internal/ui: remove renderThread

Updates #2714

internal/graphicscommand/thread.go

@@ -15,16 +15,20 @@
 package graphicscommand
 
 import (
+	"context"
+
 	"github.com/hajimehoshi/ebiten/v2/internal/thread"
 )
 
 var theRenderThread thread.Thread = thread.NewNoopThread()
 
-// SetRenderThread must be called from the rendering thread where e.g. OpenGL works.
-//
-// TODO: Create thread in this package instead of setting it externally.
-func SetRenderThread(thread thread.Thread) {
-	theRenderThread = thread
+// SetOSThreadAsRenderThread sets an OS thread as rendering thread e.g. for OpenGL.
+func SetOSThreadAsRenderThread() {
+	theRenderThread = thread.NewOSThread()
+}
+
+func LoopRenderThread(ctx context.Context) {
+	_ = theRenderThread.Loop(ctx)
 }
 
 // runOnRenderThread calls f on the rendering thread.

internal/ui/run.go

@@ -35,8 +35,7 @@ func (u *UserInterface) Run(game Game, options *RunOptions) error {
 
 func (u *UserInterface) runMultiThread(game Game, options *RunOptions) error {
 	u.mainThread = thread.NewOSThread()
-	u.renderThread = thread.NewOSThread()
-	graphicscommand.SetRenderThread(u.renderThread)
+	graphicscommand.SetOSThreadAsRenderThread()
 
 	// Set the running state true after the main thread is set, and before initOnMainThread is called (#2742).
 	// TODO: As the existence of the main thread is the same as the value of `running`, this is redundant.
@@ -58,7 +57,7 @@ func (u *UserInterface) runMultiThread(game Game, options *RunOptions) error {
 	// Run the render thread.
 	wg.Go(func() error {
 		defer cancel()
-		_ = u.renderThread.Loop(ctx)
+		graphicscommand.LoopRenderThread(ctx)
 		return nil
 	})
 
@@ -76,8 +75,6 @@ func (u *UserInterface) runMultiThread(game Game, options *RunOptions) error {
 func (u *UserInterface) runSingleThread(game Game, options *RunOptions) error {
 	// Initialize the main thread first so the thread is available at u.run (#809).
 	u.mainThread = thread.NewNoopThread()
-	u.renderThread = thread.NewNoopThread()
-	graphicscommand.SetRenderThread(u.renderThread)
 
 	u.setRunning(true)
 	defer u.setRunning(false)

internal/ui/ui.go

@@ -82,9 +82,6 @@ type UserInterface struct {
 
 	mainThread thread.Thread
 
-	// TODO: Remove this (#2714).
-	renderThread thread.Thread
-
 	userInterfaceImpl
 }
 

internal/ui/ui_mobile.go

@@ -38,7 +38,6 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/hook"
 	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
-	"github.com/hajimehoshi/ebiten/v2/internal/thread"
 )
 
 var (
@@ -91,7 +90,7 @@ func (u *UserInterface) Update() error {
 		cancel()
 	}()
 
-	_ = u.renderThread.Loop(ctx)
+	graphicscommand.LoopRenderThread(ctx)
 	return nil
 }
 
@@ -273,8 +272,7 @@ func (u *UserInterface) runMobile(game Game, mainloop bool, options *RunOptions)
 		// gl.Context so that they are called on the appropriate thread.
 		mgl = <-glContextCh
 	} else {
-		u.renderThread = thread.NewOSThread()
-		graphicscommand.SetRenderThread(u.renderThread)
+		graphicscommand.SetOSThreadAsRenderThread()
 	}
 
 	u.setRunning(true)