[Mesa-dev] [PATCH] radv: use dithered alpha-to-coverage

[Rhys Perry]

Seems I sent the wrong commit message.

It was meant to be:
    This matches the behaviour of AMDVLK and hides banding.
    It is also seems to be allowed by the Vulkan spec.

    Signed-off-by: Rhys Perry <pendingchaos02 at gmail.com>

On Wed, 9 Jan 2019 at 14:40, Rhys Perry <pendingchaos02 at gmail.com> wrote:
>
> This matches the behaviour of AMDVLK and hides banding
>
> TODO: run tests
> ---
>  src/amd/vulkan/radv_pipeline.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/src/amd/vulkan/radv_pipeline.c b/src/amd/vulkan/radv_pipeline.c
> index 3561d17aaba..26ee59f11dd 100644
> --- a/src/amd/vulkan/radv_pipeline.c
> +++ b/src/amd/vulkan/radv_pipeline.c
> @@ -681,10 +681,11 @@ radv_pipeline_init_blend_state(struct radv_pipeline *pipeline,
>         else
>                 blend.cb_color_control |= S_028808_ROP3(V_028808_ROP3_COPY);
>
> -       blend.db_alpha_to_mask = S_028B70_ALPHA_TO_MASK_OFFSET0(2) |
> -               S_028B70_ALPHA_TO_MASK_OFFSET1(2) |
> -               S_028B70_ALPHA_TO_MASK_OFFSET2(2) |
> -               S_028B70_ALPHA_TO_MASK_OFFSET3(2);
> +       blend.db_alpha_to_mask = S_028B70_ALPHA_TO_MASK_OFFSET0(3) |
> +               S_028B70_ALPHA_TO_MASK_OFFSET1(1) |
> +               S_028B70_ALPHA_TO_MASK_OFFSET2(0) |
> +               S_028B70_ALPHA_TO_MASK_OFFSET3(2) |
> +               S_028B70_OFFSET_ROUND(1);
>
>         if (vkms && vkms->alphaToCoverageEnable) {
>                 blend.db_alpha_to_mask |= S_028B70_ALPHA_TO_MASK_ENABLE(1);
> --
> 2.20.1
>