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 5644 matching lines @@
         "glDisableVertexAttribArray", "index out of range");
   }
 }
 
 void GLES2DecoderImpl::InvalidateFramebufferImpl(
     GLenum target, GLsizei count, const GLenum* attachments,
     GLint x, GLint y, GLsizei width, GLsizei height,
     const char* function_name, FramebufferOperation op) {
   Framebuffer* framebuffer = GetFramebufferInfoForTarget(GL_FRAMEBUFFER);
 
+  // Because of performance issues, no-op if the format of the attachment is
+  // DEPTH_STENCIL and only one part is intended to be invalidated.
+  bool has_depth_stencil_format = framebuffer &&
+      framebuffer->HasDepthStencilFormatAttachment(GL_DEPTH_ATTACHMENT) &&
+      framebuffer->HasDepthStencilFormatAttachment(GL_STENCIL_ATTACHMENT);
+  bool invalidate_depth = false;
+  bool invalidate_stencil = false;
+  std::unique_ptr<GLenum[]> validated_attachments(new GLenum[count]);
+  GLsizei validated_count = 0;
+
   // Validates the attachments. If one of them fails, the whole command fails.
   GLenum thresh0 = GL_COLOR_ATTACHMENT0 + group_->max_color_attachments();
   GLenum thresh1 = GL_COLOR_ATTACHMENT15;
   for (GLsizei i = 0; i < count; ++i) {
     if (framebuffer) {
       if (attachments[i] >= thresh0 && attachments[i] <= thresh1) {
         LOCAL_SET_GL_ERROR(
             GL_INVALID_OPERATION, function_name, "invalid attachment");
         return;
       }
       if (!validators_->attachment.IsValid(attachments[i])) {
         LOCAL_SET_GL_ERROR_INVALID_ENUM(
             function_name, attachments[i], "attachments");
         return;
       }
+      if (has_depth_stencil_format) {
+        switch(attachments[i]) {
+          case GL_DEPTH_ATTACHMENT:
+            invalidate_depth = true;
+            continue;
+          case GL_STENCIL_ATTACHMENT:
+            invalidate_stencil = true;
+            continue;
+        }
+      }
     } else {
       if (!validators_->backbuffer_attachment.IsValid(attachments[i])) {
         LOCAL_SET_GL_ERROR_INVALID_ENUM(
             function_name, attachments[i], "attachments");
         return;
       }
     }
+    validated_attachments[validated_count++] = attachments[i];
   }
+  if (invalidate_depth && invalidate_stencil) {
+    validated_attachments[validated_count++] = GL_DEPTH_STENCIL_ATTACHMENT;
+  }
+  count = validated_count;
 
   // If the default framebuffer is bound but we are still rendering to an
   // FBO, translate attachment names that refer to default framebuffer
   // channels to corresponding framebuffer attachments.
   std::unique_ptr<GLenum[]> translated_attachments(new GLenum[count]);
   for (GLsizei i = 0; i < count; ++i) {
-    GLenum attachment = attachments[i];
+    GLenum attachment = validated_attachments[i];
     if (!framebuffer && GetBackbufferServiceId()) {
       switch (attachment) {
         case GL_COLOR_EXT:
           attachment = GL_COLOR_ATTACHMENT0;
           break;
         case GL_DEPTH_EXT:
           attachment = GL_DEPTH_ATTACHMENT;
           break;
         case GL_STENCIL_EXT:
           attachment = GL_STENCIL_ATTACHMENT;
@@ skipping 33 matching lines @@
       // TODO(zmo): Revisit this.
       break;
   }
 
   if (!dirty)
     return;
 
   // Marks each one of them as not cleared.
   for (GLsizei i = 0; i < count; ++i) {
     if (framebuffer) {
-      framebuffer->MarkAttachmentAsCleared(renderbuffer_manager(),
-                                           texture_manager(),
-                                           attachments[i],
-                                           false);
+      if (attachments[i] == GL_DEPTH_STENCIL_ATTACHMENT) {

[Ken Russell (switch to Gerrit), 2016/07/18 18:34:20]

This looks wrong. It's referencing the attachments array, but count is the
length of the validated_attachments array, which might be less.

A unit test is needed for this change, in framebuffer_manager_unittest.cc.

+        framebuffer->MarkAttachmentAsCleared(renderbuffer_manager(),
+                                             texture_manager(),
+                                             GL_DEPTH_ATTACHMENT,
+                                             false);
+        framebuffer->MarkAttachmentAsCleared(renderbuffer_manager(),
+                                             texture_manager(),
+                                             GL_STENCIL_ATTACHMENT,
+                                             false);
+      } else {
+        framebuffer->MarkAttachmentAsCleared(renderbuffer_manager(),
+                                             texture_manager(),
+                                             attachments[i],
+                                             false);
+      }
     } else {
       switch (attachments[i]) {
         case GL_COLOR_EXT:
           backbuffer_needs_clear_bits_ |= GL_COLOR_BUFFER_BIT;
           break;
         case GL_DEPTH_EXT:
           backbuffer_needs_clear_bits_ |= GL_DEPTH_BUFFER_BIT;
           break;
         case GL_STENCIL_EXT:
           backbuffer_needs_clear_bits_ |= GL_STENCIL_BUFFER_BIT;
@@ skipping 11344 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