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_macos.go

@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+//go:build darwin && !ios && nometal
+// +build darwin,!ios,nometal
+
+package app
+
+import (
+	"errors"
+
+	"gioui.org/gpu"
+	"gioui.org/internal/gl"
+)
+
+/*
+#include <CoreFoundation/CoreFoundation.h>
+#include <CoreGraphics/CoreGraphics.h>
+#include <AppKit/AppKit.h>
+
+__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createGLContext(void);
+__attribute__ ((visibility ("hidden"))) void gio_setContextView(CFTypeRef ctx, CFTypeRef view);
+__attribute__ ((visibility ("hidden"))) void gio_makeCurrentContext(CFTypeRef ctx);
+__attribute__ ((visibility ("hidden"))) void gio_updateContext(CFTypeRef ctx);
+__attribute__ ((visibility ("hidden"))) void gio_flushContextBuffer(CFTypeRef ctx);
+__attribute__ ((visibility ("hidden"))) void gio_clearCurrentContext(void);
+__attribute__ ((visibility ("hidden"))) void gio_lockContext(CFTypeRef ctxRef);
+__attribute__ ((visibility ("hidden"))) void gio_unlockContext(CFTypeRef ctxRef);
+*/
+import "C"
+
+type glContext struct {
+	c    *gl.Functions
+	ctx  C.CFTypeRef
+	view C.CFTypeRef
+}
+
+func newContext(w *window) (*glContext, error) {
+	view := w.contextView()
+	ctx := C.gio_createGLContext()
+	if ctx == 0 {
+		return nil, errors.New("gl: failed to create NSOpenGLContext")
+	}
+	C.gio_setContextView(ctx, view)
+	c := &glContext{
+		ctx:  ctx,
+		view: view,
+	}
+	return c, nil
+}
+
+func (c *glContext) RenderTarget() gpu.RenderTarget {
+	return gpu.OpenGLRenderTarget{}
+}
+
+func (c *glContext) API() gpu.API {
+	return gpu.OpenGL{}
+}
+
+func (c *glContext) Release() {
+	if c.ctx != 0 {
+		C.gio_clearCurrentContext()
+		C.CFRelease(c.ctx)
+		c.ctx = 0
+	}
+}
+
+func (c *glContext) Present() error {
+	return nil
+}
+
+func (c *glContext) Lock() error {
+	C.gio_lockContext(c.ctx)
+	C.gio_makeCurrentContext(c.ctx)
+	return nil
+}
+
+func (c *glContext) Unlock() {
+	C.gio_clearCurrentContext()
+	C.gio_unlockContext(c.ctx)
+}
+
+func (c *glContext) Refresh() error {
+	c.Lock()
+	defer c.Unlock()
+	C.gio_updateContext(c.ctx)
+	return nil
+}
+
+func (w *window) NewContext() (context, error) {
+	return newContext(w)
+}