From 7e296b1aaeb7901da66bdcdfc041370b0cd9aa85 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Tue, 5 Jul 2016 02:57:41 +0900
Subject: [PATCH] graphics: Bug Fix: The screen image should be recreated

---
 image.go                     |  6 +++---
 imageimpl.go                 | 33 +++++++++++++++++++++++++++++++--
 internal/graphics/command.go |  2 +-
 3 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/image.go b/image.go
index c742cc857..7513ab203 100644
--- a/image.go
+++ b/image.go
@@ -231,13 +231,13 @@ func NewImageFromImage(source image.Image, filter Filter) (*Image, error) {
 }
 
 func newImageWithScreenFramebuffer(width, height int) (*Image, error) {
-	i, err := graphics.NewScreenFramebufferImage(width, height)
+	img, err := newScreenImageImpl(width, height)
 	if err != nil {
 		return nil, err
 	}
-	img, err := newImageImpl(i, FilterNearest)
+	eimg, err := theImagesForRestoring.add(img)
 	if err != nil {
 		return nil, err
 	}
-	return &Image{img}, nil
+	return eimg, nil
 }
diff --git a/imageimpl.go b/imageimpl.go
index 698a8f9b2..4338fb0b2 100644
--- a/imageimpl.go
+++ b/imageimpl.go
@@ -37,6 +37,7 @@ type imageImpl struct {
 	filter   Filter
 	pixels   []uint8
 	noSave   bool
+	screen   bool
 	m        sync.Mutex
 }
 
@@ -84,6 +85,19 @@ func newImageImplFromImage(source image.Image, filter Filter) (*imageImpl, error
 	return i, nil
 }
 
+func newScreenImageImpl(width, height int) (*imageImpl, error) {
+	i, err := graphics.NewScreenFramebufferImage(width, height)
+	if err != nil {
+		return nil, err
+	}
+	img, err := newImageImpl(i, FilterNearest)
+	if err != nil {
+		return nil, err
+	}
+	img.screen = true
+	return img, nil
+}
+
 func (i *imageImpl) Fill(clr color.Color) error {
 	i.m.Lock()
 	defer i.m.Unlock()
@@ -159,6 +173,9 @@ func (i *imageImpl) At(x, y int) color.Color {
 func (i *imageImpl) savePixels(context *opengl.Context) error {
 	i.m.Lock()
 	defer i.m.Unlock()
+	if i.screen {
+		return nil
+	}
 	if i.noSave {
 		return nil
 	}
@@ -182,6 +199,16 @@ func (i *imageImpl) restorePixels() error {
 	if i.disposed {
 		return nil
 	}
+	if i.screen {
+		// The screen image should also be recreated because framebuffer might
+		// be changed.
+		var err error
+		i.image, err = graphics.NewScreenFramebufferImage(i.width, i.height)
+		if err != nil {
+			return err
+		}
+		return nil
+	}
 	if i.pixels != nil {
 		img := image.NewRGBA(image.Rect(0, 0, i.width, i.height))
 		for j := 0; j < i.height; j++ {
@@ -208,8 +235,10 @@ func (i *imageImpl) Dispose() error {
 	if i.disposed {
 		return errors.New("ebiten: image is already disposed")
 	}
-	if err := i.image.Dispose(); err != nil {
-		return err
+	if !i.screen {
+		if err := i.image.Dispose(); err != nil {
+			return err
+		}
 	}
 	i.image = nil
 	i.disposed = true
diff --git a/internal/graphics/command.go b/internal/graphics/command.go
index 65913ae31..dae275ed7 100644
--- a/internal/graphics/command.go
+++ b/internal/graphics/command.go
@@ -167,7 +167,7 @@ type disposeCommand struct {
 }
 
 func (c *disposeCommand) Exec(context *opengl.Context) error {
-	if c.target.framebuffer != nil && c.target.framebuffer.native != context.ScreenFramebuffer() {
+	if c.target.framebuffer != nil {
 		context.DeleteFramebuffer(c.target.framebuffer.native)
 	}
 	if c.target.texture != nil {