Add command buffer support for EXT_sRGB_write_control

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 689 matching lines @@
   bool GenSamplersHelper(GLsizei n, const GLuint* client_ids);
   void DeleteSamplersHelper(GLsizei n, const volatile GLuint* client_ids);
   bool GenTransformFeedbacksHelper(GLsizei n, const GLuint* client_ids);
   void DeleteTransformFeedbacksHelper(GLsizei n,
                                       const volatile GLuint* client_ids);
   void DeleteSyncHelper(GLuint sync);
 
   // Workarounds
   void OnFboChanged() const;
   void OnUseFramebuffer() const;
+  void UpdateFramebufferSRGB(Framebuffer* framebuffer);
 
   error::ContextLostReason GetContextLostReasonFromResetStatus(
       GLenum reset_status) const;
 
   // TODO(gman): Cache these pointers?
   BufferManager* buffer_manager() {
     return group_->buffer_manager();
   }
 
   RenderbufferManager* renderbuffer_manager() {
@@ skipping 2731 matching lines @@
       return false;
     }
   }
 
   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);
+  UpdateFramebufferSRGB(nullptr);
 
   bool call_gl_clear = !surfaceless_ && !offscreen;
 #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
@@ skipping 815 matching lines @@
   }
   return true;
 }
 
 bool GLES2DecoderImpl::CheckBoundDrawFramebufferValid(const char* func_name) {
   GLenum target = features().chromium_framebuffer_multisample ?
       GL_DRAW_FRAMEBUFFER : GL_FRAMEBUFFER;
   Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
   bool valid = CheckFramebufferValid(
       framebuffer, target, GL_INVALID_FRAMEBUFFER_OPERATION, func_name);
-  if (valid && !features().chromium_framebuffer_multisample)
+  if (!valid)
+    return false;
+
+  if (!features().chromium_framebuffer_multisample)
     OnUseFramebuffer();
-  if (valid && feature_info_->feature_flags().desktop_srgb_support) {
-    // If framebuffer contains sRGB images, then enable FRAMEBUFFER_SRGB.
-    // Otherwise, disable FRAMEBUFFER_SRGB. Assume default fbo does not have
-    // sRGB image.
-    // In theory, we can just leave FRAMEBUFFER_SRGB on. However, many drivers
-    // behave incorrectly when all images are linear encoding, they still apply
-    // the sRGB conversion, but when at least one image is sRGB, then they
-    // behave correctly.
-    bool enable_framebuffer_srgb =
-        framebuffer && framebuffer->HasSRGBAttachments();
+
+  UpdateFramebufferSRGB(framebuffer);
+  return true;
+}
+
+void GLES2DecoderImpl::UpdateFramebufferSRGB(Framebuffer* framebuffer) {
+  // Manually set the value of FRAMEBUFFER_SRGB based on the state that was set
+  // by the client.
+  bool needs_enable_disable_framebuffer_srgb = false;
+  bool enable_framebuffer_srgb = true;
+  if (feature_info_->feature_flags().ext_srgb_write_control) {
+    needs_enable_disable_framebuffer_srgb = true;
+    enable_framebuffer_srgb &= state_.GetEnabled(GL_FRAMEBUFFER_SRGB);
+  }
+  // On desktop, enable FRAMEBUFFER_SRGB only if the framebuffer contains sRGB
+  // attachments. In theory, we can just leave FRAMEBUFFER_SRGB enabled,
+  // however,
+  // many drivers behave incorrectly when no attachments are sRGB. When at
+  // least one attachment is sRGB, then they behave correctly.
+  if (feature_info_->feature_flags().desktop_srgb_support) {
+    needs_enable_disable_framebuffer_srgb = true;

[Zhenyao Mo, 2016/11/30 19:31:11]

You can DCHECK this because desktop_srgb_support should set
ext_srgb_write_control to true.

[ccameron, 2016/11/30 23:59:44]

Done.

[ccameron, 2016/12/01 02:14:34]

Oops, now that I'm not enabling write control for WebGL contexts, this can't be
a DCHECK anymore.

+    // Assume that the default fbo does not have an sRGB image.
+    enable_framebuffer_srgb &= framebuffer && framebuffer->HasSRGBAttachments();
+  }
+  if (needs_enable_disable_framebuffer_srgb)
     state_.EnableDisableFramebufferSRGB(enable_framebuffer_srgb);
-  }
-  return valid;
 }
 
 bool GLES2DecoderImpl::CheckBoundReadFramebufferValid(
     const char* func_name, GLenum gl_error) {
   GLenum target = features().chromium_framebuffer_multisample ?
       GL_READ_FRAMEBUFFER : GL_FRAMEBUFFER;
   Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
   bool valid = CheckFramebufferValid(
       framebuffer, target, gl_error, func_name);
   return valid;
@@ skipping 3089 matching lines @@
 }
 
 void GLES2DecoderImpl::DoDisable(GLenum cap) {
   if (SetCapabilityState(cap, false)) {
     if (cap == GL_PRIMITIVE_RESTART_FIXED_INDEX &&
         feature_info_->feature_flags().emulate_primitive_restart_fixed_index) {
       // Enable and Disable PRIMITIVE_RESTART only before and after
       // DrawElements* for old desktop GL.
       return;
     }
+    if (cap == GL_FRAMEBUFFER_SRGB) {
+      // Enable and Disable GL_FRAMEBUFFER_SRGB is done manually in
+      // CheckBoundDrawFramebufferValid.
+      return;
+    }
     glDisable(cap);
   }
 }
 
 void GLES2DecoderImpl::DoEnable(GLenum cap) {
   if (SetCapabilityState(cap, true)) {
     if (cap == GL_PRIMITIVE_RESTART_FIXED_INDEX &&
         feature_info_->feature_flags().emulate_primitive_restart_fixed_index) {
       // Enable and Disable PRIMITIVE_RESTART only before and after
       // DrawElements* for old desktop GL.
       return;
     }
+    if (cap == GL_FRAMEBUFFER_SRGB) {
+      // Enable and Disable GL_FRAMEBUFFER_SRGB is done manually in
+      // CheckBoundDrawFramebufferValid.
+      return;
+    }
     glEnable(cap);
   }
 }
 
 void GLES2DecoderImpl::DoDepthRangef(GLclampf znear, GLclampf zfar) {
   state_.z_near = std::min(1.0f, std::max(0.0f, znear));
   state_.z_far = std::min(1.0f, std::max(0.0f, zfar));
   glDepthRange(znear, zfar);
 }
 
@@ skipping 11423 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