok {
 			p.dataTarget = k
-			events.Add(p.dataSource, transfer.RequestEvent{Type: m})
+			evts = append(evts, taggedEvent{tag: p.dataSource, event: transfer.RequestEvent{Type: m}})
-			return
+			return p, evts
 		}
 	}
 	// No valid target found, abort.
-	q.deliverTransferCancelEvent(p, events)
+	return q.deliverTransferCancelEvent(handlers, p, evts)
 }
 
-func (q *pointerQueue) deliverTransferDataEvent(p *pointerInfo, events *handlerEvents) {
+func (q *pointerQueue) deliverTransferCancelEvent(handlers map[event.Tag]*handler, p pointerInfo, evts []taggedEvent) (pointerInfo, []taggedEvent) {
-	if p.dataSource == nil {
+	evts = append(evts, taggedEvent{tag: p.dataSource, event: transfer.CancelEvent{}})
-		return
-	}
-	src := q.handlers[p.dataSource]
-	if src.data == nil {
-		// Data not received yet.
-		return
-	}
-	if p.dataTarget == nil {
-		q.deliverTransferCancelEvent(p, events)
-		return
-	}
-	// Send the offered data to the target.
-	transferIdx := len(q.transfers)
-	events.Add(p.dataTarget, transfer.DataEvent{
-		Type: src.offeredMime,
-		Open: func() io.ReadCloser {
-			q.transfers[transferIdx] = nil
-			return src.data
-		},
-	})
-	q.transfers = append(q.transfers, src.data)
-	p.dataTarget = nil
-}
-
-func (q *pointerQueue) deliverTransferCancelEvent(p *pointerInfo, events *handlerEvents) {
-	events.Add(p.dataSource, transfer.CancelEvent{})
 	// Cancel all potential targets.
-	src := q.handlers[p.dataSource]
+	src := &handlers[p.dataSource].filter.pointer
-	for k, h := range q.handlers {
+	for k, h := range handlers {
-		if _, ok := firstMimeMatch(src, h); ok {
+		if _, ok := firstMimeMatch(src, &h.filter.pointer); ok {
-			events.Add(k, transfer.CancelEvent{})
+			evts = append(evts, taggedEvent{tag: k, event: transfer.CancelEvent{}})
 		}
 	}
-	src.offeredMime = ""
-	src.data = nil
 	p.dataSource = nil
 	p.dataTarget = nil
+	return p, evts
 }
 
 // ClipFor clips r to the parents of area.
@@ -919,21 +964,17 @@ func searchTag(tags []event.Tag, tag event.Tag) (int, bool) {
 
 // addHandler adds tag to the slice if not present.
 func addHandler(tags []event.Tag, tag event.Tag) []event.Tag {
-	for _, t := range tags {
+	if slices.Contains(tags, tag) {
-		if t == tag {
+		return tags
-			return tags
-		}
 	}
 	return append(tags, tag)
 }
 
 // firstMimeMatch returns the first type match between src and tgt.
-func firstMimeMatch(src, tgt *pointerHandler) (first string, matched bool) {
+func firstMimeMatch(src, tgt *pointerFilter) (first string, matched bool) {
 	for _, m1 := range tgt.targetMimes {
-		for _, m2 := range src.sourceMimes {
+		if slices.Contains(src.sourceMimes, m1) {
-			if m1 == m2 {
+			return m1, true
-				return m1, true
-			}
 		}
 	}
 	return "", false
@@ -965,13 +1006,3 @@ func (a *areaNode) bounds() image.Rectangle {
 		Max: a.trans.Transform(f32internal.FPt(a.area.rect.Max)),
 	}.Round()
 }
-
-func setScrollEvent(scroll float32, min, max int) (left, scrolled float32) {
-	if v := float32(max); scroll > v {
-		return scroll - v, v
-	}
-	if v := float32(min); scroll < v {
-		return scroll - v, v
-	}
-	return 0, scroll
-}