func (c *Context) bindFramebufferImpl(f Framebuffer) error {
if err := c.runOnContextThread(func() error {
gl.BindFramebuffer(gl.FRAMEBUFFER, uint32(f))
return nil
}); err != nil {
return err
}
return nil
}
func (c *Context) SetViewport(f Framebuffer, width, height int) error {
gl.Flush()
gl.BindFramebuffer(gl.FRAMEBUFFER, uint32(f))
if err := gl.CheckFramebufferStatus(gl.FRAMEBUFFER); err != gl.FRAMEBUFFER_COMPLETE {
if e := gl.GetError(); e != 0 {
return errors.New(fmt.Sprintf("glBindFramebuffer failed: %d", e))
}
return errors.New("glBindFramebuffer failed: the context is different?")
}
gl.Viewport(0, 0, int32(width), int32(height))
return nil
}
func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
var f uint32
gl.GenFramebuffers(1, &f)
gl.BindFramebuffer(gl.FRAMEBUFFER, f)
gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, uint32(texture), 0)
if gl.CheckFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE {
return 0, errors.New("creating framebuffer failed")
}
return Framebuffer(f), nil
}
func (c *Context) FramebufferPixels(f Framebuffer, width, height int) ([]uint8, error) {
gl.Flush()
gl.BindFramebuffer(gl.FRAMEBUFFER, uint32(f))
pixels := make([]uint8, 4*width*height)
gl.ReadPixels(0, 0, int32(width), int32(height), gl.RGBA, gl.UNSIGNED_BYTE, gl.Ptr(pixels))
if e := gl.GetError(); e != gl.NO_ERROR {
return nil, errors.New(fmt.Sprintf("glReadPixels: %d", e))
}
return pixels, nil
}
// BindFramebuffer binds a framebuffer.
//
// http://www.khronos.org/opengles/sdk/docs/man3/html/glBindFramebuffer.xhtml
func BindFramebuffer(target Enum, fb Framebuffer) {
gl.BindFramebuffer(uint32(target), fb.Value)
}