Fix for surfaceless implementation

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 1730 matching lines @@
 
   ShaderCacheCallback shader_cache_callback_;
 
   scoped_ptr<AsyncPixelTransferManager> async_pixel_transfer_manager_;
 
   // The format of the back buffer_
   GLenum back_buffer_color_format_;
   bool back_buffer_has_depth_;
   bool back_buffer_has_stencil_;
 
+  bool surfaceless_;
+
   // Backbuffer attachments that are currently undefined.
   uint32 backbuffer_needs_clear_bits_;
 
   // The current decoder error communicates the decoder error through command
   // processing functions that do not return the error value. Should be set only
   // if not returning an error.
   error::Error current_decoder_error_;
 
   bool use_shader_translator_;
   scoped_refptr<ShaderTranslator> vertex_translator_;
@@ skipping 536 matching lines @@
       fixed_attrib_buffer_size_(0),
       offscreen_target_color_format_(0),
       offscreen_target_depth_format_(0),
       offscreen_target_stencil_format_(0),
       offscreen_target_samples_(0),
       offscreen_target_buffer_preserved_(true),
       offscreen_saved_color_format_(0),
       back_buffer_color_format_(0),
       back_buffer_has_depth_(false),
       back_buffer_has_stencil_(false),
+      surfaceless_(false),
       backbuffer_needs_clear_bits_(0),
       current_decoder_error_(error::kNoError),
       use_shader_translator_(true),
       validators_(group_->feature_info()->validators()),
       feature_info_(group_->feature_info()),
       frame_number_(0),
       has_robustness_extension_(false),
       reset_status_(GL_NO_ERROR),
       reset_by_robustness_extension_(false),
       supports_post_sub_buffer_(false),
@@ skipping 45 matching lines @@
     const scoped_refptr<gfx::GLSurface>& surface,
     const scoped_refptr<gfx::GLContext>& context,
     bool offscreen,
     const gfx::Size& size,
     const DisallowedFeatures& disallowed_features,
     const std::vector<int32>& attribs) {
   TRACE_EVENT0("gpu", "GLES2DecoderImpl::Initialize");
   DCHECK(context->IsCurrent(surface.get()));
   DCHECK(!context_.get());
 
+  surfaceless_ = surface->IsSurfaceless();
+
   set_initialized();
   gpu_tracer_.reset(new GPUTracer(this));
   gpu_state_tracer_ = GPUStateTracer::Create(&state_);
 
   if (CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableGPUDebugging)) {
     set_debug(true);
   }
 
   if (CommandLine::ForCurrentProcess()->HasSwitch(
@@ skipping 237 matching lines @@
     DoBindFramebuffer(GL_FRAMEBUFFER, 0);
   } else {
     glBindFramebufferEXT(GL_FRAMEBUFFER, GetBackbufferServiceId());
     // These are NOT if the back buffer has these proprorties. They are
     // if we want the command buffer to enforce them regardless of what
     // the real backbuffer is assuming the real back buffer gives us more than
     // we ask for. In other words, if we ask for RGB and we get RGBA then we'll
     // make it appear RGB. If on the other hand we ask for RGBA nd get RGB we
     // can't do anything about that.
 
-    GLint v = 0;
-    glGetIntegerv(GL_ALPHA_BITS, &v);
-    // This checks if the user requested RGBA and we have RGBA then RGBA. If the
-    // user requested RGB then RGB. If the user did not specify a preference
-    // than use whatever we were given. Same for DEPTH and STENCIL.
-    back_buffer_color_format_ =
-        (attrib_parser.alpha_size != 0 && v > 0) ? GL_RGBA : GL_RGB;
-    glGetIntegerv(GL_DEPTH_BITS, &v);
-    back_buffer_has_depth_ = attrib_parser.depth_size != 0 && v > 0;
-    glGetIntegerv(GL_STENCIL_BITS, &v);
-    back_buffer_has_stencil_ = attrib_parser.stencil_size != 0 && v > 0;
+    if (!surfaceless_) {
+      GLint v = 0;
+      glGetIntegerv(GL_ALPHA_BITS, &v);
+      // This checks if the user requested RGBA and we have RGBA then RGBA. If
+      // the user requested RGB then RGB. If the user did not specify a
+      // preference than use whatever we were given. Same for DEPTH and STENCIL.
+      back_buffer_color_format_ =
+          (attrib_parser.alpha_size != 0 && v > 0) ? GL_RGBA : GL_RGB;
+      glGetIntegerv(GL_DEPTH_BITS, &v);
+      back_buffer_has_depth_ = attrib_parser.depth_size != 0 && v > 0;
+      glGetIntegerv(GL_STENCIL_BITS, &v);
+      back_buffer_has_stencil_ = attrib_parser.stencil_size != 0 && v > 0;
+    }
   }
 
   // OpenGL ES 2.0 implicitly enables the desktop GL capability
   // VERTEX_PROGRAM_POINT_SIZE and doesn't expose this enum. This fact
   // isn't well documented; it was discovered in the Khronos OpenGL ES
   // mailing list archives. It also implicitly enables the desktop GL
   // capability GL_POINT_SPRITE to provide access to the gl_PointCoord
   // variable in fragment shaders.
   if (gfx::GetGLImplementation() != gfx::kGLImplementationEGLGLES2) {
     glEnable(GL_VERTEX_PROGRAM_POINT_SIZE);
@@ skipping 22 matching lines @@
   // Set all the default state because some GL drivers get it wrong.
   state_.InitCapabilities(NULL);
   state_.InitState(NULL);
   glActiveTexture(GL_TEXTURE0 + state_.active_texture_unit);
 
   DoBindBuffer(GL_ARRAY_BUFFER, 0);
   DoBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
   DoBindFramebuffer(GL_FRAMEBUFFER, 0);
   DoBindRenderbuffer(GL_RENDERBUFFER, 0);
 
-  bool call_gl_clear = true;
+  bool call_gl_clear = !surfaceless_;
 #if defined(OS_ANDROID)
   // Temporary workaround for Android WebView because this clear ignores the
   // clip and corrupts that external UI of the App. Not calling glClear is ok
   // because the system already clears the buffer before each draw. Proper
   // fix might be setting the scissor clip properly before initialize. See
   // crbug.com/259023 for details.
   call_gl_clear = surface_->GetHandle();
 #endif
   if (call_gl_clear) {
     // Clear the backbuffer.
@@ skipping 423 matching lines @@
         framebuffer_state_.bound_draw_framebuffer.get(),
         GetBackbufferServiceId());
   }
   OnFboChanged();
 }
 
 bool GLES2DecoderImpl::CheckFramebufferValid(
     Framebuffer* framebuffer,
     GLenum target, const char* func_name) {
   if (!framebuffer) {
+    if (surfaceless_)
+      return false;
     if (backbuffer_needs_clear_bits_) {
       glClearColor(0, 0, 0, (GLES2Util::GetChannelsForFormat(
           offscreen_target_color_format_) & 0x0008) != 0 ? 0 : 1);
       state_.SetDeviceColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
       glClearStencil(0);
       state_.SetDeviceStencilMaskSeparate(GL_FRONT, kDefaultStencilMask);
       state_.SetDeviceStencilMaskSeparate(GL_BACK, kDefaultStencilMask);
       glClearDepth(1.0f);
       state_.SetDeviceDepthMask(GL_TRUE);
       state_.SetDeviceCapabilityState(GL_SCISSOR_TEST, false);
@@ skipping 8139 matching lines @@
   }
 }
 
 // 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