[Mesa-dev] [PATCH 1/2] softpipe: don't attempt to blend integer formats.

[Brian Paul]

On Sun, Jan 29, 2012 at 9:35 AM, Dave Airlie <airlied at gmail.com> wrote:
> From: Dave Airlie <airlied at redhat.com>
>
> This blocks blending in the simple path, need to look at the more
> complicated paths.
>
> Signed-off-by: Dave Airlie <airlied at redhat.com>
> ---
>  src/gallium/drivers/softpipe/sp_quad_blend.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/src/gallium/drivers/softpipe/sp_quad_blend.c b/src/gallium/drivers/softpipe/sp_quad_blend.c
> index d546b14..d2a5269 100644
> --- a/src/gallium/drivers/softpipe/sp_quad_blend.c
> +++ b/src/gallium/drivers/softpipe/sp_quad_blend.c
> @@ -1155,7 +1155,8 @@ choose_blend_quad(struct quad_stage *qs,
>             softpipe->blend->rt[0].colormask == 0xf &&
>             softpipe->framebuffer.nr_cbufs == 1)
>    {
> -      if (!blend->rt[0].blend_enable) {
> +      if (!blend->rt[0].blend_enable ||
> +         util_format_is_pure_integer(softpipe->framebuffer.cbufs[0]->format)) {
>          qs->run = single_output_color;
>       }
>       else if (blend->rt[0].rgb_src_factor == blend->rt[0].alpha_src_factor &&
> --

How about checking for integer color buffers in the state tracker and
turning off blending (and alpha test) there?

If you have integer buffers and try to enable blending with a hardware
driver, does hardware typically no-opt the blend or does the driver
have to disable blending?

-Brian