opengl: Move Framebuffer from graphicscommand to opengl and rename it to FramebufferStruct

internal/graphicscommand/command.go

@@ -236,13 +236,13 @@ func (c *drawImageCommand) Exec(indexOffsetInBytes int) error {
 	// On some environments, viewport size must be within the framebuffer size.
 	// e.g. Edge (#71), Chrome on GPD Pocket (#420), macOS Mojave (#691).
 	// Use the same size of the framebuffer here.
-	opengl.GetContext().SetViewport(f.native, f.width, f.height)
+	opengl.GetContext().SetViewport(f)
 	opengl.GetContext().BlendFunc(c.mode)
 
 	if c.nindices == 0 {
 		return nil
 	}
-	proj := f.projectionMatrix()
+	proj := f.ProjectionMatrix()
 	dw, dh := c.dst.Size()
 	sw, sh := c.src.Size()
 	opengl.UseProgram(proj, c.src.texture, dw, dh, sw, sh, c.color, c.filter)
@@ -344,7 +344,7 @@ func (c *pixelsCommand) Exec(indexOffsetInBytes int) error {
 	if err != nil {
 		return err
 	}
-	p, err := opengl.GetContext().FramebufferPixels(f.native, c.img.width, c.img.height)
+	p, err := opengl.GetContext().FramebufferPixels(f, c.img.width, c.img.height)
 	if err != nil {
 		return err
 	}
@@ -385,9 +385,8 @@ func (c *disposeCommand) String() string {
 
 // Exec executes the disposeCommand.
 func (c *disposeCommand) Exec(indexOffsetInBytes int) error {
-	if c.target.framebuffer != nil &&
-		c.target.framebuffer.native != opengl.GetContext().ScreenFramebuffer() {
-		opengl.GetContext().DeleteFramebuffer(c.target.framebuffer.native)
+	if c.target.framebuffer != nil {
+		c.target.framebuffer.Delete()
 	}
 	if c.target.texture != *new(opengl.Texture) {
 		opengl.GetContext().DeleteTexture(c.target.texture)
@@ -488,7 +487,7 @@ func (c *newScreenFramebufferImageCommand) Exec(indexOffsetInBytes int) error {
 	// The (default) framebuffer size can't be converted to a power of 2.
 	// On browsers, c.width and c.height are used as viewport size and
 	// Edge can't treat a bigger viewport than the drawing area (#71).
-	c.result.framebuffer = newScreenFramebuffer(c.width, c.height)
+	c.result.framebuffer = opengl.NewScreenFramebuffer(c.width, c.height)
 	return nil
 }
 

internal/graphicscommand/image.go

@@ -43,7 +43,7 @@ func MaxImageSize() int {
 // Image represents an image that is implemented with OpenGL.
 type Image struct {
 	texture     opengl.Texture
-	framebuffer *framebuffer
+	framebuffer *opengl.FramebufferStruct
 	width       int
 	height      int
 }
@@ -121,11 +121,11 @@ func (i *Image) IsInvalidated() bool {
 	return !opengl.GetContext().IsTexture(i.texture)
 }
 
-func (i *Image) ensureFramebuffer() (*framebuffer, error) {
+func (i *Image) ensureFramebuffer() (*opengl.FramebufferStruct, error) {
 	if i.framebuffer != nil {
 		return i.framebuffer, nil
 	}
-	f, err := newFramebufferFromTexture(i.texture, math.NextPowerOf2Int(i.width), math.NextPowerOf2Int(i.height))
+	f, err := opengl.NewFramebufferFromTexture(i.texture, math.NextPowerOf2Int(i.width), math.NextPowerOf2Int(i.height))
 	if err != nil {
 		return nil, err
 	}

internal/opengl/context.go

@@ -96,24 +96,24 @@ func (c *Context) bindFramebuffer(f Framebuffer) {
 	c.lastFramebuffer = f
 }
 
-func (c *Context) SetViewport(f Framebuffer, width, height int) {
-	c.bindFramebuffer(f)
-	if c.lastViewportWidth != width || c.lastViewportHeight != height {
-		c.setViewportImpl(width, height)
+func (c *Context) SetViewport(f *FramebufferStruct) {
+	c.bindFramebuffer(f.native)
+	if c.lastViewportWidth != f.width || c.lastViewportHeight != f.height {
+		c.setViewportImpl(f.width, f.height)
 		// glViewport must be called at least at every frame on iOS.
 		// As the screen framebuffer is the last render target, next SetViewport should be
 		// the first call at a frame.
-		if f == c.screenFramebuffer {
+		if f.native == c.screenFramebuffer {
 			c.lastViewportWidth = 0
 			c.lastViewportHeight = 0
 		} else {
-			c.lastViewportWidth = width
-			c.lastViewportHeight = height
+			c.lastViewportWidth = f.width
+			c.lastViewportHeight = f.height
 		}
 	}
 }
 
-func (c *Context) ScreenFramebuffer() Framebuffer {
+func (c *Context) getScreenFramebuffer() Framebuffer {
 	return c.screenFramebuffer
 }
 

internal/opengl/context_desktop.go

@@ -169,13 +169,13 @@ func (c *Context) bindFramebufferImpl(f Framebuffer) {
 	})
 }
 
-func (c *Context) FramebufferPixels(f Framebuffer, width, height int) ([]byte, error) {
+func (c *Context) FramebufferPixels(f *FramebufferStruct, width, height int) ([]byte, error) {
 	var pixels []byte
 	_ = c.runOnContextThread(func() error {
 		gl.Flush()
 		return nil
 	})
-	c.bindFramebuffer(f)
+	c.bindFramebuffer(f.native)
 	if err := c.runOnContextThread(func() error {
 		pixels = make([]byte, 4*width*height)
 		gl.ReadPixels(0, 0, int32(width), int32(height), gl.RGBA, gl.UNSIGNED_BYTE, gl.Ptr(pixels))
@@ -232,7 +232,7 @@ func (c *Context) BeforeSwapping() {
 	c.bindFramebuffer(c.screenFramebuffer)
 }
 
-func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
+func (c *Context) newFramebuffer(texture Texture) (Framebuffer, error) {
 	var framebuffer Framebuffer
 	var f uint32
 	if err := c.runOnContextThread(func() error {
@@ -273,7 +273,7 @@ func (c *Context) setViewportImpl(width, height int) {
 	})
 }
 
-func (c *Context) DeleteFramebuffer(f Framebuffer) {
+func (c *Context) deleteFramebuffer(f Framebuffer) {
 	_ = c.runOnContextThread(func() error {
 		ff := uint32(f)
 		if !gl.IsFramebufferEXT(ff) {

internal/opengl/context_js.go

@@ -204,10 +204,10 @@ func (c *Context) bindFramebufferImpl(f Framebuffer) {
 	gl.Call("bindFramebuffer", framebuffer, js.Value(f))
 }
 
-func (c *Context) FramebufferPixels(f Framebuffer, width, height int) ([]byte, error) {
+func (c *Context) FramebufferPixels(f *FramebufferStruct, width, height int) ([]byte, error) {
 	gl := c.gl
 
-	c.bindFramebuffer(f)
+	c.bindFramebuffer(f.native)
 
 	pixels := make([]byte, 4*width*height)
 	p := js.TypedArrayOf(pixels)
@@ -252,7 +252,7 @@ func (c *Context) TexSubImage2D(t Texture, pixels []byte, x, y, width, height in
 	p.Release()
 }
 
-func (c *Context) NewFramebuffer(t Texture) (Framebuffer, error) {
+func (c *Context) newFramebuffer(t Texture) (Framebuffer, error) {
 	gl := c.gl
 	f := gl.Call("createFramebuffer")
 	c.bindFramebuffer(Framebuffer(f))
@@ -270,7 +270,7 @@ func (c *Context) setViewportImpl(width, height int) {
 	gl.Call("viewport", 0, 0, width, height)
 }
 
-func (c *Context) DeleteFramebuffer(f Framebuffer) {
+func (c *Context) deleteFramebuffer(f Framebuffer) {
 	gl := c.gl
 	if !gl.Call("isFramebuffer", js.Value(f)).Bool() {
 		return

internal/opengl/context_mobile.go

@@ -156,11 +156,11 @@ func (c *Context) bindFramebufferImpl(f Framebuffer) {
 	gl.BindFramebuffer(mgl.FRAMEBUFFER, mgl.Framebuffer(f))
 }
 
-func (c *Context) FramebufferPixels(f Framebuffer, width, height int) ([]byte, error) {
+func (c *Context) FramebufferPixels(f *FramebufferStruct, width, height int) ([]byte, error) {
 	gl := c.gl
 	gl.Flush()
 
-	c.bindFramebuffer(f)
+	c.bindFramebuffer(f.native)
 
 	pixels := make([]byte, 4*width*height)
 	gl.ReadPixels(pixels, 0, 0, width, height, mgl.RGBA, mgl.UNSIGNED_BYTE)
@@ -197,7 +197,7 @@ func (c *Context) TexSubImage2D(t Texture, p []byte, x, y, width, height int) {
 	gl.TexSubImage2D(mgl.TEXTURE_2D, 0, x, y, width, height, mgl.RGBA, mgl.UNSIGNED_BYTE, p)
 }
 
-func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
+func (c *Context) newFramebuffer(texture Texture) (Framebuffer, error) {
 	gl := c.gl
 	f := gl.CreateFramebuffer()
 	if f.Value <= 0 {
@@ -224,7 +224,7 @@ func (c *Context) setViewportImpl(width, height int) {
 	gl.Viewport(0, 0, width, height)
 }
 
-func (c *Context) DeleteFramebuffer(f Framebuffer) {
+func (c *Context) deleteFramebuffer(f Framebuffer) {
 	gl := c.gl
 	if !gl.IsFramebuffer(mgl.Framebuffer(f)) {
 		return

internal/opengl/framebuffer.go

@@ -12,51 +12,55 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package graphicscommand
+package opengl
 
-import (
-	"github.com/hajimehoshi/ebiten/internal/opengl"
-)
-
-// framebuffer is a wrapper of OpenGL's framebuffer.
-type framebuffer struct {
-	native    opengl.Framebuffer
+// FramebufferStruct is a wrapper of OpenGL's framebuffer.
+//
+// TODO: Create a new struct Image and embed this struct.
+type FramebufferStruct struct {
+	native    Framebuffer
 	proMatrix []float32
 	width     int
 	height    int
 }
 
-// newFramebufferFromTexture creates a framebuffer from the given texture.
-func newFramebufferFromTexture(texture opengl.Texture, width, height int) (*framebuffer, error) {
-	native, err := opengl.GetContext().NewFramebuffer(texture)
+// NewFramebufferFromTexture creates a framebuffer from the given texture.
+func NewFramebufferFromTexture(texture Texture, width, height int) (*FramebufferStruct, error) {
+	native, err := theContext.newFramebuffer(texture)
 	if err != nil {
 		return nil, err
 	}
-	return &framebuffer{
+	return &FramebufferStruct{
 		native: native,
 		width:  width,
 		height: height,
 	}, nil
 }
 
-// newScreenFramebuffer creates a framebuffer for the screen.
-func newScreenFramebuffer(width, height int) *framebuffer {
-	return &framebuffer{
-		native: opengl.GetContext().ScreenFramebuffer(),
+// NewScreenFramebuffer creates a framebuffer for the screen.
+func NewScreenFramebuffer(width, height int) *FramebufferStruct {
+	return &FramebufferStruct{
+		native: theContext.getScreenFramebuffer(),
 		width:  width,
 		height: height,
 	}
 }
 
-// projectionMatrix returns a projection matrix of the framebuffer.
+// ProjectionMatrix returns a projection matrix of the framebuffer.
 //
 // A projection matrix converts the coodinates on the framebuffer
 // (0, 0) - (viewport width, viewport height)
 // to the normalized device coodinates (-1, -1) - (1, 1) with adjustment.
-func (f *framebuffer) projectionMatrix() []float32 {
+func (f *FramebufferStruct) ProjectionMatrix() []float32 {
 	if f.proMatrix != nil {
 		return f.proMatrix
 	}
-	f.proMatrix = opengl.OrthoProjectionMatrix(0, f.width, 0, f.height)
+	f.proMatrix = orthoProjectionMatrix(0, f.width, 0, f.height)
 	return f.proMatrix
 }
+
+func (f *FramebufferStruct) Delete() {
+	if f.native != theContext.getScreenFramebuffer() {
+		theContext.deleteFramebuffer(f.native)
+	}
+}

internal/opengl/matrix.go

@@ -14,10 +14,10 @@
 
 package opengl
 
-// OrthoProjectionMatrix returns an orthogonal projection matrix for OpenGL.
+// orthoProjectionMatrix returns an orthogonal projection matrix for OpenGL.
 //
 // The matrix converts the coodinates (left, bottom) - (right, top) to the normalized device coodinates (-1, -1) - (1, 1).
-func OrthoProjectionMatrix(left, right, bottom, top int) []float32 {
+func orthoProjectionMatrix(left, right, bottom, top int) []float32 {
 	e11 := 2 / float32(right-left)
 	e22 := 2 / float32(top-bottom)
 	e14 := -1 * float32(right+left) / float32(right-left)