graphics: Dispose now returns errors

image.go

@@ -182,11 +182,15 @@ func (i *Image) Dispose() error {
 		return errors.New("ebiten: image is already disposed")
 	}
 	if i.framebuffer != nil {
-		i.framebuffer.Dispose(glContext)
+		if err := i.framebuffer.Dispose(glContext); err != nil {
+			return err
+		}
 		i.framebuffer = nil
 	}
 	if i.texture != nil {
-		i.texture.Dispose(glContext)
+		if err := i.texture.Dispose(glContext); err != nil {
+			return err
+		}
 		i.texture = nil
 	}
 	i.pixels = nil

internal/graphics/framebuffer.go

@@ -69,12 +69,13 @@ func (f *Framebuffer) Size() (width, height int) {
 	return f.width, f.height
 }
 
-func (f *Framebuffer) Dispose(c *opengl.Context) {
+func (f *Framebuffer) Dispose(c *opengl.Context) error {
 	// Don't delete the default framebuffer.
 	if f.native == opengl.ZeroFramebuffer {
-		return
+		return nil
 	}
 	c.DeleteFramebuffer(f.native)
+	return nil
 }
 
 func (f *Framebuffer) setAsViewport(c *opengl.Context) error {

internal/graphics/texture.go

@@ -86,6 +86,7 @@ func NewTextureFromImage(c *opengl.Context, img image.Image, filter opengl.Filte
 	return &Texture{native, origSize.X, origSize.Y}, nil
 }
 
-func (t *Texture) Dispose(c *opengl.Context) {
+func (t *Texture) Dispose(c *opengl.Context) error {
 	c.DeleteTexture(t.native)
+	return nil
 }