app: merge app/internal/wm into package app

The app and app/internal/wm packages are tightly coupled, requiring
quite a bit of forwarding types, values and constants from the internal
package to export it. Further, no other package imports package wm.

This change merges the two packages.

While here, drop the pre-Go 1.14 SIGPIPE workaround.

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

app/gl_ios.go

@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+//go:build darwin && ios && nometal
+// +build darwin,ios,nometal
+
+package app
+
+/*
+@import UIKit;
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <OpenGLES/ES2/gl.h>
+#include <OpenGLES/ES2/glext.h>
+
+__attribute__ ((visibility ("hidden"))) int gio_renderbufferStorage(CFTypeRef ctx, CFTypeRef layer, GLenum buffer);
+__attribute__ ((visibility ("hidden"))) int gio_presentRenderbuffer(CFTypeRef ctx, GLenum buffer);
+__attribute__ ((visibility ("hidden"))) int gio_makeCurrent(CFTypeRef ctx);
+__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createContext(void);
+__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createGLLayer(void);
+
+static CFTypeRef getViewLayer(CFTypeRef viewRef) {
+	@autoreleasepool {
+		UIView *view = (__bridge UIView *)viewRef;
+		return CFBridgingRetain(view.layer);
+	}
+}
+
+*/
+import "C"
+
+import (
+	"errors"
+	"fmt"
+
+	"gioui.org/gpu"
+	"gioui.org/internal/gl"
+)
+
+type context struct {
+	owner       *window
+	c           *gl.Functions
+	ctx         C.CFTypeRef
+	layer       C.CFTypeRef
+	init        bool
+	frameBuffer gl.Framebuffer
+	colorBuffer gl.Renderbuffer
+}
+
+func newContext(w *window) (*context, error) {
+	ctx := C.gio_createContext()
+	if ctx == 0 {
+		return nil, fmt.Errorf("failed to create EAGLContext")
+	}
+	api := contextAPI()
+	f, err := gl.NewFunctions(api.Context, api.ES)
+	if err != nil {
+		return nil, err
+	}
+	c := &context{
+		ctx:   ctx,
+		owner: w,
+		layer: C.getViewLayer(w.contextView()),
+		c:     f,
+	}
+	return c, nil
+}
+
+func contextAPI() gpu.OpenGL {
+	return gpu.OpenGL{}
+}
+
+func (c *context) RenderTarget() gpu.RenderTarget {
+	return gpu.OpenGLRenderTarget(c.frameBuffer)
+}
+
+func (c *context) API() gpu.API {
+	return contextAPI()
+}
+
+func (c *context) Release() {
+	if c.ctx == 0 {
+		return
+	}
+	C.gio_renderbufferStorage(c.ctx, 0, C.GLenum(gl.RENDERBUFFER))
+	c.c.DeleteFramebuffer(c.frameBuffer)
+	c.c.DeleteRenderbuffer(c.colorBuffer)
+	C.gio_makeCurrent(0)
+	C.CFRelease(c.ctx)
+	c.ctx = 0
+}
+
+func (c *context) Present() error {
+	if c.layer == 0 {
+		panic("context is not active")
+	}
+	c.c.BindRenderbuffer(gl.RENDERBUFFER, c.colorBuffer)
+	if C.gio_presentRenderbuffer(c.ctx, C.GLenum(gl.RENDERBUFFER)) == 0 {
+		return errors.New("presentRenderBuffer failed")
+	}
+	return nil
+}
+
+func (c *context) Lock() error {
+	if C.gio_makeCurrent(c.ctx) == 0 {
+		return errors.New("[EAGLContext setCurrentContext] failed")
+	}
+	return nil
+}
+
+func (c *context) Unlock() {
+	C.gio_makeCurrent(0)
+}
+
+func (c *context) Refresh() error {
+	if C.gio_makeCurrent(c.ctx) == 0 {
+		return errors.New("[EAGLContext setCurrentContext] failed")
+	}
+	if !c.init {
+		c.init = true
+		c.frameBuffer = c.c.CreateFramebuffer()
+		c.colorBuffer = c.c.CreateRenderbuffer()
+	}
+	if !c.owner.visible {
+		// Make sure any in-flight GL commands are complete.
+		c.c.Finish()
+		return nil
+	}
+	currentRB := gl.Renderbuffer{uint(c.c.GetInteger(gl.RENDERBUFFER_BINDING))}
+	c.c.BindRenderbuffer(gl.RENDERBUFFER, c.colorBuffer)
+	if C.gio_renderbufferStorage(c.ctx, c.layer, C.GLenum(gl.RENDERBUFFER)) == 0 {
+		return errors.New("renderbufferStorage failed")
+	}
+	c.c.BindRenderbuffer(gl.RENDERBUFFER, currentRB)
+	c.c.BindFramebuffer(gl.FRAMEBUFFER, c.frameBuffer)
+	c.c.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, c.colorBuffer)
+	if st := c.c.CheckFramebufferStatus(gl.FRAMEBUFFER); st != gl.FRAMEBUFFER_COMPLETE {
+		return fmt.Errorf("framebuffer incomplete, status: %#x\n", st)
+	}
+	return nil
+}
+
+func (w *window) NewContext() (Context, error) {
+	return newContext(w)
+}