Add command buffer support for EXT_sRGB_write_control

gpu/command_buffer/service/feature_info.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/feature_info.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <vector>
@@ skipping 581 matching lines @@
     AddExtensionString("GL_EXT_sRGB");
     validators_.texture_internal_format.AddValue(GL_SRGB_EXT);
     validators_.texture_internal_format.AddValue(GL_SRGB_ALPHA_EXT);
     validators_.texture_format.AddValue(GL_SRGB_EXT);
     validators_.texture_format.AddValue(GL_SRGB_ALPHA_EXT);
     validators_.render_buffer_format.AddValue(GL_SRGB8_ALPHA8_EXT);
     validators_.framebuffer_parameter.AddValue(
         GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING_EXT);
     validators_.texture_unsized_internal_format.AddValue(GL_SRGB_EXT);
     validators_.texture_unsized_internal_format.AddValue(GL_SRGB_ALPHA_EXT);
+
+    // GL_FRAMEBUFFER_SRGB_EXT is exposed by the GLES extension
+    // GL_EXT_sRGB_write_control (which is not part of the core, even in GLES3),
+    // and the desktop extension GL_ARB_framebuffer_sRGB (part of the core in
+    // 3.0).
+    if (feature_flags_.desktop_srgb_support ||
+        extensions.Contains("GL_EXT_sRGB_write_control")) {

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

Don't does this if IsWebGLContext(). Otherwise you leak this enum to WebGL
context and you will need to go to multiple function entries points in
WebGLRenderingContext to filter out it.

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

Updated to track if we support srgb framebuffers, and only add support for
write_control if we do and we aren't in a WebGL context.

+      feature_flags_.ext_srgb_write_control = true;
+      AddExtensionString("GL_EXT_sRGB_write_control");
+      validators_.capability.AddValue(GL_FRAMEBUFFER_SRGB_EXT);
+    }
   }
 
   // On desktop, GL_EXT_texture_sRGB is required regardless of GL version,
   // since the sRGB formats in OpenGL 3.0 Core do not support S3TC.
   // TODO(kainino): Support GL_EXT_texture_compression_s3tc_srgb once ratified.
   if ((gl_version_info_->is_es && extensions.Contains("GL_NV_sRGB_formats")) ||
       (!gl_version_info_->is_es &&
        extensions.Contains("GL_EXT_texture_sRGB") &&
        extensions.Contains("GL_EXT_texture_compression_s3tc"))) {
     AddExtensionString("GL_EXT_texture_compression_s3tc_srgb");
@@ skipping 927 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu