Blend TextureLayer background-color at draw time.

cc/layers/texture_layer_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/texture_layer_impl.h"
 
 #include "base/strings/stringprintf.h"
 #include "cc/layers/quad_sink.h"
 #include "cc/output/renderer.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "cc/trees/layer_tree_impl.h"
 
 namespace cc {
 
 TextureLayerImpl::TextureLayerImpl(LayerTreeImpl* tree_impl,
                                    int id,
                                    bool uses_mailbox)
     : LayerImpl(tree_impl, id),
       texture_id_(0),
       external_texture_resource_(0),
       premultiplied_alpha_(true),
+      blend_background_color_(false),
       flipped_(true),
       uv_top_left_(0.f, 0.f),
       uv_bottom_right_(1.f, 1.f),
       uses_mailbox_(uses_mailbox),
       own_mailbox_(false) {
   vertex_opacity_[0] = 1.0f;
   vertex_opacity_[1] = 1.0f;
   vertex_opacity_[2] = 1.0f;
   vertex_opacity_[3] = 1.0f;
 }
@@ skipping 65 matching lines @@
 }
 
 void TextureLayerImpl::AppendQuads(QuadSink* quad_sink,
                                    AppendQuadsData* append_quads_data) {
   DCHECK(external_texture_resource_);
 
   SharedQuadState* shared_quad_state =
       quad_sink->UseSharedQuadState(CreateSharedQuadState());
   AppendDebugBorderQuad(quad_sink, shared_quad_state, append_quads_data);
 
+  SkColor bg_color = blend_background_color_ ?
+      background_color() : SK_ColorTRANSPARENT;
   gfx::Rect quad_rect(content_bounds());
-  gfx::Rect opaque_rect(contents_opaque() ? quad_rect : gfx::Rect());
+  gfx::Rect opaque_rect = contents_opaque() || (SkColorGetA(bg_color) == 0xFF) ?

[palmer, 2013/07/11 18:37:22]

I don't understand this. It looks like it will try to assign a boolean value to
|opaque_rect|?

[alokp, 2013/07/11 19:55:00]

I do not think so, but would you prefer enclosing the conditional expression?

[danakj, 2013/07/11 20:34:05]

How about a temp var for the boolean part

[alokp, 2013/07/11 20:42:33]

Done.

+      quad_rect : gfx::Rect();
   scoped_ptr<TextureDrawQuad> quad = TextureDrawQuad::Create();
   quad->SetNew(shared_quad_state,
                quad_rect,
                opaque_rect,
                external_texture_resource_,
                premultiplied_alpha_,
                uv_top_left_,
                uv_bottom_right_,
+               bg_color,
                vertex_opacity_,
                flipped_);
 
   // Perform explicit clipping on a quad to avoid setting a scissor later.
   if (shared_quad_state->is_clipped && quad->PerformClipping())
     shared_quad_state->is_clipped = false;
   if (!quad->rect.IsEmpty())
     quad_sink->Append(quad.PassAs<DrawQuad>(), append_quads_data);
 }
 
@@ skipping 36 matching lines @@
   } else if (external_texture_resource_) {
     DCHECK(!own_mailbox_);
     ResourceProvider* resource_provider =
         layer_tree_impl()->resource_provider();
     resource_provider->DeleteResource(external_texture_resource_);
     external_texture_resource_ = 0;
   }
 }
 
 }  // namespace cc