[Mesa-dev] [PATCH 2/3] draw: reset the vertex id when injecting new primitive id

[Zack Rusin]

Don't worry about this one too much. The next patch removes draw_pipe_ia.c anyway...

----- Original Message -----
> Without reseting the vertex id, with primitives where the same
> vertex is used with different primitives (e.g. tri/lines strips)
> our vbuf module won't re-emit those vertices with the changed
> primitive id. So lets reset the vertex id whenever injecting
> new primitive id to make sure that the vertex data is correctly
> emitted.
> 
> Signed-off-by: Zack Rusin <zackr at vmware.com>
> ---
>  src/gallium/auxiliary/draw/draw_pipe_ia.c |    9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/src/gallium/auxiliary/draw/draw_pipe_ia.c
> b/src/gallium/auxiliary/draw/draw_pipe_ia.c
> index ecbb233..d64f19b 100644
> --- a/src/gallium/auxiliary/draw/draw_pipe_ia.c
> +++ b/src/gallium/auxiliary/draw/draw_pipe_ia.c
> @@ -68,6 +68,15 @@ inject_primid(struct draw_stage *stage,
>  
>     for (i = 0; i < num_verts; ++i) {
>        struct vertex_header *v = header->v[i];
> +      /* We have to reset the vertex_id because it's used by
> +       * vbuf to figure out if the vertex had already been
> +       * emitted. For line/tri strips the first vertex of
> +       * subsequent primitives would already be emitted,
> +       * but since we're changing the primitive id on the vertex
> +       * we want to make sure it's reemitted with the correct
> +       * data.
> +       */
> +      v->vertex_id = UNDEFINED_VERTEX_ID;
>        memcpy(&v->data[slot][0], &primid, sizeof(primid));
>        memcpy(&v->data[slot][1], &primid, sizeof(primid));
>        memcpy(&v->data[slot][2], &primid, sizeof(primid));
> --
> 1.7.10.4
>