Get correct backbuffer format when context is on screen....

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 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 "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <stdio.h>
 
 #include <algorithm>
 #include <list>
@@ skipping 1408 matching lines @@
 
   // The copy that is saved when SwapBuffers is called.  It is also
   // used as the destination for multi-sample resolves.
   scoped_ptr<FrameBuffer> offscreen_saved_frame_buffer_;
   scoped_ptr<Texture> offscreen_saved_color_texture_;
   GLenum offscreen_saved_color_format_;
 
   scoped_ptr<Callback1<gfx::Size>::Type> resize_callback_;
   scoped_ptr<Callback0::Type> swap_buffers_callback_;
 
+  // The format of the back buffer_
+  GLenum back_buffer_color_format_;
+
   // The last error message set.
   std::string last_error_;
 
   // The current decoder error.
   error::Error current_decoder_error_;
 
   bool use_shader_translator_;
   scoped_ptr<ShaderTranslator> vertex_translator_;
   scoped_ptr<ShaderTranslator> fragment_translator_;
 
@@ skipping 310 matching lines @@
       mask_stencil_front_(-1),
       mask_stencil_back_(-1),
       clear_depth_(1.0f),
       mask_depth_(true),
       enable_scissor_test_(false),
       offscreen_target_color_format_(0),
       offscreen_target_depth_format_(0),
       offscreen_target_stencil_format_(0),
       offscreen_target_samples_(0),
       offscreen_saved_color_format_(0),
+      back_buffer_color_format_(0),
       current_decoder_error_(error::kNoError),
       use_shader_translator_(true),
       validators_(group_->feature_info()->validators()),
       feature_info_(group_->feature_info()) {
   attrib_0_value_.v[0] = 0.0f;
   attrib_0_value_.v[1] = 0.0f;
   attrib_0_value_.v[2] = 0.0f;
   attrib_0_value_.v[3] = 1.0f;
 
   // The shader translator is used for WebGL even when running on EGL
@@ skipping 38 matching lines @@
     LOG(ERROR) << "GPUProcessor::InitializeCommon failed because group "
                << "failed to initialize.";
     Destroy();
     return false;
   }
 
   CHECK_GL_ERROR();
 
   vertex_attrib_manager_.Initialize(group_->max_vertex_attribs());
 
+  GLint v = 0;
+  glGetIntegerv(GL_ALPHA_BITS, &v);
+  back_buffer_color_format_ = v ? GL_RGBA : GL_RGB;
+
   // We have to enable vertex array 0 on OpenGL or it won't render. Note that
   // OpenGL ES 2.0 does not have this issue.
   glEnableVertexAttribArray(0);
   glGenBuffersARB(1, &attrib_0_buffer_id_);
   glBindBuffer(GL_ARRAY_BUFFER, attrib_0_buffer_id_);
   glVertexAttribPointer(0, 1, GL_FLOAT, GL_FALSE, 0, NULL);
   glBindBuffer(GL_ARRAY_BUFFER, 0);
   glGenBuffersARB(1, &fixed_attrib_buffer_id_);
 
   texture_units_.reset(
@@ skipping 389 matching lines @@
   if (bound_read_framebuffer_ != 0) {
     const FramebufferManager::FramebufferInfo::Attachment* attachment =
         bound_read_framebuffer_->GetAttachment(GL_COLOR_ATTACHMENT0);
     if (attachment) {
       return attachment->internal_format();
     }
     return 0;
   } else if (offscreen_target_frame_buffer_.get()) {
     return offscreen_target_color_format_;
   } else {
-    // TODO(gman): return correct format
-    return GL_RGBA;
+    return back_buffer_color_format_;
   }
 }
 
 bool GLES2DecoderImpl::UpdateOffscreenFrameBufferSize() {
   if (offscreen_size_ == pending_offscreen_size_)
     return true;
 
   offscreen_size_ = pending_offscreen_size_;
 
   // Reallocate the offscreen target buffers.
@@ skipping 3854 matching lines @@
   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