Add ids.go

graphics/opengl/context.go

@@ -23,23 +23,18 @@ type Context struct {
 	screenWidth            int
 	screenHeight           int
 	screenScale            int
-	textures               map[graphics.TextureId]*gtexture.Texture
-	renderTargets          map[graphics.RenderTargetId]*grendertarget.RenderTarget
-	renderTargetToTexture  map[graphics.RenderTargetId]graphics.TextureId
+	ids                    *ids
 	mainFramebufferTexture *grendertarget.RenderTarget
 	projectionMatrix       [16]float32
 }
 
 func newContext(screenWidth, screenHeight, screenScale int) *Context {
-	context := &Context{
-		screenWidth:           screenWidth,
-		screenHeight:          screenHeight,
-		screenScale:           screenScale,
-		textures:              map[graphics.TextureId]*gtexture.Texture{},
-		renderTargets:         map[graphics.RenderTargetId]*grendertarget.RenderTarget{},
-		renderTargetToTexture: map[graphics.RenderTargetId]graphics.TextureId{},
+	return &Context{
+		screenWidth:  screenWidth,
+		screenHeight: screenHeight,
+		screenScale:  screenScale,
+		ids:          newIds(),
 	}
-	return context
 }
 
 func (context *Context) Init() {
@@ -57,7 +52,7 @@ func (context *Context) Init() {
 		panic("creating main framebuffer failed: " + err.Error())
 	}
 
-	context.screenId, err = context.newRenderTarget(
+	context.screenId, err = context.createRenderTarget(
 		context.screenWidth, context.screenHeight, texture.FilterNearest)
 	if err != nil {
 		panic("initializing the offscreen failed: " + err.Error())
@@ -65,7 +60,7 @@ func (context *Context) Init() {
 }
 
 func (context *Context) ToTexture(renderTargetId graphics.RenderTargetId) graphics.TextureId {
-	return context.renderTargetToTexture[renderTargetId]
+	return context.ids.ToTexture(renderTargetId)
 }
 
 func (context *Context) Clear() {
@@ -85,10 +80,7 @@ func (context *Context) Fill(r, g, b uint8) {
 func (context *Context) DrawTexture(
 	textureId graphics.TextureId,
 	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
-	tex, ok := context.textures[textureId]
-	if !ok {
-		panic("invalid texture ID")
-	}
+	tex := context.ids.TextureAt(textureId)
 	tex.Draw(func(native interface{}, quads []gtexture.Quad) {
 		shader.DrawTexture(native.(texture.Native),
 			context.projectionMatrix, quads,
@@ -99,10 +91,7 @@ func (context *Context) DrawTexture(
 func (context *Context) DrawTextureParts(
 	textureId graphics.TextureId, parts []graphics.TexturePart,
 	geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
-	tex, ok := context.textures[textureId]
-	if !ok {
-		panic("invalid texture ID")
-	}
+	tex := context.ids.TextureAt(textureId)
 	tex.DrawParts(parts, func(native interface{}, quads []gtexture.Quad) {
 		shader.DrawTexture(native.(texture.Native),
 			context.projectionMatrix, quads,
@@ -115,7 +104,7 @@ func (context *Context) ResetOffscreen() {
 }
 
 func (context *Context) SetOffscreen(renderTargetId graphics.RenderTargetId) {
-	renderTarget := context.renderTargets[renderTargetId]
+	renderTarget := context.ids.RenderTargetAt(renderTargetId)
 	context.setOffscreen(renderTarget)
 }
 
@@ -175,49 +164,21 @@ func (context *Context) flush() {
 	C.glFlush()
 }
 
-func (context *Context) newRenderTarget(width, height int, filter texture.Filter) (
+func (context *Context) createRenderTarget(width, height int, filter texture.Filter) (
 	graphics.RenderTargetId, error) {
-	renderTarget, texture, err := rendertarget.New(width, height, filter)
+	renderTargetId, err := context.ids.CreateRenderTarget(width, height, filter)
 	if err != nil {
-		return 0, nil
+		return 0, err
 	}
-	renderTargetId := graphics.RenderTargetId(<-newId)
-	textureId := graphics.TextureId(<-newId)
-	context.renderTargets[renderTargetId] = renderTarget
-	context.textures[textureId] = texture
-	context.renderTargetToTexture[renderTargetId] = textureId
-
-	context.setOffscreen(renderTarget)
-	context.Clear()
-	// TODO: Is it OK to revert he main framebuffer?
-	context.setMainFramebufferOffscreen()
-
 	return renderTargetId, nil
 }
 
 func (context *Context) NewRenderTarget(width, height int) (
 	graphics.RenderTargetId, error) {
-	return context.newRenderTarget(width, height, texture.FilterLinear)
+	return context.createRenderTarget(width, height, texture.FilterLinear)
 }
 
 func (context *Context) NewTextureFromImage(img image.Image) (
 	graphics.TextureId, error) {
-	texture, err := texture.NewFromImage(img)
-	if err != nil {
-		return 0, err
-	}
-	textureId := graphics.TextureId(<-newId)
-	context.textures[textureId] = texture
-	return textureId, nil
-}
-
-var newId chan int
-
-func init() {
-	newId = make(chan int)
-	go func() {
-		for i := 0; ; i++ {
-			newId <- i
-		}
-	}()
+	return context.ids.CreateTextureFromImage(img)
 }

graphics/opengl/ids.go

@@ -0,0 +1,70 @@
+package opengl
+
+import (
+	"github.com/hajimehoshi/go-ebiten/graphics"
+	"github.com/hajimehoshi/go-ebiten/graphics/opengl/rendertarget"
+	"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
+	grendertarget "github.com/hajimehoshi/go-ebiten/graphics/rendertarget"
+	gtexture "github.com/hajimehoshi/go-ebiten/graphics/texture"
+	"image"
+)
+
+type ids struct {
+	textures              map[graphics.TextureId]*gtexture.Texture
+	renderTargets         map[graphics.RenderTargetId]*grendertarget.RenderTarget
+	renderTargetToTexture map[graphics.RenderTargetId]graphics.TextureId
+	counts                chan int
+}
+
+func newIds() *ids {
+	ids := &ids{
+		textures:              map[graphics.TextureId]*gtexture.Texture{},
+		renderTargets:         map[graphics.RenderTargetId]*grendertarget.RenderTarget{},
+		renderTargetToTexture: map[graphics.RenderTargetId]graphics.TextureId{},
+		counts:                make(chan int),
+	}
+	go func() {
+		for i := 1; ; i++ {
+			ids.counts <- i
+		}
+	}()
+	return ids
+}
+
+func (i *ids) TextureAt(id graphics.TextureId) *gtexture.Texture {
+	return i.textures[id]
+}
+
+func (i *ids) RenderTargetAt(id graphics.RenderTargetId) *grendertarget.RenderTarget {
+	return i.renderTargets[id]
+}
+
+func (i *ids) ToTexture(id graphics.RenderTargetId) graphics.TextureId {
+	return i.renderTargetToTexture[id]
+}
+
+func (i *ids) CreateTextureFromImage(img image.Image) (
+	graphics.TextureId, error) {
+	texture, err := texture.NewFromImage(img)
+	if err != nil {
+		return 0, err
+	}
+	textureId := graphics.TextureId(<-i.counts)
+	i.textures[textureId] = texture
+	return textureId, nil
+}
+
+func (i *ids) CreateRenderTarget(width, height int, filter texture.Filter) (
+	graphics.RenderTargetId, error) {
+	renderTarget, texture, err := rendertarget.New(width, height, filter)
+	if err != nil {
+		return 0, err
+	}
+	renderTargetId := graphics.RenderTargetId(<-i.counts)
+	textureId := graphics.TextureId(<-i.counts)
+	i.renderTargets[renderTargetId] = renderTarget
+	i.textures[textureId] = texture
+	i.renderTargetToTexture[renderTargetId] = textureId
+
+	return renderTargetId, nil
+}

graphics/opengl/rendertarget/render_target.go

@@ -6,8 +6,8 @@ package rendertarget
 import "C"
 import (
 	"github.com/hajimehoshi/go-ebiten/graphics/opengl/texture"
-	gtexture "github.com/hajimehoshi/go-ebiten/graphics/texture"
 	"github.com/hajimehoshi/go-ebiten/graphics/rendertarget"
+	gtexture "github.com/hajimehoshi/go-ebiten/graphics/texture"
 )
 
 type Framebuffer C.GLuint
@@ -29,6 +29,11 @@ func createFramebuffer(nativeTexture C.GLuint) C.GLuint {
 		panic("creating framebuffer failed")
 	}
 
+	// Set this framebuffer opaque because alpha values on a target might be
+	// confusing.
+	C.glClearColor(0, 0, 0, 1)
+	C.glClear(C.GL_COLOR_BUFFER_BIT)
+
 	return framebuffer
 }
 
@@ -38,7 +43,7 @@ func New(width, height int, filter texture.Filter) (
 	if err != nil {
 		return nil, nil, err
 	}
-	f := func(native interface{}) interface{}{
+	f := func(native interface{}) interface{} {
 		return createFramebuffer(C.GLuint(native.(texture.Native)))
 	}
 	framebuffer := tex.CreateFramebuffer(f)

graphics/opengl/texture/texture.go

@@ -54,8 +54,10 @@ func createNativeTexture(textureWidth, textureHeight int, pixels []uint8,
 	return Native(nativeTexture)
 }
 
-func create(textureWidth, textureHeight int, filter Filter) (interface{}, error) {
-	return createNativeTexture(textureWidth, textureHeight, nil, filter), nil
+func create(textureWidth, textureHeight int, filter Filter) (
+	interface{}, error) {
+	return createNativeTexture(textureWidth, textureHeight,
+		nil, filter), nil
 }
 
 func createFromImage(img *image.NRGBA) (interface{}, error) {