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>

src/mesa/state_tracker/st_atom_texture.c

@@ -239,7 +239,8 @@ update_single_texture(struct st_context *st,
          st_mesa_format_to_pipe_format(stObj->base._BufferObjectFormat);
    }
    else {
-      view_format = stObj->pt->format;
+      view_format =
+         stObj->surface_based ? stObj->surface_format : stObj->pt->format;
 
       /* If sRGB decoding is off, use the linear format */
       if (samp->sRGBDecode == GL_SKIP_DECODE_EXT) {

src/mesa/state_tracker/st_cb_eglimage.c

@@ -131,6 +131,7 @@ st_bind_surface(struct gl_context *ctx, GLenum target,
    stObj->width0 = ps->width;
    stObj->height0 = ps->height;
    stObj->depth0 = 1;
+   stObj->surface_format = ps->format;
 
    _mesa_dirty_texobj(ctx, texObj, GL_TRUE);
 }

src/mesa/state_tracker/st_cb_texture.c

@@ -1540,6 +1540,11 @@ st_finalize_texture(struct gl_context *ctx,
       pipe_sampler_view_release(st->pipe, &stObj->sampler_view);
    }
 
+   /* If this texture comes from a window system, there is nothing else to do. */
+   if (stObj->surface_based) {
+      return GL_TRUE;
+   }
+
    /* Find gallium format for the Mesa texture */
    firstImageFormat = st_mesa_format_to_pipe_format(firstImage->base.TexFormat);
 
@@ -1567,7 +1572,7 @@ st_finalize_texture(struct gl_context *ctx,
     */
    if (stObj->pt) {
       if (stObj->pt->target != gl_target_to_pipe(stObj->base.Target) ||
-          !st_sampler_compat_formats(stObj->pt->format, firstImageFormat) ||
+          stObj->pt->format != firstImageFormat ||
           stObj->pt->last_level < stObj->lastLevel ||
           stObj->pt->width0 != ptWidth ||
           stObj->pt->height0 != ptHeight ||

src/mesa/state_tracker/st_format.c

@@ -1800,41 +1800,6 @@ st_QuerySamplesForFormat(struct gl_context *ctx, GLenum target,
 }
 
 
-GLboolean
-st_sampler_compat_formats(enum pipe_format format1, enum pipe_format format2)
-{
-   if (format1 == format2)
-      return GL_TRUE;
-
-   if (format1 == PIPE_FORMAT_B8G8R8A8_UNORM &&
-       format2 == PIPE_FORMAT_B8G8R8X8_UNORM)
-      return GL_TRUE;
-
-   if (format1 == PIPE_FORMAT_B8G8R8X8_UNORM &&
-       format2 == PIPE_FORMAT_B8G8R8A8_UNORM)
-      return GL_TRUE;
-
-   if (format1 == PIPE_FORMAT_A8B8G8R8_UNORM &&
-       format2 == PIPE_FORMAT_X8B8G8R8_UNORM)
-      return GL_TRUE;
-
-   if (format1 == PIPE_FORMAT_X8B8G8R8_UNORM &&
-       format2 == PIPE_FORMAT_A8B8G8R8_UNORM)
-      return GL_TRUE;
-
-   if (format1 == PIPE_FORMAT_A8R8G8B8_UNORM &&
-       format2 == PIPE_FORMAT_X8R8G8B8_UNORM)
-      return GL_TRUE;
-
-   if (format1 == PIPE_FORMAT_X8R8G8B8_UNORM &&
-       format2 == PIPE_FORMAT_A8R8G8B8_UNORM)
-      return GL_TRUE;
-
-   return GL_FALSE;
-}
-
-
-
 /**
  * This is used for translating texture border color and the clear
  * color.  For example, the clear color is interpreted according to

src/mesa/state_tracker/st_format.h

@@ -70,10 +70,6 @@ size_t
 st_QuerySamplesForFormat(struct gl_context *ctx, GLenum target,
                          GLenum internalFormat, int samples[16]);
 
-/* can we use a sampler view to translate these formats
-   only used to make TFP so far */
-extern GLboolean
-st_sampler_compat_formats(enum pipe_format format1, enum pipe_format format2);
 
 
 extern void

src/mesa/state_tracker/st_manager.c

@@ -467,7 +467,7 @@ st_context_flush(struct st_context_iface *stctxi, unsigned flags,
 static boolean
 st_context_teximage(struct st_context_iface *stctxi,
                     enum st_texture_type tex_type,
-                    int level, enum pipe_format internal_format,
+                    int level, enum pipe_format pipe_format,
                     struct pipe_resource *tex, boolean mipmap)
 {
    struct st_context *st = (struct st_context *) stctxi;
@@ -511,29 +511,13 @@ st_context_teximage(struct st_context_iface *stctxi,
    texImage = _mesa_get_tex_image(ctx, texObj, target, level);
    stImage = st_texture_image(texImage);
    if (tex) {
-      gl_format texFormat;
+      gl_format texFormat = st_pipe_format_to_mesa_format(pipe_format);
 
-      /*
-       * XXX When internal_format and tex->format differ, st_finalize_texture
-       * needs to allocate a new texture with internal_format and copy the
-       * texture here into the new one.  It will result in surface_copy being
-       * called on surfaces whose formats differ.
-       *
-       * To avoid that, internal_format is (wrongly) ignored here.  A sane fix
-       * is to use a sampler view.
-       */
-      if (!st_sampler_compat_formats(tex->format, internal_format))
-	 internal_format = tex->format;
-     
-      if (util_format_get_component_bits(internal_format,
-               UTIL_FORMAT_COLORSPACE_RGB, 3) > 0)
+      if (util_format_has_alpha(tex->format))
          internalFormat = GL_RGBA;
       else
          internalFormat = GL_RGB;
 
-      texFormat = st_ChooseTextureFormat(ctx, target, internalFormat,
-                                         GL_BGRA, GL_UNSIGNED_BYTE);
-
       _mesa_init_teximage_fields(ctx, texImage,
                                  tex->width0, tex->height0, 1, 0,
                                  internalFormat, texFormat);
@@ -562,6 +546,7 @@ st_context_teximage(struct st_context_iface *stctxi,
    stObj->width0 = width;
    stObj->height0 = height;
    stObj->depth0 = depth;
+   stObj->surface_format = pipe_format;
 
    _mesa_dirty_texobj(ctx, texObj, GL_TRUE);
    _mesa_unlock_texture(ctx, texObj);

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;
 };