Emulate GL_PRIMITIVE_RESTART_FIXED_INDEX: part I

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 <set>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 143 matching lines @@
       map_buffer_range(false),
       ext_discard_framebuffer(false),
       angle_depth_texture(false),
       is_swiftshader(false),
       angle_texture_usage(false),
       ext_texture_storage(false),
       chromium_path_rendering(false),
       blend_equation_advanced(false),
       blend_equation_advanced_coherent(false),
       ext_texture_rg(false),
-      enable_subscribe_uniform(false) {
+      enable_subscribe_uniform(false),
+      emulate_primitive_restart_fixed_index(false) {
 }
 
 FeatureInfo::Workarounds::Workarounds() :
 #define GPU_OP(type, name) name(false),
     GPU_DRIVER_BUG_WORKAROUNDS(GPU_OP)
 #undef GPU_OP
     max_texture_size(0),
     max_cube_map_texture_size(0),
     max_fragment_uniform_vectors(0),
     max_varying_vectors(0),
@@ skipping 915 matching lines @@
       texture_format_validators_[GL_RG_EXT].AddValue(GL_HALF_FLOAT_OES);
     }
   }
   UMA_HISTOGRAM_BOOLEAN("GPU.TextureRG", feature_flags_.ext_texture_rg);
 
 #if !defined(OS_MACOSX)
   if (workarounds_.ignore_egl_sync_failures) {
     gfx::GLFenceEGL::SetIgnoreFailures();
   }
 #endif
+
+  if (gl_version_info_->IsLowerThanGL(4, 3)) {
+    // crbug.com/481184.
+    // GL_PRIMITIVE_RESTART_FIXED_INDEX is only available on Desktop GL 4.3+,
+    // but we emulate ES 3.0 on top of Desktop GL 4.2+.
+    feature_flags_.emulate_primitive_restart_fixed_index = true;
+  }
 }
 
 bool FeatureInfo::IsES3Capable() const {
   if (gl_version_info_->IsAtLeastGLES(3, 0))
     return true;
   // TODO(zmo): For Desktop GL, with anything lower than 4.2, we need to check
   // the existence of a few extensions to have full WebGL 2 capabilities.
   if (gl_version_info_->IsAtLeastGL(4, 2))
     return true;
 #if defined(OS_MACOSX)
@@ skipping 76 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu