Make invalidateFramebuffer no-op for DEPTH_STENCIL attachment

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 <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 6963 matching lines @@
     glFramebufferRenderbufferEXT(
         target, GL_DEPTH_ATTACHMENT, renderbuffertarget, service_id);
     glFramebufferRenderbufferEXT(
         target, GL_STENCIL_ATTACHMENT, renderbuffertarget, service_id);
   } else {
     glFramebufferRenderbufferEXT(
         target, attachment, renderbuffertarget, service_id);
   }
   GLenum error = LOCAL_PEEK_GL_ERROR("glFramebufferRenderbuffer");
   if (error == GL_NO_ERROR) {
-    framebuffer->AttachRenderbuffer(attachment, renderbuffer);
+    if (attachment == GL_DEPTH_STENCIL_ATTACHMENT) {
+      framebuffer->AttachRenderbuffer(GL_DEPTH_ATTACHMENT, renderbuffer);
+      framebuffer->AttachRenderbuffer(GL_STENCIL_ATTACHMENT, renderbuffer);
+    } else {
+      framebuffer->AttachRenderbuffer(attachment, renderbuffer);
+    }
   }
   if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
     framebuffer_state_.clear_state_dirty = true;
   }
   OnFboChanged();
 }
 
 void GLES2DecoderImpl::DoDisable(GLenum cap) {
   if (SetCapabilityState(cap, false)) {
     if (cap == GL_PRIMITIVE_RESTART_FIXED_INDEX &&
@@ skipping 4200 matching lines @@
         GL_FRAMEBUFFER_COMPLETE) {
       return false;
     }
     glClearStencil(0);
     state_.SetDeviceStencilMaskSeparate(GL_FRONT, kDefaultStencilMask);
     state_.SetDeviceStencilMaskSeparate(GL_BACK, kDefaultStencilMask);
     glClearDepth(1.0f);
     state_.SetDeviceDepthMask(GL_TRUE);
     state_.SetDeviceCapabilityState(GL_SCISSOR_TEST, true);
     glScissor(xoffset, yoffset, width, height);
-    glClear(GL_DEPTH_BUFFER_BIT | (have_stencil ? GL_STENCIL_BUFFER_BIT : 0));
-
+    if (format != GL_DEPTH_STENCIL) {
+      glClear(GL_DEPTH_BUFFER_BIT | (have_stencil ? GL_STENCIL_BUFFER_BIT : 0));
+    } else {
+      // When format is DEPTH_STENCIL, only clear the uncleared part.
+      GLbitfield clear_bits = 0;
+      if (!texture->IsLevelCleared(target, level, GL_DEPTH_ATTACHMENT))
+        clear_bits |= GL_DEPTH_BUFFER_BIT;
+      if (have_stencil && !texture->IsLevelCleared(target, level,

[qiankun, 2016/07/14 06:48:21]

new line after &&

+                                                   GL_STENCIL_ATTACHMENT))
+        clear_bits |= GL_STENCIL_BUFFER_BIT;
+      glClear(clear_bits);
+    }
     RestoreClearState();
 
     glDeleteFramebuffersEXT(1, &fb);
     Framebuffer* framebuffer =
         GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
     GLuint fb_service_id =
         framebuffer ? framebuffer->service_id() : GetBackbufferServiceId();
     glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, fb_service_id);
     return true;
   }
@@ skipping 5889 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 "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu