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

[Brian Paul]

On 12/22/2012 05:49 AM, Christoph Bumiller wrote:
> v2: Update to handle BufferSize being -1 and return a NULL sampler
> view if the specified range would cause out of bounds access.
> ---
>   src/mesa/state_tracker/st_atom_texture.c |   22 +++++++++++++++++++++-
>   src/mesa/state_tracker/st_extensions.c   |    6 ++++++
>   2 files changed, 27 insertions(+), 1 deletions(-)
>
> diff --git a/src/mesa/state_tracker/st_atom_texture.c b/src/mesa/state_tracker/st_atom_texture.c
> index dba1d82..4b43b2a 100644
> --- a/src/mesa/state_tracker/st_atom_texture.c
> +++ b/src/mesa/state_tracker/st_atom_texture.c
> @@ -152,7 +152,27 @@ st_create_texture_sampler_view_from_stobj(struct pipe_context *pipe,
>      u_sampler_view_default_template(&templ,
>                                      stObj->pt,
>                                      format);
> -   templ.u.tex.first_level = stObj->base.BaseLevel;
> +
> +   if (stObj->pt->target == PIPE_BUFFER) {
> +      unsigned base, size;
> +      unsigned f, n;
> +      const struct util_format_description *desc
> +         = util_format_description(templ.format);
> +
> +      base = stObj->base.BufferOffset;
> +      if (base>= stObj->pt->width0)
> +         return NULL;
> +      size = MIN2(stObj->pt->width0 - base, (unsigned)stObj->base.BufferSize);
> +
> +      f = ((base * 8) / desc->block.bits) * desc->block.width;
> +      n = ((size * 8) / desc->block.bits) * desc->block.width;
> +      if (!n)
> +         return NULL;
> +      templ.u.buf.first_element = f;
> +      templ.u.buf.last_element  = f + (n - 1);
> +   } else {
> +      templ.u.tex.first_level = stObj->base.BaseLevel;
> +   }
>
>      if (swizzle != SWIZZLE_NOOP) {
>         templ.swizzle_r = GET_SWZ(swizzle, 0);
> diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
> index e7cf4f3..5011e97 100644
> --- a/src/mesa/state_tracker/st_extensions.c
> +++ b/src/mesa/state_tracker/st_extensions.c
> @@ -673,7 +673,13 @@ void st_init_extensions(struct st_context *st)
>         ctx->Extensions.ARB_map_buffer_alignment = GL_TRUE;
>      }
>      if (screen->get_param(screen, PIPE_CAP_TEXTURE_BUFFER_OBJECTS)) {
> +      ctx->Const.TextureBufferOffsetAlignment =
> +         screen->get_param(screen, PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT);
> +
>         ctx->Extensions.ARB_texture_buffer_object = GL_TRUE;
> +      if (ctx->Const.TextureBufferOffsetAlignment)
> +         ctx->Extensions.ARB_texture_buffer_range = GL_TRUE;
> +
>         init_format_extensions(st, tbo_rgb32, Elements(tbo_rgb32),
>                                PIPE_BUFFER, PIPE_BIND_SAMPLER_VIEW);
>      }

I'd re-order the lines in that last chunk:

   if (screen->get_param(screen, PIPE_CAP_TEXTURE_BUFFER_OBJECTS)) {
      ctx->Extensions.ARB_texture_buffer_object = GL_TRUE;

      ctx->Const.TextureBufferOffsetAlignment =
           screen->get_param(screen, 
PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT);

      if (ctx->Const.TextureBufferOffsetAlignment)
         ctx->Extensions.ARB_texture_buffer_range = GL_TRUE;
   ...


Otherwise, for patches 2 and 3, Reviewed-by: Brian Paul 
<brianp at vmware.com>

-Brian