mobile/ebitenmobileview: Use the common uiContext for layouting

This means that the whole offscreen is cleared correctly.

This change is a little breaking change: SetScreenSize or other
functions no longer works on ebitenmobile. Use Layout instead.

Fixes #1019

cmd/ebitenmobile/gobind.go

@@ -220,16 +220,7 @@ const objcM = `// Code generated by ebitenmobile. DO NOT EDIT.
   [super viewDidLayoutSubviews];
   CGRect viewRect = [[self view] frame];
 
-  EbitenmobileviewLayout(viewRect.size.width, viewRect.size.height, (id<EbitenmobileviewViewRectSetter>)self);
-}
-
-- (void)setViewRect:(long)x y:(long)y width:(long)width height:(long)height {
-  CGRect viewRect = CGRectMake(x, y, width, height);
-#if EBITEN_METAL
-  [[self metalView] setFrame:viewRect];
-#else
-  [[self glkView] setFrame:viewRect];
-#endif
+  EbitenmobileviewLayout(viewRect.size.width, viewRect.size.height);
 }
 
 - (void)didReceiveMemoryWarning {
@@ -341,7 +332,6 @@ import android.util.Log;
 import android.view.ViewGroup;
 
 import {{.JavaPkg}}.ebitenmobileview.Ebitenmobileview;
-import {{.JavaPkg}}.ebitenmobileview.ViewRectSetter;
 
 public class EbitenView extends ViewGroup {
     private double getDeviceScale() {
@@ -373,30 +363,16 @@ public class EbitenView extends ViewGroup {
 
     private void initialize() {
         ebitenSurfaceView_ = new EbitenSurfaceView(getContext());
-        LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
+        LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
         addView(ebitenSurfaceView_, params);
     }
 
     @Override
     protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
-        int widthInDp = (int)Math.ceil(pxToDp(right - left));
-        int heightInDp = (int)Math.ceil(pxToDp(bottom - top));
-        Ebitenmobileview.layout(widthInDp, heightInDp, new ViewRectSetter() {
-            @Override
-            public void setViewRect(long xInDp, long yInDp, long widthInDp, long heightInDp) {
-                // Use Math.floor to use smaller and safer values, or glitches can appear (#956).
-                final int widthInPx = (int)Math.floor(dpToPx(widthInDp));
-                final int heightInPx = (int)Math.floor(dpToPx(heightInDp));
-                final int xInPx = (int)Math.floor(dpToPx(xInDp));
-                final int yInPx = (int)Math.floor(dpToPx(yInDp));
-                new Handler(Looper.getMainLooper()).post(new Runnable() {
-                    @Override
-                    public void run() {
-                        ebitenSurfaceView_.layout(xInPx, yInPx, xInPx + widthInPx, yInPx + heightInPx);
-                    }
-                });
-            }
-        });
+        ebitenSurfaceView_.layout(0, 0, right - left, bottom - top);
+        double widthInDp = pxToDp(right - left);
+        double heightInDp = pxToDp(bottom - top);
+        Ebitenmobileview.layout(widthInDp, heightInDp);
     }
 
     // suspendGame suspends the game.

internal/driver/ui.go

@@ -32,7 +32,7 @@ var RegularTermination = errors.New("regular termination")
 
 type UI interface {
 	Run(context UIContext) error
-	RunWithoutMainLoop(width, height int, scale float64, title string, context UIContext) <-chan error
+	RunWithoutMainLoop(context UIContext) <-chan error
 
 	DeviceScaleFactor() float64
 	CursorMode() CursorMode

internal/uidriver/glfw/ui.go

@@ -543,7 +543,7 @@ func (u *UserInterface) Run(uicontext driver.UIContext) error {
 	return <-ch
 }
 
-func (u *UserInterface) RunWithoutMainLoop(width, height int, scale float64, title string, context driver.UIContext) <-chan error {
+func (u *UserInterface) RunWithoutMainLoop(context driver.UIContext) <-chan error {
 	panic("glfw: RunWithoutMainLoop is not implemented")
 }
 

internal/uidriver/js/ui.go

@@ -425,7 +425,7 @@ func (u *UserInterface) Run(context driver.UIContext) error {
 	return nil
 }
 
-func (u *UserInterface) RunWithoutMainLoop(width, height int, scale float64, title string, context driver.UIContext) <-chan error {
+func (u *UserInterface) RunWithoutMainLoop(context driver.UIContext) <-chan error {
 	panic("js: RunWithoutMainLoop is not implemented")
 }
 

internal/uidriver/mobile/ui.go

@@ -102,10 +102,8 @@ func (u *UserInterface) Update() {
 }
 
 type UserInterface struct {
-	// TODO: Remove these members: the driver layer should not care about the game screen size.
-	width  int
-	height int
-	scale  float64
+	outsideWidth  float64
+	outsideHeight float64
 
 	sizeChanged bool
 	foreground  bool
@@ -207,11 +205,9 @@ func (u *UserInterface) SetForeground(foreground bool) {
 }
 
 func (u *UserInterface) Run(context driver.UIContext) error {
-	// TODO: Remove width/height/scale arguments. They are not used from gomobile-build.
-
 	u.setGBuildSizeCh = make(chan struct{})
 	go func() {
-		if err := u.run(16, 16, 1, context, true); err != nil {
+		if err := u.run(context, true); err != nil {
 			// As mobile apps never ends, Loop can't return. Just panic here.
 			panic(err)
 		}
@@ -220,12 +216,12 @@ func (u *UserInterface) Run(context driver.UIContext) error {
 	return nil
 }
 
-func (u *UserInterface) RunWithoutMainLoop(width, height int, scale float64, title string, context driver.UIContext) <-chan error {
+func (u *UserInterface) RunWithoutMainLoop(context driver.UIContext) <-chan error {
 	ch := make(chan error)
 	go func() {
 		defer close(ch)
 		// title is ignored?
-		if err := u.run(width, height, scale, context, false); err != nil {
+		if err := u.run(context, false); err != nil {
 			ch <- err
 		}
 	}()
@@ -233,7 +229,7 @@ func (u *UserInterface) RunWithoutMainLoop(width, height int, scale float64, tit
 	return ch
 }
 
-func (u *UserInterface) run(width, height int, scale float64, context driver.UIContext, mainloop bool) (err error) {
+func (u *UserInterface) run(context driver.UIContext, mainloop bool) (err error) {
 	// Convert the panic to a regular error so that Java/Objective-C layer can treat this easily e.g., for
 	// Crashlytics. A panic is treated as SIGABRT, and there is no way to handle this on Java/Objective-C layer
 	// unfortunately.
@@ -245,9 +241,6 @@ func (u *UserInterface) run(width, height int, scale float64, context driver.UIC
 	}()
 
 	u.m.Lock()
-	u.width = width
-	u.height = height
-	u.scale = scale
 	u.sizeChanged = true
 	u.context = context
 	u.m.Unlock()
@@ -280,36 +273,26 @@ func (u *UserInterface) run(width, height int, scale float64, context driver.UIC
 }
 
 func (u *UserInterface) updateSize(context driver.UIContext) {
-	var width, height float64
+	var outsideWidth, outsideHeight float64
 
 	u.m.Lock()
 	sizeChanged := u.sizeChanged
 	if sizeChanged {
 		if u.gbuildWidthPx == 0 || u.gbuildHeightPx == 0 {
-			s := u.scale
-			width = float64(u.width) * s
-			height = float64(u.height) * s
+			outsideWidth = u.outsideWidth
+			outsideHeight = u.outsideHeight
 		} else {
 			// gomobile build
 			d := deviceScale()
-			width = float64(u.gbuildWidthPx) / d
-			height = float64(u.gbuildHeightPx) / d
+			outsideWidth = float64(u.gbuildWidthPx) / d
+			outsideHeight = float64(u.gbuildHeightPx) / d
 		}
 	}
 	u.sizeChanged = false
 	u.m.Unlock()
 
 	if sizeChanged {
-		// Dirty hack to set the offscreen size for gomobile-bind.
-		// TODO: Remove this. The layouting logic must be in the package ebiten, not here.
-		if u.gbuildWidthPx == 0 || u.gbuildHeightPx == 0 {
-			context.(interface {
-				SetScreenSize(width, height int)
-			}).SetScreenSize(u.width, u.height)
-		}
-
-		// Sizing also calls GL functions
-		context.Layout(width, height)
+		context.Layout(outsideWidth, outsideHeight)
 	}
 }
 
@@ -333,14 +316,13 @@ func (u *UserInterface) ScreenSizeInFullscreen() (int, int) {
 	return 0, 0
 }
 
-// SetScreenSizeAndScale is called from mobile/ebitenmobileview.
-func (u *UserInterface) SetScreenSizeAndScale(width, height int, scale float64) {
+// SetOutsideSize is called from mobile/ebitenmobileview.
+func (u *UserInterface) SetOutsideSize(outsideWidth, outsideHeight float64) {
 	// Called from ebitenmobileview.
 	u.m.Lock()
-	if u.width != width || u.height != height || u.scale != scale {
-		u.width = width
-		u.height = height
-		u.scale = scale
+	if u.outsideWidth != outsideWidth || u.outsideHeight != outsideHeight {
+		u.outsideWidth = outsideWidth
+		u.outsideHeight = outsideHeight
 		u.sizeChanged = true
 	}
 	u.m.Unlock()
@@ -358,11 +340,6 @@ func (u *UserInterface) setGBuildSize(widthPx, heightPx int) {
 }
 
 func (u *UserInterface) adjustPosition(x, y int) (int, int) {
-	// This function's caller already protects this function by the mutex.
-	if u.gbuildWidthPx == 0 || u.gbuildHeightPx == 0 {
-		s := u.scale
-		return int(float64(x) / s), int(float64(y) / s)
-	}
 	xf, yf := u.context.AdjustPosition(float64(x), float64(y))
 	return int(xf), int(yf)
 }

mobile/compat.go

@@ -17,8 +17,6 @@
 package mobile
 
 import (
-	"math"
-
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/mobile/ebitenmobileview"
 )
@@ -57,9 +55,9 @@ func Start(f func(*ebiten.Image) error, width, height int, scale float64, title
 		height: height,
 	})
 	// As the view layout is already determined, ignore the layout calculation at ebitenmobileview.
-	w := int(math.Ceil((float64(width) * scale)))
-	h := int(math.Ceil((float64(height) * scale)))
-	ebitenmobileview.Layout(w, h, nil)
+	w := float64(width) * scale
+	h := float64(height) * scale
+	ebitenmobileview.Layout(w, h)
 	return nil
 }
 

mobile/ebitenmobileview/funcs.go

@@ -26,54 +26,30 @@ package ebitenmobileview
 import "C"
 
 import (
-	"math"
 	"runtime"
 
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/internal/uidriver/mobile"
 )
 
-type ViewRectSetter interface {
-	SetViewRect(x, y, width, height int)
-}
-
-func Layout(viewWidth, viewHeight int, viewRectSetter ViewRectSetter) {
+func Layout(viewWidth, viewHeight float64) {
 	theState.m.Lock()
 	defer theState.m.Unlock()
-	layout(viewWidth, viewHeight, viewRectSetter)
+	layout(viewWidth, viewHeight)
 }
 
-func layout(viewWidth, viewHeight int, viewRectSetter ViewRectSetter) {
+func layout(viewWidth, viewHeight float64) {
 	if theState.game == nil {
 		// It is fine to override the existing function since only the last layout result matters.
 		theState.delayedLayout = func() {
-			layout(viewWidth, viewHeight, viewRectSetter)
+			layout(viewWidth, viewHeight)
 		}
 		return
 	}
 
-	// TODO: Layout must be called every frame like uiContext already did.
-	w, h := theState.game.Layout(int(viewWidth), int(viewHeight))
-	scaleX := float64(viewWidth) / float64(w)
-	scaleY := float64(viewHeight) / float64(h)
-	scale := math.Min(scaleX, scaleY)
-
-	// To convert a logical offscreen size to the actual screen size, use Math.floor to use smaller and safer
-	// values, or glitches can appear (#956).
-	width := int(math.Floor(float64(w) * scale))
-	height := int(math.Floor(float64(h) * scale))
-	x := (viewWidth - width) / 2
-	y := (viewHeight - height) / 2
-
-	if theState.isRunning() {
-		mobile.Get().SetScreenSizeAndScale(w, h, scale)
-	} else {
-		// The last argument 'title' is not used on mobile platforms, so just pass an empty string.
-		theState.errorCh = ebiten.RunWithoutMainLoop(theState.game.Update, w, h, scale, "")
-	}
-
-	if viewRectSetter != nil {
-		viewRectSetter.SetViewRect(x, y, width, height)
+	mobile.Get().SetOutsideSize(viewWidth, viewHeight)
+	if !theState.isRunning() {
+		theState.errorCh = ebiten.RunGameWithoutMainLoop(theState.game)
 	}
 }
 

run.go

@@ -238,19 +238,16 @@ func runGame(game Game, scale float64) error {
 	return nil
 }
 
-// RunWithoutMainLoop runs the game, but don't call the loop on the main (UI) thread.
-// Different from Run, RunWithoutMainLoop returns immediately.
+// RunGameWithoutMainLoop runs the game, but don't call the loop on the main (UI) thread.
+// Different from Run, RunGameWithoutMainLoop returns immediately.
 //
-// Ebiten users should NOT call RunWithoutMainLoop.
+// Ebiten users should NOT call RunGameWithoutMainLoop.
 // Instead, functions in github.com/hajimehoshi/ebiten/mobile package calls this.
-func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64, title string) <-chan error {
-	game := &defaultGame{
-		update: (&imageDumper{f: f}).update,
-		width:  width,
-		height: height,
-	}
-	theUIContext.set(game, scale)
-	return uiDriver().RunWithoutMainLoop(width, height, scale, title, theUIContext)
+func RunGameWithoutMainLoop(game Game) <-chan error {
+	game = &imageDumperGame{game: game}
+	fixWindowPosition(WindowSize())
+	theUIContext.set(game, 0)
+	return uiDriver().RunWithoutMainLoop(theUIContext)
 }
 
 // ScreenSizeInFullscreen is deprecated as of 1.11.0-alpha.
@@ -270,7 +267,7 @@ func SetScreenSize(width, height int) {
 	if width <= 0 || height <= 0 {
 		panic("ebiten: width and height must be positive")
 	}
-	theUIContext.SetScreenSize(width, height)
+	theUIContext.setScreenSize(width, height)
 }
 
 // SetScreenScale is deprecated as of 1.11.0-alpha. Use SetWindowSize instead.

uicontext.go

@@ -118,11 +118,10 @@ func (c *uiContext) getScaleForWindow() float64 {
 	return s
 }
 
-// SetScreenSize sets the (logical) screen size and adjusts the window size.
+// setScreenSize sets the (logical) screen size and adjusts the window size.
 //
-// SetScreenSize is for backward compatibility. This is called from ebiten.SetScreenSize and
-// uidriver/mobile.UserInterface.
-func (c *uiContext) SetScreenSize(width, height int) {
+// setScreenSize is for backward compatibility. This is called from ebiten.SetScreenSize.
+func (c *uiContext) setScreenSize(width, height int) {
 	c.m.Lock()
 	defer c.m.Unlock()
 
@@ -179,7 +178,7 @@ func (c *uiContext) updateOffscreen() {
 
 	// The window size is automatically adjusted when Run is used.
 	if _, ok := c.game.(*defaultGame); ok {
-		c.SetScreenSize(sw, sh)
+		c.setScreenSize(sw, sh)
 	}
 
 	// TODO: This is duplicated with mobile/ebitenmobileview/funcs.go. Refactor this.