[PATCH weston] compositor: automatically set opaque region for color formats

[Kristian Høgsberg]

On Wed, Sep 05, 2012 at 09:36:59AM +0300, Pekka Paalanen wrote:
> Some color formats are naturally opaque: RGB, XRGB, YUV formats without
> A channel. For these, automatically set the opaque region to whole
> surface.
> 
> Note:
> If a client first sends a buffer with opaque color format, and then
> sends another buffer of the same size but with non-opaque color format,
> the opaque region in the server is no longer what the client expects
> based on protocol: it has been changed from what the client earlier
> specified into whole surface. Therefore this is a protocol change.
> 
> ---
> 
> This patch has been only compile-tested, because I'm not sure we can do
> it like this, and temporary opaque region setup would be more complex.
> 
> Kristian, do we really want to go there?

We do want to make sure we can disable blend when possible and clip
obscured changes, regardless of whether or not the client sets the
opaque region.  But maybe not this way... I think we can do it in
weston_surface_draw(), where we compute the surface_blend region.

I'm working on abstracting out the gles2 rendering code, so let's put
this off for just a couple of days.

Kristian

> ---
>  src/compositor.c |   21 +++++++++++++++++++--
>  1 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/src/compositor.c b/src/compositor.c
> index 2b963f5..e7c2c88 100644
> --- a/src/compositor.c
> +++ b/src/compositor.c
> @@ -798,10 +798,15 @@ weston_surface_attach(struct wl_surface *surface, struct wl_buffer *buffer)
>  		glTexImage2D(GL_TEXTURE_2D, 0, GL_BGRA_EXT,
>  			     es->pitch, es->buffer->height, 0,
>  			     GL_BGRA_EXT, GL_UNSIGNED_BYTE, NULL);
> -		if (wl_shm_buffer_get_format(buffer) == WL_SHM_FORMAT_XRGB8888)
> +		if (wl_shm_buffer_get_format(buffer) == WL_SHM_FORMAT_XRGB8888) {
>  			es->shader = &ec->texture_shader_rgbx;
> -		else
> +			pixman_region32_union_rect(&es->opaque, &es->opaque,
> +						   0, 0,
> +						   buffer->width,
> +						   buffer->height);
> +		} else {
>  			es->shader = &ec->texture_shader_rgba;
> +		}
>  	} else if (ec->query_buffer(ec->egl_display, buffer,
>  				    EGL_TEXTURE_FORMAT, &format)) {
>  		for (i = 0; i < es->num_images; i++)
> @@ -834,6 +839,18 @@ weston_surface_attach(struct wl_surface *surface, struct wl_buffer *buffer)
>  			break;
>  		}
>  
> +		/* opaque color formats */
> +		switch (format) {
> +		case EGL_TEXTURE_RGB:
> +		case EGL_TEXTURE_Y_UV_WL:
> +		case EGL_TEXTURE_Y_U_V_WL:
> +		case EGL_TEXTURE_Y_XUXV_WL:
> +			pixman_region32_union_rect(&es->opaque, &es->opaque,
> +						   0, 0,
> +						   buffer->width,
> +						   buffer->height);
> +		}
> +
>  		ensure_textures(es, num_planes);
>  		for (i = 0; i < num_planes; i++) {
>  			attribs[0] = EGL_WAYLAND_PLANE_WL;
> -- 
> 1.7.8.6
>