[Mesa-dev] [PATCH 2/2] st/mesa: simplify st_generate_mipmap()

[Jose Fonseca]

On 26/03/16 17:21, Brian Paul wrote:
> The whole st_generate_mipmap() function was overly complicated.  Now
> we just call the new _mesa_prepare_mipmap_levels() function to prepare
> the texture mipmap memory, then call the generate function which fills
> in the texture images.
>
> This fixes a failed assertion in llvmpipe/softpipe which is hit with the
> new piglit generatemipmap-base-change test.  Also fixes some device errors
> (format mismatches) with the VMware svga driver.
> ---
>   src/mesa/state_tracker/st_gen_mipmap.c | 102 ++++++++-------------------------
>   1 file changed, 24 insertions(+), 78 deletions(-)
>
> diff --git a/src/mesa/state_tracker/st_gen_mipmap.c b/src/mesa/state_tracker/st_gen_mipmap.c
> index c4b3492..d854e20 100644
> --- a/src/mesa/state_tracker/st_gen_mipmap.c
> +++ b/src/mesa/state_tracker/st_gen_mipmap.c
> @@ -82,7 +82,6 @@ st_generate_mipmap(struct gl_context *ctx, GLenum target,
>      const uint baseLevel = texObj->BaseLevel;
>      enum pipe_format format;
>      uint lastLevel, first_layer, last_layer;
> -   uint dstLevel;
>
>      if (!pt)
>         return;
> @@ -103,42 +102,33 @@ st_generate_mipmap(struct gl_context *ctx, GLenum target,
>      stObj->lastLevel = lastLevel;
>
>      if (!texObj->Immutable) {
> -      if (pt->last_level < lastLevel) {
> -         /* The current gallium texture doesn't have space for all the
> -         * mipmap levels we need to generate.  So allocate a new texture.
> -         */
> -         struct pipe_resource *oldTex = stObj->pt;
> -
> -         /* create new texture with space for more levels */
> -         stObj->pt = st_texture_create(st,
> -                                       oldTex->target,
> -                                       oldTex->format,
> -                                       lastLevel,
> -                                       oldTex->width0,
> -                                       oldTex->height0,
> -                                       oldTex->depth0,
> -                                       oldTex->array_size,
> -                                       0,
> -                                       oldTex->bind);
> -
> -         /* This will copy the old texture's base image into the new texture
> -         * which we just allocated.
> -         */
> -         st_finalize_texture(ctx, st->pipe, texObj);
> -
> -         /* release the old tex (will likely be freed too) */
> -         pipe_resource_reference(&oldTex, NULL);
> -         st_texture_release_all_sampler_views(st, stObj);
> -      }
> -      else {
> -         /* Make sure that the base texture image data is present in the
> -         * texture buffer.
> -         */
> -         st_finalize_texture(ctx, st->pipe, texObj);
> -      }
> +      const GLboolean genSave = texObj->GenerateMipmap;
> +
> +      /* Temporarily set GenerateMipmap to true so that allocate_full_mipmap()
> +       * makes the right decision about full mipmap allocation.
> +       */
> +      texObj->GenerateMipmap = GL_TRUE;

I wonder if there's any assertion we could add somewhere to ensure it 
did indeed make the right decision.

Either way, series is:

Reviewed-by: Jose Fonseca <jfonseca at vmware.com>