cmd/ebitenmobile/_files/EbitenSurfaceView.java

@@ -25,10 +25,10 @@ import javax.microedition.khronos.egl.EGLConfig;
 import javax.microedition.khronos.opengles.GL10;
 
 import {{.JavaPkg}}.ebitenmobileview.Ebitenmobileview;
-import {{.JavaPkg}}.ebitenmobileview.Renderer;
+import {{.JavaPkg}}.ebitenmobileview.RenderRequester;
 import {{.JavaPkg}}.{{.PrefixLower}}.EbitenView;
 
-class EbitenSurfaceView extends GLSurfaceView implements Renderer {
+class EbitenSurfaceView extends GLSurfaceView implements RenderRequester {
 
     private class EbitenRenderer implements GLSurfaceView.Renderer {
 
@@ -63,10 +63,6 @@ class EbitenSurfaceView extends GLSurfaceView implements Renderer {
                 onceSurfaceCreated_ = true;
                 return;
             }
-            if (hasStrictContextRestoration()) {
-                Ebitenmobileview.onContextLost();
-                return;
-            }
             contextLost_ = true;
             new Handler(Looper.getMainLooper()).post(new Runnable() {
                 @Override
@@ -81,8 +77,6 @@ class EbitenSurfaceView extends GLSurfaceView implements Renderer {
         }
     }
 
-    private boolean strictContextRestoration_ = false;
-
     public EbitenSurfaceView(Context context) {
         super(context);
         initialize();
@@ -96,11 +90,9 @@ class EbitenSurfaceView extends GLSurfaceView implements Renderer {
     private void initialize() {
         setEGLContextClientVersion(3);
         setEGLConfigChooser(8, 8, 8, 8, 0, 0);
-        // setRenderer must be called before setRenderRequester.
-        // Or, the application crashes.
         setRenderer(new EbitenRenderer());
-
-        Ebitenmobileview.setRenderer(this);
+        setPreserveEGLContextOnPause(true);
+        Ebitenmobileview.setRenderRequester(this);
     }
 
     private void onErrorOnGameUpdate(Exception e) {
@@ -122,16 +114,6 @@ class EbitenSurfaceView extends GLSurfaceView implements Renderer {
         }
     }
 
-    @Override
-    public synchronized void setStrictContextRestoration(boolean strictContextRestoration) {
-        strictContextRestoration_ = strictContextRestoration;
-        setPreserveEGLContextOnPause(!strictContextRestoration);
-    }
-
-    private synchronized boolean hasStrictContextRestoration() {
-        return strictContextRestoration_;
-    }
-
     @Override
     public synchronized void requestRenderIfNeeded() {
         if (getRenderMode() == RENDERMODE_WHEN_DIRTY) {

cmd/ebitenmobile/_files/EbitenViewController.m

@@ -20,7 +20,7 @@
 
 #import "Ebitenmobileview.objc.h"
 
-@interface {{.PrefixUpper}}EbitenViewController : UIViewController<EbitenmobileviewRenderer, EbitenmobileviewSetGameNotifier>
+@interface {{.PrefixUpper}}EbitenViewController : UIViewController<EbitenmobileviewRenderRequester, EbitenmobileviewSetGameNotifier>
 @end
 
 @implementation {{.PrefixUpper}}EbitenViewController {
@@ -149,7 +149,7 @@
 
   displayLink_ = [CADisplayLink displayLinkWithTarget:self selector:@selector(drawFrame)];
   [displayLink_ addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
-  EbitenmobileviewSetRenderer(self);
+  EbitenmobileviewSetRenderRequester(self);
 
   // Run the loop. This will never return.
   [[NSRunLoop currentRunLoop] run];
@@ -364,10 +364,6 @@
   }
 }
 
-- (void)setStrictContextRestoration:(BOOL)strictContextRestoration {
-  // Do nothing.
-}
-
 - (void)setExplicitRenderingMode:(BOOL)explicitRendering {
   @synchronized(self) {
     explicitRendering_ = explicitRendering;

gameforui.go

@@ -66,10 +66,6 @@ func (g *gameForUI) NewOffscreenImage(width, height int) *ui.Image {
 	// An image on an atlas is surrounded by a transparent edge,
 	// and the shader program unexpectedly picks the pixel on the edges.
 	imageType := atlas.ImageTypeUnmanaged
-	if ui.Get().IsScreenClearedEveryFrame() {
-		// A volatile image is also always isolated.
-		imageType = atlas.ImageTypeVolatile
-	}
 	g.offscreen = newImage(image.Rect(0, 0, width, height), imageType)
 	return g.offscreen.image
 }

internal/atlas/image.go

@@ -22,10 +22,11 @@ import (
 	"runtime"
 	"sync"
 
+	"github.com/hajimehoshi/ebiten/v2/internal/debug"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/packing"
-	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
 )
 
@@ -89,8 +90,11 @@ func putImagesOnSourceBackend() {
 // backend is a big texture atlas that can have multiple images.
 // backend is a texture in GPU.
 type backend struct {
-	// restorable is an atlas on which there might be multiple images.
-	restorable *restorable.Image
+	// image is an atlas on which there might be multiple images.
+	image *graphicscommand.Image
+
+	width  int
+	height int
 
 	// page is an atlas map. Each part is called a node.
 	// If page is nil, the backend's image is isolated and not on an atlas.
@@ -117,11 +121,73 @@ func (b *backend) tryAlloc(width, height int) (*packing.Node, bool) {
 		return nil, false
 	}
 
-	b.restorable = b.restorable.Extend(b.page.Size())
+	b.extendIfNeeded(b.page.Size())
 
 	return n, true
 }
 
+// extendIfNeeded extends the image by the given size if necessary.
+// extendIfNeeded creates a new image with the given size and copies the pixels of the given source image.
+// extendIfNeeded disposes an old image after its call when a new image is created.
+func (b *backend) extendIfNeeded(width, height int) {
+	if b.width >= width && b.height >= height {
+		return
+	}
+
+	// Assume that the screen image is never extended.
+	newImg := newClearedImage(width, height, false)
+
+	srcs := [graphics.ShaderSrcImageCount]*graphicscommand.Image{b.image}
+	sw, sh := b.image.InternalSize()
+	vs := make([]float32, 4*graphics.VertexFloatCount)
+	graphics.QuadVerticesFromDstAndSrc(vs, 0, 0, float32(sw), float32(sh), 0, 0, float32(sw), float32(sh), 1, 1, 1, 1)
+	is := graphics.QuadIndices()
+	dr := image.Rect(0, 0, sw, sh)
+	newImg.DrawTriangles(srcs, vs, is, graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, NearestFilterShader.ensureShader(), nil, graphicsdriver.FillRuleFillAll)
+	b.image.Dispose()
+
+	b.image = newImg
+	b.width = width
+	b.height = height
+}
+
+// newClearedImage creates an emtpy image with the given size.
+//
+// Note that Dispose is not called automatically.
+func newClearedImage(width, height int, screen bool) *graphicscommand.Image {
+	i := graphicscommand.NewImage(width, height, screen)
+
+	// This needs to use 'InternalSize' to render the whole region, or edges are unexpectedly cleared on some
+	// devices.
+	iw, ih := i.InternalSize()
+	clearImage(i, image.Rect(0, 0, iw, ih))
+	return i
+}
+
+func clearImage(i *graphicscommand.Image, region image.Rectangle) {
+	vs := make([]float32, 4*graphics.VertexFloatCount)
+	graphics.QuadVerticesFromDstAndSrc(vs, float32(region.Min.X), float32(region.Min.Y), float32(region.Max.X), float32(region.Max.Y), 0, 0, 0, 0, 0, 0, 0, 0)
+	is := graphics.QuadIndices()
+	i.DrawTriangles([graphics.ShaderSrcImageCount]*graphicscommand.Image{}, vs, is, graphicsdriver.BlendClear, region, [graphics.ShaderSrcImageCount]image.Rectangle{}, clearShader.ensureShader(), nil, graphicsdriver.FillRuleFillAll)
+}
+
+func (b *backend) clearPixels(region image.Rectangle) {
+	if region.Dx() <= 0 || region.Dy() <= 0 {
+		panic("atlas: width/height must be positive")
+	}
+	clearImage(b.image, region.Intersect(image.Rect(0, 0, b.width, b.height)))
+}
+
+func (b *backend) writePixels(pixels *graphics.ManagedBytes, region image.Rectangle) {
+	if region.Dx() <= 0 || region.Dy() <= 0 {
+		panic("atlas: width/height must be positive")
+	}
+	if !region.In(image.Rect(0, 0, b.width, b.height)) {
+		panic(fmt.Sprintf("atlas: out of range %v", region))
+	}
+	b.image.WritePixels(pixels, region)
+}
+
 var (
 	// backendsM is a mutex for critical sections of the backend and packing.Node objects.
 	backendsM sync.Mutex
@@ -139,6 +205,8 @@ var (
 
 	imagesUsedAsDestination smallImageSet
 
+	graphicsDriverInitialized bool
+
 	deferred []func()
 
 	// deferredM is a mutex for the slice operations. This must not be used for other usages.
@@ -156,8 +224,6 @@ const (
 	// A screen image is also unmanaged.
 	ImageTypeScreen
 
-	ImageTypeVolatile
-
 	// ImageTypeUnmanaged is an unmanaged image that is not on an atlas.
 	ImageTypeUnmanaged
 )
@@ -176,7 +242,7 @@ type Image struct {
 	// usedAsSourceCount represents how long the image is used as a rendering source and kept not modified with
 	// DrawTriangles.
 	// In the current implementation, if an image is being modified by DrawTriangles, the image is separated from
-	// a restorable image on an atlas by ensureIsolatedFromSource.
+	// a graphicscommand.Image on an atlas by ensureIsolatedFromSource.
 	//
 	// The type is int64 instead of int to avoid overflow when comparing the limitation.
 	//
@@ -367,6 +433,11 @@ func (i *Image) DrawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertice
 }
 
 func (i *Image) drawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertices []float32, indices []uint32, blend graphicsdriver.Blend, dstRegion image.Rectangle, srcRegions [graphics.ShaderSrcImageCount]image.Rectangle, shader *Shader, uniforms []uint32, fillRule graphicsdriver.FillRule) {
+	if len(vertices) == 0 {
+		return
+	}
+
+	// This slice is not escaped to the heap. This can be checked by `go build -gcflags=-m`.
 	backends := make([]*backend, 0, len(srcs))
 	for _, src := range srcs {
 		if src == nil {
@@ -386,7 +457,7 @@ func (i *Image) drawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertice
 	for _, src := range srcs {
 		// Compare i and source images after ensuring i is not on an atlas, or
 		// i and a source image might share the same atlas even though i != src.
-		if src != nil && i.backend.restorable == src.backend.restorable {
+		if src != nil && i.backend.image == src.backend.image {
 			panic("atlas: Image.DrawTriangles: source must be different from the receiver")
 		}
 	}
@@ -408,8 +479,8 @@ func (i *Image) drawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertice
 			vertices[i+2] += oxf
 			vertices[i+3] += oyf
 		}
-		if shader.ensureShader().Unit() == shaderir.Texels {
-			sw, sh := srcs[0].backend.restorable.InternalSize()
+		if shader.ir.Unit == shaderir.Texels {
+			sw, sh := srcs[0].backend.image.InternalSize()
 			swf, shf := float32(sw), float32(sh)
 			for i := 0; i < n; i += graphics.VertexFloatCount {
 				vertices[i+2] /= swf
@@ -439,15 +510,15 @@ func (i *Image) drawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertice
 		srcRegions[i] = srcRegions[i].Add(r.Min)
 	}
 
-	var imgs [graphics.ShaderSrcImageCount]*restorable.Image
+	var imgs [graphics.ShaderSrcImageCount]*graphicscommand.Image
 	for i, src := range srcs {
 		if src == nil {
 			continue
 		}
-		imgs[i] = src.backend.restorable
+		imgs[i] = src.backend.image
 	}
 
-	i.backend.restorable.DrawTriangles(imgs, vertices, indices, blend, dstRegion, srcRegions, shader.ensureShader(), uniforms, fillRule)
+	i.backend.image.DrawTriangles(imgs, vertices, indices, blend, dstRegion, srcRegions, shader.ensureShader(), uniforms, fillRule)
 
 	for _, src := range srcs {
 		if src == nil {
@@ -499,7 +570,7 @@ func (i *Image) writePixels(pix []byte, region image.Rectangle) {
 		region = region.Add(r.Min)
 
 		if pix == nil {
-			i.backend.restorable.ClearPixels(region)
+			i.backend.clearPixels(region)
 			return
 		}
 
@@ -507,7 +578,7 @@ func (i *Image) writePixels(pix []byte, region image.Rectangle) {
 		pix2 := graphics.NewManagedBytes(len(pix), func(bs []byte) {
 			copy(bs, pix)
 		})
-		i.backend.restorable.WritePixels(pix2, region)
+		i.backend.writePixels(pix2, region)
 		return
 	}
 
@@ -536,7 +607,7 @@ func (i *Image) writePixels(pix []byte, region image.Rectangle) {
 			copy(bs[4*j*r.Dx():], pix[4*j*region.Dx():4*(j+1)*region.Dx()])
 		}
 	})
-	i.backend.restorable.WritePixels(pixb, r)
+	i.backend.writePixels(pixb, r)
 }
 
 func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte, region image.Rectangle) (ok bool, err error) {
@@ -552,19 +623,31 @@ func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte
 	// To prevent memory leaks, flush the deferred functions here.
 	flushDeferred()
 
-	if i.backend == nil || i.backend.restorable == nil {
-		for i := range pixels {
-			pixels[i] = 0
-		}
-		return true, nil
-	}
-
-	if err := i.backend.restorable.ReadPixels(graphicsDriver, pixels, region.Add(i.regionWithPadding().Min)); err != nil {
+	if err := i.readPixels(graphicsDriver, pixels, region); err != nil {
 		return false, err
 	}
 	return true, nil
 }
 
+func (i *Image) readPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte, region image.Rectangle) error {
+	if i.backend == nil {
+		for i := range pixels {
+			pixels[i] = 0
+		}
+		return nil
+	}
+
+	if err := i.backend.image.ReadPixels(graphicsDriver, []graphicsdriver.PixelsArgs{
+		{
+			Pixels: pixels,
+			Region: region.Add(i.regionWithPadding().Min),
+		},
+	}); err != nil {
+		return err
+	}
+	return nil
+}
+
 // Deallocate deallocates the internal state.
 // Even after this call, the image is still available as a new cleared image.
 func (i *Image) Deallocate() {
@@ -603,12 +686,13 @@ func (i *Image) deallocate() {
 		if !i.backend.page.IsEmpty() {
 			// As this part can be reused, this should be cleared explicitly.
 			r := i.regionWithPadding()
-			i.backend.restorable.ClearPixels(r)
+			i.backend.clearPixels(r)
 			return
 		}
 	}
 
-	i.backend.restorable.Dispose()
+	i.backend.image.Dispose()
+	i.backend.image = nil
 
 	for idx, sh := range theBackends {
 		if sh == i.backend {
@@ -651,24 +735,16 @@ func (i *Image) finalize() {
 }
 
 func (i *Image) allocate(forbiddenBackends []*backend, asSource bool) {
+	if !graphicsDriverInitialized {
+		panic("atlas: graphics driver must be ready at allocate but not")
+	}
+
 	if i.backend != nil {
 		panic("atlas: the image is already allocated")
 	}
 
 	runtime.SetFinalizer(i, (*Image).finalize)
 
-	if i.imageType == ImageTypeScreen {
-		if asSource {
-			panic("atlas: a screen image cannot be created as a source")
-		}
-		// A screen image doesn't have a padding.
-		i.backend = &backend{
-			restorable: restorable.NewImage(i.width, i.height, restorable.ImageTypeScreen),
-		}
-		theBackends = append(theBackends, i.backend)
-		return
-	}
-
 	wp := i.width + i.paddingSize()
 	hp := i.height + i.paddingSize()
 
@@ -677,13 +753,11 @@ func (i *Image) allocate(forbiddenBackends []*backend, asSource bool) {
 			panic(fmt.Sprintf("atlas: the image being put on an atlas is too big: width: %d, height: %d", i.width, i.height))
 		}
 
-		typ := restorable.ImageTypeRegular
-		if i.imageType == ImageTypeVolatile {
-			typ = restorable.ImageTypeVolatile
-		}
 		i.backend = &backend{
-			restorable: restorable.NewImage(wp, hp, typ),
-			source:     asSource && typ == restorable.ImageTypeRegular,
+			image:  newClearedImage(wp, hp, i.imageType == ImageTypeScreen),
+			width:  wp,
+			height: hp,
+			source: asSource && i.imageType == ImageTypeRegular,
 		}
 		theBackends = append(theBackends, i.backend)
 		return
@@ -727,14 +801,12 @@ loop:
 		height *= 2
 	}
 
-	typ := restorable.ImageTypeRegular
-	if i.imageType == ImageTypeVolatile {
-		typ = restorable.ImageTypeVolatile
-	}
 	b := &backend{
-		restorable: restorable.NewImage(width, height, typ),
-		page:       packing.NewPage(width, height, maxSize),
-		source:     asSource,
+		image:  newClearedImage(width, height, false),
+		width:  width,
+		height: height,
+		page:   packing.NewPage(width, height, maxSize),
+		source: asSource,
 	}
 	theBackends = append(theBackends, b)
 
@@ -754,7 +826,7 @@ func (i *Image) DumpScreenshot(graphicsDriver graphicsdriver.Graphics, path stri
 		panic("atlas: DumpScreenshots must be called in between BeginFrame and EndFrame")
 	}
 
-	return i.backend.restorable.Dump(graphicsDriver, path, blackbg, image.Rect(0, 0, i.width, i.height))
+	return i.backend.image.Dump(graphicsDriver, path, blackbg, image.Rect(0, 0, i.width, i.height))
 }
 
 func EndFrame() error {
@@ -785,7 +857,15 @@ func SwapBuffers(graphicsDriver graphicsdriver.Graphics) error {
 		}
 	}()
 
-	if err := restorable.SwapBuffers(graphicsDriver); err != nil {
+	if debug.IsDebug {
+		debug.FrameLogf("Internal image sizes:\n")
+		imgs := make([]*graphicscommand.Image, 0, len(theBackends))
+		for _, backend := range theBackends {
+			imgs = append(imgs, backend.image)
+		}
+		graphicscommand.LogImagesInfo(imgs)
+	}
+	if err := graphicscommand.FlushCommands(graphicsDriver, true); err != nil {
 		return err
 	}
 	return nil
@@ -810,7 +890,7 @@ func BeginFrame(graphicsDriver graphicsdriver.Graphics) error {
 
 	var err error
 	initOnce.Do(func() {
-		err = restorable.InitializeGraphicsDriverState(graphicsDriver)
+		err = graphicscommand.InitializeGraphicsDriverState(graphicsDriver)
 		if err != nil {
 			return
 		}
@@ -826,18 +906,15 @@ func BeginFrame(graphicsDriver graphicsdriver.Graphics) error {
 			minDestinationSize = 16
 		}
 		if maxSize == 0 {
-			maxSize = floorPowerOf2(restorable.MaxImageSize(graphicsDriver))
+			maxSize = floorPowerOf2(graphicscommand.MaxImageSize(graphicsDriver))
 		}
+
+		graphicsDriverInitialized = true
 	})
 	if err != nil {
 		return err
 	}
 
-	// Restore images first before other image manipulations (#2075).
-	if err := restorable.RestoreIfNeeded(graphicsDriver); err != nil {
-		return err
-	}
-
 	flushDeferred()
 	putImagesOnSourceBackend()
 
@@ -852,5 +929,9 @@ func DumpImages(graphicsDriver graphicsdriver.Graphics, dir string) (string, err
 		panic("atlas: DumpImages must be called in between BeginFrame and EndFrame")
 	}
 
-	return restorable.DumpImages(graphicsDriver, dir)
+	images := make([]*graphicscommand.Image, 0, len(theBackends))
+	for _, backend := range theBackends {
+		images = append(images, backend.image)
+	}
+	return graphicscommand.DumpImages(images, graphicsDriver, dir)
 }

internal/atlas/image_test.go

@@ -174,8 +174,8 @@ func TestReputOnSourceBackend(t *testing.T) {
 	}
 	img2.WritePixels(pix, image.Rect(0, 0, size, size))
 
-	// Create a volatile image. This should always be on a non-source backend.
-	img3 := atlas.NewImage(size, size, atlas.ImageTypeVolatile)
+	// Create an unmanaged image. This should always be on a non-source backend.
+	img3 := atlas.NewImage(size, size, atlas.ImageTypeUnmanaged)
 	defer img3.Deallocate()
 	img3.WritePixels(make([]byte, 4*size*size), image.Rect(0, 0, size, size))
 	if got, want := img3.IsOnSourceBackendForTesting(), false; got != want {
@@ -685,7 +685,7 @@ func TestImageIsNotReputOnSourceBackendWithoutUsingAsSource(t *testing.T) {
 }
 
 func TestImageWritePixelsModify(t *testing.T) {
-	for _, typ := range []atlas.ImageType{atlas.ImageTypeRegular, atlas.ImageTypeVolatile, atlas.ImageTypeUnmanaged} {
+	for _, typ := range []atlas.ImageType{atlas.ImageTypeRegular, atlas.ImageTypeRegular, atlas.ImageTypeUnmanaged} {
 		const size = 16
 		img := atlas.NewImage(size, size, typ)
 		defer img.Deallocate()

internal/atlas/shader.go

@@ -15,15 +15,20 @@
 package atlas
 
 import (
+	"fmt"
 	"runtime"
 
-	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
+	"golang.org/x/sync/errgroup"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
+	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
 )
 
 type Shader struct {
 	ir     *shaderir.Program
-	shader *restorable.Shader
+	shader *graphicscommand.Shader
 }
 
 func NewShader(ir *shaderir.Program) *Shader {
@@ -41,11 +46,11 @@ func (s *Shader) finalize() {
 	})
 }
 
-func (s *Shader) ensureShader() *restorable.Shader {
+func (s *Shader) ensureShader() *graphicscommand.Shader {
 	if s.shader != nil {
 		return s.shader
 	}
-	s.shader = restorable.NewShader(s.ir)
+	s.shader = graphicscommand.NewShader(s.ir)
 	runtime.SetFinalizer(s, (*Shader).finalize)
 	return s.shader
 }
@@ -75,6 +80,38 @@ func (s *Shader) deallocate() {
 }
 
 var (
-	NearestFilterShader = &Shader{shader: restorable.NearestFilterShader}
-	LinearFilterShader  = &Shader{shader: restorable.LinearFilterShader}
+	NearestFilterShader *Shader
+	LinearFilterShader  *Shader
+	clearShader         *Shader
 )
+
+func init() {
+	var wg errgroup.Group
+	wg.Go(func() error {
+		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterNearest, builtinshader.AddressUnsafe, false)))
+		if err != nil {
+			return fmt.Errorf("atlas: compiling the nearest shader failed: %w", err)
+		}
+		NearestFilterShader = NewShader(ir)
+		return nil
+	})
+	wg.Go(func() error {
+		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterLinear, builtinshader.AddressUnsafe, false)))
+		if err != nil {
+			return fmt.Errorf("atlas: compiling the linear shader failed: %w", err)
+		}
+		LinearFilterShader = NewShader(ir)
+		return nil
+	})
+	wg.Go(func() error {
+		ir, err := graphics.CompileShader([]byte(builtinshader.ClearShaderSource))
+		if err != nil {
+			return fmt.Errorf("atlas: compiling the clear shader failed: %w", err)
+		}
+		clearShader = NewShader(ir)
+		return nil
+	})
+	if err := wg.Wait(); err != nil {
+		panic(err)
+	}
+}

internal/buffered/image.go

@@ -21,7 +21,6 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/atlas"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
-	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
 )
 
 var whiteImage *Image
@@ -47,8 +46,6 @@ type Image struct {
 	// pixels is cached pixels for ReadPixels.
 	// pixels might be out of sync with GPU.
 	// The data of pixels is the secondary data of pixels for ReadPixels.
-	//
-	// pixels is always nil when restorable.AlwaysReadPixelsFromGPU() returns false.
 	pixels []byte
 
 	// pixelsUnsynced represents whether the pixels in CPU and GPU are not synced.
@@ -71,6 +68,9 @@ func (i *Image) Deallocate() {
 }
 
 func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte, region image.Rectangle) (bool, error) {
+	// Do not call flushDotsBufferIfNeeded here. This would slow (image/draw).Draw.
+	// See ebiten.TestImageDrawOver.
+
 	if region.Dx() == 1 && region.Dy() == 1 {
 		if c, ok := i.dotsBuffer[region.Min]; ok {
 			copy(pixels, c[:])
@@ -78,19 +78,6 @@ func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte
 		}
 	}
 
-	// If restorable.AlwaysReadPixelsFromGPU() returns false, the pixel data is cached in the restorable package.
-	if !restorable.AlwaysReadPixelsFromGPU() {
-		i.syncPixelsIfNeeded()
-		ok, err := i.img.ReadPixels(graphicsDriver, pixels, region)
-		if err != nil {
-			return false, err
-		}
-		return ok, nil
-	}
-
-	// Do not call syncPixelsIfNeeded here. This would slow (image/draw).Draw.
-	// See ebiten.TestImageDrawOver.
-
 	if i.pixels == nil {
 		pix := make([]byte, 4*i.width*i.height)
 		ok, err := i.img.ReadPixels(graphicsDriver, pix, image.Rect(0, 0, i.width, i.height))

internal/graphicscommand/command.go

@@ -72,23 +72,14 @@ type drawTrianglesCommand struct {
 }
 
 func (c *drawTrianglesCommand) String() string {
-	var blend string
-	switch c.blend {
-	case graphicsdriver.BlendSourceOver:
-		blend = "(source-over)"
-	case graphicsdriver.BlendClear:
-		blend = "(clear)"
-	case graphicsdriver.BlendCopy:
-		blend = "(copy)"
-	default:
-		blend = fmt.Sprintf("{src-rgb: %d, src-alpha: %d, dst-rgb: %d, dst-alpha: %d, op-rgb: %d, op-alpha: %d}",
-			c.blend.BlendFactorSourceRGB,
-			c.blend.BlendFactorSourceAlpha,
-			c.blend.BlendFactorDestinationRGB,
-			c.blend.BlendFactorDestinationAlpha,
-			c.blend.BlendOperationRGB,
-			c.blend.BlendOperationAlpha)
-	}
+	// TODO: Improve readability
+	blend := fmt.Sprintf("{src-color: %d, src-alpha: %d, dst-color: %d, dst-alpha: %d, op-color: %d, op-alpha: %d}",
+		c.blend.BlendFactorSourceRGB,
+		c.blend.BlendFactorSourceAlpha,
+		c.blend.BlendFactorDestinationRGB,
+		c.blend.BlendFactorDestinationAlpha,
+		c.blend.BlendOperationRGB,
+		c.blend.BlendOperationAlpha)
 
 	dst := fmt.Sprintf("%d", c.dst.id)
 	if c.dst.screen {

internal/restorable/doc.go

@@ -1,68 +0,0 @@
-// Copyright 2017 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package restorable offers an Image struct that stores image commands
-// and restores its pixel data from the commands when context lost happens.
-//
-// When a function like DrawImage or Fill is called, an Image tries to record
-// the information for restoration.
-//
-// * Context lost
-//
-// Contest lost is a process that information on GPU memory are removed by OS
-// to make more room on GPU memory.
-// This can happen e.g. when GPU memory usage is high, or just switching applications
-// might cause context lost on mobiles.
-// As Ebitengine's image data is on GPU memory, the game can't continue when context lost happens
-// without restoring image information.
-// The package restorable is the package to record information for such restoration.
-//
-// * DrawImage
-//
-// DrawImage function tries to record an item of 'draw image history' in the target image.
-// If a target image is stale or volatile, no item is created.
-// If an item of the history is created,
-// it can be said that the target image depends on the source image.
-// In other words, If A.DrawImage(B, ...) is called,
-// it can be said that the image A depends on the image B.
-//
-// * Fill, WritePixels and Dispose
-//
-// These functions are also drawing functions and the target image stores the pixel data
-// instead of draw image history items. There is no dependency here.
-//
-// * Making images stale
-//
-// After any of the drawing functions is called, the target image can't be depended on by
-// any other images. For example, if an image A depends on an image B, and B is changed
-// by a Fill call after that, the image A can't depend on the image B anymore.
-// In this case, as the image B can no longer be used to restore the image A,
-// the image A becomes 'stale'.
-// As all the stale images are resolved before context lost happens,
-// draw image history items are kept as they are
-// (even if an image C depends on the stale image A, it is still fine).
-//
-// * Stale image
-//
-// A stale image is an image that can't be restored from the recorded information.
-// All stale images must be resolved by reading pixels from GPU before the frame ends.
-// If a source image of DrawImage is a stale image, the target always becomes stale.
-//
-// * Volatile image
-//
-// A volatile image is a special image that is always cleared when a frame starts.
-// For instance, the game screen passed via the update function is a volatile image.
-// A volatile image doesn't have to record the drawing history.
-// If a source image of DrawImage is a volatile image, the target always becomes stale.
-package restorable

internal/restorable/export_test.go

@@ -1,28 +0,0 @@
-// Copyright 2023 The Ebitengine Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package restorable
-
-import (
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
-)
-
-// EnableRestorationForTesting forces to enable restoration for testing.
-func EnableRestorationForTesting() {
-	forceRestoration = true
-}
-
-func ResolveStaleImages(graphicsDriver graphicsdriver.Graphics) error {
-	return resolveStaleImages(graphicsDriver, false)
-}

internal/restorable/image.go

@@ -1,736 +0,0 @@
-// Copyright 2016 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package restorable
-
-import (
-	"fmt"
-	"image"
-	"sort"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
-)
-
-type Pixels struct {
-	pixelsRecords *pixelsRecords
-}
-
-// Apply applies the Pixels state to the given image especially for restoration.
-func (p *Pixels) Apply(img *graphicscommand.Image) {
-	// Pixels doesn't clear the image. This is a caller's responsibility.
-
-	if p.pixelsRecords == nil {
-		return
-	}
-	p.pixelsRecords.apply(img)
-}
-
-func (p *Pixels) AddOrReplace(pix *graphics.ManagedBytes, region image.Rectangle) {
-	if p.pixelsRecords == nil {
-		p.pixelsRecords = &pixelsRecords{}
-	}
-	p.pixelsRecords.addOrReplace(pix, region)
-}
-
-func (p *Pixels) Clear(region image.Rectangle) {
-	// Note that we don't care whether the region is actually removed or not here. There is an actual case that
-	// the region is allocated but nothing is rendered. See TestDisposeImmediately at shareable package.
-	if p.pixelsRecords == nil {
-		return
-	}
-	p.pixelsRecords.clear(region)
-}
-
-func (p *Pixels) ReadPixels(pixels []byte, region image.Rectangle, imageWidth, imageHeight int) {
-	if p.pixelsRecords == nil {
-		for i := range pixels {
-			pixels[i] = 0
-		}
-		return
-	}
-	p.pixelsRecords.readPixels(pixels, region, imageWidth, imageHeight)
-}
-
-func (p *Pixels) AppendRegion(regions []image.Rectangle) []image.Rectangle {
-	if p.pixelsRecords == nil {
-		return regions
-	}
-	return p.pixelsRecords.appendRegions(regions)
-}
-
-func (p *Pixels) Dispose() {
-	if p.pixelsRecords == nil {
-		return
-	}
-	p.pixelsRecords.dispose()
-}
-
-// drawTrianglesHistoryItem is an item for history of draw-image commands.
-type drawTrianglesHistoryItem struct {
-	images     [graphics.ShaderSrcImageCount]*Image
-	vertices   []float32
-	indices    []uint32
-	blend      graphicsdriver.Blend
-	dstRegion  image.Rectangle
-	srcRegions [graphics.ShaderSrcImageCount]image.Rectangle
-	shader     *Shader
-	uniforms   []uint32
-	fillRule   graphicsdriver.FillRule
-}
-
-type ImageType int
-
-const (
-	// ImageTypeRegular indicates the image is a regular image.
-	ImageTypeRegular ImageType = iota
-
-	// ImageTypeScreen indicates the image is used as an actual screen.
-	ImageTypeScreen
-
-	// ImageTypeVolatile indicates the image is cleared whenever a frame starts.
-	//
-	// Regular non-volatile images need to record drawing history or read its pixels from GPU if necessary so that all
-	// the images can be restored automatically from the context lost. However, such recording the drawing history or
-	// reading pixels from GPU are expensive operations. Volatile images can skip such operations, but the image content
-	// is cleared every frame instead.
-	ImageTypeVolatile
-)
-
-// Image represents an image that can be restored when GL context is lost.
-type Image struct {
-	image *graphicscommand.Image
-
-	width  int
-	height int
-
-	basePixels Pixels
-
-	// drawTrianglesHistory is a set of draw-image commands.
-	// TODO: This should be merged with the similar command queue in package graphics (#433).
-	drawTrianglesHistory []*drawTrianglesHistoryItem
-
-	// stale indicates whether the image needs to be synced with GPU as soon as possible.
-	stale bool
-
-	// staleRegions indicates the regions to restore.
-	// staleRegions is valid only when stale is true.
-	// staleRegions is not used when AlwaysReadPixelsFromGPU() returns true.
-	staleRegions []image.Rectangle
-
-	// pixelsCache is cached byte slices for pixels.
-	// pixelsCache is just a cache to avoid allocations (#2375).
-	//
-	// A key is the region and a value is a byte slice for the region.
-	//
-	// It is fine to reuse the same byte slice for the same region for basePixels,
-	// as old pixels for the same region will be invalidated at basePixel.AddOrReplace.
-	pixelsCache map[image.Rectangle][]byte
-
-	// regionsCache is cached regions.
-	// regionsCache is just a cache to avoid allocations (#2375).
-	regionsCache []image.Rectangle
-
-	imageType ImageType
-}
-
-// NewImage creates an emtpy image with the given size.
-//
-// The returned image is cleared.
-//
-// Note that Dispose is not called automatically.
-func NewImage(width, height int, imageType ImageType) *Image {
-	if !graphicsDriverInitialized {
-		panic("restorable: graphics driver must be ready at NewImage but not")
-	}
-
-	i := &Image{
-		image:     graphicscommand.NewImage(width, height, imageType == ImageTypeScreen),
-		width:     width,
-		height:    height,
-		imageType: imageType,
-	}
-
-	// This needs to use 'InternalSize' to render the whole region, or edges are unexpectedly cleared on some
-	// devices.
-	iw, ih := i.image.InternalSize()
-	clearImage(i.image, image.Rect(0, 0, iw, ih))
-	theImages.add(i)
-	return i
-}
-
-// Extend extends the image by the given size.
-// Extend creates a new image with the given size and copies the pixels of the given source image.
-// Extend disposes itself after its call.
-func (i *Image) Extend(width, height int) *Image {
-	if i.width >= width && i.height >= height {
-		return i
-	}
-
-	newImg := NewImage(width, height, i.imageType)
-
-	// Use DrawTriangles instead of WritePixels because the image i might be stale and not have its pixels
-	// information.
-	srcs := [graphics.ShaderSrcImageCount]*Image{i}
-	sw, sh := i.image.InternalSize()
-	vs := make([]float32, 4*graphics.VertexFloatCount)
-	graphics.QuadVerticesFromDstAndSrc(vs, 0, 0, float32(sw), float32(sh), 0, 0, float32(sw), float32(sh), 1, 1, 1, 1)
-	is := graphics.QuadIndices()
-	dr := image.Rect(0, 0, sw, sh)
-	newImg.DrawTriangles(srcs, vs, is, graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, NearestFilterShader, nil, graphicsdriver.FillRuleFillAll)
-	i.Dispose()
-
-	return newImg
-}
-
-func clearImage(i *graphicscommand.Image, region image.Rectangle) {
-	vs := make([]float32, 4*graphics.VertexFloatCount)
-	graphics.QuadVerticesFromDstAndSrc(vs, float32(region.Min.X), float32(region.Min.Y), float32(region.Max.X), float32(region.Max.Y), 0, 0, 0, 0, 0, 0, 0, 0)
-	is := graphics.QuadIndices()
-	i.DrawTriangles([graphics.ShaderSrcImageCount]*graphicscommand.Image{}, vs, is, graphicsdriver.BlendClear, region, [graphics.ShaderSrcImageCount]image.Rectangle{}, clearShader.shader, nil, graphicsdriver.FillRuleFillAll)
-}
-
-// BasePixelsForTesting returns the image's basePixels for testing.
-func (i *Image) BasePixelsForTesting() *Pixels {
-	return &i.basePixels
-}
-
-// makeStale makes the image stale.
-func (i *Image) makeStale(rect image.Rectangle) {
-	i.stale = true
-
-	// If ReadPixels always reads pixels from GPU, staleRegions are never used.
-	if AlwaysReadPixelsFromGPU() {
-		return
-	}
-
-	origSize := len(i.staleRegions)
-	i.staleRegions = i.appendRegionsForDrawTriangles(i.staleRegions)
-	if !rect.Empty() {
-		i.staleRegions = append(i.staleRegions, rect)
-	}
-
-	i.clearDrawTrianglesHistory()
-
-	// Clear pixels to save memory.
-	for _, r := range i.staleRegions[origSize:] {
-		i.basePixels.Clear(r)
-	}
-
-	// Don't have to call makeStale recursively here.
-	// Restoration is done after topological sorting is done.
-	// If an image depends on another stale image, this means that
-	// the former image can be restored from the latest state of the latter image.
-}
-
-// ClearPixels clears the specified region by WritePixels.
-func (i *Image) ClearPixels(region image.Rectangle) {
-	i.WritePixels(nil, region)
-}
-
-func (i *Image) needsRestoration() bool {
-	return i.imageType == ImageTypeRegular
-}
-
-// WritePixels replaces the image pixels with the given pixels slice.
-//
-// The specified region must not be overlapped with other regions by WritePixels.
-func (i *Image) WritePixels(pixels *graphics.ManagedBytes, region image.Rectangle) {
-	if region.Dx() <= 0 || region.Dy() <= 0 {
-		panic("restorable: width/height must be positive")
-	}
-	w, h := i.width, i.height
-	if !region.In(image.Rect(0, 0, w, h)) {
-		panic(fmt.Sprintf("restorable: out of range %v", region))
-	}
-
-	// TODO: Avoid making other images stale if possible. (#514)
-	// For this purpose, images should remember which part of that is used for DrawTriangles.
-	theImages.makeStaleIfDependingOn(i)
-
-	if pixels != nil {
-		i.image.WritePixels(pixels, region)
-	} else {
-		clearImage(i.image, region)
-	}
-
-	// Even if the image is already stale, call makeStale to extend the stale region.
-	if !needsRestoration() || !i.needsRestoration() || i.stale {
-		i.makeStale(region)
-		return
-	}
-
-	if region.Eq(image.Rect(0, 0, w, h)) {
-		if pixels != nil {
-			// Clone a ManagedBytes as the package graphicscommand has a different lifetime management.
-			i.basePixels.AddOrReplace(pixels.Clone(), image.Rect(0, 0, w, h))
-		} else {
-			i.basePixels.Clear(image.Rect(0, 0, w, h))
-		}
-		i.clearDrawTrianglesHistory()
-		i.stale = false
-		i.staleRegions = i.staleRegions[:0]
-		return
-	}
-
-	// Records for DrawTriangles cannot come before records for WritePixels.
-	if len(i.drawTrianglesHistory) > 0 {
-		i.makeStale(region)
-		return
-	}
-
-	if pixels != nil {
-		// Clone a ManagedBytes as the package graphicscommand has a different lifetime management.
-		i.basePixels.AddOrReplace(pixels.Clone(), region)
-	} else {
-		i.basePixels.Clear(region)
-	}
-}
-
-// DrawTriangles draws triangles with the given image.
-//
-// The vertex floats are:
-//
-//	0: Destination X in pixels
-//	1: Destination Y in pixels
-//	2: Source X in texels
-//	3: Source Y in texels
-//	4: Color R [0.0-1.0]
-//	5: Color G
-//	6: Color B
-//	7: Color Y
-func (i *Image) DrawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertices []float32, indices []uint32, blend graphicsdriver.Blend, dstRegion image.Rectangle, srcRegions [graphics.ShaderSrcImageCount]image.Rectangle, shader *Shader, uniforms []uint32, fillRule graphicsdriver.FillRule) {
-	if len(vertices) == 0 {
-		return
-	}
-	theImages.makeStaleIfDependingOn(i)
-
-	// TODO: Add tests to confirm this logic.
-	var srcstale bool
-	for _, src := range srcs {
-		if src == nil {
-			continue
-		}
-		if src.stale || src.imageType == ImageTypeVolatile {
-			srcstale = true
-			break
-		}
-	}
-
-	// Even if the image is already stale, call makeStale to extend the stale region.
-	if srcstale || !needsRestoration() || !i.needsRestoration() || i.stale {
-		i.makeStale(dstRegion)
-	} else {
-		i.appendDrawTrianglesHistory(srcs, vertices, indices, blend, dstRegion, srcRegions, shader, uniforms, fillRule)
-	}
-
-	var imgs [graphics.ShaderSrcImageCount]*graphicscommand.Image
-	for i, src := range srcs {
-		if src == nil {
-			continue
-		}
-		imgs[i] = src.image
-	}
-	i.image.DrawTriangles(imgs, vertices, indices, blend, dstRegion, srcRegions, shader.shader, uniforms, fillRule)
-}
-
-// appendDrawTrianglesHistory appends a draw-image history item to the image.
-func (i *Image) appendDrawTrianglesHistory(srcs [graphics.ShaderSrcImageCount]*Image, vertices []float32, indices []uint32, blend graphicsdriver.Blend, dstRegion image.Rectangle, srcRegions [graphics.ShaderSrcImageCount]image.Rectangle, shader *Shader, uniforms []uint32, fillRule graphicsdriver.FillRule) {
-	if i.stale || !i.needsRestoration() {
-		panic("restorable: an image must not be stale or need restoration at appendDrawTrianglesHistory")
-	}
-	if AlwaysReadPixelsFromGPU() {
-		panic("restorable: appendDrawTrianglesHistory must not be called when AlwaysReadPixelsFromGPU() returns true")
-	}
-
-	// TODO: Would it be possible to merge draw image history items?
-	const maxDrawTrianglesHistoryCount = 1024
-	if len(i.drawTrianglesHistory)+1 > maxDrawTrianglesHistoryCount {
-		i.makeStale(dstRegion)
-		return
-	}
-	// All images must be resolved and not stale each after frame.
-	// So we don't have to care if image is stale or not here.
-
-	vs := make([]float32, len(vertices))
-	copy(vs, vertices)
-
-	is := make([]uint32, len(indices))
-	copy(is, indices)
-
-	us := make([]uint32, len(uniforms))
-	copy(us, uniforms)
-
-	item := &drawTrianglesHistoryItem{
-		images:     srcs,
-		vertices:   vs,
-		indices:    is,
-		blend:      blend,
-		dstRegion:  dstRegion,
-		srcRegions: srcRegions,
-		shader:     shader,
-		uniforms:   us,
-		fillRule:   fillRule,
-	}
-	i.drawTrianglesHistory = append(i.drawTrianglesHistory, item)
-}
-
-func (i *Image) readPixelsFromGPUIfNeeded(graphicsDriver graphicsdriver.Graphics) error {
-	if len(i.drawTrianglesHistory) > 0 || i.stale {
-		if err := i.readPixelsFromGPU(graphicsDriver); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func (i *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte, region image.Rectangle) error {
-	if AlwaysReadPixelsFromGPU() {
-		if err := i.image.ReadPixels(graphicsDriver, []graphicsdriver.PixelsArgs{
-			{
-				Pixels: pixels,
-				Region: region,
-			},
-		}); err != nil {
-			return err
-		}
-		return nil
-	}
-
-	if err := i.readPixelsFromGPUIfNeeded(graphicsDriver); err != nil {
-		return err
-	}
-	if got, want := len(pixels), 4*region.Dx()*region.Dy(); got != want {
-		return fmt.Errorf("restorable: len(pixels) must be %d but %d at ReadPixels", want, got)
-	}
-	i.basePixels.ReadPixels(pixels, region, i.width, i.height)
-	return nil
-}
-
-// makeStaleIfDependingOn makes the image stale if the image depends on target.
-func (i *Image) makeStaleIfDependingOn(target *Image) {
-	if i.stale {
-		return
-	}
-	if i.dependsOn(target) {
-		// There is no new region to make stale.
-		i.makeStale(image.Rectangle{})
-	}
-}
-
-// makeStaleIfDependingOnShader makes the image stale if the image depends on shader.
-func (i *Image) makeStaleIfDependingOnShader(shader *Shader) {
-	if i.stale {
-		return
-	}
-	if i.dependsOnShader(shader) {
-		// There is no new region to make stale.
-		i.makeStale(image.Rectangle{})
-	}
-}
-
-// readPixelsFromGPU reads the pixels from GPU and resolves the image's 'stale' state.
-func (i *Image) readPixelsFromGPU(graphicsDriver graphicsdriver.Graphics) error {
-	var rs []image.Rectangle
-	if i.stale {
-		rs = i.staleRegions
-	} else {
-		i.regionsCache = i.appendRegionsForDrawTriangles(i.regionsCache)
-		defer func() {
-			i.regionsCache = i.regionsCache[:0]
-		}()
-		rs = i.regionsCache
-	}
-
-	// Remove duplications. Is this heavy?
-	rs = rs[:removeDuplicatedRegions(rs)]
-
-	args := make([]graphicsdriver.PixelsArgs, 0, len(rs))
-	for _, r := range rs {
-		if r.Empty() {
-			continue
-		}
-
-		if i.pixelsCache == nil {
-			i.pixelsCache = map[image.Rectangle][]byte{}
-		}
-
-		pix, ok := i.pixelsCache[r]
-		if !ok {
-			pix = make([]byte, 4*r.Dx()*r.Dy())
-			i.pixelsCache[r] = pix
-		}
-
-		args = append(args, graphicsdriver.PixelsArgs{
-			Pixels: pix,
-			Region: r,
-		})
-	}
-
-	if err := i.image.ReadPixels(graphicsDriver, args); err != nil {
-		return err
-	}
-
-	for _, a := range args {
-		bs := graphics.NewManagedBytes(len(a.Pixels), func(bs []byte) {
-			copy(bs, a.Pixels)
-		})
-		i.basePixels.AddOrReplace(bs, a.Region)
-	}
-
-	i.clearDrawTrianglesHistory()
-	i.stale = false
-	i.staleRegions = i.staleRegions[:0]
-	return nil
-}
-
-// resolveStale resolves the image's 'stale' state.
-func (i *Image) resolveStale(graphicsDriver graphicsdriver.Graphics) error {
-	if !needsRestoration() {
-		return nil
-	}
-	if !i.needsRestoration() {
-		return nil
-	}
-	if !i.stale {
-		return nil
-	}
-	return i.readPixelsFromGPU(graphicsDriver)
-}
-
-// dependsOn reports whether the image depends on target.
-func (i *Image) dependsOn(target *Image) bool {
-	for _, c := range i.drawTrianglesHistory {
-		for _, img := range c.images {
-			if img == nil {
-				continue
-			}
-			if img == target {
-				return true
-			}
-		}
-	}
-	return false
-}
-
-// dependsOnShader reports whether the image depends on shader.
-func (i *Image) dependsOnShader(shader *Shader) bool {
-	for _, c := range i.drawTrianglesHistory {
-		if c.shader == shader {
-			return true
-		}
-	}
-	return false
-}
-
-// dependingImages returns all images that is depended on the image.
-func (i *Image) dependingImages() map[*Image]struct{} {
-	r := map[*Image]struct{}{}
-	for _, c := range i.drawTrianglesHistory {
-		for _, img := range c.images {
-			if img == nil {
-				continue
-			}
-			r[img] = struct{}{}
-		}
-	}
-	return r
-}
-
-// hasDependency returns a boolean value indicating whether the image depends on another image.
-func (i *Image) hasDependency() bool {
-	if i.stale {
-		return false
-	}
-	return len(i.drawTrianglesHistory) > 0
-}
-
-// Restore restores *graphicscommand.Image from the pixels using its state.
-func (i *Image) restore(graphicsDriver graphicsdriver.Graphics) error {
-	w, h := i.width, i.height
-	// Do not dispose the image here. The image should be already disposed.
-
-	switch i.imageType {
-	case ImageTypeScreen:
-		// The screen image should also be recreated because framebuffer might
-		// be changed.
-		i.image = graphicscommand.NewImage(w, h, true)
-		i.basePixels.Dispose()
-		i.basePixels = Pixels{}
-		i.clearDrawTrianglesHistory()
-		i.stale = false
-		i.staleRegions = i.staleRegions[:0]
-		return nil
-	case ImageTypeVolatile:
-		i.image = graphicscommand.NewImage(w, h, false)
-		iw, ih := i.image.InternalSize()
-		clearImage(i.image, image.Rect(0, 0, iw, ih))
-		return nil
-	}
-
-	if i.stale {
-		panic("restorable: pixels must not be stale when restoring")
-	}
-
-	gimg := graphicscommand.NewImage(w, h, false)
-	// Clear the image explicitly.
-	iw, ih := gimg.InternalSize()
-	clearImage(gimg, image.Rect(0, 0, iw, ih))
-
-	i.basePixels.Apply(gimg)
-
-	for _, c := range i.drawTrianglesHistory {
-		var imgs [graphics.ShaderSrcImageCount]*graphicscommand.Image
-		for i, img := range c.images {
-			if img == nil {
-				continue
-			}
-			if img.hasDependency() {
-				panic("restorable: all dependencies must be already resolved but not")
-			}
-			imgs[i] = img.image
-		}
-		gimg.DrawTriangles(imgs, c.vertices, c.indices, c.blend, c.dstRegion, c.srcRegions, c.shader.shader, c.uniforms, c.fillRule)
-	}
-
-	// In order to clear the draw-triangles history, read pixels from GPU.
-	if len(i.drawTrianglesHistory) > 0 {
-		i.regionsCache = i.appendRegionsForDrawTriangles(i.regionsCache)
-		defer func() {
-			i.regionsCache = i.regionsCache[:0]
-		}()
-
-		args := make([]graphicsdriver.PixelsArgs, 0, len(i.regionsCache))
-		for _, r := range i.regionsCache {
-			if r.Empty() {
-				continue
-			}
-
-			if i.pixelsCache == nil {
-				i.pixelsCache = map[image.Rectangle][]byte{}
-			}
-
-			pix, ok := i.pixelsCache[r]
-			if !ok {
-				pix = make([]byte, 4*r.Dx()*r.Dy())
-				i.pixelsCache[r] = pix
-			}
-			args = append(args, graphicsdriver.PixelsArgs{
-				Pixels: pix,
-				Region: r,
-			})
-		}
-
-		if err := gimg.ReadPixels(graphicsDriver, args); err != nil {
-			return err
-		}
-
-		for _, a := range args {
-			bs := graphics.NewManagedBytes(len(a.Pixels), func(bs []byte) {
-				copy(bs, a.Pixels)
-			})
-			i.basePixels.AddOrReplace(bs, a.Region)
-		}
-	}
-
-	i.image = gimg
-	i.clearDrawTrianglesHistory()
-	i.stale = false
-	i.staleRegions = i.staleRegions[:0]
-	return nil
-}
-
-// Dispose disposes the image.
-//
-// After disposing, calling the function of the image causes unexpected results.
-func (i *Image) Dispose() {
-	theImages.remove(i)
-	i.image.Dispose()
-	i.image = nil
-	i.basePixels.Dispose()
-	i.basePixels = Pixels{}
-	i.pixelsCache = nil
-	i.clearDrawTrianglesHistory()
-	i.stale = false
-	i.staleRegions = i.staleRegions[:0]
-}
-
-func (i *Image) Dump(graphicsDriver graphicsdriver.Graphics, path string, blackbg bool, rect image.Rectangle) (string, error) {
-	return i.image.Dump(graphicsDriver, path, blackbg, rect)
-}
-
-func (i *Image) clearDrawTrianglesHistory() {
-	// Clear the items explicitly, or the references might remain (#1803).
-	for idx := range i.drawTrianglesHistory {
-		i.drawTrianglesHistory[idx] = nil
-	}
-	i.drawTrianglesHistory = i.drawTrianglesHistory[:0]
-}
-
-func (i *Image) InternalSize() (int, int) {
-	return i.image.InternalSize()
-}
-
-func (i *Image) appendRegionsForDrawTriangles(regions []image.Rectangle) []image.Rectangle {
-	for _, d := range i.drawTrianglesHistory {
-		if d.dstRegion.Empty() {
-			continue
-		}
-		regions = append(regions, d.dstRegion)
-	}
-	return regions
-}
-
-// removeDuplicatedRegions removes duplicated regions and returns a shrunk slice.
-// If a region covers preceding regions, the covered regions are removed.
-func removeDuplicatedRegions(regions []image.Rectangle) int {
-	// Sweep and prune algorithm
-
-	sort.Slice(regions, func(i, j int) bool {
-		return regions[i].Min.X < regions[j].Min.X
-	})
-
-	for i, r := range regions {
-		if r.Empty() {
-			continue
-		}
-		for j := i + 1; j < len(regions); j++ {
-			rr := regions[j]
-			if rr.Empty() {
-				continue
-			}
-			if r.Max.X <= rr.Min.X {
-				break
-			}
-			if rr.In(r) {
-				regions[j] = image.Rectangle{}
-			} else if r.In(rr) {
-				regions[i] = image.Rectangle{}
-				break
-			}
-		}
-	}
-
-	var n int
-	for _, r := range regions {
-		if r.Empty() {
-			continue
-		}
-		regions[n] = r
-		n++
-	}
-
-	return n
-}

internal/restorable/images.go

@@ -1,291 +0,0 @@
-// Copyright 2017 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package restorable
-
-import (
-	"image"
-	"runtime"
-	"sync"
-	"sync/atomic"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/debug"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
-)
-
-// forceRestoration reports whether restoration forcibly happens or not.
-// This is used only for testing.
-var forceRestoration = false
-
-// disabled indicates that restoration is disabled or not.
-// Restoration is enabled by default for some platforms like Android for safety.
-// Before SetGame, it is not possible to determine whether restoration is needed or not.
-var disabled atomic.Bool
-
-var disabledOnce sync.Once
-
-// Disable disables restoration.
-func Disable() {
-	disabled.Store(true)
-}
-
-// needsRestoration reports whether restoration process works or not.
-func needsRestoration() bool {
-	if forceRestoration {
-		return true
-	}
-	// TODO: If Vulkan is introduced, restoration might not be needed.
-	if runtime.GOOS == "android" {
-		return !disabled.Load()
-	}
-	return false
-}
-
-// AlwaysReadPixelsFromGPU reports whether ReadPixels always reads pixels from GPU or not.
-func AlwaysReadPixelsFromGPU() bool {
-	return !needsRestoration()
-}
-
-// images is a set of Image objects.
-type images struct {
-	images      map[*Image]struct{}
-	shaders     map[*Shader]struct{}
-	lastTarget  *Image
-	contextLost atomic.Bool
-}
-
-// theImages represents the images for the current process.
-var theImages = &images{
-	images:  map[*Image]struct{}{},
-	shaders: map[*Shader]struct{}{},
-}
-
-func SwapBuffers(graphicsDriver graphicsdriver.Graphics) error {
-	if debug.IsDebug {
-		debug.FrameLogf("Internal image sizes:\n")
-		imgs := make([]*graphicscommand.Image, 0, len(theImages.images))
-		for i := range theImages.images {
-			imgs = append(imgs, i.image)
-		}
-		graphicscommand.LogImagesInfo(imgs)
-	}
-	return resolveStaleImages(graphicsDriver, true)
-}
-
-// resolveStaleImages flushes the queued draw commands and resolves all stale images.
-// If endFrame is true, the current screen might be used to present when flushing the commands.
-func resolveStaleImages(graphicsDriver graphicsdriver.Graphics, endFrame bool) error {
-	// When Disable is called, all the images data should be evicted once.
-	if disabled.Load() {
-		disabledOnce.Do(func() {
-			for img := range theImages.images {
-				img.makeStale(image.Rectangle{})
-			}
-		})
-	}
-
-	if err := graphicscommand.FlushCommands(graphicsDriver, endFrame); err != nil {
-		return err
-	}
-	if !needsRestoration() {
-		return nil
-	}
-	return theImages.resolveStaleImages(graphicsDriver)
-}
-
-// RestoreIfNeeded restores the images.
-//
-// Restoration means to make all *graphicscommand.Image objects have their textures and framebuffers.
-func RestoreIfNeeded(graphicsDriver graphicsdriver.Graphics) error {
-	if !needsRestoration() {
-		return nil
-	}
-
-	if !forceRestoration && !theImages.contextLost.Load() {
-		return nil
-	}
-
-	if err := graphicscommand.ResetGraphicsDriverState(graphicsDriver); err != nil {
-		return err
-	}
-	return theImages.restore(graphicsDriver)
-}
-
-// DumpImages dumps all the current images to the specified directory.
-//
-// This is for testing usage.
-func DumpImages(graphicsDriver graphicsdriver.Graphics, dir string) (string, error) {
-	images := make([]*graphicscommand.Image, 0, len(theImages.images))
-	for img := range theImages.images {
-		images = append(images, img.image)
-	}
-
-	return graphicscommand.DumpImages(images, graphicsDriver, dir)
-}
-
-// add adds img to the images.
-func (i *images) add(img *Image) {
-	i.images[img] = struct{}{}
-}
-
-func (i *images) addShader(shader *Shader) {
-	i.shaders[shader] = struct{}{}
-}
-
-// remove removes img from the images.
-func (i *images) remove(img *Image) {
-	i.makeStaleIfDependingOn(img)
-	delete(i.images, img)
-}
-
-func (i *images) removeShader(shader *Shader) {
-	i.makeStaleIfDependingOnShader(shader)
-	delete(i.shaders, shader)
-}
-
-// resolveStaleImages resolves stale images.
-func (i *images) resolveStaleImages(graphicsDriver graphicsdriver.Graphics) error {
-	i.lastTarget = nil
-	for img := range i.images {
-		if err := img.resolveStale(graphicsDriver); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// makeStaleIfDependingOn makes all the images stale that depend on target.
-//
-// When target is modified, all images depending on target can't be restored with target.
-// makeStaleIfDependingOn is called in such situation.
-func (i *images) makeStaleIfDependingOn(target *Image) {
-	if target == nil {
-		panic("restorable: target must not be nil at makeStaleIfDependingOn")
-	}
-	if i.lastTarget == target {
-		return
-	}
-	i.lastTarget = target
-	for img := range i.images {
-		img.makeStaleIfDependingOn(target)
-	}
-}
-
-// makeStaleIfDependingOn makes all the images stale that depend on shader.
-func (i *images) makeStaleIfDependingOnShader(shader *Shader) {
-	if shader == nil {
-		panic("restorable: shader must not be nil at makeStaleIfDependingOnShader")
-	}
-	for img := range i.images {
-		img.makeStaleIfDependingOnShader(shader)
-	}
-}
-
-// restore restores the images.
-//
-// Restoration means to make all *graphicscommand.Image objects have their textures and framebuffers.
-func (i *images) restore(graphicsDriver graphicsdriver.Graphics) error {
-	if !needsRestoration() {
-		panic("restorable: restore cannot be called when restoration is disabled")
-	}
-
-	// Dispose all the shaders ahead of restoration. A current shader ID and a new shader ID can be duplicated.
-	for s := range i.shaders {
-		s.shader.Dispose()
-		s.shader = nil
-	}
-	for s := range i.shaders {
-		s.restore()
-	}
-
-	// Dispose all the images ahead of restoration. A current texture ID and a new texture ID can be duplicated.
-	// TODO: Write a test to confirm that ID duplication never happens.
-	for i := range i.images {
-		i.image.Dispose()
-		i.image = nil
-	}
-
-	// Let's do topological sort based on dependencies of drawing history.
-	// It is assured that there are not loops since cyclic drawing makes images stale.
-	type edge struct {
-		source *Image
-		target *Image
-	}
-	images := map[*Image]struct{}{}
-	for i := range i.images {
-		images[i] = struct{}{}
-	}
-	edges := map[edge]struct{}{}
-	for t := range images {
-		for s := range t.dependingImages() {
-			edges[edge{source: s, target: t}] = struct{}{}
-		}
-	}
-
-	var sorted []*Image
-	for len(images) > 0 {
-		// current represents images that have no incoming edges.
-		current := map[*Image]struct{}{}
-		for i := range images {
-			current[i] = struct{}{}
-		}
-		for e := range edges {
-			if _, ok := current[e.target]; ok {
-				delete(current, e.target)
-			}
-		}
-		for i := range current {
-			delete(images, i)
-			sorted = append(sorted, i)
-		}
-		removed := []edge{}
-		for e := range edges {
-			if _, ok := current[e.source]; ok {
-				removed = append(removed, e)
-			}
-		}
-		for _, e := range removed {
-			delete(edges, e)
-		}
-	}
-
-	for _, img := range sorted {
-		if err := img.restore(graphicsDriver); err != nil {
-			return err
-		}
-	}
-
-	i.contextLost.Store(false)
-
-	return nil
-}
-
-var graphicsDriverInitialized bool
-
-// InitializeGraphicsDriverState initializes the graphics driver state.
-func InitializeGraphicsDriverState(graphicsDriver graphicsdriver.Graphics) error {
-	graphicsDriverInitialized = true
-	return graphicscommand.InitializeGraphicsDriverState(graphicsDriver)
-}
-
-// MaxImageSize returns the maximum size of an image.
-func MaxImageSize(graphicsDriver graphicsdriver.Graphics) int {
-	return graphicscommand.MaxImageSize(graphicsDriver)
-}
-
-// OnContextLost is called when the context lost is detected in an explicit way.
-func OnContextLost() {
-	theImages.contextLost.Store(true)
-}

internal/restorable/pixelrecords.go

@@ -1,159 +0,0 @@
-// Copyright 2019 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package restorable
-
-import (
-	"fmt"
-	"image"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
-)
-
-type pixelsRecord struct {
-	rect image.Rectangle
-	pix  *graphics.ManagedBytes
-}
-
-func (p *pixelsRecord) readPixels(pixels []byte, region image.Rectangle, imageWidth, imageHeight int) {
-	r := p.rect.Intersect(region.Intersect(image.Rect(0, 0, imageWidth, imageHeight)))
-	if r.Empty() {
-		return
-	}
-
-	dstBaseX := r.Min.X - region.Min.X
-	dstBaseY := r.Min.Y - region.Min.Y
-	lineWidth := 4 * r.Dx()
-	if p.pix != nil {
-		srcBaseX := r.Min.X - p.rect.Min.X
-		srcBaseY := r.Min.Y - p.rect.Min.Y
-		for j := 0; j < r.Dy(); j++ {
-			dstX := 4 * ((dstBaseY+j)*region.Dx() + dstBaseX)
-			srcX := 4 * ((srcBaseY+j)*p.rect.Dx() + srcBaseX)
-			p.pix.Read(pixels[dstX:dstX+lineWidth], srcX, srcX+lineWidth)
-		}
-	} else {
-		for j := 0; j < r.Dy(); j++ {
-			dstX := 4 * ((dstBaseY+j)*region.Dx() + dstBaseX)
-			for i := 0; i < lineWidth; i++ {
-				pixels[i+dstX] = 0
-			}
-		}
-	}
-}
-
-type pixelsRecords struct {
-	records []*pixelsRecord
-}
-
-func (pr *pixelsRecords) addOrReplace(pixels *graphics.ManagedBytes, region image.Rectangle) {
-	if pixels.Len() != 4*region.Dx()*region.Dy() {
-		msg := fmt.Sprintf("restorable: len(pixels) must be 4*%d*%d = %d but %d", region.Dx(), region.Dy(), 4*region.Dx()*region.Dy(), pixels.Len())
-		if pixels == nil {
-			msg += " (nil)"
-		}
-		panic(msg)
-	}
-
-	// Remove or update the duplicated records first.
-	var n int
-	for _, r := range pr.records {
-		if r.rect.In(region) {
-			continue
-		}
-		pr.records[n] = r
-		n++
-	}
-	for i := n; i < len(pr.records); i++ {
-		pr.records[i] = nil
-	}
-	pr.records = pr.records[:n]
-
-	// Add the new record.
-	pr.records = append(pr.records, &pixelsRecord{
-		rect: region,
-		pix:  pixels,
-	})
-}
-
-func (pr *pixelsRecords) clear(region image.Rectangle) {
-	if region.Empty() {
-		return
-	}
-
-	var n int
-	var needsClear bool
-	for _, r := range pr.records {
-		if r.rect.In(region) {
-			continue
-		}
-		if r.rect.Overlaps(region) {
-			needsClear = true
-		}
-		pr.records[n] = r
-		n++
-	}
-	for i := n; i < len(pr.records); i++ {
-		pr.records[i] = nil
-	}
-	pr.records = pr.records[:n]
-	if needsClear {
-		pr.records = append(pr.records, &pixelsRecord{
-			rect: region,
-		})
-	}
-}
-
-func (pr *pixelsRecords) readPixels(pixels []byte, region image.Rectangle, imageWidth, imageHeight int) {
-	for i := range pixels {
-		pixels[i] = 0
-	}
-	for _, r := range pr.records {
-		r.readPixels(pixels, region, imageWidth, imageHeight)
-	}
-}
-
-func (pr *pixelsRecords) apply(img *graphicscommand.Image) {
-	// TODO: Isn't this too heavy? Can we merge the operations?
-	for _, r := range pr.records {
-		if r.pix != nil {
-			// Clone a ManagedBytes as the package graphicscommand has a different lifetime management.
-			img.WritePixels(r.pix.Clone(), r.rect)
-		} else {
-			clearImage(img, r.rect)
-		}
-	}
-}
-
-func (pr *pixelsRecords) appendRegions(regions []image.Rectangle) []image.Rectangle {
-	for _, r := range pr.records {
-		if r.rect.Empty() {
-			continue
-		}
-		regions = append(regions, r.rect)
-	}
-	return regions
-}
-
-func (pr *pixelsRecords) dispose() {
-	for _, r := range pr.records {
-		if r.pix == nil {
-			continue
-		}
-		// As the package graphicscommands already has cloned ManagedBytes objects, it is OK to release it.
-		_, f := r.pix.GetAndRelease()
-		f()
-	}
-}

internal/restorable/shader.go

@@ -1,96 +0,0 @@
-// Copyright 2020 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package restorable
-
-import (
-	"fmt"
-
-	"golang.org/x/sync/errgroup"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/builtinshader"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
-	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
-)
-
-type Shader struct {
-	shader *graphicscommand.Shader
-	ir     *shaderir.Program
-}
-
-func NewShader(ir *shaderir.Program) *Shader {
-	s := &Shader{
-		shader: graphicscommand.NewShader(ir),
-		ir:     ir,
-	}
-	theImages.addShader(s)
-	return s
-}
-
-func (s *Shader) Dispose() {
-	theImages.removeShader(s)
-	s.shader.Dispose()
-	s.shader = nil
-	s.ir = nil
-}
-
-func (s *Shader) restore() {
-	s.shader = graphicscommand.NewShader(s.ir)
-}
-
-func (s *Shader) Unit() shaderir.Unit {
-	return s.ir.Unit
-}
-
-var (
-	NearestFilterShader *Shader
-	LinearFilterShader  *Shader
-	clearShader         *Shader
-)
-
-func init() {
-	var wg errgroup.Group
-	var nearestIR, linearIR, clearIR *shaderir.Program
-	wg.Go(func() error {
-		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterNearest, builtinshader.AddressUnsafe, false)))
-		if err != nil {
-			return fmt.Errorf("restorable: compiling the nearest shader failed: %w", err)
-		}
-		nearestIR = ir
-		return nil
-	})
-	wg.Go(func() error {
-		ir, err := graphics.CompileShader([]byte(builtinshader.ShaderSource(builtinshader.FilterLinear, builtinshader.AddressUnsafe, false)))
-		if err != nil {
-			return fmt.Errorf("restorable: compiling the linear shader failed: %w", err)
-		}
-		linearIR = ir
-		return nil
-	})
-	wg.Go(func() error {
-		ir, err := graphics.CompileShader([]byte(builtinshader.ClearShaderSource))
-		if err != nil {
-			return fmt.Errorf("restorable: compiling the clear shader failed: %w", err)
-		}
-		clearIR = ir
-		return nil
-	})
-	if err := wg.Wait(); err != nil {
-		panic(err)
-	}
-	NearestFilterShader = NewShader(nearestIR)
-	LinearFilterShader = NewShader(linearIR)
-	clearShader = NewShader(clearIR)
-}

internal/restorable/shader_test.go

@@ -1,200 +0,0 @@
-// Copyright 2018 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package restorable_test
-
-import (
-	"image"
-	"image/color"
-	"testing"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
-	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
-	etesting "github.com/hajimehoshi/ebiten/v2/internal/testing"
-	"github.com/hajimehoshi/ebiten/v2/internal/ui"
-)
-
-func clearImage(img *restorable.Image, w, h int) {
-	emptyImage := restorable.NewImage(3, 3, restorable.ImageTypeRegular)
-	defer emptyImage.Dispose()
-
-	dx0 := float32(0)
-	dy0 := float32(0)
-	dx1 := float32(w)
-	dy1 := float32(h)
-	sx0 := float32(1)
-	sy0 := float32(1)
-	sx1 := float32(2)
-	sy1 := float32(2)
-	vs := []float32{
-		dx0, dy0, sx0, sy0, 0, 0, 0, 0,
-		dx1, dy0, sx1, sy0, 0, 0, 0, 0,
-		dx0, dy1, sx0, sy1, 0, 0, 0, 0,
-		dx1, dy1, sx1, sy1, 0, 0, 0, 0,
-	}
-	is := graphics.QuadIndices()
-	dr := image.Rect(0, 0, w, h)
-	img.DrawTriangles([graphics.ShaderSrcImageCount]*restorable.Image{emptyImage}, vs, is, graphicsdriver.BlendClear, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, restorable.NearestFilterShader, nil, graphicsdriver.FillRuleFillAll)
-}
-
-func TestShader(t *testing.T) {
-	img := restorable.NewImage(1, 1, restorable.ImageTypeRegular)
-	defer img.Dispose()
-
-	s := restorable.NewShader(etesting.ShaderProgramFill(0xff, 0, 0, 0xff))
-	dr := image.Rect(0, 0, 1, 1)
-	img.DrawTriangles([graphics.ShaderSrcImageCount]*restorable.Image{}, quadVertices(1, 1, 0, 0), graphics.QuadIndices(), graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, s, nil, graphicsdriver.FillRuleFillAll)
-
-	if err := restorable.ResolveStaleImages(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-	if err := restorable.RestoreIfNeeded(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-
-	want := color.RGBA{R: 0xff, A: 0xff}
-	got := pixelsToColor(img.BasePixelsForTesting(), 0, 0, 1, 1)
-	if !sameColors(got, want, 1) {
-		t.Errorf("got %v, want %v", got, want)
-	}
-}
-
-func TestShaderChain(t *testing.T) {
-	const num = 10
-	imgs := []*restorable.Image{}
-	for i := 0; i < num; i++ {
-		img := restorable.NewImage(1, 1, restorable.ImageTypeRegular)
-		defer img.Dispose()
-		imgs = append(imgs, img)
-	}
-
-	imgs[0].WritePixels(bytesToManagedBytes([]byte{0xff, 0, 0, 0xff}), image.Rect(0, 0, 1, 1))
-
-	s := restorable.NewShader(etesting.ShaderProgramImages(1))
-	for i := 0; i < num-1; i++ {
-		dr := image.Rect(0, 0, 1, 1)
-		imgs[i+1].DrawTriangles([graphics.ShaderSrcImageCount]*restorable.Image{imgs[i]}, quadVertices(1, 1, 0, 0), graphics.QuadIndices(), graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, s, nil, graphicsdriver.FillRuleFillAll)
-	}
-
-	if err := restorable.ResolveStaleImages(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-	if err := restorable.RestoreIfNeeded(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-
-	for i, img := range imgs {
-		want := color.RGBA{R: 0xff, A: 0xff}
-		got := pixelsToColor(img.BasePixelsForTesting(), 0, 0, 1, 1)
-		if !sameColors(got, want, 1) {
-			t.Errorf("%d: got %v, want %v", i, got, want)
-		}
-	}
-}
-
-func TestShaderMultipleSources(t *testing.T) {
-	var srcs [graphics.ShaderSrcImageCount]*restorable.Image
-	for i := range srcs {
-		srcs[i] = restorable.NewImage(1, 1, restorable.ImageTypeRegular)
-	}
-	srcs[0].WritePixels(bytesToManagedBytes([]byte{0x40, 0, 0, 0xff}), image.Rect(0, 0, 1, 1))
-	srcs[1].WritePixels(bytesToManagedBytes([]byte{0, 0x80, 0, 0xff}), image.Rect(0, 0, 1, 1))
-	srcs[2].WritePixels(bytesToManagedBytes([]byte{0, 0, 0xc0, 0xff}), image.Rect(0, 0, 1, 1))
-
-	dst := restorable.NewImage(1, 1, restorable.ImageTypeRegular)
-
-	s := restorable.NewShader(etesting.ShaderProgramImages(3))
-	dr := image.Rect(0, 0, 1, 1)
-	dst.DrawTriangles(srcs, quadVertices(1, 1, 0, 0), graphics.QuadIndices(), graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, s, nil, graphicsdriver.FillRuleFillAll)
-
-	// Clear one of the sources after DrawTriangles. dst should not be affected.
-	clearImage(srcs[0], 1, 1)
-
-	if err := restorable.ResolveStaleImages(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-	if err := restorable.RestoreIfNeeded(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-
-	want := color.RGBA{R: 0x40, G: 0x80, B: 0xc0, A: 0xff}
-	got := pixelsToColor(dst.BasePixelsForTesting(), 0, 0, 1, 1)
-	if !sameColors(got, want, 1) {
-		t.Errorf("got %v, want %v", got, want)
-	}
-}
-
-func TestShaderMultipleSourcesOnOneTexture(t *testing.T) {
-	src := restorable.NewImage(3, 1, restorable.ImageTypeRegular)
-	src.WritePixels(bytesToManagedBytes([]byte{
-		0x40, 0, 0, 0xff,
-		0, 0x80, 0, 0xff,
-		0, 0, 0xc0, 0xff,
-	}), image.Rect(0, 0, 3, 1))
-	srcs := [graphics.ShaderSrcImageCount]*restorable.Image{src, src, src}
-
-	dst := restorable.NewImage(1, 1, restorable.ImageTypeRegular)
-
-	s := restorable.NewShader(etesting.ShaderProgramImages(3))
-	dr := image.Rect(0, 0, 1, 1)
-	srcRegions := [graphics.ShaderSrcImageCount]image.Rectangle{
-		image.Rect(0, 0, 1, 1),
-		image.Rect(1, 0, 2, 1),
-		image.Rect(2, 0, 3, 1),
-	}
-	dst.DrawTriangles(srcs, quadVertices(1, 1, 0, 0), graphics.QuadIndices(), graphicsdriver.BlendCopy, dr, srcRegions, s, nil, graphicsdriver.FillRuleFillAll)
-
-	// Clear one of the sources after DrawTriangles. dst should not be affected.
-	clearImage(srcs[0], 3, 1)
-
-	if err := restorable.ResolveStaleImages(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-	if err := restorable.RestoreIfNeeded(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-
-	want := color.RGBA{R: 0x40, G: 0x80, B: 0xc0, A: 0xff}
-	got := pixelsToColor(dst.BasePixelsForTesting(), 0, 0, 1, 1)
-	if !sameColors(got, want, 1) {
-		t.Errorf("got %v, want %v", got, want)
-	}
-}
-
-func TestShaderDispose(t *testing.T) {
-	img := restorable.NewImage(1, 1, restorable.ImageTypeRegular)
-	defer img.Dispose()
-
-	s := restorable.NewShader(etesting.ShaderProgramFill(0xff, 0, 0, 0xff))
-	dr := image.Rect(0, 0, 1, 1)
-	img.DrawTriangles([graphics.ShaderSrcImageCount]*restorable.Image{}, quadVertices(1, 1, 0, 0), graphics.QuadIndices(), graphicsdriver.BlendCopy, dr, [graphics.ShaderSrcImageCount]image.Rectangle{}, s, nil, graphicsdriver.FillRuleFillAll)
-
-	// Dispose the shader. This should invalidate all the images using this shader i.e., all the images become
-	// stale.
-	s.Dispose()
-
-	if err := restorable.ResolveStaleImages(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-	if err := restorable.RestoreIfNeeded(ui.Get().GraphicsDriverForTesting()); err != nil {
-		t.Fatal(err)
-	}
-
-	want := color.RGBA{R: 0xff, A: 0xff}
-	got := pixelsToColor(img.BasePixelsForTesting(), 0, 0, 1, 1)
-	if !sameColors(got, want, 1) {
-		t.Errorf("got %v, want %v", got, want)
-	}
-}

internal/ui/context.go

@@ -180,12 +180,6 @@ func (c *context) newOffscreenImage(w, h int) *Image {
 }
 
 func (c *context) drawGame(graphicsDriver graphicsdriver.Graphics, ui *UserInterface, forceDraw bool) error {
-	if (c.offscreen.imageType == atlas.ImageTypeVolatile) != ui.IsScreenClearedEveryFrame() {
-		w, h := c.offscreen.width, c.offscreen.height
-		c.offscreen.Deallocate()
-		c.offscreen = c.newOffscreenImage(w, h)
-	}
-
 	// isOffscreenModified is updated when an offscreen's modifyCallback.
 	c.isOffscreenModified = false
 

internal/ui/image.go

@@ -15,7 +15,6 @@
 package ui
 
 import (
-	"fmt"
 	"image"
 	"math"
 
@@ -86,16 +85,7 @@ func (i *Image) DrawTriangles(srcs [graphics.ShaderSrcImageCount]*Image, vertice
 
 	if antialias {
 		if i.bigOffscreenBuffer == nil {
-			var imageType atlas.ImageType
-			switch i.imageType {
-			case atlas.ImageTypeRegular, atlas.ImageTypeUnmanaged:
-				imageType = atlas.ImageTypeUnmanaged
-			case atlas.ImageTypeScreen, atlas.ImageTypeVolatile:
-				imageType = atlas.ImageTypeVolatile
-			default:
-				panic(fmt.Sprintf("ui: unexpected image type: %d", imageType))
-			}
-			i.bigOffscreenBuffer = i.ui.newBigOffscreenImage(i, imageType)
+			i.bigOffscreenBuffer = i.ui.newBigOffscreenImage(i, atlas.ImageTypeUnmanaged)
 		}
 
 		i.bigOffscreenBuffer.drawTriangles(srcs, vertices, indices, blend, dstRegion, srcRegions, shader, uniforms, fillRule, canSkipMipmap)

internal/ui/ui.go

@@ -172,16 +172,15 @@ func (u *UserInterface) dumpImages(dir string) (string, error) {
 }
 
 type RunOptions struct {
-	GraphicsLibrary          GraphicsLibrary
-	InitUnfocused            bool
-	ScreenTransparent        bool
-	SkipTaskbar              bool
-	SingleThread             bool
-	DisableHiDPI             bool
-	ColorSpace               graphicsdriver.ColorSpace
-	X11ClassName             string
-	X11InstanceName          string
-	StrictContextRestoration bool
+	GraphicsLibrary   GraphicsLibrary
+	InitUnfocused     bool
+	ScreenTransparent bool
+	SkipTaskbar       bool
+	SingleThread      bool
+	DisableHiDPI      bool
+	ColorSpace        graphicsdriver.ColorSpace
+	X11ClassName      string
+	X11InstanceName   string
 }
 
 // InitialWindowPosition returns the position for centering the given second width/height pair within the first width/height pair.

internal/ui/ui_mobile.go

@@ -28,7 +28,6 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicscommand"
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/v2/internal/hook"
-	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
 )
 
 var (
@@ -98,11 +97,8 @@ type userInterfaceImpl struct {
 	inputState InputState
 	touches    []TouchForInput
 
-	fpsMode  atomic.Int32
-	renderer Renderer
-
-	strictContextRestoration     bool
-	strictContextRestorationOnce sync.Once
+	fpsMode         atomic.Int32
+	renderRequester RenderRequester
 
 	m sync.RWMutex
 }
@@ -156,11 +152,6 @@ func (u *UserInterface) runMobile(game Game, options *RunOptions) (err error) {
 	u.graphicsDriver = g
 	u.setGraphicsLibrary(lib)
 	close(u.graphicsLibraryInitCh)
-	u.strictContextRestoration = options.StrictContextRestoration
-	if !u.strictContextRestoration {
-		restorable.Disable()
-	}
-	u.renderer.SetStrictContextRestoration(u.strictContextRestoration)
 
 	for {
 		if err := u.update(); err != nil {
@@ -248,10 +239,10 @@ func (u *UserInterface) SetFPSMode(mode FPSModeType) {
 }
 
 func (u *UserInterface) updateExplicitRenderingModeIfNeeded(fpsMode FPSModeType) {
-	if u.renderer == nil {
+	if u.renderRequester == nil {
 		return
 	}
-	u.renderer.SetExplicitRenderingMode(fpsMode == FPSModeVsyncOffMinimum)
+	u.renderRequester.SetExplicitRenderingMode(fpsMode == FPSModeVsyncOffMinimum)
 }
 
 func (u *UserInterface) readInputState(inputState *InputState) {
@@ -306,24 +297,23 @@ func (u *UserInterface) Monitor() *Monitor {
 func (u *UserInterface) UpdateInput(keys map[Key]struct{}, runes []rune, touches []TouchForInput) {
 	u.updateInputStateFromOutside(keys, runes, touches)
 	if FPSModeType(u.fpsMode.Load()) == FPSModeVsyncOffMinimum {
-		u.renderer.RequestRenderIfNeeded()
+		u.renderRequester.RequestRenderIfNeeded()
 	}
 }
 
-type Renderer interface {
+type RenderRequester interface {
 	SetExplicitRenderingMode(explicitRendering bool)
-	SetStrictContextRestoration(strictContextRestoration bool)
 	RequestRenderIfNeeded()
 }
 
-func (u *UserInterface) SetRenderer(renderer Renderer) {
-	u.renderer = renderer
+func (u *UserInterface) SetRenderRequester(renderRequester RenderRequester) {
+	u.renderRequester = renderRequester
 	u.updateExplicitRenderingModeIfNeeded(FPSModeType(u.fpsMode.Load()))
 }
 
 func (u *UserInterface) ScheduleFrame() {
-	if u.renderer != nil && FPSModeType(u.fpsMode.Load()) == FPSModeVsyncOffMinimum {
-		u.renderer.RequestRenderIfNeeded()
+	if u.renderRequester != nil && FPSModeType(u.fpsMode.Load()) == FPSModeVsyncOffMinimum {
+		u.renderRequester.RequestRenderIfNeeded()
 	}
 }
 

mobile/ebitenmobileview/mobile.go

@@ -30,7 +30,6 @@ import (
 	"sync"
 
 	"github.com/hajimehoshi/ebiten/v2"
-	"github.com/hajimehoshi/ebiten/v2/internal/restorable"
 	"github.com/hajimehoshi/ebiten/v2/internal/ui"
 )
 
@@ -113,20 +112,17 @@ func Resume() error {
 	return ui.Get().SetForeground(true)
 }
 
-func OnContextLost() {
-	restorable.OnContextLost()
-}
-
 func DeviceScale() float64 {
 	return ui.Get().Monitor().DeviceScaleFactor()
 }
 
-type Renderer interface {
-	ui.Renderer
+type RenderRequester interface {
+	SetExplicitRenderingMode(explicitRendering bool)
+	RequestRenderIfNeeded()
 }
 
-func SetRenderer(renderer Renderer) {
-	ui.Get().SetRenderer(renderer)
+func SetRenderRequester(renderRequester RenderRequester) {
+	ui.Get().SetRenderRequester(renderRequester)
 }
 
 func SetSetGameNotifier(setGameNotifier SetGameNotifier) {

run.go

@@ -297,24 +297,6 @@ type RunGameOptions struct {
 
 	// X11InstanceName is an instance name in the ICCCM WM_CLASS window property.
 	X11InstanceName string
-
-	// StrictContextRestration indicates whether the context lost should be restored strictly by Ebitengine or not.
-	//
-	// StrictContextRestration is available only on Android. Otherwise, StrictContextRestration is ignored.
-	//
-	// When StrictContextRestration is false, Ebitengine tries to rely on the OS to restore the context.
-	// In Android, Ebitengien uses `GLSurfaceView`'s `setPreserveEGLContextOnPause(true)`.
-	// This works in most cases, but it is still possible that the context is lost in some minor cases.
-	// With StrictContextRestration false, the activity's launch mode should be singleInstance,
-	// or the activity no longer works correctly after the context is lost.
-	//
-	// When StrictContextRestration is true, Ebitengine tries to restore the context more strictly.
-	// This is useful when you want to restore the context in any case.
-	// However, this might cause a performance issue since Ebitengine tries to keep all the information
-	// to restore the context.
-	//
-	// The default (zero) value is false.
-	StrictContextRestration bool
 }
 
 // RunGameWithOptions starts the main loop and runs the game with the specified options.
@@ -734,16 +716,15 @@ func toUIRunOptions(options *RunGameOptions) *ui.RunOptions {
 		options.X11InstanceName = defaultX11InstanceName
 	}
 	return &ui.RunOptions{
-		GraphicsLibrary:          ui.GraphicsLibrary(options.GraphicsLibrary),
-		InitUnfocused:            options.InitUnfocused,
-		ScreenTransparent:        options.ScreenTransparent,
-		SkipTaskbar:              options.SkipTaskbar,
-		SingleThread:             options.SingleThread,
-		DisableHiDPI:             options.DisableHiDPI,
-		ColorSpace:               graphicsdriver.ColorSpace(options.ColorSpace),
-		X11ClassName:             options.X11ClassName,
-		X11InstanceName:          options.X11InstanceName,
-		StrictContextRestoration: options.StrictContextRestration,
+		GraphicsLibrary:   ui.GraphicsLibrary(options.GraphicsLibrary),
+		InitUnfocused:     options.InitUnfocused,
+		ScreenTransparent: options.ScreenTransparent,
+		SkipTaskbar:       options.SkipTaskbar,
+		SingleThread:      options.SingleThread,
+		DisableHiDPI:      options.DisableHiDPI,
+		ColorSpace:        graphicsdriver.ColorSpace(options.ColorSpace),
+		X11ClassName:      options.X11ClassName,
+		X11InstanceName:   options.X11InstanceName,
 	}
 }