[Mesa-dev] [PATCH] draw: fix incorrect vertex size computation in LLVM drawing code

[Brian Paul]

Ping.


On 01/14/2014 05:47 PM, Brian Paul wrote:
> We were calling draw_total_vs_outputs() too early.  The call to
> draw_pt_emit_prepare() could result in the vertex size changing.
> So call draw_total_vs_outputs() after draw_pt_emit_prepare().
>
> This fix would seem to be needed for the non-LLVM code as well,
> but it's not obvious.  Instead, I added an assertion there to
> try to catch this problem if it were to occur there.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72926
> Cc: 10.0 <mesa-stable at lists.freedesktop.org>
> ---
>   .../auxiliary/draw/draw_pt_fetch_shade_pipeline.c  |    7 +++++--
>   .../draw/draw_pt_fetch_shade_pipeline_llvm.c       |   22 ++++++++++++--------
>   2 files changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
> index 8fcc170..2c5c4cd 100644
> --- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
> +++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
> @@ -72,8 +72,8 @@ static void fetch_pipeline_prepare( struct draw_pt_middle_end *middle,
>
>      const unsigned gs_out_prim = (gs ? gs->output_primitive :
>                                    u_assembled_prim(prim));
> -   unsigned nr = MAX2( vs->info.num_inputs,
> -		       draw_total_vs_outputs(draw) );
> +   unsigned nr_vs_outputs = draw_total_vs_outputs(draw);
> +   unsigned nr = MAX2(vs->info.num_inputs, nr_vs_outputs);
>
>      if (gs) {
>         nr = MAX2(nr, gs->info.num_outputs + 1);
> @@ -129,6 +129,9 @@ static void fetch_pipeline_prepare( struct draw_pt_middle_end *middle,
>      /* No need to prepare the shader.
>       */
>      vs->prepare(vs, draw);
> +
> +   /* Make sure that the vertex size didn't change at any point above */
> +   assert(nr_vs_outputs == draw_total_vs_outputs(draw));
>   }
>
>
> diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
> index 9f17241..60ec528 100644
> --- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
> +++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
> @@ -141,19 +141,11 @@ llvm_middle_end_prepare( struct draw_pt_middle_end *middle,
>      struct draw_geometry_shader *gs = draw->gs.geometry_shader;
>      const unsigned out_prim = gs ? gs->output_primitive :
>         u_assembled_prim(in_prim);
> -   const unsigned nr = MAX2(vs->info.num_inputs,
> -                            draw_total_vs_outputs(draw));
> +   unsigned nr;
>
>      fpme->input_prim = in_prim;
>      fpme->opt = opt;
>
> -   /* Always leave room for the vertex header whether we need it or
> -    * not.  It's hard to get rid of it in particular because of the
> -    * viewport code in draw_pt_post_vs.c.
> -    */
> -   fpme->vertex_size = sizeof(struct vertex_header) + nr * 4 * sizeof(float);
> -
> -
>      draw_pt_post_vs_prepare( fpme->post_vs,
>                               draw->clip_xy,
>                               draw->clip_z,
> @@ -177,6 +169,18 @@ llvm_middle_end_prepare( struct draw_pt_middle_end *middle,
>         *max_vertices = 4096;
>      }
>
> +   /* Get the number of float[4] attributes per vertex.
> +    * Note: this must be done after draw_pt_emit_prepare() since that
> +    * can effect the vertex size.
> +    */
> +   nr = MAX2(vs->info.num_inputs, draw_total_vs_outputs(draw));
> +
> +   /* Always leave room for the vertex header whether we need it or
> +    * not.  It's hard to get rid of it in particular because of the
> +    * viewport code in draw_pt_post_vs.c.
> +    */
> +   fpme->vertex_size = sizeof(struct vertex_header) + nr * 4 * sizeof(float);
> +
>      /* return even number */
>      *max_vertices = *max_vertices & ~1;
>
>