[Mesa-dev] [PATCH 1/2] mesa: Fold error generation into _mesa_valid_prim_mode().

[Brian Paul]

On 03/14/2012 04:25 PM, Eric Anholt wrote:
> We want to start emitting an INVALID_OPERATION from here for transform
> feedback.  Note that this forced dlist.c to almost not use this
> function, since it wants different behavior during dlist compile.
> Just pull the non-TF, non-GS test out for compile, because:
>
> 1) TF doesn't matter in that case because there's no drawing.
> 2) I don't think we're going to see GSes and display lists in the same
>     context, if we don't do GL_ARB_compatibility.
> ---
>   src/mesa/main/api_validate.c |   24 +++++++++---------------
>   src/mesa/main/api_validate.h |    2 +-
>   src/mesa/main/dlist.c        |   10 ++++++++--
>   src/mesa/vbo/vbo_exec_api.c  |    3 +--
>   4 files changed, 19 insertions(+), 20 deletions(-)
>
> diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
> index 4e94f47..17da5d0 100644
> --- a/src/mesa/main/api_validate.c
> +++ b/src/mesa/main/api_validate.c
> @@ -204,13 +204,15 @@ check_index_bounds(struct gl_context *ctx, GLsizei count, GLenum type,
>    * are supported.
>    */
>   GLboolean
> -_mesa_valid_prim_mode(const struct gl_context *ctx, GLenum mode)
> +_mesa_valid_prim_mode(struct gl_context *ctx, GLenum mode, const char *name)
>   {
>      if (ctx->Extensions.ARB_geometry_shader4&&
>          mode>  GL_TRIANGLE_STRIP_ADJACENCY_ARB) {
> +      _mesa_error(ctx, GL_INVALID_ENUM, "%s(mode=%x)", name, mode);
>         return GL_FALSE;
>      }
>      else if (mode>  GL_POLYGON) {
> +      _mesa_error(ctx, GL_INVALID_ENUM, "%s(mode=%x)", name, mode);
>         return GL_FALSE;
>      }
>      else {


Actually, I think the above code is wrong.  If ARB_gs is true and 
mode=GL_TRIANGLES_ADJACENCY_ARB then the first if test will be false 
and the second will be true and we'll incorrectly generate an error.

What we really want is:

GLenum maxPrim = ctx->Extensions.ARB_geometry_shader4 ?
    GL_TRIANGLE_STRIP_ADJACENCY_ARB : GL_POLYGON;

if (prim > maxPrim) {
    _mesa_error(ctx, GL_INVALID_ENUM, "%s(mode=%x)", name, mode);
    return GL_FALSE;
}


BTW, I think that I'm the original author of that mistake. :(

-Brian