[Mesa-dev] [PATCH] st/mesa: use base level size as "guess" when available

[Nicolai Hähnle]

Ping?

On 06.06.2016 23:28, Nicolai Hähnle wrote:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
>
> When an applications specifies mip levels _before_ setting a mipmap texture
> filter, we will initially guess a single texture level. When the second level
> image is created, we try to allocate the full texture -- however, we get the
> base level size guess wrong if that size is odd. This leads to yet another
> re-allocation of the texture later during st_finalize_texture.
>
> Even worse, this re-allocation breaks a (reasonable) assumption made by
> st_generate_mipmaps, because the re-allocation in the finalization call will
> again allocate a single-level pipe texture (based on the non-mipmap texture
> filter!). As a result, mipmap generation fails in interesting ways.
>
> All of this can be avoided by just using the fact that we already know the
> size of the base level.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95529
> Cc: 12.0 <mesa-stable at lists.freedesktop.org>
> ---
>   src/mesa/state_tracker/st_cb_texture.c | 33 +++++++++++++++++++++++++++------
>   1 file changed, 27 insertions(+), 6 deletions(-)
>
> diff --git a/src/mesa/state_tracker/st_cb_texture.c b/src/mesa/state_tracker/st_cb_texture.c
> index d38f24c..44e21b1 100644
> --- a/src/mesa/state_tracker/st_cb_texture.c
> +++ b/src/mesa/state_tracker/st_cb_texture.c
> @@ -456,21 +456,42 @@ guess_and_alloc_texture(struct st_context *st,
>   			struct st_texture_object *stObj,
>   			const struct st_texture_image *stImage)
>   {
> +   const struct gl_texture_image *firstImage;
>      GLuint lastLevel, width, height, depth;
>      GLuint bindings;
>      GLuint ptWidth, ptHeight, ptDepth, ptLayers;
>      enum pipe_format fmt;
> +   bool guessed_box = false;
>
>      DBG("%s\n", __func__);
>
>      assert(!stObj->pt);
>
> -   if (!guess_base_level_size(stObj->base.Target,
> -                              stImage->base.Width2,
> -                              stImage->base.Height2,
> -                              stImage->base.Depth2,
> -                              stImage->base.Level,
> -                              &width, &height, &depth)) {
> +   /* If a base level image with compatible size exists, use that as our guess.
> +    */
> +   firstImage = _mesa_base_tex_image(&stObj->base);
> +   if (firstImage &&
> +       guess_base_level_size(stObj->base.Target,
> +                             firstImage->Width2,
> +                             firstImage->Height2,
> +                             firstImage->Depth2,
> +                             firstImage->Level,
> +                             &width, &height, &depth)) {
> +      if (stImage->base.Width2 == u_minify(width, stImage->base.Level) &&
> +          stImage->base.Height2 == u_minify(height, stImage->base.Level) &&
> +          stImage->base.Depth2 == u_minify(depth, stImage->base.Level))
> +         guessed_box = true;
> +   }
> +
> +   if (!guessed_box)
> +      guessed_box = guess_base_level_size(stObj->base.Target,
> +                                          stImage->base.Width2,
> +                                          stImage->base.Height2,
> +                                          stImage->base.Depth2,
> +                                          stImage->base.Level,
> +                                          &width, &height, &depth);
> +
> +   if (!guessed_box) {
>         /* we can't determine the image size at level=0 */
>         stObj->width0 = stObj->height0 = stObj->depth0 = 0;
>         /* this is not an out of memory error */
>