app: [X11] don't recreate EGL surface during resize

According to #565 X11 GPU drivers don't deal well with recreation of
EGL surfaces.

Thanks to Walter Schneider for debugging this issue and coming up with
the original patch.

Fixes: https://todo.sr.ht/~eliasnaur/gio/565
Co-authored-by: Walter Werner SCHNEIDER <contact@schnwalter.eu>
Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/egl_android.go

@@ -17,9 +17,8 @@ import (
 )
 
 type androidContext struct {
-	win           *window
-	eglSurf       egl.NativeWindowType
-	width, height int
+	win     *window
+	eglSurf egl.NativeWindowType
 	*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

@@ -69,7 +69,7 @@ func (c *wlContext) Refresh() error {
 	}
 	c.eglWin = eglWin
 	eglSurf := egl.NativeWindowType(uintptr(unsafe.Pointer(eglWin)))
-	if err := c.Context.CreateSurface(eglSurf, width, height); err != nil {
+	if err := c.Context.CreateSurface(eglSurf); err != nil {
 		return err
 	}
 	if err := c.Context.MakeCurrent(); err != nil {

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
-	}
-	defer c.Context.ReleaseCurrent()
-	c.Context.EnableVSync(true)
 	return nil
 }
 

internal/egl/egl.go

@@ -15,10 +15,9 @@ import (
 )
 
 type Context struct {
-	disp          _EGLDisplay
-	eglCtx        *eglContext
-	eglSurf       _EGLSurface
-	width, height int
+	disp    _EGLDisplay
+	eglCtx  *eglContext
+	eglSurf _EGLSurface
 }
 
 type eglContext struct {
@@ -121,11 +120,9 @@ 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
 }