texImage(canvas) isn't gpu->gpu yet. texImage(video) is the only gpu->gpu right now. Because of the shape of the API though (support for arbitrary unpack forma

texImage(canvas) isn't gpu->gpu yet. texImage(video) is the only gpu->gpu right now. Because of the shape of the API though (support for arbitrary unpack format/type requests), depending on the underlying pixel formats, gpu->gpu blit isn't guaranteed. We're looking into ways to provide a reliable fast-path.