ui: Unify the context thread and the UI thread

internal/graphics/opengl/context_desktop.go

@@ -67,31 +67,18 @@ func init() {
 }
 
 type context struct {
-	funcs chan func()
 	init            bool
+	runOnMainThread func(func() error) error
 }
 
-func NewContext() (*Context, error) {
+func NewContext(runOnMainThread func(func() error) error) (*Context, error) {
 	c := &Context{}
-	c.funcs = make(chan func())
+	c.runOnMainThread = runOnMainThread
 	return c, nil
 }
 
-func (c *Context) Loop() {
-	for f := range c.funcs {
-		f()
-	}
-}
-
 func (c *Context) RunOnContextThread(f func() error) error {
-	ch := make(chan struct{})
-	var err error
-	c.funcs <- func() {
-		err = f()
-		close(ch)
-	}
-	<-ch
-	return err
+	return c.runOnMainThread(f)
 }
 
 func (c *Context) Reset() error {

internal/ui/ui_glfw.go

@@ -70,29 +70,18 @@ func initialize() error {
 	if err != nil {
 		return err
 	}
-
 	u := &userInterface{
 		window:      window,
 		funcs:       make(chan func()),
 		sizeChanged: true,
 	}
-	ch := make(chan error)
-	go func() {
-		runtime.LockOSThread()
 	u.window.MakeContextCurrent()
 	glfw.SwapInterval(1)
-		var err error
-		u.context, err = opengl.NewContext()
+	u.context, err = opengl.NewContext(u.runOnMainThread)
 	if err != nil {
-			ch <- err
-		}
-		close(ch)
-		u.context.Loop()
-	}()
-	currentUI = u
-	if err := <-ch; err != nil {
 		return err
 	}
+	currentUI = u
 	return nil
 }
 
@@ -258,11 +247,8 @@ func (u *userInterface) swapBuffers() error {
 	if err := u.context.BindScreenFramebuffer(); err != nil {
 		return err
 	}
-	u.context.RunOnContextThread(func() error {
 	u.window.SwapBuffers()
 	return nil
-	})
-	return nil
 }
 
 func (u *userInterface) FinishRendering() error {