st/mesa: handle texture_from_pixmap and other surface-based textures correctly

There were 2 issues with it:
1) The texture format which should be used for texturing was only set
   in gl_texture_image::TexFormat, which wasn't used for sampler views.
2) Textures are sometimes reallocated under some circumstances
   in st_finalize_texture, which is unacceptable if the texture comes
   from a window system.

The issues are resolved as follows:
1) If surface_based is true (texture_from_pixmap, etc.), store the format
   in a new variable st_texture_object::surface_format.
2) Don't reallocate a surface-based texture in st_finalize_texture.

Also don't use st_ChooseTextureFormat is st_context_teximage, because
the format is dictated by the caller.

This fixes the glx-tfp piglit test.

Reviewed-by: Adam Jackson <ajax@redhat.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/src/mesa/state_tracker/st_texture.h b/src/mesa/state_tracker/st_texture.h
index da899c9..c15aeae 100644
--- a/src/mesa/state_tracker/st_texture.h
+++ b/src/mesa/state_tracker/st_texture.h
@@ -87,10 +87,16 @@ struct st_texture_object
     */
    struct pipe_sampler_view *sampler_view;
 
-   /* True if there is/was a surface bound to this texture object.  It helps
-    * track whether the texture object is surface based or not.
+   /* True if this texture comes from the window system. Such a texture
+    * cannot be reallocated and the format can only be changed with a sampler
+    * view or a surface.
     */
    GLboolean surface_based;
+
+   /* If surface_based is true, this format should be used for all sampler
+    * views and surfaces instead of pt->format.
+    */
+   enum pipe_format surface_format;
 };