gpu/command_buffer/service/feature_info.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "gpu/command_buffer/service/feature_info.h"
   6
   7 #include <set>
   8
   9 #include "base/command_line.h"
  10 #include "base/macros.h"
  11 #include "base/metrics/histogram.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/strings/string_split.h"
  14 #include "base/strings/string_util.h"
  15 #include "gpu/command_buffer/service/gl_utils.h"
  16 #include "gpu/command_buffer/service/gpu_switches.h"
  17 #include "gpu/command_buffer/service/texture_definition.h"
  18 #include "gpu/config/gpu_switches.h"
  19 #include "ui/gl/gl_fence.h"
  20 #include "ui/gl/gl_implementation.h"
  21
  22 #if !defined(OS_MACOSX)
  23 #include "ui/gl/gl_fence_egl.h"
  24 #endif
  25
  26 namespace gpu {
  27 namespace gles2 {
  28
  29 namespace {
  30
  31 struct FormatInfo {
  32   GLenum format;
  33   const GLenum* types;
  34   size_t count;
  35 };
  36
  37 class StringSet {
  38  public:
  39   StringSet() {}
  40
  41   StringSet(const char* s) {
  42     Init(s);
  43   }
  44
  45   StringSet(const std::string& str) {
  46     Init(str);
  47   }
  48
  49   StringSet(const std::vector<std::string>& strs) {
  50     string_set_.insert(strs.begin(), strs.end());
  51   }
  52
  53   void Init(const char* s) {
  54     std::string str(s ? s : "");
  55     Init(str);
  56   }
  57
  58   void Init(const std::string& str) {
  59     std::vector<std::string> tokens;
  60     Tokenize(str, " ", &tokens);
  61     string_set_.insert(tokens.begin(), tokens.end());
  62   }
  63
  64   bool Contains(const char* s) {
  65     return string_set_.find(s) != string_set_.end();
  66   }
  67
  68   bool Contains(const std::string& s) {
  69     return string_set_.find(s) != string_set_.end();
  70   }
  71
  72   const std::set<std::string>& GetImpl() {
  73     return string_set_;
  74   }
  75
  76  private:
  77   std::set<std::string> string_set_;
  78 };
  79
  80 // Process a string of wordaround type IDs (seperated by ',') and set up
  81 // the corresponding Workaround flags.
  82 void StringToWorkarounds(
  83     const std::string& types, FeatureInfo::Workarounds* workarounds) {
  84   DCHECK(workarounds);
  85   std::vector<std::string> pieces;
  86   base::SplitString(types, ',', &pieces);
  87   for (size_t i = 0; i < pieces.size(); ++i) {
  88     int number = 0;
  89     bool succeed = base::StringToInt(pieces[i], &number);
  90     DCHECK(succeed);
  91     switch (number) {
  92 #define GPU_OP(type, name)    \
  93   case gpu::type:             \
  94     workarounds->name = true; \
  95     break;
  96       GPU_DRIVER_BUG_WORKAROUNDS(GPU_OP)
  97 #undef GPU_OP
  98       default:
  99         NOTIMPLEMENTED();
 100     }
 101   }
 102   if (workarounds->max_texture_size_limit_4096)
 103     workarounds->max_texture_size = 4096;
 104   if (workarounds->max_cube_map_texture_size_limit_4096)
 105     workarounds->max_cube_map_texture_size = 4096;
 106   if (workarounds->max_cube_map_texture_size_limit_1024)
 107     workarounds->max_cube_map_texture_size = 1024;
 108   if (workarounds->max_cube_map_texture_size_limit_512)
 109     workarounds->max_cube_map_texture_size = 512;
 110
 111   if (workarounds->max_fragment_uniform_vectors_32)
 112     workarounds->max_fragment_uniform_vectors = 32;
 113   if (workarounds->max_varying_vectors_16)
 114     workarounds->max_varying_vectors = 16;
 115   if (workarounds->max_vertex_uniform_vectors_256)
 116     workarounds->max_vertex_uniform_vectors = 256;
 117 }
 118
 119 }  // anonymous namespace.
 120
 121 FeatureInfo::FeatureFlags::FeatureFlags()
 122     : chromium_color_buffer_float_rgba(false),
 123       chromium_color_buffer_float_rgb(false),
 124       chromium_framebuffer_multisample(false),
 125       chromium_sync_query(false),
 126       use_core_framebuffer_multisample(false),
 127       multisampled_render_to_texture(false),
 128       use_img_for_multisampled_render_to_texture(false),
 129       oes_standard_derivatives(false),
 130       oes_egl_image_external(false),
 131       oes_depth24(false),
 132       oes_compressed_etc1_rgb8_texture(false),
 133       packed_depth24_stencil8(false),
 134       npot_ok(false),
 135       enable_texture_float_linear(false),
 136       enable_texture_half_float_linear(false),
 137       angle_translated_shader_source(false),
 138       angle_pack_reverse_row_order(false),
 139       arb_texture_rectangle(false),
 140       angle_instanced_arrays(false),
 141       occlusion_query_boolean(false),
 142       use_arb_occlusion_query2_for_occlusion_query_boolean(false),
 143       use_arb_occlusion_query_for_occlusion_query_boolean(false),
 144       native_vertex_array_object(false),
 145       ext_texture_format_atc(false),
 146       ext_texture_format_bgra8888(false),
 147       ext_texture_format_dxt1(false),
 148       ext_texture_format_dxt5(false),
 149       enable_shader_name_hashing(false),
 150       enable_samplers(false),
 151       ext_draw_buffers(false),
 152       nv_draw_buffers(false),
 153       ext_frag_depth(false),
 154       ext_shader_texture_lod(false),
 155       use_async_readpixels(false),
 156       map_buffer_range(false),
 157       ext_discard_framebuffer(false),
 158       angle_depth_texture(false),
 159       is_swiftshader(false),
 160       angle_texture_usage(false),
 161       ext_texture_storage(false),
 162       chromium_path_rendering(false),
 163       blend_equation_advanced(false),
 164       blend_equation_advanced_coherent(false),
 165       ext_texture_rg(false),
 166       enable_subscribe_uniform(false),
 167       emulate_primitive_restart_fixed_index(false) {
 168 }
 169
 170 FeatureInfo::Workarounds::Workarounds() :
 171 #define GPU_OP(type, name) name(false),
 172     GPU_DRIVER_BUG_WORKAROUNDS(GPU_OP)
 173 #undef GPU_OP
 174     max_texture_size(0),
 175     max_cube_map_texture_size(0),
 176     max_fragment_uniform_vectors(0),
 177     max_varying_vectors(0),
 178     max_vertex_uniform_vectors(0) {
 179 }
 180
 181 FeatureInfo::FeatureInfo() {
 182   InitializeBasicState(*base::CommandLine::ForCurrentProcess());
 183 }
 184
 185 FeatureInfo::FeatureInfo(const base::CommandLine& command_line) {
 186   InitializeBasicState(command_line);
 187 }
 188
 189 void FeatureInfo::InitializeBasicState(const base::CommandLine& command_line) {
 190   if (command_line.HasSwitch(switches::kGpuDriverBugWorkarounds)) {
 191     std::string types = command_line.GetSwitchValueASCII(
 192         switches::kGpuDriverBugWorkarounds);
 193     StringToWorkarounds(types, &workarounds_);
 194   }
 195   feature_flags_.enable_shader_name_hashing =
 196       !command_line.HasSwitch(switches::kDisableShaderNameHashing);
 197
 198   feature_flags_.is_swiftshader =
 199       (command_line.GetSwitchValueASCII(switches::kUseGL) == "swiftshader");
 200
 201   feature_flags_.enable_subscribe_uniform =
 202       command_line.HasSwitch(switches::kEnableSubscribeUniformExtension);
 203
 204   enable_unsafe_es3_apis_switch_ =
 205       command_line.HasSwitch(switches::kEnableUnsafeES3APIs);
 206
 207   unsafe_es3_apis_enabled_ = false;
 208 }
 209
 210 bool FeatureInfo::Initialize() {
 211   disallowed_features_ = DisallowedFeatures();
 212   InitializeFeatures();
 213   return true;
 214 }
 215
 216 bool FeatureInfo::Initialize(const DisallowedFeatures& disallowed_features) {
 217   disallowed_features_ = disallowed_features;
 218   InitializeFeatures();
 219   return true;
 220 }
 221
 222 bool IsGL_REDSupportedOnFBOs() {
 223   // Skia uses GL_RED with frame buffers, unfortunately, Mesa claims to support
 224   // GL_EXT_texture_rg, but it doesn't support it on frame buffers.  To fix
 225   // this, we try it, and if it fails, we don't expose GL_EXT_texture_rg.
 226   GLint fb_binding = 0;
 227   GLint tex_binding = 0;
 228   glGetIntegerv(GL_FRAMEBUFFER_BINDING, &fb_binding);
 229   glGetIntegerv(GL_TEXTURE_BINDING_2D, &tex_binding);
 230
 231   GLuint textureId = 0;
 232   glGenTextures(1, &textureId);
 233   glBindTexture(GL_TEXTURE_2D, textureId);
 234   GLubyte data[1] = {0};
 235   glTexImage2D(GL_TEXTURE_2D, 0, GL_RED_EXT, 1, 1, 0, GL_RED_EXT,
 236                GL_UNSIGNED_BYTE, data);
 237   GLuint textureFBOID = 0;
 238   glGenFramebuffersEXT(1, &textureFBOID);
 239   glBindFramebufferEXT(GL_FRAMEBUFFER, textureFBOID);
 240   glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
 241                             textureId, 0);
 242   bool result =
 243       glCheckFramebufferStatusEXT(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_UNSUPPORTED;
 244   glDeleteFramebuffersEXT(1, &textureFBOID);
 245   glDeleteTextures(1, &textureId);
 246
 247   glBindFramebufferEXT(GL_FRAMEBUFFER, static_cast<GLuint>(fb_binding));
 248   glBindTexture(GL_TEXTURE_2D, static_cast<GLuint>(tex_binding));
 249
 250   DCHECK(glGetError() == GL_NO_ERROR);
 251
 252   return result;
 253 }
 254
 255 void FeatureInfo::InitializeFeatures() {
 256   // Figure out what extensions to turn on.
 257   StringSet extensions;
 258   // We need to figure out how to query the extension string before we
 259   // have a GLVersionInfo available.
 260   const char* version_str =
 261       reinterpret_cast<const char*>(glGetString(GL_VERSION));
 262   unsigned major_version, minor_version;
 263   bool is_es, is_es3;
 264   gfx::GLVersionInfo::ParseVersionString(
 265       version_str, &major_version, &minor_version, &is_es, &is_es3);
 266   if (!is_es && major_version >= 3) {
 267     std::vector<std::string> exts;
 268     GLint num_extensions = 0;
 269     glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
 270     for (GLint i = 0; i < num_extensions; ++i) {
 271       const char* extension = reinterpret_cast<const char*>(
 272           glGetStringi(GL_EXTENSIONS, i));
 273       DCHECK(extension != NULL);
 274       exts.push_back(extension);
 275     }
 276     extensions = exts;
 277   } else {
 278     extensions = reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS));
 279   }
 280
 281   const char* renderer_str =
 282       reinterpret_cast<const char*>(glGetString(GL_RENDERER));
 283
 284   gl_version_info_.reset(new gfx::GLVersionInfo(
 285       version_str, renderer_str, extensions.GetImpl()));
 286
 287   AddExtensionString("GL_ANGLE_translated_shader_source");
 288   AddExtensionString("GL_CHROMIUM_async_pixel_transfers");
 289   AddExtensionString("GL_CHROMIUM_bind_uniform_location");
 290   AddExtensionString("GL_CHROMIUM_command_buffer_query");
 291   AddExtensionString("GL_CHROMIUM_command_buffer_latency_query");
 292   AddExtensionString("GL_CHROMIUM_copy_texture");
 293   AddExtensionString("GL_CHROMIUM_get_error_query");
 294   AddExtensionString("GL_CHROMIUM_lose_context");
 295   AddExtensionString("GL_CHROMIUM_pixel_transfer_buffer_object");
 296   AddExtensionString("GL_CHROMIUM_rate_limit_offscreen_context");
 297   AddExtensionString("GL_CHROMIUM_resize");
 298   AddExtensionString("GL_CHROMIUM_resource_safe");
 299   AddExtensionString("GL_CHROMIUM_strict_attribs");
 300   AddExtensionString("GL_CHROMIUM_texture_mailbox");
 301   AddExtensionString("GL_CHROMIUM_trace_marker");
 302   AddExtensionString("GL_EXT_debug_marker");
 303
 304   if (feature_flags_.enable_subscribe_uniform) {
 305     AddExtensionString("GL_CHROMIUM_subscribe_uniform");
 306   }
 307
 308   // OES_vertex_array_object is emulated if not present natively,
 309   // so the extension string is always exposed.
 310   AddExtensionString("GL_OES_vertex_array_object");
 311
 312   if (!disallowed_features_.gpu_memory_manager)
 313     AddExtensionString("GL_CHROMIUM_gpu_memory_manager");
 314
 315   if (extensions.Contains("GL_ANGLE_translated_shader_source")) {
 316     feature_flags_.angle_translated_shader_source = true;
 317   }
 318
 319   // Check if we should allow GL_EXT_texture_compression_dxt1 and
 320   // GL_EXT_texture_compression_s3tc.
 321   bool enable_dxt1 = false;
 322   bool enable_dxt3 = false;
 323   bool enable_dxt5 = false;
 324   bool have_s3tc = extensions.Contains("GL_EXT_texture_compression_s3tc");
 325   bool have_dxt3 =
 326       have_s3tc || extensions.Contains("GL_ANGLE_texture_compression_dxt3");
 327   bool have_dxt5 =
 328       have_s3tc || extensions.Contains("GL_ANGLE_texture_compression_dxt5");
 329
 330   if (extensions.Contains("GL_EXT_texture_compression_dxt1") || have_s3tc) {
 331     enable_dxt1 = true;
 332   }
 333   if (have_dxt3) {
 334     enable_dxt3 = true;
 335   }
 336   if (have_dxt5) {
 337     enable_dxt5 = true;
 338   }
 339
 340   if (enable_dxt1) {
 341     feature_flags_.ext_texture_format_dxt1 = true;
 342
 343     AddExtensionString("GL_EXT_texture_compression_dxt1");
 344     validators_.compressed_texture_format.AddValue(
 345         GL_COMPRESSED_RGB_S3TC_DXT1_EXT);
 346     validators_.compressed_texture_format.AddValue(
 347         GL_COMPRESSED_RGBA_S3TC_DXT1_EXT);
 348   }
 349
 350   if (enable_dxt3) {
 351     // The difference between GL_EXT_texture_compression_s3tc and
 352     // GL_CHROMIUM_texture_compression_dxt3 is that the former
 353     // requires on the fly compression. The latter does not.
 354     AddExtensionString("GL_CHROMIUM_texture_compression_dxt3");
 355     validators_.compressed_texture_format.AddValue(
 356         GL_COMPRESSED_RGBA_S3TC_DXT3_EXT);
 357   }
 358
 359   if (enable_dxt5) {
 360     feature_flags_.ext_texture_format_dxt5 = true;
 361
 362     // The difference between GL_EXT_texture_compression_s3tc and
 363     // GL_CHROMIUM_texture_compression_dxt5 is that the former
 364     // requires on the fly compression. The latter does not.
 365     AddExtensionString("GL_CHROMIUM_texture_compression_dxt5");
 366     validators_.compressed_texture_format.AddValue(
 367         GL_COMPRESSED_RGBA_S3TC_DXT5_EXT);
 368   }
 369
 370   bool have_atc = extensions.Contains("GL_AMD_compressed_ATC_texture") ||
 371                   extensions.Contains("GL_ATI_texture_compression_atitc");
 372   if (have_atc) {
 373     feature_flags_.ext_texture_format_atc = true;
 374
 375     AddExtensionString("GL_AMD_compressed_ATC_texture");
 376     validators_.compressed_texture_format.AddValue(GL_ATC_RGB_AMD);
 377     validators_.compressed_texture_format.AddValue(
 378         GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD);
 379   }
 380
 381   // Check if we should enable GL_EXT_texture_filter_anisotropic.
 382   if (extensions.Contains("GL_EXT_texture_filter_anisotropic")) {
 383     AddExtensionString("GL_EXT_texture_filter_anisotropic");
 384     validators_.texture_parameter.AddValue(
 385         GL_TEXTURE_MAX_ANISOTROPY_EXT);
 386     validators_.g_l_state.AddValue(
 387         GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT);
 388   }
 389
 390   // Check if we should support GL_OES_packed_depth_stencil and/or
 391   // GL_GOOGLE_depth_texture / GL_CHROMIUM_depth_texture.
 392   //
 393   // NOTE: GL_OES_depth_texture requires support for depth cubemaps.
 394   // GL_ARB_depth_texture requires other features that
 395   // GL_OES_packed_depth_stencil does not provide.
 396   //
 397   // Therefore we made up GL_GOOGLE_depth_texture / GL_CHROMIUM_depth_texture.
 398   //
 399   // GL_GOOGLE_depth_texture is legacy. As we exposed it into NaCl we can't
 400   // get rid of it.
 401   //
 402   bool enable_depth_texture = false;
 403   if (!workarounds_.disable_depth_texture &&
 404       (extensions.Contains("GL_ARB_depth_texture") ||
 405        extensions.Contains("GL_OES_depth_texture") ||
 406        extensions.Contains("GL_ANGLE_depth_texture") ||
 407        gl_version_info_->is_es3 ||
 408        gl_version_info_->is_desktop_core_profile)) {
 409     enable_depth_texture = true;
 410     feature_flags_.angle_depth_texture =
 411         extensions.Contains("GL_ANGLE_depth_texture");
 412   }
 413
 414   if (enable_depth_texture) {
 415     AddExtensionString("GL_CHROMIUM_depth_texture");
 416     AddExtensionString("GL_GOOGLE_depth_texture");
 417     validators_.texture_internal_format.AddValue(GL_DEPTH_COMPONENT);
 418     validators_.texture_format.AddValue(GL_DEPTH_COMPONENT);
 419     validators_.pixel_type.AddValue(GL_UNSIGNED_SHORT);
 420     validators_.pixel_type.AddValue(GL_UNSIGNED_INT);
 421   }
 422
 423   if (extensions.Contains("GL_EXT_packed_depth_stencil") ||
 424       extensions.Contains("GL_OES_packed_depth_stencil") ||
 425       gl_version_info_->is_es3 ||
 426       gl_version_info_->is_desktop_core_profile) {
 427     AddExtensionString("GL_OES_packed_depth_stencil");
 428     feature_flags_.packed_depth24_stencil8 = true;
 429     if (enable_depth_texture) {
 430       validators_.texture_internal_format.AddValue(GL_DEPTH_STENCIL);
 431       validators_.texture_format.AddValue(GL_DEPTH_STENCIL);
 432       validators_.pixel_type.AddValue(GL_UNSIGNED_INT_24_8);
 433     }
 434     validators_.render_buffer_format.AddValue(GL_DEPTH24_STENCIL8);
 435   }
 436
 437   if (gl_version_info_->is_es3 ||
 438       gl_version_info_->is_desktop_core_profile ||
 439       extensions.Contains("GL_OES_vertex_array_object") ||
 440       extensions.Contains("GL_ARB_vertex_array_object") ||
 441       extensions.Contains("GL_APPLE_vertex_array_object")) {
 442     feature_flags_.native_vertex_array_object = true;
 443   }
 444
 445   // If we're using client_side_arrays we have to emulate
 446   // vertex array objects since vertex array objects do not work
 447   // with client side arrays.
 448   if (workarounds_.use_client_side_arrays_for_stream_buffers) {
 449     feature_flags_.native_vertex_array_object = false;
 450   }
 451
 452   if (gl_version_info_->is_es3 ||
 453       extensions.Contains("GL_OES_element_index_uint") ||
 454       gfx::HasDesktopGLFeatures()) {
 455     AddExtensionString("GL_OES_element_index_uint");
 456     validators_.index_type.AddValue(GL_UNSIGNED_INT);
 457   }
 458
 459   // With EXT_sRGB, unsized SRGB_EXT and SRGB_ALPHA_EXT are accepted by the
 460   // <format> and <internalformat> parameter of TexImage2D. GLES3 adds support
 461   // for SRGB Textures but the accepted internal formats for TexImage2D are only
 462   // sized formats GL_SRGB8 and GL_SRGB8_ALPHA8. Also, SRGB_EXT isn't a valid
 463   // <format> in this case. So, even with GLES3 explicitly check for
 464   // GL_EXT_sRGB.
 465   if (((gl_version_info_->is_es3 ||
 466         extensions.Contains("GL_OES_rgb8_rgba8")) &&
 467       extensions.Contains("GL_EXT_sRGB")) || gfx::HasDesktopGLFeatures()) {
 468     AddExtensionString("GL_EXT_sRGB");
 469     validators_.texture_internal_format.AddValue(GL_SRGB_EXT);
 470     validators_.texture_internal_format.AddValue(GL_SRGB_ALPHA_EXT);
 471     validators_.texture_format.AddValue(GL_SRGB_EXT);
 472     validators_.texture_format.AddValue(GL_SRGB_ALPHA_EXT);
 473     validators_.render_buffer_format.AddValue(GL_SRGB8_ALPHA8_EXT);
 474     validators_.frame_buffer_parameter.AddValue(
 475         GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING_EXT);
 476   }
 477
 478   bool enable_texture_format_bgra8888 = false;
 479   bool enable_read_format_bgra = false;
 480   bool enable_render_buffer_bgra = false;
 481   bool enable_immutable_texture_format_bgra_on_es3 =
 482       extensions.Contains("GL_APPLE_texture_format_BGRA8888");
 483
 484   // Check if we should allow GL_EXT_texture_format_BGRA8888
 485   if (extensions.Contains("GL_EXT_texture_format_BGRA8888") ||
 486       enable_immutable_texture_format_bgra_on_es3 ||
 487       extensions.Contains("GL_EXT_bgra")) {
 488     enable_texture_format_bgra8888 = true;
 489   }
 490
 491   // Only desktop GL extension GL_EXT_bgra or ANGLE guarantee that we can
 492   // allocate a renderbuffer with this format.
 493   if (extensions.Contains("GL_EXT_bgra") || gl_version_info_->is_angle) {
 494     enable_render_buffer_bgra = true;
 495   }
 496
 497   if (extensions.Contains("GL_EXT_read_format_bgra") ||
 498       extensions.Contains("GL_EXT_bgra")) {
 499     enable_read_format_bgra = true;
 500   }
 501
 502   if (enable_texture_format_bgra8888) {
 503     feature_flags_.ext_texture_format_bgra8888 = true;
 504     AddExtensionString("GL_EXT_texture_format_BGRA8888");
 505     validators_.texture_internal_format.AddValue(GL_BGRA_EXT);
 506     validators_.texture_format.AddValue(GL_BGRA_EXT);
 507   }
 508
 509   if (enable_read_format_bgra) {
 510     AddExtensionString("GL_EXT_read_format_bgra");
 511     validators_.read_pixel_format.AddValue(GL_BGRA_EXT);
 512   }
 513
 514   if (enable_render_buffer_bgra) {
 515     AddExtensionString("GL_CHROMIUM_renderbuffer_format_BGRA8888");
 516     validators_.render_buffer_format.AddValue(GL_BGRA8_EXT);
 517   }
 518
 519   if (extensions.Contains("GL_OES_rgb8_rgba8") || gfx::HasDesktopGLFeatures()) {
 520     AddExtensionString("GL_OES_rgb8_rgba8");
 521     validators_.render_buffer_format.AddValue(GL_RGB8_OES);
 522     validators_.render_buffer_format.AddValue(GL_RGBA8_OES);
 523   }
 524
 525   // Check if we should allow GL_OES_texture_npot
 526   if (gl_version_info_->is_es3 ||
 527       gl_version_info_->is_desktop_core_profile ||
 528       extensions.Contains("GL_ARB_texture_non_power_of_two") ||
 529       extensions.Contains("GL_OES_texture_npot")) {
 530     AddExtensionString("GL_OES_texture_npot");
 531     feature_flags_.npot_ok = true;
 532   }
 533
 534   // Check if we should allow GL_OES_texture_float, GL_OES_texture_half_float,
 535   // GL_OES_texture_float_linear, GL_OES_texture_half_float_linear
 536   bool enable_texture_float = false;
 537   bool enable_texture_float_linear = false;
 538   bool enable_texture_half_float = false;
 539   bool enable_texture_half_float_linear = false;
 540
 541   bool may_enable_chromium_color_buffer_float = false;
 542
 543   if (extensions.Contains("GL_ARB_texture_float") ||
 544       gl_version_info_->is_desktop_core_profile) {
 545     enable_texture_float = true;
 546     enable_texture_float_linear = true;
 547     enable_texture_half_float = true;
 548     enable_texture_half_float_linear = true;
 549     may_enable_chromium_color_buffer_float = true;
 550   } else {
 551     // GLES3 adds support for Float type by default but it doesn't support all
 552     // formats as GL_OES_texture_float(i.e.LUMINANCE_ALPHA,LUMINANCE and Alpha)
 553     if (extensions.Contains("GL_OES_texture_float")) {
 554       enable_texture_float = true;
 555       if (extensions.Contains("GL_OES_texture_float_linear")) {
 556         enable_texture_float_linear = true;
 557       }
 558       // This extension allows a variety of floating point formats to be
 559       // rendered to via framebuffer objects. Enable it's usage only if
 560       // support for Floating textures is enabled.
 561       if ((gl_version_info_->is_es3 &&
 562            extensions.Contains("GL_EXT_color_buffer_float")) ||
 563           gl_version_info_->is_angle) {
 564         may_enable_chromium_color_buffer_float = true;
 565       }
 566     }
 567
 568     // TODO(dshwang): GLES3 supports half float by default but GL_HALF_FLOAT_OES
 569     // isn't equal to GL_HALF_FLOAT.
 570     if (extensions.Contains("GL_OES_texture_half_float")) {
 571       enable_texture_half_float = true;
 572       if (extensions.Contains("GL_OES_texture_half_float_linear")) {
 573         enable_texture_half_float_linear = true;
 574       }
 575     }
 576   }
 577
 578   if (enable_texture_float) {
 579     validators_.pixel_type.AddValue(GL_FLOAT);
 580     validators_.read_pixel_type.AddValue(GL_FLOAT);
 581     AddExtensionString("GL_OES_texture_float");
 582     if (enable_texture_float_linear) {
 583       AddExtensionString("GL_OES_texture_float_linear");
 584     }
 585   }
 586
 587   if (enable_texture_half_float) {
 588     validators_.pixel_type.AddValue(GL_HALF_FLOAT_OES);
 589     validators_.read_pixel_type.AddValue(GL_HALF_FLOAT_OES);
 590     AddExtensionString("GL_OES_texture_half_float");
 591     if (enable_texture_half_float_linear) {
 592       AddExtensionString("GL_OES_texture_half_float_linear");
 593     }
 594   }
 595
 596   if (may_enable_chromium_color_buffer_float) {
 597     static_assert(GL_RGBA32F_ARB == GL_RGBA32F &&
 598                   GL_RGBA32F_EXT == GL_RGBA32F &&
 599                   GL_RGB32F_ARB == GL_RGB32F &&
 600                   GL_RGB32F_EXT == GL_RGB32F,
 601                   "sized float internal format variations must match");
 602     // We don't check extension support beyond ARB_texture_float on desktop GL,
 603     // and format support varies between GL configurations. For example, spec
 604     // prior to OpenGL 3.0 mandates framebuffer support only for one
 605     // implementation-chosen format, and ES3.0 EXT_color_buffer_float does not
 606     // support rendering to RGB32F. Check for framebuffer completeness with
 607     // formats that the extensions expose, and only enable an extension when a
 608     // framebuffer created with its texture format is reported as complete.
 609     GLint fb_binding = 0;
 610     GLint tex_binding = 0;
 611     glGetIntegerv(GL_FRAMEBUFFER_BINDING, &fb_binding);
 612     glGetIntegerv(GL_TEXTURE_BINDING_2D, &tex_binding);
 613
 614     GLuint tex_id = 0;
 615     GLuint fb_id = 0;
 616     GLsizei width = 16;
 617
 618     glGenTextures(1, &tex_id);
 619     glGenFramebuffersEXT(1, &fb_id);
 620     glBindTexture(GL_TEXTURE_2D, tex_id);
 621     // Nearest filter needed for framebuffer completeness on some drivers.
 622     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 623     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, width, 0, GL_RGBA,
 624                  GL_FLOAT, NULL);
 625     glBindFramebufferEXT(GL_FRAMEBUFFER, fb_id);
 626     glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 627                               GL_TEXTURE_2D, tex_id, 0);
 628     GLenum statusRGBA = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER);
 629     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, width, width, 0, GL_RGB,
 630                  GL_FLOAT, NULL);
 631     GLenum statusRGB = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER);
 632     glDeleteFramebuffersEXT(1, &fb_id);
 633     glDeleteTextures(1, &tex_id);
 634
 635     glBindFramebufferEXT(GL_FRAMEBUFFER, static_cast<GLuint>(fb_binding));
 636     glBindTexture(GL_TEXTURE_2D, static_cast<GLuint>(tex_binding));
 637
 638     DCHECK(glGetError() == GL_NO_ERROR);
 639
 640     if (statusRGBA == GL_FRAMEBUFFER_COMPLETE) {
 641       validators_.texture_internal_format.AddValue(GL_RGBA32F);
 642       feature_flags_.chromium_color_buffer_float_rgba = true;
 643       AddExtensionString("GL_CHROMIUM_color_buffer_float_rgba");
 644     }
 645     if (statusRGB == GL_FRAMEBUFFER_COMPLETE) {
 646       validators_.texture_internal_format.AddValue(GL_RGB32F);
 647       feature_flags_.chromium_color_buffer_float_rgb = true;
 648       AddExtensionString("GL_CHROMIUM_color_buffer_float_rgb");
 649     }
 650   }
 651
 652   // Check for multisample support
 653   if (!workarounds_.disable_chromium_framebuffer_multisample) {
 654     bool ext_has_multisample =
 655         extensions.Contains("GL_EXT_framebuffer_multisample") ||
 656         gl_version_info_->is_es3 ||
 657         gl_version_info_->is_desktop_core_profile;
 658     if (gl_version_info_->is_angle) {
 659       ext_has_multisample |=
 660           extensions.Contains("GL_ANGLE_framebuffer_multisample");
 661     }
 662     feature_flags_.use_core_framebuffer_multisample =
 663         gl_version_info_->is_es3 || gl_version_info_->is_desktop_core_profile;
 664     if (ext_has_multisample) {
 665       feature_flags_.chromium_framebuffer_multisample = true;
 666       validators_.frame_buffer_target.AddValue(GL_READ_FRAMEBUFFER_EXT);
 667       validators_.frame_buffer_target.AddValue(GL_DRAW_FRAMEBUFFER_EXT);
 668       validators_.g_l_state.AddValue(GL_READ_FRAMEBUFFER_BINDING_EXT);
 669       validators_.g_l_state.AddValue(GL_MAX_SAMPLES_EXT);
 670       validators_.render_buffer_parameter.AddValue(GL_RENDERBUFFER_SAMPLES_EXT);
 671       AddExtensionString("GL_CHROMIUM_framebuffer_multisample");
 672     }
 673   }
 674
 675   if (!workarounds_.disable_multisampled_render_to_texture) {
 676     if (extensions.Contains("GL_EXT_multisampled_render_to_texture")) {
 677       feature_flags_.multisampled_render_to_texture = true;
 678     } else if (extensions.Contains("GL_IMG_multisampled_render_to_texture")) {
 679       feature_flags_.multisampled_render_to_texture = true;
 680       feature_flags_.use_img_for_multisampled_render_to_texture = true;
 681     }
 682     if (feature_flags_.multisampled_render_to_texture) {
 683       validators_.render_buffer_parameter.AddValue(
 684           GL_RENDERBUFFER_SAMPLES_EXT);
 685       validators_.g_l_state.AddValue(GL_MAX_SAMPLES_EXT);
 686       validators_.frame_buffer_parameter.AddValue(
 687           GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_SAMPLES_EXT);
 688       AddExtensionString("GL_EXT_multisampled_render_to_texture");
 689     }
 690   }
 691
 692   if (extensions.Contains("GL_OES_depth24") || gfx::HasDesktopGLFeatures() ||
 693       gl_version_info_->is_es3) {
 694     AddExtensionString("GL_OES_depth24");
 695     feature_flags_.oes_depth24 = true;
 696     validators_.render_buffer_format.AddValue(GL_DEPTH_COMPONENT24);
 697   }
 698
 699   if (!workarounds_.disable_oes_standard_derivatives &&
 700       (gl_version_info_->is_es3 ||
 701        extensions.Contains("GL_OES_standard_derivatives") ||
 702        gfx::HasDesktopGLFeatures())) {
 703     AddExtensionString("GL_OES_standard_derivatives");
 704     feature_flags_.oes_standard_derivatives = true;
 705     validators_.hint_target.AddValue(GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
 706     validators_.g_l_state.AddValue(GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
 707   }
 708
 709   if (extensions.Contains("GL_OES_EGL_image_external")) {
 710     AddExtensionString("GL_OES_EGL_image_external");
 711     feature_flags_.oes_egl_image_external = true;
 712     validators_.texture_bind_target.AddValue(GL_TEXTURE_EXTERNAL_OES);
 713     validators_.get_tex_param_target.AddValue(GL_TEXTURE_EXTERNAL_OES);
 714     validators_.texture_parameter.AddValue(GL_REQUIRED_TEXTURE_IMAGE_UNITS_OES);
 715     validators_.g_l_state.AddValue(GL_TEXTURE_BINDING_EXTERNAL_OES);
 716   }
 717
 718   if (extensions.Contains("GL_OES_compressed_ETC1_RGB8_texture")) {
 719     AddExtensionString("GL_OES_compressed_ETC1_RGB8_texture");
 720     feature_flags_.oes_compressed_etc1_rgb8_texture = true;
 721     validators_.compressed_texture_format.AddValue(GL_ETC1_RGB8_OES);
 722   }
 723
 724   if (extensions.Contains("GL_AMD_compressed_ATC_texture")) {
 725     AddExtensionString("GL_AMD_compressed_ATC_texture");
 726     validators_.compressed_texture_format.AddValue(
 727         GL_ATC_RGB_AMD);
 728     validators_.compressed_texture_format.AddValue(
 729         GL_ATC_RGBA_EXPLICIT_ALPHA_AMD);
 730     validators_.compressed_texture_format.AddValue(
 731         GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD);
 732   }
 733
 734   if (extensions.Contains("GL_IMG_texture_compression_pvrtc")) {
 735     AddExtensionString("GL_IMG_texture_compression_pvrtc");
 736     validators_.compressed_texture_format.AddValue(
 737         GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG);
 738     validators_.compressed_texture_format.AddValue(
 739         GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG);
 740     validators_.compressed_texture_format.AddValue(
 741         GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG);
 742     validators_.compressed_texture_format.AddValue(
 743         GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG);
 744   }
 745
 746   // Ideally we would only expose this extension on Mac OS X, to
 747   // support GL_CHROMIUM_iosurface and the compositor. We don't want
 748   // applications to start using it; they should use ordinary non-
 749   // power-of-two textures. However, for unit testing purposes we
 750   // expose it on all supported platforms.
 751   if (extensions.Contains("GL_ARB_texture_rectangle") ||
 752       gl_version_info_->is_desktop_core_profile) {
 753     AddExtensionString("GL_ARB_texture_rectangle");
 754     feature_flags_.arb_texture_rectangle = true;
 755     validators_.texture_bind_target.AddValue(GL_TEXTURE_RECTANGLE_ARB);
 756     // For the moment we don't add this enum to the texture_target
 757     // validator. This implies that the only way to get image data into a
 758     // rectangular texture is via glTexImageIOSurface2DCHROMIUM, which is
 759     // just fine since again we don't want applications depending on this
 760     // extension.
 761     validators_.get_tex_param_target.AddValue(GL_TEXTURE_RECTANGLE_ARB);
 762     validators_.g_l_state.AddValue(GL_TEXTURE_BINDING_RECTANGLE_ARB);
 763   }
 764
 765 #if defined(OS_MACOSX)
 766   AddExtensionString("GL_CHROMIUM_iosurface");
 767 #endif
 768
 769   // TODO(gman): Add support for these extensions.
 770   //     GL_OES_depth32
 771
 772   feature_flags_.enable_texture_float_linear |= enable_texture_float_linear;
 773   feature_flags_.enable_texture_half_float_linear |=
 774       enable_texture_half_float_linear;
 775
 776   if (extensions.Contains("GL_ANGLE_pack_reverse_row_order")) {
 777     AddExtensionString("GL_ANGLE_pack_reverse_row_order");
 778     feature_flags_.angle_pack_reverse_row_order = true;
 779     validators_.pixel_store.AddValue(GL_PACK_REVERSE_ROW_ORDER_ANGLE);
 780     validators_.g_l_state.AddValue(GL_PACK_REVERSE_ROW_ORDER_ANGLE);
 781   }
 782
 783   if (extensions.Contains("GL_ANGLE_texture_usage")) {
 784     feature_flags_.angle_texture_usage = true;
 785     AddExtensionString("GL_ANGLE_texture_usage");
 786     validators_.texture_parameter.AddValue(GL_TEXTURE_USAGE_ANGLE);
 787   }
 788
 789   // Note: Only APPLE_texture_format_BGRA8888 extension allows BGRA8_EXT in
 790   // ES3's glTexStorage2D. We prefer support BGRA to texture storage.
 791   // So we don't expose GL_EXT_texture_storage when ES3 +
 792   // GL_EXT_texture_format_BGRA8888 because we fail the GL_BGRA8 requirement.
 793   // However we expose GL_EXT_texture_storage when just ES3 because we don't
 794   // claim to handle GL_BGRA8.
 795   bool support_texture_storage_on_es3 =
 796       (gl_version_info_->is_es3 &&
 797        enable_immutable_texture_format_bgra_on_es3) ||
 798       (gl_version_info_->is_es3 &&
 799        !enable_texture_format_bgra8888);
 800   if (extensions.Contains("GL_EXT_texture_storage") ||
 801       extensions.Contains("GL_ARB_texture_storage") ||
 802       support_texture_storage_on_es3 ||
 803       gl_version_info_->is_desktop_core_profile) {
 804     feature_flags_.ext_texture_storage = true;
 805     AddExtensionString("GL_EXT_texture_storage");
 806     validators_.texture_parameter.AddValue(GL_TEXTURE_IMMUTABLE_FORMAT_EXT);
 807     if (enable_texture_format_bgra8888)
 808         validators_.texture_internal_format_storage.AddValue(GL_BGRA8_EXT);
 809     if (enable_texture_float) {
 810         validators_.texture_internal_format_storage.AddValue(GL_RGBA32F_EXT);
 811         validators_.texture_internal_format_storage.AddValue(GL_RGB32F_EXT);
 812         validators_.texture_internal_format_storage.AddValue(GL_ALPHA32F_EXT);
 813         validators_.texture_internal_format_storage.AddValue(
 814             GL_LUMINANCE32F_EXT);
 815         validators_.texture_internal_format_storage.AddValue(
 816             GL_LUMINANCE_ALPHA32F_EXT);
 817     }
 818     if (enable_texture_half_float) {
 819         validators_.texture_internal_format_storage.AddValue(GL_RGBA16F_EXT);
 820         validators_.texture_internal_format_storage.AddValue(GL_RGB16F_EXT);
 821         validators_.texture_internal_format_storage.AddValue(GL_ALPHA16F_EXT);
 822         validators_.texture_internal_format_storage.AddValue(
 823             GL_LUMINANCE16F_EXT);
 824         validators_.texture_internal_format_storage.AddValue(
 825             GL_LUMINANCE_ALPHA16F_EXT);
 826     }
 827   }
 828
 829   bool have_ext_occlusion_query_boolean =
 830       extensions.Contains("GL_EXT_occlusion_query_boolean");
 831   bool have_arb_occlusion_query2 =
 832       extensions.Contains("GL_ARB_occlusion_query2");
 833   bool have_arb_occlusion_query =
 834       extensions.Contains("GL_ARB_occlusion_query");
 835
 836   if (!workarounds_.disable_ext_occlusion_query &&
 837       (have_ext_occlusion_query_boolean ||
 838        have_arb_occlusion_query2 ||
 839        have_arb_occlusion_query)) {
 840     AddExtensionString("GL_EXT_occlusion_query_boolean");
 841     feature_flags_.occlusion_query_boolean = true;
 842     feature_flags_.use_arb_occlusion_query2_for_occlusion_query_boolean =
 843         !have_ext_occlusion_query_boolean && have_arb_occlusion_query2;
 844     feature_flags_.use_arb_occlusion_query_for_occlusion_query_boolean =
 845         !have_ext_occlusion_query_boolean && have_arb_occlusion_query &&
 846         !have_arb_occlusion_query2;
 847   }
 848
 849   if (!workarounds_.disable_angle_instanced_arrays &&
 850       (extensions.Contains("GL_ANGLE_instanced_arrays") ||
 851        (extensions.Contains("GL_ARB_instanced_arrays") &&
 852         extensions.Contains("GL_ARB_draw_instanced")) ||
 853        gl_version_info_->is_es3)) {
 854     AddExtensionString("GL_ANGLE_instanced_arrays");
 855     feature_flags_.angle_instanced_arrays = true;
 856     validators_.vertex_attribute.AddValue(GL_VERTEX_ATTRIB_ARRAY_DIVISOR_ANGLE);
 857   }
 858
 859   bool vendor_agnostic_draw_buffers =
 860       extensions.Contains("GL_ARB_draw_buffers") ||
 861       extensions.Contains("GL_EXT_draw_buffers");
 862   if (!workarounds_.disable_ext_draw_buffers &&
 863       (vendor_agnostic_draw_buffers ||
 864        (extensions.Contains("GL_NV_draw_buffers") &&
 865         gl_version_info_->is_es3) ||
 866        gl_version_info_->is_desktop_core_profile)) {
 867     AddExtensionString("GL_EXT_draw_buffers");
 868     feature_flags_.ext_draw_buffers = true;
 869
 870     // This flag is set to enable emulation of EXT_draw_buffers when we're
 871     // running on GLES 3.0+, NV_draw_buffers extension is supported and
 872     // glDrawBuffers from GLES 3.0 core has been bound. It toggles using the
 873     // NV_draw_buffers extension directive instead of EXT_draw_buffers extension
 874     // directive in ESSL 100 shaders translated by ANGLE, enabling them to write
 875     // into multiple gl_FragData values, which is not by default possible in
 876     // ESSL 100 with core GLES 3.0. For more information, see the
 877     // NV_draw_buffers specification.
 878     feature_flags_.nv_draw_buffers = !vendor_agnostic_draw_buffers;
 879
 880     GLint max_color_attachments = 0;
 881     glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS_EXT, &max_color_attachments);
 882     for (GLenum i = GL_COLOR_ATTACHMENT1_EXT;
 883          i < static_cast<GLenum>(GL_COLOR_ATTACHMENT0 + max_color_attachments);
 884          ++i) {
 885       validators_.attachment.AddValue(i);
 886     }
 887     static_assert(GL_COLOR_ATTACHMENT0_EXT == GL_COLOR_ATTACHMENT0,
 888                   "GL_COLOR_ATTACHMENT0_EXT should equal GL_COLOR_ATTACHMENT0");
 889
 890     validators_.g_l_state.AddValue(GL_MAX_COLOR_ATTACHMENTS_EXT);
 891     validators_.g_l_state.AddValue(GL_MAX_DRAW_BUFFERS_ARB);
 892     GLint max_draw_buffers = 0;
 893     glGetIntegerv(GL_MAX_DRAW_BUFFERS_ARB, &max_draw_buffers);
 894     for (GLenum i = GL_DRAW_BUFFER0_ARB;
 895          i < static_cast<GLenum>(GL_DRAW_BUFFER0_ARB + max_draw_buffers);
 896          ++i) {
 897       validators_.g_l_state.AddValue(i);
 898     }
 899   }
 900
 901   if (gl_version_info_->is_es3 ||
 902       extensions.Contains("GL_EXT_blend_minmax") ||
 903       gfx::HasDesktopGLFeatures()) {
 904     AddExtensionString("GL_EXT_blend_minmax");
 905     validators_.equation.AddValue(GL_MIN_EXT);
 906     validators_.equation.AddValue(GL_MAX_EXT);
 907     static_assert(GL_MIN_EXT == GL_MIN && GL_MAX_EXT == GL_MAX,
 908                   "min & max variations must match");
 909   }
 910
 911   // TODO(dshwang): GLES3 supports gl_FragDepth, not gl_FragDepthEXT.
 912   if (extensions.Contains("GL_EXT_frag_depth") || gfx::HasDesktopGLFeatures()) {
 913     AddExtensionString("GL_EXT_frag_depth");
 914     feature_flags_.ext_frag_depth = true;
 915   }
 916
 917   if (extensions.Contains("GL_EXT_shader_texture_lod") ||
 918       gfx::HasDesktopGLFeatures()) {
 919     AddExtensionString("GL_EXT_shader_texture_lod");
 920     feature_flags_.ext_shader_texture_lod = true;
 921   }
 922
 923 #if !defined(OS_MACOSX)
 924   if (workarounds_.disable_egl_khr_fence_sync) {
 925     gfx::g_driver_egl.ext.b_EGL_KHR_fence_sync = false;
 926   }
 927   if (workarounds_.disable_egl_khr_wait_sync) {
 928     gfx::g_driver_egl.ext.b_EGL_KHR_wait_sync = false;
 929   }
 930 #endif
 931   if (workarounds_.disable_arb_sync)
 932     gfx::g_driver_gl.ext.b_GL_ARB_sync = false;
 933   bool ui_gl_fence_works = gfx::GLFence::IsSupported();
 934   UMA_HISTOGRAM_BOOLEAN("GPU.FenceSupport", ui_gl_fence_works);
 935
 936   feature_flags_.map_buffer_range =
 937       gl_version_info_->is_es3 ||
 938       gl_version_info_->is_desktop_core_profile ||
 939       extensions.Contains("GL_ARB_map_buffer_range") ||
 940       extensions.Contains("GL_EXT_map_buffer_range");
 941
 942   // Really it's part of core OpenGL 2.1 and up, but let's assume the
 943   // extension is still advertised.
 944   bool has_pixel_buffers =
 945       gl_version_info_->is_es3 ||
 946       gl_version_info_->is_desktop_core_profile ||
 947       extensions.Contains("GL_ARB_pixel_buffer_object") ||
 948       extensions.Contains("GL_NV_pixel_buffer_object");
 949
 950   // We will use either glMapBuffer() or glMapBufferRange() for async readbacks.
 951   if (has_pixel_buffers && ui_gl_fence_works &&
 952       !workarounds_.disable_async_readpixels) {
 953     feature_flags_.use_async_readpixels = true;
 954   }
 955
 956   if (gl_version_info_->is_es3 ||
 957       extensions.Contains("GL_ARB_sampler_objects")) {
 958     feature_flags_.enable_samplers = true;
 959     // TODO(dsinclair): Add AddExtensionString("GL_CHROMIUM_sampler_objects")
 960     // when available.
 961   }
 962
 963   if ((gl_version_info_->is_es3 ||
 964        extensions.Contains("GL_EXT_discard_framebuffer")) &&
 965       !workarounds_.disable_discard_framebuffer) {
 966     // DiscardFramebufferEXT is automatically bound to InvalidateFramebuffer.
 967     AddExtensionString("GL_EXT_discard_framebuffer");
 968     feature_flags_.ext_discard_framebuffer = true;
 969   }
 970
 971   if (ui_gl_fence_works) {
 972     AddExtensionString("GL_CHROMIUM_sync_query");
 973     feature_flags_.chromium_sync_query = true;
 974   }
 975
 976   if (!workarounds_.disable_blend_equation_advanced) {
 977     bool blend_equation_advanced_coherent =
 978         extensions.Contains("GL_NV_blend_equation_advanced_coherent") ||
 979         extensions.Contains("GL_KHR_blend_equation_advanced_coherent");
 980
 981     if (blend_equation_advanced_coherent ||
 982         extensions.Contains("GL_NV_blend_equation_advanced") ||
 983         extensions.Contains("GL_KHR_blend_equation_advanced")) {
 984       const GLenum equations[] = {GL_MULTIPLY_KHR,
 985                                   GL_SCREEN_KHR,
 986                                   GL_OVERLAY_KHR,
 987                                   GL_DARKEN_KHR,
 988                                   GL_LIGHTEN_KHR,
 989                                   GL_COLORDODGE_KHR,
 990                                   GL_COLORBURN_KHR,
 991                                   GL_HARDLIGHT_KHR,
 992                                   GL_SOFTLIGHT_KHR,
 993                                   GL_DIFFERENCE_KHR,
 994                                   GL_EXCLUSION_KHR,
 995                                   GL_HSL_HUE_KHR,
 996                                   GL_HSL_SATURATION_KHR,
 997                                   GL_HSL_COLOR_KHR,
 998                                   GL_HSL_LUMINOSITY_KHR};
 999
1000       for (GLenum equation : equations)
1001         validators_.equation.AddValue(equation);
1002       if (blend_equation_advanced_coherent)
1003         AddExtensionString("GL_KHR_blend_equation_advanced_coherent");
1004
1005       AddExtensionString("GL_KHR_blend_equation_advanced");
1006       feature_flags_.blend_equation_advanced = true;
1007       feature_flags_.blend_equation_advanced_coherent =
1008           blend_equation_advanced_coherent;
1009     }
1010   }
1011
1012   if (extensions.Contains("GL_NV_path_rendering")) {
1013     if (extensions.Contains("GL_EXT_direct_state_access") ||
1014         gl_version_info_->is_es3) {
1015       AddExtensionString("GL_CHROMIUM_path_rendering");
1016       feature_flags_.chromium_path_rendering = true;
1017       validators_.g_l_state.AddValue(GL_PATH_MODELVIEW_MATRIX_CHROMIUM);
1018       validators_.g_l_state.AddValue(GL_PATH_PROJECTION_MATRIX_CHROMIUM);
1019     }
1020   }
1021
1022   if ((gl_version_info_->is_es3 || gl_version_info_->is_desktop_core_profile ||
1023        extensions.Contains("GL_EXT_texture_rg") ||
1024        extensions.Contains("GL_ARB_texture_rg")) &&
1025       IsGL_REDSupportedOnFBOs()) {
1026     feature_flags_.ext_texture_rg = true;
1027     AddExtensionString("GL_EXT_texture_rg");
1028
1029     validators_.texture_format.AddValue(GL_RED_EXT);
1030     validators_.texture_format.AddValue(GL_RG_EXT);
1031     validators_.texture_internal_format.AddValue(GL_RED_EXT);
1032     validators_.texture_internal_format.AddValue(GL_R8_EXT);
1033     validators_.texture_internal_format.AddValue(GL_RG_EXT);
1034     validators_.texture_internal_format.AddValue(GL_RG8_EXT);
1035     validators_.read_pixel_format.AddValue(GL_RED_EXT);
1036     validators_.read_pixel_format.AddValue(GL_RG_EXT);
1037     validators_.render_buffer_format.AddValue(GL_R8_EXT);
1038     validators_.render_buffer_format.AddValue(GL_RG8_EXT);
1039   }
1040   UMA_HISTOGRAM_BOOLEAN("GPU.TextureRG", feature_flags_.ext_texture_rg);
1041
1042 #if !defined(OS_MACOSX)
1043   if (workarounds_.ignore_egl_sync_failures) {
1044     gfx::GLFenceEGL::SetIgnoreFailures();
1045   }
1046 #endif
1047
1048   if (workarounds_.avoid_egl_image_target_texture_reuse) {
1049     TextureDefinition::AvoidEGLTargetTextureReuse();
1050   }
1051
1052   if (gl_version_info_->IsLowerThanGL(4, 3)) {
1053     // crbug.com/481184.
1054     // GL_PRIMITIVE_RESTART_FIXED_INDEX is only available on Desktop GL 4.3+,
1055     // but we emulate ES 3.0 on top of Desktop GL 4.2+.
1056     feature_flags_.emulate_primitive_restart_fixed_index = true;
1057   }
1058 }
1059
1060 bool FeatureInfo::IsES3Capable() const {
1061   if (!enable_unsafe_es3_apis_switch_)
1062     return false;
1063   if (gl_version_info_)
1064     return gl_version_info_->IsES3Capable();
1065   return false;
1066 }
1067
1068 void FeatureInfo::EnableES3Validators() {
1069   DCHECK(IsES3Capable());
1070   validators_.UpdateValuesES3();
1071
1072   GLint max_color_attachments = 0;
1073   glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS, &max_color_attachments);
1074   const int kTotalColorAttachmentEnums = 16;
1075   const GLenum kColorAttachments[] = {
1076     GL_COLOR_ATTACHMENT0,
1077     GL_COLOR_ATTACHMENT1,
1078     GL_COLOR_ATTACHMENT2,
1079     GL_COLOR_ATTACHMENT3,
1080     GL_COLOR_ATTACHMENT4,
1081     GL_COLOR_ATTACHMENT5,
1082     GL_COLOR_ATTACHMENT6,
1083     GL_COLOR_ATTACHMENT7,
1084     GL_COLOR_ATTACHMENT8,
1085     GL_COLOR_ATTACHMENT9,
1086     GL_COLOR_ATTACHMENT10,
1087     GL_COLOR_ATTACHMENT11,
1088     GL_COLOR_ATTACHMENT12,
1089     GL_COLOR_ATTACHMENT13,
1090     GL_COLOR_ATTACHMENT14,
1091     GL_COLOR_ATTACHMENT15,
1092   };
1093   if (max_color_attachments < kTotalColorAttachmentEnums) {
1094     validators_.attachment.RemoveValues(
1095         kColorAttachments + max_color_attachments,
1096         kTotalColorAttachmentEnums - max_color_attachments);
1097   }
1098
1099   GLint max_draw_buffers = 0;
1100   glGetIntegerv(GL_MAX_DRAW_BUFFERS, &max_draw_buffers);
1101   const int kTotalDrawBufferEnums = 16;
1102   const GLenum kDrawBuffers[] = {
1103     GL_DRAW_BUFFER0,
1104     GL_DRAW_BUFFER1,
1105     GL_DRAW_BUFFER2,
1106     GL_DRAW_BUFFER3,
1107     GL_DRAW_BUFFER4,
1108     GL_DRAW_BUFFER5,
1109     GL_DRAW_BUFFER6,
1110     GL_DRAW_BUFFER7,
1111     GL_DRAW_BUFFER8,
1112     GL_DRAW_BUFFER9,
1113     GL_DRAW_BUFFER10,
1114     GL_DRAW_BUFFER11,
1115     GL_DRAW_BUFFER12,
1116     GL_DRAW_BUFFER13,
1117     GL_DRAW_BUFFER14,
1118     GL_DRAW_BUFFER15,
1119   };
1120   if (max_draw_buffers < kTotalDrawBufferEnums) {
1121     validators_.g_l_state.RemoveValues(
1122         kDrawBuffers + max_draw_buffers,
1123         kTotalDrawBufferEnums - max_draw_buffers);
1124   }
1125
1126   unsafe_es3_apis_enabled_ = true;
1127 }
1128
1129 void FeatureInfo::AddExtensionString(const char* s) {
1130   std::string str(s);
1131   size_t pos = extensions_.find(str);
1132   while (pos != std::string::npos &&
1133          pos + str.length() < extensions_.length() &&
1134          extensions_.substr(pos + str.length(), 1) != " ") {
1135     // This extension name is a substring of another.
1136     pos = extensions_.find(str, pos + str.length());
1137   }
1138   if (pos == std::string::npos) {
1139     extensions_ += (extensions_.empty() ? "" : " ") + str;
1140   }
1141 }
1142
1143 FeatureInfo::~FeatureInfo() {
1144 }
1145
1146 }  // namespace gles2
1147 }  // namespace gpu