cc: Adding support for RGBA_4444 tile textures

cc/output/gl_renderer.cc

 // Copyright 2010 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/output/gl_renderer.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <string>
@@ skipping 644 matching lines @@
   int top, right, bottom, left;
   filters.GetOutsets(&top, &right, &bottom, &left);
   window_rect.Inset(-left, -top, -right, -bottom);
 
   window_rect.Intersect(
       MoveFromDrawToWindowSpace(frame->current_render_pass->output_rect));
 
   scoped_ptr<ScopedResource> device_background_texture =
       ScopedResource::create(resource_provider_);
   if (!device_background_texture->Allocate(window_rect.size(),
-                                           GL_RGB,
-                                           ResourceProvider::TextureUsageAny)) {
+                                           GL_RGBA,

[vangelis, 2013/09/11 06:11:37]

Is the switch from RGB to RGBA done on purpose here? 

[kaanb, 2013/09/12 07:53:44]

Yes, epenner@ thought it was a bug we were using GL_RGB here.

+                                           ResourceProvider::TextureUsageAny,
+                                           ResourceProvider::RGBA_8888)) {
     return scoped_ptr<ScopedResource>();
   } else {
     ResourceProvider::ScopedWriteLockGL lock(resource_provider_,
                                              device_background_texture->id());
     GetFramebufferTexture(lock.texture_id(),
                           device_background_texture->format(),
                           window_rect);
   }
 
   SkBitmap filtered_device_background =
       ApplyFilters(this,
                    frame->offscreen_context_provider,
                    filters,
                    device_background_texture.get());
   if (!filtered_device_background.getTexture())
     return scoped_ptr<ScopedResource>();
 
   GrTexture* texture =
       reinterpret_cast<GrTexture*>(filtered_device_background.getTexture());
   int filtered_device_background_texture_id = texture->getTextureHandle();
 
   scoped_ptr<ScopedResource> background_texture =
       ScopedResource::create(resource_provider_);
   if (!background_texture->Allocate(quad->rect.size(),
                                     GL_RGBA,
-                                    ResourceProvider::TextureUsageFramebuffer))
+                                    ResourceProvider::TextureUsageFramebuffer,
+                                    ResourceProvider::RGBA_8888))
     return scoped_ptr<ScopedResource>();
 
   const RenderPass* target_render_pass = frame->current_render_pass;
   bool using_background_texture =
       UseScopedTexture(frame, background_texture.get(), quad->rect);
 
   if (using_background_texture) {
     // Copy the readback pixels from device to the background texture for the
     // surface.
     gfx::Transform device_to_framebuffer_transform;
@@ skipping 1004 matching lines @@
     on_demand_tile_raster_bitmap_.allocPixels();
 
     if (on_demand_tile_raster_resource_id_)
       resource_provider_->DeleteResource(on_demand_tile_raster_resource_id_);
 
     on_demand_tile_raster_resource_id_ = resource_provider_->CreateGLTexture(
         quad->texture_size,
         GL_RGBA,
         GL_TEXTURE_POOL_UNMANAGED_CHROMIUM,
         GL_CLAMP_TO_EDGE,
-        ResourceProvider::TextureUsageAny);
+        ResourceProvider::TextureUsageAny,
+        settings_->use_rgba_4444_textures
+            ? ResourceProvider::RGBA_4444 : ResourceProvider::RGBA_8888);
   }
 
   SkBitmapDevice device(on_demand_tile_raster_bitmap_);
   SkCanvas canvas(&device);
 
   quad->picture_pile->RasterToBitmap(&canvas, quad->content_rect,
                                      quad->contents_scale, NULL);
 
+  const uint8_t* bitmap_pixels = NULL;
+  if (settings_->use_rgba_4444_textures) {
+    on_demand_tile_raster_bitmap_.copyTo(
+        &on_demand_tile_raster_bitmap_4444_, SkBitmap::kARGB_4444_Config);
+    bitmap_pixels = reinterpret_cast<uint8_t*>(
+        on_demand_tile_raster_bitmap_4444_.getPixels());
+  } else {
+    bitmap_pixels = reinterpret_cast<uint8_t*>(
+        on_demand_tile_raster_bitmap_.getPixels());
+  }
+
   resource_provider_->SetPixels(
       on_demand_tile_raster_resource_id_,
-      reinterpret_cast<uint8_t*>(on_demand_tile_raster_bitmap_.getPixels()),
+      bitmap_pixels,
       gfx::Rect(quad->texture_size),
       gfx::Rect(quad->texture_size),
       gfx::Vector2d());
 
   DrawContentQuad(frame, quad, on_demand_tile_raster_resource_id_);
 }
 
 struct TextureProgramBinding {
   template <class Program>
   void Set(Program* program, WebKit::WebGraphicsContext3D* context) {
@@ skipping 1401 matching lines @@
     return;
   offscreen_context_labelled_ = true;
   std::string unique_context_name = base::StringPrintf(
       "%s-Offscreen-%p", settings_->compositor_name.c_str(), context_);
   offscreen_context_provider->Context3d()
       ->pushGroupMarkerEXT(unique_context_name.c_str());
 }
 
 
 }  // namespace cc