graphics: Restoring by recording drawing-images history

graphicscontext.go

@@ -89,11 +89,13 @@ func (c *graphicsContext) initializeIfNeeded(context *opengl.Context) error {
 	if err != nil {
 		return err
 	}
-	if r {
-		if err := c.restore(context); err != nil {
-			return err
-		}
+	if !r {
+		return nil
 	}
+	if err := c.restore(context); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -144,11 +146,6 @@ func (c *graphicsContext) UpdateAndDraw(context *opengl.Context, updateCount int
 	if err := c.drawToDefaultRenderTarget(context); err != nil {
 		return err
 	}
-	if 0 < updateCount {
-		if err := theImagesForRestoring.savePixels(context); err != nil {
-			return err
-		}
-	}
 	return nil
 }
 

image.go

@@ -42,17 +42,20 @@ func (i *images) add(img *imageImpl) (*Image, error) {
 }
 
 func (i *images) remove(img *Image) {
+	if err := img.Dispose(); err != nil {
+		panic(err)
+	}
 	i.m.Lock()
 	defer i.m.Unlock()
 	delete(i.images, img.impl)
 	runtime.SetFinalizer(img, nil)
 }
 
-func (i *images) savePixels(context *opengl.Context) error {
+func (i *images) resetHistoryIfNeeded(target *Image) error {
 	i.m.Lock()
 	defer i.m.Unlock()
 	for img := range i.images {
-		if err := img.savePixels(context); err != nil {
+		if err := img.resetHistoryIfNeeded(target); err != nil {
 			return err
 		}
 	}
@@ -73,8 +76,24 @@ func (i *images) restore(context *opengl.Context) error {
 			return err
 		}
 	}
+	imagesWithoutHistory := []*imageImpl{}
+	imagesWithHistory := []*imageImpl{}
 	for img := range i.images {
-		if err := img.restore(); err != nil {
+		if img.hasHistory() {
+			imagesWithHistory = append(imagesWithHistory, img)
+		} else {
+			imagesWithoutHistory = append(imagesWithoutHistory, img)
+		}
+	}
+	// Images with history can depend on other images. Let's process images without history
+	// first.
+	for _, img := range imagesWithoutHistory {
+		if err := img.restore(context); err != nil {
+			return err
+		}
+	}
+	for _, img := range imagesWithHistory {
+		if err := img.restore(context); err != nil {
 			return err
 		}
 	}
@@ -110,6 +129,9 @@ func (i *Image) Size() (width, height int) {
 //
 // This function is concurrent-safe.
 func (i *Image) Clear() error {
+	if err := theImagesForRestoring.resetHistoryIfNeeded(i); err != nil {
+		return err
+	}
 	return i.impl.Fill(color.Transparent)
 }
 
@@ -117,6 +139,9 @@ func (i *Image) Clear() error {
 //
 // This function is concurrent-safe.
 func (i *Image) Fill(clr color.Color) error {
+	if err := theImagesForRestoring.resetHistoryIfNeeded(i); err != nil {
+		return err
+	}
 	return i.impl.Fill(clr)
 }
 
@@ -137,6 +162,9 @@ func (i *Image) Fill(clr color.Color) error {
 //
 // This function is concurrent-safe.
 func (i *Image) DrawImage(image *Image, options *DrawImageOptions) error {
+	if err := theImagesForRestoring.resetHistoryIfNeeded(i); err != nil {
+		return err
+	}
 	return i.impl.DrawImage(image, options)
 }
 
@@ -172,6 +200,12 @@ func (i *Image) At(x, y int) color.Color {
 //
 // This function is concurrent-safe.
 func (i *Image) Dispose() error {
+	if err := theImagesForRestoring.resetHistoryIfNeeded(i); err != nil {
+		return err
+	}
+	if i.impl.isDisposed() {
+		return nil
+	}
 	return i.impl.Dispose()
 }
 
@@ -183,6 +217,9 @@ func (i *Image) Dispose() error {
 //
 // This function is concurrent-safe.
 func (i *Image) ReplacePixels(p []uint8) error {
+	if err := theImagesForRestoring.resetHistoryIfNeeded(i); err != nil {
+		return err
+	}
 	return i.impl.ReplacePixels(p)
 }
 

imageimpl.go

@@ -29,16 +29,26 @@ import (
 	"github.com/hajimehoshi/ebiten/internal/ui"
 )
 
+type drawImageHistoryItem struct {
+	image    *Image
+	vertices []int16
+	geom     GeoM
+	colorm   ColorM
+	mode     opengl.CompositeMode
+}
+
 type imageImpl struct {
-	image    *graphics.Image
-	disposed bool
-	width    int
-	height   int
-	filter   Filter
-	pixels   []uint8
-	volatile bool
-	screen   bool
-	m        sync.Mutex
+	image            *graphics.Image
+	disposed         bool
+	width            int
+	height           int
+	filter           Filter
+	pixels           []uint8
+	baseColor        color.Color
+	drawImageHistory []*drawImageHistoryItem
+	volatile         bool
+	screen           bool
+	m                sync.Mutex
 }
 
 func newImageImpl(width, height int, filter Filter, volatile bool) (*imageImpl, error) {
@@ -52,6 +62,7 @@ func newImageImpl(width, height int, filter Filter, volatile bool) (*imageImpl,
 		height:   height,
 		filter:   filter,
 		volatile: volatile,
+		pixels:   make([]uint8, width*height*4),
 	}
 	runtime.SetFinalizer(i, (*imageImpl).Dispose)
 	return i, nil
@@ -100,6 +111,7 @@ func newScreenImageImpl(width, height int) (*imageImpl, error) {
 		height:   height,
 		volatile: true,
 		screen:   true,
+		pixels:   make([]uint8, width*height*4),
 	}
 	runtime.SetFinalizer(i, (*imageImpl).Dispose)
 	return i, nil
@@ -112,6 +124,8 @@ func (i *imageImpl) Fill(clr color.Color) error {
 		return errors.New("ebiten: image is already disposed")
 	}
 	i.pixels = nil
+	i.baseColor = clr
+	i.drawImageHistory = nil
 	return i.image.Fill(clr)
 }
 
@@ -125,6 +139,8 @@ func (i *imageImpl) clearIfVolatile() error {
 		return nil
 	}
 	i.pixels = nil
+	i.baseColor = nil
+	i.drawImageHistory = nil
 	return i.image.Fill(color.Transparent)
 }
 
@@ -159,11 +175,18 @@ func (i *imageImpl) DrawImage(image *Image, options *DrawImageOptions) error {
 	if i.disposed {
 		return errors.New("ebiten: image is already disposed")
 	}
-	i.pixels = nil
+	c := &drawImageHistoryItem{
+		image:    image,
+		vertices: vertices,
+		geom:     options.GeoM,
+		colorm:   options.ColorM,
+		mode:     opengl.CompositeMode(options.CompositeMode),
+	}
+	i.drawImageHistory = append(i.drawImageHistory, c)
 	geom := &options.GeoM
 	colorm := &options.ColorM
 	mode := opengl.CompositeMode(options.CompositeMode)
-	if err := i.image.DrawImage(image.impl.image, vertices[:16*n], geom, colorm, mode); err != nil {
+	if err := i.image.DrawImage(image.impl.image, vertices, geom, colorm, mode); err != nil {
 		return err
 	}
 	return nil
@@ -178,42 +201,57 @@ func (i *imageImpl) At(x, y int) color.Color {
 	if i.disposed {
 		return color.Transparent
 	}
-	if i.pixels == nil {
+	if i.pixels == nil || i.drawImageHistory != nil {
 		var err error
 		i.pixels, err = i.image.Pixels(ui.GLContext())
 		if err != nil {
 			panic(err)
 		}
+		i.drawImageHistory = nil
 	}
 	idx := 4*x + 4*y*i.width
 	r, g, b, a := i.pixels[idx], i.pixels[idx+1], i.pixels[idx+2], i.pixels[idx+3]
 	return color.RGBA{r, g, b, a}
 }
 
-func (i *imageImpl) savePixels(context *opengl.Context) error {
+func (i *imageImpl) hasHistoryWith(target *Image) bool {
+	for _, c := range i.drawImageHistory {
+		if c.image == target {
+			return true
+		}
+	}
+	return false
+}
+
+func (i *imageImpl) resetHistoryIfNeeded(target *Image) error {
 	i.m.Lock()
 	defer i.m.Unlock()
-	if i.screen {
-		return nil
-	}
-	if i.volatile {
-		return nil
-	}
 	if i.disposed {
 		return nil
 	}
-	if i.pixels != nil {
+	if i.drawImageHistory == nil {
+		return nil
+	}
+	if !i.hasHistoryWith(target) {
 		return nil
 	}
 	var err error
-	i.pixels, err = i.image.Pixels(context)
+	i.pixels, err = i.image.Pixels(ui.GLContext())
 	if err != nil {
-		return err
+		return nil
 	}
+	i.baseColor = nil
+	i.drawImageHistory = nil
 	return nil
 }
 
-func (i *imageImpl) restore() error {
+func (i *imageImpl) hasHistory() bool {
+	i.m.Lock()
+	defer i.m.Unlock()
+	return i.drawImageHistory != nil
+}
+
+func (i *imageImpl) restore(context *opengl.Context) error {
 	i.m.Lock()
 	defer i.m.Unlock()
 	if i.disposed {
@@ -229,16 +267,43 @@ func (i *imageImpl) restore() error {
 		}
 		return nil
 	}
-	if i.pixels != nil {
+	if !i.volatile {
 		img := image.NewRGBA(image.Rect(0, 0, i.width, i.height))
-		for j := 0; j < i.height; j++ {
-			copy(img.Pix[j*img.Stride:], i.pixels[j*i.width*4:(j+1)*i.width*4])
+		if i.pixels != nil {
+			for j := 0; j < i.height; j++ {
+				copy(img.Pix[j*img.Stride:], i.pixels[j*i.width*4:(j+1)*i.width*4])
+			}
+		} else if i.baseColor != nil {
+			r32, g32, b32, a32 := i.baseColor.RGBA()
+			r, g, b, a := uint8(r32), uint8(g32), uint8(b32), uint8(a32)
+			for idx := 0; idx < len(img.Pix)/4; idx++ {
+				img.Pix[4*idx] = r
+				img.Pix[4*idx+1] = g
+				img.Pix[4*idx+2] = b
+				img.Pix[4*idx+3] = a
+			}
 		}
 		var err error
 		i.image, err = graphics.NewImageFromImage(img, glFilter(i.filter))
 		if err != nil {
 			return err
 		}
+		for _, c := range i.drawImageHistory {
+			if c.image.impl.hasHistory() {
+				panic("not reach")
+			}
+			if err := i.image.DrawImage(c.image.impl.image, c.vertices, &c.geom, &c.colorm, c.mode); err != nil {
+				return err
+			}
+		}
+		if 0 < len(i.drawImageHistory) {
+			i.pixels, err = i.image.Pixels(context)
+			if err != nil {
+				return err
+			}
+		}
+		i.baseColor = nil
+		i.drawImageHistory = nil
 		return nil
 	}
 	var err error
@@ -263,6 +328,8 @@ func (i *imageImpl) Dispose() error {
 	i.image = nil
 	i.disposed = true
 	i.pixels = nil
+	i.baseColor = nil
+	i.drawImageHistory = nil
 	runtime.SetFinalizer(i, nil)
 	return nil
 }
@@ -274,9 +341,11 @@ func (i *imageImpl) ReplacePixels(p []uint8) error {
 	i.m.Lock()
 	defer i.m.Unlock()
 	if i.pixels == nil {
-		i.pixels = make([]uint8, len(p))
+		i.pixels = make([]uint8, i.width*i.height*4)
 	}
 	copy(i.pixels, p)
+	i.baseColor = nil
+	i.drawImageHistory = nil
 	if i.disposed {
 		return errors.New("ebiten: image is already disposed")
 	}

internal/graphics/opengl/context_desktop.go

@@ -394,6 +394,9 @@ func (c *Context) UseProgram(p Program) {
 
 func (c *Context) DeleteProgram(p Program) {
 	c.RunOnContextThread(func() error {
+		if !gl.IsProgram(uint32(p)) {
+			return nil
+		}
 		gl.DeleteProgram(uint32(p))
 		return nil
 	})

internal/graphics/opengl/context_js.go

@@ -319,6 +319,9 @@ func (c *Context) UseProgram(p Program) {
 
 func (c *Context) DeleteProgram(p Program) {
 	gl := c.gl
+	if !gl.IsProgram(p.Object) {
+		return
+	}
 	gl.DeleteProgram(p.Object)
 }
 

internal/graphics/opengl/context_mobile.go

@@ -298,6 +298,9 @@ func (c *Context) UseProgram(p Program) {
 
 func (c *Context) DeleteProgram(p Program) {
 	gl := c.gl
+	if !gl.IsProgram(mgl.Program(p)) {
+		return
+	}
 	gl.DeleteProgram(mgl.Program(p))
 }