Implement Discard and EnsureBackbufferCHROMIUM using command buffer instead of IPC.

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 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 "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <stdio.h>
 
 #include <algorithm>
 #include <list>
@@ skipping 571 matching lines @@
   virtual gfx::GLSurface* GetGLSurface() { return surface_.get(); }
   virtual ContextGroup* GetContextGroup() { return group_.get(); }
   virtual QueryManager* GetQueryManager() { return query_manager_.get(); }
   virtual bool ProcessPendingQueries();
 
   virtual void SetGLError(GLenum error, const char* msg);
   virtual void SetResizeCallback(
       const base::Callback<void(gfx::Size)>& callback);
 
   virtual void SetMsgCallback(const MsgCallback& callback);
+  virtual void SetDiscardBackbufferCallback(
+      const DiscardBackbufferCallback& callback);
+  virtual void SetEnsureBackbufferCallback(
+      const EnsureBackbufferCallback& callback);
 
   virtual void SetStreamTextureManager(StreamTextureManager* manager);
   virtual bool GetServiceTextureId(uint32 client_texture_id,
                                    uint32* service_texture_id);
 
   // Restores the current state to the user's settings.
   void RestoreCurrentFramebufferBindings();
   void RestoreCurrentRenderbufferBindings();
   void RestoreCurrentTexture2DBindings();
 
@@ skipping 916 matching lines @@
   scoped_ptr<FrameBuffer> offscreen_resolved_frame_buffer_;
   scoped_ptr<Texture> offscreen_resolved_color_texture_;
   GLenum offscreen_saved_color_format_;
 
   scoped_ptr<QueryManager> query_manager_;
   QueryManager::Query::Ref current_query_;
 
   base::Callback<void(gfx::Size)> resize_callback_;
 
   MsgCallback msg_callback_;
+  DiscardBackbufferCallback discard_backbuffer_callback_;
+  EnsureBackbufferCallback ensure_backbuffer_callback_;
 
   StreamTextureManager* stream_texture_manager_;
 
   // The format of the back buffer_
   GLenum back_buffer_color_format_;
   bool back_buffer_has_depth_;
   bool back_buffer_has_stencil_;
 
   bool teximage2d_faster_than_texsubimage2d_;
   bool bufferdata_faster_than_buffersubdata_;
@@ skipping 1209 matching lines @@
 
 void GLES2DecoderImpl::SetResizeCallback(
     const base::Callback<void(gfx::Size)>& callback) {
   resize_callback_ = callback;
 }
 
 void GLES2DecoderImpl::SetMsgCallback(const MsgCallback& callback) {
   msg_callback_ = callback;
 }
 
+void GLES2DecoderImpl::SetDiscardBackbufferCallback(
+    const DiscardBackbufferCallback& callback) {
+  discard_backbuffer_callback_ = callback;
+}
+
+void GLES2DecoderImpl::SetEnsureBackbufferCallback(
+    const EnsureBackbufferCallback& callback) {
+  ensure_backbuffer_callback_ = callback;
+}
+
 void GLES2DecoderImpl::SetStreamTextureManager(StreamTextureManager* manager) {
   stream_texture_manager_ = manager;
 }
 
 bool GLES2DecoderImpl::GetServiceTextureId(uint32 client_texture_id,
                                            uint32* service_texture_id) {
   TextureManager::TextureInfo* texture =
       texture_manager()->GetTextureInfo(client_texture_id);
   if (texture) {
     *service_texture_id = texture->service_id();
@@ skipping 5636 matching lines @@
       texture_manager()->SetLevelInfo(
           info, target, 0, format, level_width, level_height, 1, 0, format,
           type, false);
       level_width = std::max(1, level_width >> 1);
       level_height = std::max(1, level_height >> 1);
     }
     info->SetImmutable(true);
   }
 }
 
+error::Error GLES2DecoderImpl::HandleDiscardBackbufferCHROMIUM(
+    uint32 immediate_data_size, const gles2::DiscardBackbufferCHROMIUM& c) {
+  TRACE_EVENT0("gpu", "glDiscardBackbuffer");
+  if (!discard_backbuffer_callback_.is_null())
+    discard_backbuffer_callback_.Run();
+  return error::kNoError;
+}
+
+error::Error GLES2DecoderImpl::HandleEnsureBackbufferCHROMIUM(
+    uint32 immediate_data_size, const gles2::EnsureBackbufferCHROMIUM& c) {
+  TRACE_EVENT0("gpu", "glEnsureBackbuffer");
+  if (!ensure_backbuffer_callback_.is_null())
+    ensure_backbuffer_callback_.Run();
+  return error::kNoError;
+}
+
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu