image.go
func (i *Image) Fill(clr color.Color) error {
	i.copyCheck()
	if i.isDisposed() {
		return nil
	}

	// TODO: Implement this.
	if i.isSubImage() {
		panic("ebiten: render to a subimage is not implemented (Fill)")
	}

	i.resolvePendingPixels(false)

	r16, g16, b16, a16 := clr.RGBA()
	r, g, b, a := uint8(r16>>8), uint8(g16>>8), uint8(b16>>8), uint8(a16>>8)
	i.mipmap.original().Fill(r, g, b, a)
	i.disposeMipmaps()
	return nil
}
func (i *Image) Fill(clr color.Color) error {
	i.copyCheck()
	if i.isDisposed() {
		return nil
	}

	// TODO: Implement this.
	if i.isSubImage() {
		panic("ebiten: render to a subimage is not implemented (Fill)")
	}

	i.resolvePendingPixels(false)

	r16, g16, b16, a16 := clr.RGBA()
	r, g, b, a := uint8(r16>>8), uint8(g16>>8), uint8(b16>>8), uint8(a16>>8)
	i.mipmap.original().Fill(r, g, b, a)
	i.disposeMipmaps()
	return nil
}
// Fill fills the image with a solid color.
//
// When the image is disposed, Fill does nothing.
//
// Fill always returns nil as of 1.5.0-alpha.