Add opengl.Framebuffer.SetAsViewport

graphicscontext.go

@@ -20,7 +20,7 @@ import (
 )
 
 func newGraphicsContext(c *opengl.Context, screenWidth, screenHeight, screenScale int) (*graphicsContext, error) {
-	f, err := graphics.NewZeroFramebuffer(screenWidth*screenScale, screenHeight*screenScale)
+	f, err := graphics.NewZeroFramebuffer(c, screenWidth*screenScale, screenHeight*screenScale)
 	if err != nil {
 		return nil, err
 	}
@@ -29,7 +29,7 @@ func newGraphicsContext(c *opengl.Context, screenWidth, screenHeight, screenScal
 	if err != nil {
 		return nil, err
 	}
-	screen, err := newInnerImage(texture)
+	screen, err := newInnerImage(c, texture)
 	if err != nil {
 		return nil, err
 	}

image.go

@@ -17,6 +17,7 @@ package ebiten
 import (
 	"github.com/hajimehoshi/ebiten/internal"
 	"github.com/hajimehoshi/ebiten/internal/graphics"
+	"github.com/hajimehoshi/ebiten/internal/opengl"
 	"image"
 	"image/color"
 )
@@ -26,8 +27,8 @@ type innerImage struct {
 	texture     *graphics.Texture
 }
 
-func newInnerImage(texture *graphics.Texture) (*innerImage, error) {
+func newInnerImage(c *opengl.Context, texture *graphics.Texture) (*innerImage, error) {
-	framebuffer, err := graphics.NewFramebufferFromTexture(texture)
+	framebuffer, err := graphics.NewFramebufferFromTexture(c, texture)
 	if err != nil {
 		return nil, err
 	}

internal/graphics/framebuffer.go

@@ -15,11 +15,10 @@
 package graphics
 
 import (
-	"errors"
-	"fmt"
 	"github.com/go-gl/gl"
 	"github.com/hajimehoshi/ebiten/internal"
 	"github.com/hajimehoshi/ebiten/internal/graphics/internal/shader"
+	"github.com/hajimehoshi/ebiten/internal/opengl"
 )
 
 func orthoProjectionMatrix(left, right, bottom, top int) [4][4]float64 {
@@ -37,13 +36,13 @@ func orthoProjectionMatrix(left, right, bottom, top int) [4][4]float64 {
 }
 
 type Framebuffer struct {
-	framebuffer gl.Framebuffer
+	framebuffer opengl.Framebuffer
 	width       int
 	height      int
 	flipY       bool
 }
 
-func NewZeroFramebuffer(width, height int) (*Framebuffer, error) {
+func NewZeroFramebuffer(c *opengl.Context, width, height int) (*Framebuffer, error) {
 	r := &Framebuffer{
 		width:  width,
 		height: height,
@@ -52,8 +51,8 @@ func NewZeroFramebuffer(width, height int) (*Framebuffer, error) {
 	return r, nil
 }
 
-func NewFramebufferFromTexture(texture *Texture) (*Framebuffer, error) {
+func NewFramebufferFromTexture(c *opengl.Context, texture *Texture) (*Framebuffer, error) {
-	framebuffer, err := createFramebuffer(gl.Texture(texture.native))
+	framebuffer, err := c.NewFramebuffer(opengl.Texture(texture.native))
 	if err != nil {
 		return nil, err
 	}
@@ -73,33 +72,10 @@ func (f *Framebuffer) Dispose() {
 	f.framebuffer.Delete()
 }
 
-func createFramebuffer(nativeTexture gl.Texture) (gl.Framebuffer, error) {
-	framebuffer := gl.GenFramebuffer()
-	framebuffer.Bind()
-
-	gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, nativeTexture, 0)
-	if gl.CheckFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE {
-		return 0, errors.New("creating framebuffer failed")
-	}
-
-	return framebuffer, nil
-}
-
 func (f *Framebuffer) setAsViewport() error {
-	gl.Flush()
-	f.framebuffer.Bind()
-	err := gl.CheckFramebufferStatus(gl.FRAMEBUFFER)
-	if err != gl.FRAMEBUFFER_COMPLETE {
-		if gl.GetError() != 0 {
-			return errors.New(fmt.Sprintf("glBindFramebuffer failed: %d", gl.GetError()))
-		}
-		return errors.New("glBindFramebuffer failed: the context is different?")
-	}
-
 	width := internal.NextPowerOf2Int(f.width)
 	height := internal.NextPowerOf2Int(f.height)
-	gl.Viewport(0, 0, width, height)
+	return f.framebuffer.SetAsViewport(width, height)
-	return nil
 }
 
 func (f *Framebuffer) projectionMatrix() [4][4]float64 {

internal/opengl/context.go

@@ -50,6 +50,26 @@ func (t Texture) Delete() {
 	gl.Texture(t).Delete()
 }
 
+type Framebuffer gl.Framebuffer
+
+func (f Framebuffer) SetAsViewport(width, height int) error {
+	gl.Flush()
+	gl.Framebuffer(f).Bind()
+	err := gl.CheckFramebufferStatus(gl.FRAMEBUFFER)
+	if err != gl.FRAMEBUFFER_COMPLETE {
+		if gl.GetError() != 0 {
+			return errors.New(fmt.Sprintf("glBindFramebuffer failed: %d", gl.GetError()))
+		}
+		return errors.New("glBindFramebuffer failed: the context is different?")
+	}
+	gl.Viewport(0, 0, width, height)
+	return nil
+}
+
+func (f Framebuffer) Delete() {
+	gl.Framebuffer(f).Delete()
+}
+
 func NewContext() *Context {
 	c := &Context{
 		Nearest: filterNearest,
@@ -83,3 +103,15 @@ func (c *Context) NewTexture(width, height int, pixels []uint8, filter Filter) (
 
 	return Texture(t), nil
 }
+
+func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
+	f := gl.GenFramebuffer()
+	f.Bind()
+
+	gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, gl.Texture(texture), 0)
+	if gl.CheckFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE {
+		return 0, errors.New("creating framebuffer failed")
+	}
+
+	return Framebuffer(f), nil
+}

ui.go

@@ -156,7 +156,7 @@ func (u *ui) newImageFromImage(img image.Image, filter Filter) (*Image, error) {
 		if err != nil {
 			return
 		}
-		innerImage, err = newInnerImage(texture)
+		innerImage, err = newInnerImage(u.glContext, texture)
 	})
 	if err != nil {
 		return nil, err
@@ -173,7 +173,7 @@ func (u *ui) newImage(width, height int, filter Filter) (*Image, error) {
 		if err != nil {
 			return
 		}
-		innerImage, err = newInnerImage(texture)
+		innerImage, err = newInnerImage(u.glContext, texture)
 		innerImage.Clear()
 	})
 	if err != nil {