[Mesa-dev] [PATCH 3/5] st/mesa: add support for ARB_sample_locations

[Ian Romanick]

On 05/04/2018 05:09 AM, Rhys Perry wrote:
> Signed-off-by: Rhys Perry <pendingchaos02 at gmail.com>
> ---
>  src/mesa/state_tracker/st_atom_framebuffer.c | 64 ++++++++++++++++++++++++++++
>  src/mesa/state_tracker/st_cb_msaa.c          | 22 ++++++++++
>  src/mesa/state_tracker/st_extensions.c       |  1 +
>  3 files changed, 87 insertions(+)
> 
> diff --git a/src/mesa/state_tracker/st_atom_framebuffer.c b/src/mesa/state_tracker/st_atom_framebuffer.c
> index 3ef3ff34a9..bb5f02125f 100644
> --- a/src/mesa/state_tracker/st_atom_framebuffer.c
> +++ b/src/mesa/state_tracker/st_atom_framebuffer.c
> @@ -102,6 +102,68 @@ framebuffer_quantize_num_samples(struct st_context *st, unsigned num_samples)
>     return quantized_samples;
>  }
>  
> +/**
> + * Update the pipe_context's sample location state
> + */
> +static void
> +update_sample_locations(struct st_context *st,
> +                        const struct pipe_framebuffer_state *fb_state)
> +{
> +   struct pipe_sample_locations_state locations;
> +   struct gl_framebuffer *fb = st->ctx->DrawBuffer;
> +
> +   if (!st->ctx->Extensions.ARB_sample_locations)
> +      return;
> +
> +   locations.enabled = fb->ProgrammableSampleLocations;
> +   if (locations.enabled) {
> +      unsigned grid_width, grid_height;
> +      int samples = _mesa_geometric_samples(fb);
> +      int pixel, sample_index;
> +      bool sample_location_pixel_grid = fb->SampleLocationPixelGrid;
> +
> +      st->pipe->get_sample_pixel_grid(st->pipe, samples, &grid_width, &grid_height);
> +
> +      /**

Since Brian picked some nits...  Don't use /** inside functions.  It's a
marker for Doxygen that has no meaning here.  Put /* and the first words
of the comment on the same line.

> +       * when a dimension is greater than MAX_SAMPLE_LOCATION_GRID_SIZE,
> +       * st->ctx->Driver.GetSamplePixelGrid() returns 1 for both dimensions.
> +       */
> +      if (grid_width>MAX_SAMPLE_LOCATION_GRID_SIZE ||
> +          grid_height>MAX_SAMPLE_LOCATION_GRID_SIZE)
> +         sample_location_pixel_grid = false;
> +
> +      for (pixel = 0; pixel < grid_width * grid_height; pixel++) {
> +         for (sample_index = 0; sample_index < samples; sample_index++) {
> +            int table_index = sample_index;
> +            float x = 0.5f, y = 0.5f;
> +            uint8_t loc;
> +            if (sample_location_pixel_grid)
> +               table_index = pixel * samples + sample_index;
> +            if (fb->SampleLocationTable) {
> +               x = fb->SampleLocationTable[table_index*2];
> +               y = fb->SampleLocationTable[table_index*2+1];
> +            }
> +            if (st->state.fb_orientation == Y_0_BOTTOM)
> +               y = 1.0 - y;
> +
> +            loc = roundf(CLAMP(x*16.0f, 0.0f, 15.0f));
> +            loc |= (int)roundf(CLAMP(y*16.0f, 0.0f, 15.0f)) << 4;
> +            locations.locations[pixel*samples+sample_index] = loc;
> +         }
> +      }
> +
> +      util_sample_locations_flip_y(st->pipe, &locations, fb_state);
> +   } else {
> +      /**
> +       * util_sample_locations_flip_y() initializes unused data to 0x88, so
> +       * this memset is not useful when locations.enabled is true.
> +       */
> +      memset(locations.locations, 0x88, sizeof(locations.locations));
> +   }
> +
> +   cso_set_sample_locations(st->cso_context, &locations);
> +}
> +
>  /**
>   * Update framebuffer state (color, depth, stencil, etc. buffers)
>   */
> @@ -209,4 +271,6 @@ st_update_framebuffer_state( struct st_context *st )
>     st->state.fb_num_samples = util_framebuffer_get_num_samples(&framebuffer);
>     st->state.fb_num_layers = util_framebuffer_get_num_layers(&framebuffer);
>     st->state.fb_num_cb = framebuffer.nr_cbufs;
> +
> +   update_sample_locations(st, &framebuffer);
>  }
> diff --git a/src/mesa/state_tracker/st_cb_msaa.c b/src/mesa/state_tracker/st_cb_msaa.c
> index 7f1b4fde91..092e74d28e 100644
> --- a/src/mesa/state_tracker/st_cb_msaa.c
> +++ b/src/mesa/state_tracker/st_cb_msaa.c
> @@ -56,8 +56,30 @@ st_GetSamplePosition(struct gl_context *ctx,
>  }
>  
>  
> +static void
> +st_GetProgrammableSampleCaps(struct gl_context *ctx, struct gl_framebuffer *fb,
> +                             GLuint *outBits, GLuint *outWidth, GLuint *outHeight)
> +{
> +   struct st_context *st = st_context(ctx);
> +
> +   st_validate_state(st, ST_PIPELINE_UPDATE_FRAMEBUFFER);
> +
> +   if (st->pipe->get_sample_pixel_grid)
> +      st->pipe->get_sample_pixel_grid(st->pipe, _mesa_geometric_samples(fb),
> +                                      outWidth, outHeight);
> +   *outBits = 4;
> +
> +   /* We could handle this better in some circumstances,
> +    * but it's not really an issue */
> +   if (*outWidth>MAX_SAMPLE_LOCATION_GRID_SIZE || *outHeight>MAX_SAMPLE_LOCATION_GRID_SIZE) {
> +      *outWidth = 1;
> +      *outHeight = 1;
> +   }
> +}
> +
>  void
>  st_init_msaa_functions(struct dd_function_table *functions)
>  {
>     functions->GetSamplePosition = st_GetSamplePosition;
> +   functions->GetProgrammableSampleCaps = st_GetProgrammableSampleCaps;
>  }
> diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
> index 0dc8adb262..b74fb63cef 100644
> --- a/src/mesa/state_tracker/st_extensions.c
> +++ b/src/mesa/state_tracker/st_extensions.c
> @@ -636,6 +636,7 @@ void st_init_extensions(struct pipe_screen *screen,
>        { o(ARB_query_buffer_object),          PIPE_CAP_QUERY_BUFFER_OBJECT              },
>        { o(ARB_robust_buffer_access_behavior), PIPE_CAP_ROBUST_BUFFER_ACCESS_BEHAVIOR   },
>        { o(ARB_sample_shading),               PIPE_CAP_SAMPLE_SHADING                   },
> +      { o(ARB_sample_locations),             PIPE_CAP_PROGRAMMABLE_SAMPLE_LOCATIONS    },
>        { o(ARB_seamless_cube_map),            PIPE_CAP_SEAMLESS_CUBE_MAP                },
>        { o(ARB_shader_ballot),                PIPE_CAP_TGSI_BALLOT                      },
>        { o(ARB_shader_clock),                 PIPE_CAP_TGSI_CLOCK                       },
>