buffered: Allow Set before the game runs

Fixes #949

image.go

@@ -40,8 +40,6 @@ type Image struct {
 	bounds   image.Rectangle
 	original *Image
 
-	pendingPixels []byte
-
 	filter Filter
 }
 
@@ -92,8 +90,6 @@ func (i *Image) Fill(clr color.Color) error {
 		panic("ebiten: render to a subimage is not implemented (Fill)")
 	}
 
-	i.invalidatePendingPixels()
-
 	i.mipmap.fill(color.RGBAModel.Convert(clr).(color.RGBA))
 	return nil
 }
@@ -150,9 +146,6 @@ func (i *Image) DrawImage(img *Image, options *DrawImageOptions) error {
 		panic("ebiten: render to a subimage is not implemented (drawImage)")
 	}
 
-	img.resolvePendingPixels(true)
-	i.resolvePendingPixels(false)
-
 	// Calculate vertices before locking because the user can do anything in
 	// options.ImageParts interface without deadlock (e.g. Call Image functions).
 	if options == nil {
@@ -293,9 +286,6 @@ func (i *Image) DrawTriangles(vertices []Vertex, indices []uint16, img *Image, o
 		panic("ebiten: render to a subimage is not implemented (DrawTriangles)")
 	}
 
-	img.resolvePendingPixels(true)
-	i.resolvePendingPixels(false)
-
 	if len(indices)%3 != 0 {
 		panic("ebiten: len(indices) % 3 must be 0")
 	}
@@ -390,8 +380,6 @@ func (i *Image) At(x, y int) color.Color {
 	if i.isSubImage() && !image.Pt(x, y).In(i.bounds) {
 		return color.RGBA{}
 	}
-	// TODO: Use pending pixels
-	i.resolvePendingPixels(true)
 	r, g, b, a := i.mipmap.at(x, y)
 	return color.RGBA{r, g, b, a}
 }
@@ -400,66 +388,23 @@ func (i *Image) At(x, y int) color.Color {
 //
 // Set loads pixels from GPU to system memory if necessary, which means that Set can be slow.
 //
-// Set can't be called outside the main loop (ebiten.Run's updating function) starts.
+// In the current implementation, successive calls of Set invokes loading pixels at most once, so this is efficient.
 //
 // If the image is disposed, Set does nothing.
-func (img *Image) Set(x, y int, clr color.Color) {
-	img.copyCheck()
-	if img.isDisposed() {
+func (i *Image) Set(x, y int, clr color.Color) {
+	i.copyCheck()
+	if i.isDisposed() {
 		return
 	}
-	if !image.Pt(x, y).In(img.Bounds()) {
+	if !image.Pt(x, y).In(i.Bounds()) {
 		return
 	}
-	if img.isSubImage() {
-		img = img.original
+	if i.isSubImage() {
+		i = i.original
 	}
 
-	w, h := img.Size()
-	if img.pendingPixels == nil {
-		pix := make([]byte, 4*w*h)
-		idx := 0
-		for j := 0; j < h; j++ {
-			for i := 0; i < w; i++ {
-				r, g, b, a := img.mipmap.at(i, j)
-				pix[4*idx] = r
-				pix[4*idx+1] = g
-				pix[4*idx+2] = b
-				pix[4*idx+3] = a
-				idx++
-			}
-		}
-		img.pendingPixels = pix
-	}
 	r, g, b, a := clr.RGBA()
-	img.pendingPixels[4*(x+y*w)] = byte(r >> 8)
-	img.pendingPixels[4*(x+y*w)+1] = byte(g >> 8)
-	img.pendingPixels[4*(x+y*w)+2] = byte(b >> 8)
-	img.pendingPixels[4*(x+y*w)+3] = byte(a >> 8)
-}
-
-func (i *Image) invalidatePendingPixels() {
-	if i.isSubImage() {
-		i.original.invalidatePendingPixels()
-		return
-	}
-	i.pendingPixels = nil
-}
-
-func (i *Image) resolvePendingPixels(keepPendingPixels bool) {
-	if i.isSubImage() {
-		i.original.resolvePendingPixels(keepPendingPixels)
-		return
-	}
-
-	if i.pendingPixels == nil {
-		return
-	}
-
-	i.mipmap.replacePixels(i.pendingPixels)
-	if !keepPendingPixels {
-		i.pendingPixels = nil
-	}
+	i.mipmap.set(x, y, byte(r>>8), byte(g>>8), byte(b>>8), byte(a>>8))
 }
 
 // Dispose disposes the image data. After disposing, most of image functions do nothing and returns meaningless values.
@@ -480,7 +425,6 @@ func (i *Image) Dispose() error {
 		return nil
 	}
 	i.mipmap.dispose()
-	i.invalidatePendingPixels()
 	return nil
 }
 
@@ -505,7 +449,6 @@ func (i *Image) ReplacePixels(p []byte) error {
 	if i.isSubImage() {
 		panic("ebiten: render to a subimage is not implemented (ReplacePixels)")
 	}
-	i.invalidatePendingPixels()
 	s := i.Bounds().Size()
 	if l := 4 * s.X * s.Y; len(p) != l {
 		panic(fmt.Sprintf("ebiten: len(p) was %d but must be %d", len(p), l))

internal/buffered/image.go

@@ -24,6 +24,10 @@ import (
 
 type Image struct {
 	img    *shareable.Image
+	width  int
+	height int
+
+	pendingPixels []byte
 }
 
 func BeginFrame() error {
@@ -44,6 +48,8 @@ func NewImage(width, height int, volatile bool) *Image {
 	if needsToDelayCommands {
 		delayedCommands = append(delayedCommands, func() {
 			i.img = shareable.NewImage(width, height, volatile)
+			i.width = width
+			i.height = height
 		})
 		delayedCommandsM.Unlock()
 		return i
@@ -51,6 +57,8 @@ func NewImage(width, height int, volatile bool) *Image {
 	delayedCommandsM.Unlock()
 
 	i.img = shareable.NewImage(width, height, volatile)
+	i.width = width
+	i.height = height
 	return i
 }
 
@@ -60,6 +68,8 @@ func NewScreenFramebufferImage(width, height int) *Image {
 	if needsToDelayCommands {
 		delayedCommands = append(delayedCommands, func() {
 			i.img = shareable.NewScreenFramebufferImage(width, height)
+			i.width = width
+			i.height = height
 		})
 		delayedCommandsM.Unlock()
 		return i
@@ -67,17 +77,38 @@ func NewScreenFramebufferImage(width, height int) *Image {
 	delayedCommandsM.Unlock()
 
 	i.img = shareable.NewScreenFramebufferImage(width, height)
+	i.width = width
+	i.height = height
 	return i
 }
 
+func (i *Image) invalidatePendingPixels() {
+	i.pendingPixels = nil
+}
+
+func (i *Image) resolvePendingPixels(keepPendingPixels bool) {
+	if i.pendingPixels == nil {
+		return
+	}
+
+	i.img.ReplacePixels(i.pendingPixels)
+	if !keepPendingPixels {
+		i.pendingPixels = nil
+	}
+}
+
 func (i *Image) MarkDisposed() {
 	delayedCommandsM.Lock()
 	if needsToDelayCommands {
 		delayedCommands = append(delayedCommands, func() {
 			i.img.MarkDisposed()
 		})
+		delayedCommandsM.Unlock()
+		return
 	}
 	delayedCommandsM.Unlock()
+
+	i.invalidatePendingPixels()
 }
 
 func (i *Image) At(x, y int) (r, g, b, a byte) {
@@ -86,9 +117,48 @@ func (i *Image) At(x, y int) (r, g, b, a byte) {
 	if needsToDelayCommands {
 		panic("buffered: the command queue is not available yet at At")
 	}
+	// TODO: Use pending pixels
+	i.resolvePendingPixels(true)
 	return i.img.At(x, y)
 }
 
+func (i *Image) Set(x, y int, r, g, b, a byte) {
+	delayedCommandsM.Lock()
+	if needsToDelayCommands {
+		delayedCommands = append(delayedCommands, func() {
+			i.set(x, y, r, g, b, a)
+		})
+		delayedCommandsM.Unlock()
+		return
+	}
+	delayedCommandsM.Unlock()
+
+	i.set(x, y, r, g, b, a)
+}
+
+func (img *Image) set(x, y int, r, g, b, a byte) {
+	w, h := img.width, img.height
+	if img.pendingPixels == nil {
+		pix := make([]byte, 4*w*h)
+		idx := 0
+		for j := 0; j < h; j++ {
+			for i := 0; i < w; i++ {
+				r, g, b, a := img.img.At(i, j)
+				pix[4*idx] = r
+				pix[4*idx+1] = g
+				pix[4*idx+2] = b
+				pix[4*idx+3] = a
+				idx++
+			}
+		}
+		img.pendingPixels = pix
+	}
+	img.pendingPixels[4*(x+y*w)] = r
+	img.pendingPixels[4*(x+y*w)+1] = g
+	img.pendingPixels[4*(x+y*w)+2] = b
+	img.pendingPixels[4*(x+y*w)+3] = a
+}
+
 func (i *Image) Dump(name string) error {
 	delayedCommandsM.Lock()
 	defer delayedCommandsM.Unlock()
@@ -109,6 +179,7 @@ func (i *Image) Fill(clr color.RGBA) {
 	}
 	delayedCommandsM.Unlock()
 
+	i.invalidatePendingPixels()
 	i.img.Fill(clr)
 }
 
@@ -137,6 +208,7 @@ func (i *Image) ReplacePixels(pix []byte) {
 	}
 	delayedCommandsM.Unlock()
 
+	i.invalidatePendingPixels()
 	i.img.ReplacePixels(pix)
 }
 
@@ -155,5 +227,7 @@ func (i *Image) DrawTriangles(src *Image, vertices []float32, indices []uint16,
 	}
 	delayedCommandsM.Unlock()
 
+	src.resolvePendingPixels(true)
+	i.resolvePendingPixels(false)
 	i.img.DrawTriangles(src.img, vertices, indices, colorm, mode, filter, address)
 }

internal/buffered/image_test.go

@@ -0,0 +1,72 @@
+// 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 buffered_test
+
+import (
+	"errors"
+	"image/color"
+	"os"
+	"testing"
+
+	"github.com/hajimehoshi/ebiten"
+)
+
+var mainCh = make(chan func())
+
+func runOnMainThread(f func()) {
+	ch := make(chan struct{})
+	mainCh <- func() {
+		f()
+		close(ch)
+	}
+	<-ch
+}
+
+func TestMain(m *testing.M) {
+	go func() {
+		os.Exit(m.Run())
+	}()
+
+	for {
+		select {
+		case f := <-mainCh:
+			f()
+		}
+	}
+}
+
+func TestSetBeforeRun(t *testing.T) {
+	clr := color.RGBA{1, 2, 3, 4}
+
+	img, _ := ebiten.NewImage(16, 16, ebiten.FilterDefault)
+	img.Set(0, 0, clr)
+
+	want := clr
+	var got color.RGBA
+
+	runOnMainThread(func() {
+		quit := errors.New("quit")
+		if err := ebiten.Run(func(*ebiten.Image) error {
+			got = img.At(0, 0).(color.RGBA)
+			return quit
+		}, 320, 240, 1, ""); err != nil && err != quit {
+			t.Fatal(err)
+		}
+	})
+
+	if got != want {
+		t.Errorf("got: %v, want: %v", got, want)
+	}
+}

mipmap.go

@@ -77,6 +77,10 @@ func (m *mipmap) at(x, y int) (r, g, b, a byte) {
 	return m.orig.At(x, y)
 }
 
+func (m *mipmap) set(x, y int, r, g, b, a byte) {
+	m.orig.Set(x, y, r, g, b, a)
+}
+
 func (m *mipmap) drawImage(src *mipmap, bounds image.Rectangle, geom *GeoM, colorm *affine.ColorM, mode driver.CompositeMode, filter driver.Filter) {
 	if det := geom.det(); det == 0 {
 		return