ui: Scale is now float64 (#236)

examples/paint/main.go

@@ -107,7 +107,7 @@ func main() {
 	}
 	canvasImage.Fill(color.White)
 
-	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Paint (Ebiten Demo)"); err != nil {
+	if err := ebiten.Run(update, screenWidth, screenHeight, 1.5, "Paint (Ebiten Demo)"); err != nil {
 		log.Fatal(err)
 	}
 }

graphicscontext.go

@@ -30,11 +30,11 @@ type graphicsContext struct {
 	f           func(*Image) error
 	offscreen   *Image
 	screen      *Image
-	screenScale int
+	screenScale float64
 	initialized bool
 }
 
-func (c *graphicsContext) SetSize(screenWidth, screenHeight, screenScale int) error {
+func (c *graphicsContext) SetSize(screenWidth, screenHeight int, screenScale float64) error {
 	if c.screen != nil {
 		c.screen.Dispose()
 	}
@@ -45,7 +45,9 @@ func (c *graphicsContext) SetSize(screenWidth, screenHeight, screenScale int) er
 	if err != nil {
 		return err
 	}
-	c.screen, err = newImageWithScreenFramebuffer(screenWidth*screenScale, screenHeight*screenScale)
+	w := int(float64(screenWidth) * screenScale)
+	h := int(float64(screenHeight) * screenScale)
+	c.screen, err = newImageWithScreenFramebuffer(w, h)
 	if err != nil {
 		return err
 	}

internal/loop/run.go

@@ -98,12 +98,12 @@ func (c *runContext) setRunningSlowly(isRunningSlowly bool) {
 }
 
 type GraphicsContext interface {
-	SetSize(width, height, scale int) error
+	SetSize(width, height int, scale float64) error
 	UpdateAndDraw() error
 	Draw() error
 }
 
-func Run(g GraphicsContext, width, height, scale int, title string, fps int) error {
+func Run(g GraphicsContext, width, height int, scale float64, title string, fps int) error {
 	if currentRunContext != nil {
 		return errors.New("loop: The game is already running")
 	}

internal/ui/event.go

@@ -20,7 +20,7 @@ type CloseEvent struct {
 type ScreenSizeEvent struct {
 	Width       int
 	Height      int
-	ActualScale int
+	ActualScale float64
 }
 
 type RenderEvent struct {

internal/ui/input_glfw.go

@@ -20,8 +20,6 @@
 package ui
 
 import (
-	"math"
-
 	glfw "github.com/go-gl/glfw/v3.1/glfw"
 )
 
@@ -31,7 +29,7 @@ var glfwMouseButtonToMouseButton = map[glfw.MouseButton]MouseButton{
 	glfw.MouseButtonMiddle: MouseButtonMiddle,
 }
 
-func (i *input) update(window *glfw.Window, scale int) error {
+func (i *input) update(window *glfw.Window, scale float64) error {
 	i.m.Lock()
 	defer i.m.Unlock()
 
@@ -42,8 +40,8 @@ func (i *input) update(window *glfw.Window, scale int) error {
 		i.mouseButtonPressed[e] = window.GetMouseButton(g) == glfw.Press
 	}
 	x, y := window.GetCursorPos()
-	i.cursorX = int(math.Floor(x)) / scale
+	i.cursorX = int(x / scale)
-	i.cursorY = int(math.Floor(y)) / scale
+	i.cursorY = int(y / scale)
 	for id := glfw.Joystick(0); id < glfw.Joystick(len(i.gamepads)); id++ {
 		if !glfw.JoystickPresent(id) {
 			continue

internal/ui/ui.go

@@ -15,11 +15,11 @@
 package ui
 
 type UserInterface interface {
-	Start(width, height, scale int, title string) error
+	Start(width, height int, scale float64, title string) error
 	Update() (interface{}, error)
 	SwapBuffers() error
 	Terminate() error
-	ScreenScale() int
+	ScreenScale() float64
 	SetScreenSize(width, height int) bool
-	SetScreenScale(scale int) bool
+	SetScreenScale(scale float64) bool
 }

internal/ui/ui_glfw.go

@@ -32,9 +32,9 @@ type userInterface struct {
 	window           *glfw.Window
 	width            int
 	height           int
-	scale            int
+	scale            float64
 	deviceScale      float64
-	framebufferScale int
+	framebufferScale float64
 	context          *opengl.Context
 	funcs            chan func()
 	sizeChanged      bool
@@ -125,7 +125,7 @@ func (u *userInterface) SetScreenSize(width, height int) bool {
 	return r
 }
 
-func (u *userInterface) SetScreenScale(scale int) bool {
+func (u *userInterface) SetScreenScale(scale float64) bool {
 	r := false
 	u.runOnMainThread(func() {
 		r = u.setScreenSize(u.width, u.height, scale)
@@ -133,22 +133,21 @@ func (u *userInterface) SetScreenScale(scale int) bool {
 	return r
 }
 
-func (u *userInterface) ScreenScale() int {
+func (u *userInterface) ScreenScale() float64 {
-	s := 0
+	s := 0.0
 	u.runOnMainThread(func() {
 		s = u.scale
 	})
 	return s
 }
 
-func (u *userInterface) Start(width, height, scale int, title string) error {
+func (u *userInterface) Start(width, height int, scale float64, title string) error {
 	var err error
 	u.runOnMainThread(func() {
 		m := glfw.GetPrimaryMonitor()
 		v := m.GetVideoMode()
 		u.deviceScale = deviceScale()
 		u.framebufferScale = 1
-
 		if !u.setScreenSize(width, height, scale) {
 			err = errors.New("ui: Fail to set the screen size")
 			return
@@ -156,18 +155,18 @@ func (u *userInterface) Start(width, height, scale int, title string) error {
 		u.window.SetTitle(title)
 		u.window.Show()
 
-		x := (v.Width - width*u.windowScale()) / 2
+		x := (v.Width - int(float64(width)*u.windowScale())) / 2
-		y := (v.Height - height*u.windowScale()) / 3
+		y := (v.Height - int(float64(height)*u.windowScale())) / 3
 		u.window.SetPos(x, y)
 	})
 	return err
 }
 
-func (u *userInterface) windowScale() int {
+func (u *userInterface) windowScale() float64 {
-	return u.scale * int(u.deviceScale)
+	return u.scale * u.deviceScale
 }
 
-func (u *userInterface) actualScreenScale() int {
+func (u *userInterface) actualScreenScale() float64 {
 	return u.windowScale() * u.framebufferScale
 }
 
@@ -260,7 +259,7 @@ func (u *userInterface) FinishRendering() error {
 	return nil
 }
 
-func (u *userInterface) setScreenSize(width, height, scale int) bool {
+func (u *userInterface) setScreenSize(width, height int, scale float64) bool {
 	if u.width == width && u.height == height && u.scale == scale {
 		return false
 	}
@@ -273,7 +272,7 @@ func (u *userInterface) setScreenSize(width, height, scale int) bool {
 	// To prevent hanging up, return asap if the width is too small.
 	// 252 is an arbitrary number and I guess this is small enough.
 	const minWindowWidth = 252
-	if width*u.actualScreenScale() < minWindowWidth {
+	if int(float64(width)*u.actualScreenScale()) < minWindowWidth {
 		u.scale = origScale
 		return false
 	}
@@ -290,7 +289,7 @@ func (u *userInterface) setScreenSize(width, height, scale int) bool {
 		window.SetFramebufferSizeCallback(nil)
 		close(ch)
 	})
-	window.SetSize(width*u.windowScale(), height*u.windowScale())
+	window.SetSize(int(float64(width)*u.windowScale()), int(float64(height)*u.windowScale()))
 
 event:
 	for {
@@ -303,7 +302,7 @@ event:
 	}
 	// This is usually 1, but sometimes more than 1 (e.g. Retina Mac)
 	fw, _ := window.GetFramebufferSize()
-	u.framebufferScale = fw / width / u.windowScale()
+	u.framebufferScale = float64(fw) / float64(width) / u.windowScale()
 	u.sizeChanged = true
 	return true
 }

internal/ui/ui_js.go

@@ -26,7 +26,7 @@ import (
 var canvas *js.Object
 
 type userInterface struct {
-	scale       int
+	scale       float64
 	deviceScale float64
 	sizeChanged bool
 }
@@ -66,17 +66,17 @@ func (u *userInterface) SetScreenSize(width, height int) bool {
 	return u.setScreenSize(width, height, u.scale)
 }
 
-func (u *userInterface) SetScreenScale(scale int) bool {
+func (u *userInterface) SetScreenScale(scale float64) bool {
 	width, height := u.size()
 	return u.setScreenSize(width, height, scale)
 }
 
-func (u *userInterface) ScreenScale() int {
+func (u *userInterface) ScreenScale() float64 {
 	return u.scale
 }
 
-func (u *userInterface) ActualScreenScale() int {
+func (u *userInterface) ActualScreenScale() float64 {
-	return u.scale * int(u.deviceScale)
+	return u.scale * u.deviceScale
 }
 
 func (u *userInterface) Update() (interface{}, error) {
@@ -122,8 +122,8 @@ func touchEventToTouches(e *js.Object) []touch {
 	for i := 0; i < len(t); i++ {
 		jj := j.Call("item", i)
 		t[i].id = jj.Get("identifier").Int()
-		t[i].x = (jj.Get("clientX").Int() - left) / scale
+		t[i].x = int(float64(jj.Get("clientX").Int()-left) / scale)
-		t[i].y = (jj.Get("clientY").Int() - top) / scale
+		t[i].y = int(float64(jj.Get("clientY").Int()-top) / scale)
 	}
 	return t
 }
@@ -242,7 +242,7 @@ func setMouseCursorFromEvent(e *js.Object) {
 	x, y := e.Get("clientX").Int(), e.Get("clientY").Int()
 	x -= rect.Get("left").Int()
 	y -= rect.Get("top").Int()
-	currentInput.setMouseCursor(x/scale, y/scale)
+	currentInput.setMouseCursor(int(float64(x)/scale), int(float64(y)/scale))
 }
 
 func devicePixelRatio() float64 {
@@ -258,7 +258,7 @@ func Main() error {
 	return nil
 }
 
-func (u *userInterface) Start(width, height, scale int, title string) error {
+func (u *userInterface) Start(width, height int, scale float64, title string) error {
 	doc := js.Global.Get("document")
 	doc.Set("title", title)
 	u.setScreenSize(width, height, scale)
@@ -277,7 +277,7 @@ func (u *userInterface) size() (width, height int) {
 	return
 }
 
-func (u *userInterface) setScreenSize(width, height, scale int) bool {
+func (u *userInterface) setScreenSize(width, height int, scale float64) bool {
 	w, h := u.size()
 	s := u.scale
 	if w == width && h == height && s == scale {
@@ -285,12 +285,12 @@ func (u *userInterface) setScreenSize(width, height, scale int) bool {
 	}
 	u.scale = scale
 	u.deviceScale = devicePixelRatio()
-	canvas.Set("width", width*u.ActualScreenScale())
+	canvas.Set("width", int(float64(width)*u.ActualScreenScale()))
-	canvas.Set("height", height*u.ActualScreenScale())
+	canvas.Set("height", int(float64(height)*u.ActualScreenScale()))
 	canvasStyle := canvas.Get("style")
 
-	cssWidth := width * scale
+	cssWidth := int(float64(width) * scale)
-	cssHeight := height * scale
+	cssHeight := int(float64(height) * scale)
 	canvasStyle.Set("width", strconv.Itoa(cssWidth)+"px")
 	canvasStyle.Set("height", strconv.Itoa(cssHeight)+"px")
 	// CSS calc requires space chars.

internal/ui/ui_mobile.go

@@ -76,7 +76,7 @@ loop:
 type userInterface struct {
 	width       int
 	height      int
-	scale       int
+	scale       float64
 	sizeChanged bool
 }
 
@@ -94,7 +94,7 @@ func CurrentUI() UserInterface {
 	return currentUI
 }
 
-func (u *userInterface) Start(width, height, scale int, title string) error {
+func (u *userInterface) Start(width, height int, scale float64, title string) error {
 	u.width = width
 	u.height = height
 	u.scale = scale
@@ -135,17 +135,17 @@ func (u *userInterface) SetScreenSize(width, height int) bool {
 	return false
 }
 
-func (u *userInterface) SetScreenScale(scale int) bool {
+func (u *userInterface) SetScreenScale(scale float64) bool {
 	// TODO: Implement
 	return false
 }
 
-func (u *userInterface) ScreenScale() int {
+func (u *userInterface) ScreenScale() float64 {
 	return u.scale
 }
 
-func (u *userInterface) actualScreenScale() int {
+func (u *userInterface) actualScreenScale() float64 {
-	return u.scale * int(deviceScale())
+	return u.scale * deviceScale()
 }
 
 func UpdateTouches(touches []Touch) {

mobile/run.go

@@ -29,7 +29,7 @@ var chError <-chan error
 
 type EventDispatcher interface {
 	SetScreenSize(width, height int)
-	SetScreenScale(scale int)
+	SetScreenScale(scale float64)
 	Render() error
 	UpdateTouchesOnAndroid(action int, id int, x, y int)
 	UpdateTouchesOnIOS(phase int, ptr int, x, y int)
@@ -38,7 +38,7 @@ type EventDispatcher interface {
 // Start starts the game and returns immediately.
 //
 // Different from ebiten.Run, this invokes only the game loop and not the main (UI) loop.
-func Start(f func(*ebiten.Image) error, width, height, scale int, title string) (EventDispatcher, error) {
+func Start(f func(*ebiten.Image) error, width, height int, scale float64, title string) (EventDispatcher, error) {
 	chError = ebiten.RunWithoutMainLoop(f, width, height, scale, title)
 	return &eventDispatcher{
 		touches: map[int]position{},
@@ -58,7 +58,7 @@ func (e *eventDispatcher) SetScreenSize(width, height int) {
 	ui.CurrentUI().SetScreenSize(width, height)
 }
 
-func (e *eventDispatcher) SetScreenScale(scale int) {
+func (e *eventDispatcher) SetScreenScale(scale float64) {
 	ui.CurrentUI().SetScreenScale(scale)
 }
 
@@ -81,8 +81,8 @@ func (t touch) ID() int {
 
 func (t touch) Position() (int, int) {
 	// TODO: Is this OK to adjust the position here?
-	return t.position.x / ui.CurrentUI().ScreenScale(),
+	return int(float64(t.position.x) / ui.CurrentUI().ScreenScale()),
-		t.position.y / ui.CurrentUI().ScreenScale()
+		int(float64(t.position.y) / ui.CurrentUI().ScreenScale())
 }
 
 // UpdateTouchesOnAndroid updates the touch state on Android.

run.go

@@ -53,7 +53,7 @@ func IsRunningSlowly() bool {
 // The given function f is guaranteed to be called 60 times a second
 // even if a rendering frame is skipped.
 // f is not called when the screen is not shown.
-func Run(f func(*Image) error, width, height, scale int, title string) error {
+func Run(f func(*Image) error, width, height int, scale float64, title string) error {
 	ch := make(chan error)
 	go func() {
 		g := newGraphicsContext(f)
@@ -68,7 +68,7 @@ func Run(f func(*Image) error, width, height, scale int, title string) error {
 //
 // Typically, Ebiten users don't have to call this directly.
 // Instead, functions in github.com/hajimehoshi/ebiten/mobile module call this.
-func RunWithoutMainLoop(f func(*Image) error, width, height, scale int, title string) <-chan error {
+func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64, title string) <-chan error {
 	ch := make(chan error)
 	go func() {
 		g := newGraphicsContext(f)
@@ -94,7 +94,7 @@ func SetScreenSize(width, height int) {
 // SetScreenScale changes the scale of the screen.
 //
 // This function is concurrent-safe.
-func SetScreenScale(scale int) {
+func SetScreenScale(scale float64) {
 	if scale <= 0 {
 		panic("ebiten: scale must be positive")
 	}
@@ -104,6 +104,6 @@ func SetScreenScale(scale int) {
 // ScreenScale returns the current screen scale.
 //
 // This function is concurrent-safe.
-func ScreenScale() int {
+func ScreenScale() float64 {
 	return ui.CurrentUI().ScreenScale()
 }