ui: Add CurrentUI()

internal/ui/ui_glfw.go

@@ -30,7 +30,21 @@ func Now() int64 {
 	return time.Now().UnixNano()
 }
 
-var currentUI *userInterface
+type UserInterface struct {
+	window           *glfw.Window
+	width            int
+	height           int
+	scale            int
+	deviceScale      float64
+	framebufferScale int
+	context          *opengl.Context
+}
+
+var currentUI *UserInterface
+
+func CurrentUI() *UserInterface {
+	return currentUI
+}
 
 func Init() *opengl.Context {
 	runtime.LockOSThread()
@@ -50,7 +64,7 @@ func Init() *opengl.Context {
 		panic(err)
 	}
 
-	u := &userInterface{
+	u := &UserInterface{
 		window: window,
 	}
 	ch := make(chan struct{})
@@ -69,53 +83,23 @@ func Init() *opengl.Context {
 	return u.context
 }
 
-func Start(width, height, scale int, title string) error {
-	return currentUI.start(width, height, scale, title)
+func (u *UserInterface) SetScreenSize(width, height int) bool {
+	return u.setScreenSize(width, height, currentUI.scale)
 }
 
-func Terminate() {
-	currentUI.terminate()
+func (u *UserInterface) SetScreenScale(scale int) bool {
+	return u.setScreenSize(currentUI.width, currentUI.height, scale)
 }
 
-func DoEvents() error {
-	return currentUI.doEvents()
+func (u *UserInterface) ScreenScale() int {
+	return u.scale
 }
 
-func IsClosed() bool {
-	return currentUI.isClosed()
+func (u *UserInterface) ActualScreenScale() int {
+	return u.actualScreenScale()
 }
 
-func SwapBuffers() {
-	currentUI.swapBuffers()
-}
-
-func SetScreenSize(width, height int) bool {
-	return currentUI.setScreenSize(width, height, currentUI.scale)
-}
-
-func SetScreenScale(scale int) bool {
-	return currentUI.setScreenSize(currentUI.width, currentUI.height, scale)
-}
-
-func ScreenScale() int {
-	return currentUI.scale
-}
-
-func ActualScreenScale() int {
-	return currentUI.actualScreenScale()
-}
-
-type userInterface struct {
-	window           *glfw.Window
-	width            int
-	height           int
-	scale            int
-	deviceScale      float64
-	framebufferScale int
-	context          *opengl.Context
-}
-
-func (u *userInterface) start(width, height, scale int, title string) error {
+func (u *UserInterface) Start(width, height, scale int, title string) error {
 	m := glfw.GetPrimaryMonitor()
 	v := m.GetVideoMode()
 	mw, _ := m.GetPhysicalSize()
@@ -143,20 +127,20 @@ func (u *userInterface) start(width, height, scale int, title string) error {
 	return nil
 }
 
-func (u *userInterface) windowScale() int {
+func (u *UserInterface) windowScale() int {
 	return u.scale * int(u.deviceScale)
 }
 
-func (u *userInterface) actualScreenScale() int {
+func (u *UserInterface) actualScreenScale() int {
 	return u.windowScale() * u.framebufferScale
 }
 
-func (u *userInterface) pollEvents() error {
+func (u *UserInterface) pollEvents() error {
 	glfw.PollEvents()
 	return currentInput.update(u.window, u.windowScale())
 }
 
-func (u *userInterface) doEvents() error {
+func (u *UserInterface) DoEvents() error {
 	if err := u.pollEvents(); err != nil {
 		return err
 	}
@@ -166,22 +150,22 @@ func (u *userInterface) doEvents() error {
 		if err := u.pollEvents(); err != nil {
 			return err
 		}
-		if u.isClosed() {
+		if u.IsClosed() {
 			return nil
 		}
 	}
 	return nil
 }
 
-func (u *userInterface) terminate() {
+func (u *UserInterface) Terminate() {
 	glfw.Terminate()
 }
 
-func (u *userInterface) isClosed() bool {
+func (u *UserInterface) IsClosed() bool {
 	return u.window.ShouldClose()
 }
 
-func (u *userInterface) swapBuffers() {
+func (u *UserInterface) SwapBuffers() {
 	// The bound framebuffer must be the default one (0) before swapping buffers.
 	u.context.BindZeroFramebuffer()
 	// Call glFinish before glfwSwapBuffer to make sure
@@ -192,7 +176,7 @@ func (u *userInterface) swapBuffers() {
 	})
 }
 
-func (u *userInterface) setScreenSize(width, height, scale int) bool {
+func (u *UserInterface) setScreenSize(width, height, scale int) bool {
 	if u.width == width && u.height == height && u.scale == scale {
 		return false
 	}
@@ -214,7 +198,7 @@ func (u *userInterface) setScreenSize(width, height, scale int) bool {
 
 	// To make sure the current existing framebuffers are rendered,
 	// swap buffers here before SetSize is called.
-	u.swapBuffers()
+	u.SwapBuffers()
 
 	ch := make(chan struct{})
 	window := u.window

internal/ui/ui_js.go

@@ -29,49 +29,33 @@ func Now() int64 {
 	return int64(js.Global.Get("performance").Call("now").Float() * float64(time.Millisecond))
 }
 
-func Start(width, height, scale int, title string) error {
-	return currentUI.start(width, height, scale, title)
-}
-
-func Terminate() {
-	currentUI.terminate()
-}
-
-func DoEvents() error {
-	return currentUI.doEvents()
-}
-
-func IsClosed() bool {
-	return currentUI.isClosed()
-}
-
-func SwapBuffers() {
-	currentUI.swapBuffers()
-}
-
-func SetScreenSize(width, height int) bool {
+func (u *UserInterface) SetScreenSize(width, height int) bool {
 	scale := canvas.Get("dataset").Get("ebitenScreenScale").Int()
-	return currentUI.setScreenSize(width, height, scale)
+	return u.setScreenSize(width, height, scale)
 }
 
-func SetScreenScale(scale int) bool {
+func (u *UserInterface) SetScreenScale(scale int) bool {
 	width, height := currentUI.size()
-	return currentUI.setScreenSize(width, height, scale)
+	return u.setScreenSize(width, height, scale)
 }
 
-func ScreenScale() int {
+func (u *UserInterface) ScreenScale() int {
 	return canvas.Get("dataset").Get("ebitenScreenScale").Int()
 }
 
-func ActualScreenScale() int {
+func (u *UserInterface) ActualScreenScale() int {
 	return canvas.Get("dataset").Get("ebitenActualScreenScale").Int()
 }
 
 var canvas *js.Object
 
-type userInterface struct{}
+type UserInterface struct{}
 
-var currentUI = &userInterface{}
+var currentUI = &UserInterface{}
+
+func CurrentUI() *UserInterface {
+	return currentUI
+}
 
 // NOTE: This returns true even when the browser is not active.
 func shown() bool {
@@ -96,20 +80,20 @@ func vsync() {
 	<-ch
 }
 
-func (*userInterface) doEvents() error {
+func (u *UserInterface) DoEvents() error {
 	currentInput.UpdateGamepads()
 	return nil
 }
 
-func (*userInterface) terminate() {
+func (u *UserInterface) Terminate() {
 	// Do nothing.
 }
 
-func (*userInterface) isClosed() bool {
+func (u *UserInterface) IsClosed() bool {
 	return false
 }
 
-func (*userInterface) swapBuffers() {
+func (u *UserInterface) SwapBuffers() {
 	vsync()
 	for !shown() {
 		vsync()
@@ -243,7 +227,7 @@ func devicePixelRatio() int {
 	return ratio
 }
 
-func (u *userInterface) start(width, height, scale int, title string) error {
+func (u *UserInterface) Start(width, height, scale int, title string) error {
 	doc := js.Global.Get("document")
 	doc.Set("title", title)
 	u.setScreenSize(width, height, scale)
@@ -251,7 +235,7 @@ func (u *userInterface) start(width, height, scale int, title string) error {
 	return nil
 }
 
-func (*userInterface) size() (width, height int) {
+func (*UserInterface) size() (width, height int) {
 	a := canvas.Get("dataset").Get("ebitenActualScreenScale").Int()
 	if a == 0 {
 		// a == 0 only on the initial state.
@@ -262,7 +246,7 @@ func (*userInterface) size() (width, height int) {
 	return
 }
 
-func (u *userInterface) setScreenSize(width, height, scale int) bool {
+func (u *UserInterface) setScreenSize(width, height, scale int) bool {
 	w, h := u.size()
 	s := canvas.Get("dataset").Get("ebitenScreenScale").Int()
 	if w == width && h == height && s == scale {

run.go

@@ -54,6 +54,7 @@ func IsRunningSlowly() bool {
 // The argument (*Image) is the render target that represents the screen.
 //
 // This function must be called from the main thread.
+// Note that ebiten bounds the main goroutine to the main OS thread by runtime.LockOSThread.
 //
 // The given function f is guaranteed to be called 60 times a second
 // even if a rendering frame is skipped.
@@ -64,13 +65,13 @@ func Run(f func(*Image) error, width, height, scale int, title string) error {
 		runContext.running = false
 	}()
 
-	if err := ui.Start(width, height, scale, title); err != nil {
+	if err := ui.CurrentUI().Start(width, height, scale, title); err != nil {
 		return err
 	}
-	defer ui.Terminate()
+	defer ui.CurrentUI().Terminate()
 
 	glContext.Check()
-	graphicsContext, err := newGraphicsContext(width, height, ui.ActualScreenScale())
+	graphicsContext, err := newGraphicsContext(width, height, ui.CurrentUI().ActualScreenScale())
 	if err != nil {
 		return err
 	}
@@ -84,16 +85,16 @@ func Run(f func(*Image) error, width, height, scale int, title string) error {
 		if 0 < runContext.newScreenWidth || 0 < runContext.newScreenHeight || 0 < runContext.newScreenScale {
 			changed := false
 			if 0 < runContext.newScreenWidth || 0 < runContext.newScreenHeight {
-				c := ui.SetScreenSize(runContext.newScreenWidth, runContext.newScreenHeight)
+				c := ui.CurrentUI().SetScreenSize(runContext.newScreenWidth, runContext.newScreenHeight)
 				changed = changed || c
 			}
 			if 0 < runContext.newScreenScale {
-				c := ui.SetScreenScale(runContext.newScreenScale)
+				c := ui.CurrentUI().SetScreenScale(runContext.newScreenScale)
 				changed = changed || c
 			}
 			if changed {
 				w, h := runContext.newScreenWidth, runContext.newScreenHeight
-				if err := graphicsContext.setSize(w, h, ui.ActualScreenScale()); err != nil {
+				if err := graphicsContext.setSize(w, h, ui.CurrentUI().ActualScreenScale()); err != nil {
 					return err
 				}
 			}
@@ -102,10 +103,10 @@ func Run(f func(*Image) error, width, height, scale int, title string) error {
 		runContext.newScreenHeight = 0
 		runContext.newScreenScale = 0
 
-		if err := ui.DoEvents(); err != nil {
+		if err := ui.CurrentUI().DoEvents(); err != nil {
 			return err
 		}
-		if ui.IsClosed() {
+		if ui.CurrentUI().IsClosed() {
 			return nil
 		}
 		now := ui.Now()
@@ -117,10 +118,10 @@ func Run(f func(*Image) error, width, height, scale int, title string) error {
 			c := float64(now-beforeForUpdate) * FPS / float64(time.Second)
 			runContext.isRunningSlowly = c >= 2.5
 			for i := 0; i < int(c); i++ {
-				if err := ui.DoEvents(); err != nil {
+				if err := ui.CurrentUI().DoEvents(); err != nil {
 					return err
 				}
-				if ui.IsClosed() {
+				if ui.CurrentUI().IsClosed() {
 					return nil
 				}
 				if err := graphicsContext.update(f); err != nil {
@@ -128,7 +129,7 @@ func Run(f func(*Image) error, width, height, scale int, title string) error {
 				}
 			}
 			beforeForUpdate += int64(c) * int64(time.Second/FPS)
-			ui.SwapBuffers()
+			ui.CurrentUI().SwapBuffers()
 		}
 
 		// Calc the current FPS.
@@ -168,5 +169,5 @@ func SetScreenScale(scale int) {
 
 // ScreenScale returns the current screen scale.
 func ScreenScale() int {
-	return ui.ScreenScale()
+	return ui.CurrentUI().ScreenScale()
 }