[virglrenderer-devel] [PATCH] renderer: swizzle sampler border color channel if we emulate alpha format

[Erik Faye-Lund]

On 11. juli 2018 18:06, Elie Tournier wrote:
> Fixes:
> dEQP-GLES31.functional.texture.border_clamp.formats.alpha.nearest_size_pot
> dEQP-GLES31.functional.texture.border_clamp.formats.alpha.nearest_size_npot
> dEQP-GLES31.functional.texture.border_clamp.formats.alpha.linear_size_pot
> dEQP-GLES31.functional.texture.border_clamp.formats.alpha.linear_size_npot
> dEQP-GLES31.functional.texture.border_clamp.unused_channels.alpha
>
> Signed-off-by: Elie Tournier <elie.tournier at collabora.com>
> ---
>   src/vrend_renderer.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/src/vrend_renderer.c b/src/vrend_renderer.c
> index cc99087..f32e8fd 100644
> --- a/src/vrend_renderer.c
> +++ b/src/vrend_renderer.c
> @@ -4173,7 +4173,19 @@ static void vrend_apply_sampler_state(struct vrend_context *ctx,
>         return;
>      }
>   
> +   /*
> +    * If we emulate alpha format with red, we need to tell
> +    * the sampler to use the red channel and not the alpha one
> +    * by swizzling the GL_TEXTURE_BORDER_COLOR parameter.
> +    */
>      if (vrend_state.have_samplers) {
> +      if (vrend_format_is_emulated_alpha(res->base.format)) {
> +         union pipe_color_union border_color;
> +         border_color = vstate->base.border_color;
> +         border_color.ui[0] = border_color.ui[3];
> +         border_color.ui[3] = 0;
> +         glSamplerParameterIuiv(vstate->id, GL_TEXTURE_BORDER_COLOR, border_color.ui);
> +      }
>         glBindSampler(sampler_id, vstate->id);
>         glSamplerParameteri(vstate->id, GL_TEXTURE_SRGB_DECODE_EXT,
>                             srgb_decode);

I suspect that the glTexParameterIuiv-variant also needs a similar 
fix... something along these lines?

---8<---
diff --git a/src/vrend_renderer.c b/src/vrend_renderer.c
index e5015a6..3202ba6 100644
--- a/src/vrend_renderer.c
+++ b/src/vrend_renderer.c
@@ -4605,8 +4605,18 @@ static void vrend_apply_sampler_state(struct 
vrend_context *ctx,
        }
     }

-   if (memcmp(&tex->state.border_color, &state->border_color, 16) || 
set_all)
-      glTexParameterIuiv(target, GL_TEXTURE_BORDER_COLOR, 
state->border_color.ui);
+   bool is_emulated_alpha = 
vrend_format_is_emulated_alpha(res->base.format);
+   if (memcmp(&tex->state.border_color, &state->border_color, 16) || 
set_all ||
+       is_emulated_alpha) {
+      if (is_emulated_alpha) {
+         union pipe_color_union border_color;
+         border_color = vstate->base.border_color;
+         border_color.ui[0] = border_color.ui[3];
+         border_color.ui[3] = 0;
+         glTexParameterIuiv(target, GL_TEXTURE_BORDER_COLOR, 
border_color.ui);
+      } else
+         glTexParameterIuiv(target, GL_TEXTURE_BORDER_COLOR, 
state->border_color.ui);
+   }
     tex->state = *state;
  }

---8<---