internal/ui: refactoring: move updateVsyncOnRenderThread to the OpenGL driver

Updates #2714

internal/graphicsdriver/opengl/graphics.go

@@ -35,6 +35,7 @@ type activatedTexture struct {
 type Graphics struct {
 	state   openGLState
 	context context
+	vsync   bool
 
 	nextImageID graphicsdriver.ImageID
 	images      map[graphicsdriver.ImageID]*Image
@@ -56,7 +57,9 @@ type Graphics struct {
 }
 
 func newGraphics(ctx gl.Context) *Graphics {
-	g := &Graphics{}
+	g := &Graphics{
+		vsync: true,
+	}
 	if isDebug {
 		g.context.ctx = &gl.DebugContext{Context: ctx}
 	} else {
@@ -78,7 +81,9 @@ func (g *Graphics) End(present bool) error {
 	// The last uniforms must be reset before swapping the buffer (#2517).
 	if present {
 		g.state.resetLastUniforms()
-		g.swapBuffers()
+		if err := g.swapBuffers(); err != nil {
+			return err
+		}
 	}
 
 	return nil
@@ -298,7 +303,7 @@ func (g *Graphics) DrawTriangles(dstID graphicsdriver.ImageID, srcIDs [graphics.
 }
 
 func (g *Graphics) SetVsyncEnabled(enabled bool) {
-	// Do nothing
+	g.vsync = enabled
 }
 
 func (g *Graphics) NeedsRestoring() bool {

internal/graphicsdriver/opengl/graphics_glfw.go

@@ -45,8 +45,25 @@ func (g *Graphics) makeContextCurrent() {
 	// TODO: Implement this (#2714).
 }
 
-func (g *Graphics) swapBuffers() {
+func (g *Graphics) swapBuffers() error {
+	// Call SwapIntervals even though vsync is not changed.
+	// When toggling to fullscreen, vsync state might be reset unexpectedly (#1787).
+
+	// SwapInterval is affected by the current monitor of the window.
+	// This needs to be called at least after SetMonitor.
+	// Without SwapInterval after SetMonitor, vsynch doesn't work (#375).
+	if g.vsync {
+		if err := glfw.SwapInterval(1); err != nil {
+			return err
+		}
+	} else {
+		if err := glfw.SwapInterval(0); err != nil {
+			return err
+		}
+	}
+
 	// TODO: Implement this (#2714).
+	return nil
 }
 
 func (g *Graphics) SetGLFWClientAPI() error {

internal/graphicsdriver/opengl/graphics_js.go

@@ -49,5 +49,6 @@ func NewGraphics(canvas js.Value) (graphicsdriver.Graphics, error) {
 func (g *Graphics) makeContextCurrent() {
 }
 
-func (g *Graphics) swapBuffers() {
+func (g *Graphics) swapBuffers() error {
+	return nil
 }

internal/graphicsdriver/opengl/graphics_mobile.go

@@ -43,5 +43,6 @@ func NewGraphics(context mgl.Context) (graphicsdriver.Graphics, error) {
 func (g *Graphics) makeContextCurrent() {
 }
 
-func (g *Graphics) swapBuffers() {
+func (g *Graphics) swapBuffers() error {
+	return nil
 }

internal/graphicsdriver/opengl/graphics_nintendosdk.go

@@ -39,6 +39,7 @@ func (g *Graphics) makeContextCurrent() {
 	theEGL.makeContextCurrent()
 }
 
-func (g *Graphics) swapBuffers() {
+func (g *Graphics) swapBuffers() error {
 	theEGL.swapBuffers()
+	return nil
 }

internal/ui/ui_glfw.go

@@ -1336,7 +1336,7 @@ func (u *UserInterface) update() (float64, float64, error) {
 		}
 	}
 
-	// Initialize vsync after SetMonitor is called. See the comment in updateVsync.
+	// Initialize vsync after SetMonitor is called.
 	// Calling this inside setWindowSize didn't work (#1363).
 	// Also, setFPSMode has to be called after graphicscommand.SetRenderThread is called (#2714).
 	if !u.fpsModeInited {
@@ -1466,13 +1466,6 @@ func (u *UserInterface) updateGame() error {
 	}
 
 	if err := u.context.updateFrame(u.graphicsDriver, outsideWidth, outsideHeight, deviceScaleFactor, u, func() {
-		// Call updateVsync even though fpsMode is not updated.
-		// When toggling to fullscreen, vsync state might be reset unexpectedly (#1787).
-		if err := u.updateVsyncOnRenderThread(); err != nil {
-			u.setError(err)
-			return
-		}
-
 		// This works only for OpenGL.
 		if err := u.swapBuffersOnRenderThread(); err != nil {
 			u.setError(err)
@@ -1861,28 +1854,6 @@ func (u *UserInterface) minimumWindowWidth() (int, error) {
 	return 1, nil
 }
 
-func (u *UserInterface) updateVsyncOnRenderThread() error {
-	if u.GraphicsLibrary() == GraphicsLibraryOpenGL {
-		// SwapInterval is affected by the current monitor of the window.
-		// This needs to be called at least after SetMonitor.
-		// Without SwapInterval after SetMonitor, vsynch doesn't work (#375).
-		//
-		// TODO: (#405) If triple buffering is needed, SwapInterval(0) should be called,
-		// but is this correct? If glfw.SwapInterval(0) and the driver doesn't support triple
-		// buffering, what will happen?
-		if u.fpsMode == FPSModeVsyncOn {
-			if err := glfw.SwapInterval(1); err != nil {
-				return err
-			}
-		} else {
-			if err := glfw.SwapInterval(0); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
 // currentMonitor returns the current active monitor.
 //
 // currentMonitor must be called on the main thread.