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      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/strings/string_number_conversions.h"
     11 #include "base/strings/string_split.h"
     12 #include "base/strings/string_util.h"
     13 #include "gpu/command_buffer/service/gl_utils.h"
     14 #include "gpu/command_buffer/service/gpu_switches.h"
     15 #include "ui/gl/gl_implementation.h"
     16 
     17 #if defined(OS_MACOSX)
     18 #include "ui/gl/io_surface_support_mac.h"
     19 #endif
     20 
     21 namespace gpu {
     22 namespace gles2 {
     23 
     24 namespace {
     25 
     26 struct FormatInfo {
     27   GLenum format;
     28   const GLenum* types;
     29   size_t count;
     30 };
     31 
     32 class StringSet {
     33  public:
     34   StringSet() {}
     35 
     36   StringSet(const char* s) {
     37     Init(s);
     38   }
     39 
     40   StringSet(const std::string& str) {
     41     Init(str);
     42   }
     43 
     44   void Init(const char* s) {
     45     std::string str(s ? s : "");
     46     Init(str);
     47   }
     48 
     49   void Init(const std::string& str) {
     50     std::vector<std::string> tokens;
     51     Tokenize(str, " ", &tokens);
     52     string_set_.insert(tokens.begin(), tokens.end());
     53   }
     54 
     55   bool Contains(const char* s) {
     56     return string_set_.find(s) != string_set_.end();
     57   }
     58 
     59   bool Contains(const std::string& s) {
     60     return string_set_.find(s) != string_set_.end();
     61   }
     62 
     63  private:
     64   std::set<std::string> string_set_;
     65 };
     66 
     67 // Process a string of wordaround type IDs (seperated by ',') and set up
     68 // the corresponding Workaround flags.
     69 void StringToWorkarounds(
     70     const std::string& types, FeatureInfo::Workarounds* workarounds) {
     71   DCHECK(workarounds);
     72   std::vector<std::string> pieces;
     73   base::SplitString(types, ',', &pieces);
     74   for (size_t i = 0; i < pieces.size(); ++i) {
     75     int number = 0;
     76     bool succeed = base::StringToInt(pieces[i], &number);
     77     DCHECK(succeed);
     78     switch (number) {
     79 #define GPU_OP(type, name)    \
     80   case gpu::type:             \
     81     workarounds->name = true; \
     82     break;
     83       GPU_DRIVER_BUG_WORKAROUNDS(GPU_OP)
     84 #undef GPU_OP
     85       default:
     86         NOTIMPLEMENTED();
     87     }
     88   }
     89   if (workarounds->max_texture_size_limit_4096)
     90     workarounds->max_texture_size = 4096;
     91   if (workarounds->max_cube_map_texture_size_limit_4096)
     92     workarounds->max_cube_map_texture_size = 4096;
     93   if (workarounds->max_cube_map_texture_size_limit_1024)
     94     workarounds->max_cube_map_texture_size = 1024;
     95   if (workarounds->max_cube_map_texture_size_limit_512)
     96     workarounds->max_cube_map_texture_size = 512;
     97 }
     98 
     99 }  // anonymous namespace.
    100 
    101 FeatureInfo::FeatureFlags::FeatureFlags()
    102     : chromium_framebuffer_multisample(false),
    103       multisampled_render_to_texture(false),
    104       use_img_for_multisampled_render_to_texture(false),
    105       oes_standard_derivatives(false),
    106       oes_egl_image_external(false),
    107       npot_ok(false),
    108       enable_texture_float_linear(false),
    109       enable_texture_half_float_linear(false),
    110       chromium_stream_texture(false),
    111       angle_translated_shader_source(false),
    112       angle_pack_reverse_row_order(false),
    113       arb_texture_rectangle(false),
    114       angle_instanced_arrays(false),
    115       occlusion_query_boolean(false),
    116       use_arb_occlusion_query2_for_occlusion_query_boolean(false),
    117       use_arb_occlusion_query_for_occlusion_query_boolean(false),
    118       native_vertex_array_object(false),
    119       enable_shader_name_hashing(false),
    120       enable_samplers(false),
    121       ext_draw_buffers(false),
    122       ext_frag_depth(false),
    123       use_async_readpixels(false) {
    124 }
    125 
    126 FeatureInfo::Workarounds::Workarounds() :
    127 #define GPU_OP(type, name) name(false),
    128     GPU_DRIVER_BUG_WORKAROUNDS(GPU_OP)
    129 #undef GPU_OP
    130     max_texture_size(0),
    131     max_cube_map_texture_size(0) {
    132 }
    133 
    134 FeatureInfo::FeatureInfo() {
    135   static const GLenum kAlphaTypes[] = {
    136       GL_UNSIGNED_BYTE,
    137   };
    138   static const GLenum kRGBTypes[] = {
    139       GL_UNSIGNED_BYTE,
    140       GL_UNSIGNED_SHORT_5_6_5,
    141   };
    142   static const GLenum kRGBATypes[] = {
    143       GL_UNSIGNED_BYTE,
    144       GL_UNSIGNED_SHORT_4_4_4_4,
    145       GL_UNSIGNED_SHORT_5_5_5_1,
    146   };
    147   static const GLenum kLuminanceTypes[] = {
    148       GL_UNSIGNED_BYTE,
    149   };
    150   static const GLenum kLuminanceAlphaTypes[] = {
    151       GL_UNSIGNED_BYTE,
    152   };
    153   static const FormatInfo kFormatTypes[] = {
    154     { GL_ALPHA, kAlphaTypes, arraysize(kAlphaTypes), },
    155     { GL_RGB, kRGBTypes, arraysize(kRGBTypes), },
    156     { GL_RGBA, kRGBATypes, arraysize(kRGBATypes), },
    157     { GL_LUMINANCE, kLuminanceTypes, arraysize(kLuminanceTypes), },
    158     { GL_LUMINANCE_ALPHA, kLuminanceAlphaTypes,
    159       arraysize(kLuminanceAlphaTypes), } ,
    160   };
    161   for (size_t ii = 0; ii < arraysize(kFormatTypes); ++ii) {
    162     const FormatInfo& info = kFormatTypes[ii];
    163     ValueValidator<GLenum>& validator = texture_format_validators_[info.format];
    164     for (size_t jj = 0; jj < info.count; ++jj) {
    165       validator.AddValue(info.types[jj]);
    166     }
    167   }
    168 }
    169 
    170 bool FeatureInfo::Initialize(const char* allowed_features) {
    171   disallowed_features_ = DisallowedFeatures();
    172   AddFeatures(*CommandLine::ForCurrentProcess());
    173   return true;
    174 }
    175 
    176 bool FeatureInfo::Initialize(const DisallowedFeatures& disallowed_features,
    177                              const char* allowed_features) {
    178   disallowed_features_ = disallowed_features;
    179   AddFeatures(*CommandLine::ForCurrentProcess());
    180   return true;
    181 }
    182 
    183 void FeatureInfo::AddFeatures(const CommandLine& command_line) {
    184   // Figure out what extensions to turn on.
    185   StringSet extensions(
    186       reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS)));
    187 
    188   if (command_line.HasSwitch(switches::kGpuDriverBugWorkarounds)) {
    189     std::string types = command_line.GetSwitchValueASCII(
    190         switches::kGpuDriverBugWorkarounds);
    191     StringToWorkarounds(types, &workarounds_);
    192   }
    193 
    194   feature_flags_.enable_shader_name_hashing =
    195       !command_line.HasSwitch(switches::kDisableShaderNameHashing);
    196 
    197   bool npot_ok = false;
    198 
    199   AddExtensionString("GL_ANGLE_translated_shader_source");
    200   AddExtensionString("GL_CHROMIUM_async_pixel_transfers");
    201   AddExtensionString("GL_CHROMIUM_bind_uniform_location");
    202   AddExtensionString("GL_CHROMIUM_command_buffer_query");
    203   AddExtensionString("GL_CHROMIUM_command_buffer_latency_query");
    204   AddExtensionString("GL_CHROMIUM_copy_texture");
    205   AddExtensionString("GL_CHROMIUM_discard_backbuffer");
    206   AddExtensionString("GL_CHROMIUM_get_error_query");
    207   AddExtensionString("GL_CHROMIUM_lose_context");
    208   AddExtensionString("GL_CHROMIUM_pixel_transfer_buffer_object");
    209   AddExtensionString("GL_CHROMIUM_rate_limit_offscreen_context");
    210   AddExtensionString("GL_CHROMIUM_resize");
    211   AddExtensionString("GL_CHROMIUM_resource_safe");
    212   AddExtensionString("GL_CHROMIUM_set_visibility");
    213   AddExtensionString("GL_CHROMIUM_strict_attribs");
    214   AddExtensionString("GL_CHROMIUM_stream_texture");
    215   AddExtensionString("GL_CHROMIUM_texture_mailbox");
    216   AddExtensionString("GL_EXT_debug_marker");
    217 
    218   if (workarounds_.enable_chromium_fast_npot_mo8_textures)
    219     AddExtensionString("GL_CHROMIUM_fast_NPOT_MO8_textures");
    220 
    221   feature_flags_.chromium_stream_texture = true;
    222 
    223   // OES_vertex_array_object is emulated if not present natively,
    224   // so the extension string is always exposed.
    225   AddExtensionString("GL_OES_vertex_array_object");
    226 
    227   if (!disallowed_features_.gpu_memory_manager)
    228     AddExtensionString("GL_CHROMIUM_gpu_memory_manager");
    229 
    230   if (extensions.Contains("GL_ANGLE_translated_shader_source")) {
    231     feature_flags_.angle_translated_shader_source = true;
    232   }
    233 
    234   // Check if we should allow GL_EXT_texture_compression_dxt1 and
    235   // GL_EXT_texture_compression_s3tc.
    236   bool enable_dxt1 = false;
    237   bool enable_dxt3 = false;
    238   bool enable_dxt5 = false;
    239   bool have_s3tc = extensions.Contains("GL_EXT_texture_compression_s3tc");
    240   bool have_dxt3 =
    241       have_s3tc || extensions.Contains("GL_ANGLE_texture_compression_dxt3");
    242   bool have_dxt5 =
    243       have_s3tc || extensions.Contains("GL_ANGLE_texture_compression_dxt5");
    244 
    245   if (extensions.Contains("GL_EXT_texture_compression_dxt1") || have_s3tc) {
    246     enable_dxt1 = true;
    247   }
    248   if (have_dxt3) {
    249     enable_dxt3 = true;
    250   }
    251   if (have_dxt5) {
    252     enable_dxt5 = true;
    253   }
    254 
    255   if (enable_dxt1) {
    256     AddExtensionString("GL_EXT_texture_compression_dxt1");
    257     validators_.compressed_texture_format.AddValue(
    258         GL_COMPRESSED_RGB_S3TC_DXT1_EXT);
    259     validators_.compressed_texture_format.AddValue(
    260         GL_COMPRESSED_RGBA_S3TC_DXT1_EXT);
    261   }
    262 
    263   if (enable_dxt3) {
    264     // The difference between GL_EXT_texture_compression_s3tc and
    265     // GL_CHROMIUM_texture_compression_dxt3 is that the former
    266     // requires on the fly compression. The latter does not.
    267     AddExtensionString("GL_CHROMIUM_texture_compression_dxt3");
    268     validators_.compressed_texture_format.AddValue(
    269         GL_COMPRESSED_RGBA_S3TC_DXT3_EXT);
    270   }
    271 
    272   if (enable_dxt5) {
    273     // The difference between GL_EXT_texture_compression_s3tc and
    274     // GL_CHROMIUM_texture_compression_dxt5 is that the former
    275     // requires on the fly compression. The latter does not.
    276     AddExtensionString("GL_CHROMIUM_texture_compression_dxt5");
    277     validators_.compressed_texture_format.AddValue(
    278         GL_COMPRESSED_RGBA_S3TC_DXT5_EXT);
    279   }
    280 
    281   // Check if we should enable GL_EXT_texture_filter_anisotropic.
    282   if (extensions.Contains("GL_EXT_texture_filter_anisotropic")) {
    283     AddExtensionString("GL_EXT_texture_filter_anisotropic");
    284     validators_.texture_parameter.AddValue(
    285         GL_TEXTURE_MAX_ANISOTROPY_EXT);
    286     validators_.g_l_state.AddValue(
    287         GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT);
    288   }
    289 
    290   // Check if we should support GL_OES_packed_depth_stencil and/or
    291   // GL_GOOGLE_depth_texture / GL_CHROMIUM_depth_texture.
    292   //
    293   // NOTE: GL_OES_depth_texture requires support for depth cubemaps.
    294   // GL_ARB_depth_texture requires other features that
    295   // GL_OES_packed_depth_stencil does not provide.
    296   //
    297   // Therefore we made up GL_GOOGLE_depth_texture / GL_CHROMIUM_depth_texture.
    298   //
    299   // GL_GOOGLE_depth_texture is legacy. As we exposed it into NaCl we can't
    300   // get rid of it.
    301   //
    302   bool enable_depth_texture = false;
    303   if (!workarounds_.disable_depth_texture &&
    304       (extensions.Contains("GL_ARB_depth_texture") ||
    305        extensions.Contains("GL_OES_depth_texture") ||
    306        extensions.Contains("GL_ANGLE_depth_texture"))) {
    307     enable_depth_texture = true;
    308   }
    309 
    310   if (enable_depth_texture) {
    311     AddExtensionString("GL_CHROMIUM_depth_texture");
    312     AddExtensionString("GL_GOOGLE_depth_texture");
    313     texture_format_validators_[GL_DEPTH_COMPONENT].AddValue(GL_UNSIGNED_SHORT);
    314     texture_format_validators_[GL_DEPTH_COMPONENT].AddValue(GL_UNSIGNED_INT);
    315     validators_.texture_internal_format.AddValue(GL_DEPTH_COMPONENT);
    316     validators_.texture_format.AddValue(GL_DEPTH_COMPONENT);
    317     validators_.pixel_type.AddValue(GL_UNSIGNED_SHORT);
    318     validators_.pixel_type.AddValue(GL_UNSIGNED_INT);
    319   }
    320 
    321   if (extensions.Contains("GL_EXT_packed_depth_stencil") ||
    322       extensions.Contains("GL_OES_packed_depth_stencil")) {
    323     AddExtensionString("GL_OES_packed_depth_stencil");
    324     if (enable_depth_texture) {
    325       texture_format_validators_[GL_DEPTH_STENCIL].AddValue(
    326           GL_UNSIGNED_INT_24_8);
    327       validators_.texture_internal_format.AddValue(GL_DEPTH_STENCIL);
    328       validators_.texture_format.AddValue(GL_DEPTH_STENCIL);
    329       validators_.pixel_type.AddValue(GL_UNSIGNED_INT_24_8);
    330     }
    331     validators_.render_buffer_format.AddValue(GL_DEPTH24_STENCIL8);
    332   }
    333 
    334   if (extensions.Contains("GL_OES_vertex_array_object") ||
    335       extensions.Contains("GL_ARB_vertex_array_object") ||
    336       extensions.Contains("GL_APPLE_vertex_array_object")) {
    337     feature_flags_.native_vertex_array_object = true;
    338   }
    339 
    340   // If we're using client_side_arrays we have to emulate
    341   // vertex array objects since vertex array objects do not work
    342   // with client side arrays.
    343   if (workarounds_.use_client_side_arrays_for_stream_buffers) {
    344     feature_flags_.native_vertex_array_object = false;
    345   }
    346 
    347   if (extensions.Contains("GL_OES_element_index_uint") ||
    348       gfx::HasDesktopGLFeatures()) {
    349     AddExtensionString("GL_OES_element_index_uint");
    350     validators_.index_type.AddValue(GL_UNSIGNED_INT);
    351   }
    352 
    353   bool enable_texture_format_bgra8888 = false;
    354   bool enable_read_format_bgra = false;
    355   // Check if we should allow GL_EXT_texture_format_BGRA8888
    356   if (extensions.Contains("GL_EXT_texture_format_BGRA8888") ||
    357       extensions.Contains("GL_APPLE_texture_format_BGRA8888") ||
    358       extensions.Contains("GL_EXT_bgra")) {
    359     enable_texture_format_bgra8888 = true;
    360   }
    361 
    362   if (extensions.Contains("GL_EXT_bgra")) {
    363     enable_texture_format_bgra8888 = true;
    364     enable_read_format_bgra = true;
    365   }
    366 
    367   if (extensions.Contains("GL_EXT_read_format_bgra") ||
    368       extensions.Contains("GL_EXT_bgra")) {
    369     enable_read_format_bgra = true;
    370   }
    371 
    372   if (enable_texture_format_bgra8888) {
    373     AddExtensionString("GL_EXT_texture_format_BGRA8888");
    374     texture_format_validators_[GL_BGRA_EXT].AddValue(GL_UNSIGNED_BYTE);
    375     validators_.texture_internal_format.AddValue(GL_BGRA_EXT);
    376     validators_.texture_format.AddValue(GL_BGRA_EXT);
    377   }
    378 
    379   if (enable_read_format_bgra) {
    380     AddExtensionString("GL_EXT_read_format_bgra");
    381     validators_.read_pixel_format.AddValue(GL_BGRA_EXT);
    382   }
    383 
    384   if (extensions.Contains("GL_OES_rgb8_rgba8") || gfx::HasDesktopGLFeatures()) {
    385     AddExtensionString("GL_OES_rgb8_rgba8");
    386     validators_.render_buffer_format.AddValue(GL_RGB8_OES);
    387     validators_.render_buffer_format.AddValue(GL_RGBA8_OES);
    388   }
    389 
    390   // Check if we should allow GL_OES_texture_npot
    391   if (extensions.Contains("GL_ARB_texture_non_power_of_two") ||
    392       extensions.Contains("GL_OES_texture_npot")) {
    393     AddExtensionString("GL_OES_texture_npot");
    394     npot_ok = true;
    395   }
    396 
    397   // Check if we should allow GL_OES_texture_float, GL_OES_texture_half_float,
    398   // GL_OES_texture_float_linear, GL_OES_texture_half_float_linear
    399   bool enable_texture_float = false;
    400   bool enable_texture_float_linear = false;
    401   bool enable_texture_half_float = false;
    402   bool enable_texture_half_float_linear = false;
    403 
    404   bool have_arb_texture_float = extensions.Contains("GL_ARB_texture_float");
    405 
    406   if (have_arb_texture_float) {
    407     enable_texture_float = true;
    408     enable_texture_float_linear = true;
    409     enable_texture_half_float = true;
    410     enable_texture_half_float_linear = true;
    411   } else {
    412     if (extensions.Contains("GL_OES_texture_float") || have_arb_texture_float) {
    413       enable_texture_float = true;
    414       if (extensions.Contains("GL_OES_texture_float_linear") ||
    415           have_arb_texture_float) {
    416         enable_texture_float_linear = true;
    417       }
    418     }
    419     if (extensions.Contains("GL_OES_texture_half_float") ||
    420         have_arb_texture_float) {
    421       enable_texture_half_float = true;
    422       if (extensions.Contains("GL_OES_texture_half_float_linear") ||
    423           have_arb_texture_float) {
    424         enable_texture_half_float_linear = true;
    425       }
    426     }
    427   }
    428 
    429   if (enable_texture_float) {
    430     texture_format_validators_[GL_ALPHA].AddValue(GL_FLOAT);
    431     texture_format_validators_[GL_RGB].AddValue(GL_FLOAT);
    432     texture_format_validators_[GL_RGBA].AddValue(GL_FLOAT);
    433     texture_format_validators_[GL_LUMINANCE].AddValue(GL_FLOAT);
    434     texture_format_validators_[GL_LUMINANCE_ALPHA].AddValue(GL_FLOAT);
    435     validators_.pixel_type.AddValue(GL_FLOAT);
    436     validators_.read_pixel_type.AddValue(GL_FLOAT);
    437     AddExtensionString("GL_OES_texture_float");
    438     if (enable_texture_float_linear) {
    439       AddExtensionString("GL_OES_texture_float_linear");
    440     }
    441   }
    442 
    443   if (enable_texture_half_float) {
    444     texture_format_validators_[GL_ALPHA].AddValue(GL_HALF_FLOAT_OES);
    445     texture_format_validators_[GL_RGB].AddValue(GL_HALF_FLOAT_OES);
    446     texture_format_validators_[GL_RGBA].AddValue(GL_HALF_FLOAT_OES);
    447     texture_format_validators_[GL_LUMINANCE].AddValue(GL_HALF_FLOAT_OES);
    448     texture_format_validators_[GL_LUMINANCE_ALPHA].AddValue(GL_HALF_FLOAT_OES);
    449     validators_.pixel_type.AddValue(GL_HALF_FLOAT_OES);
    450     validators_.read_pixel_type.AddValue(GL_HALF_FLOAT_OES);
    451     AddExtensionString("GL_OES_texture_half_float");
    452     if (enable_texture_half_float_linear) {
    453       AddExtensionString("GL_OES_texture_half_float_linear");
    454     }
    455   }
    456 
    457   // Check for multisample support
    458   if (!disallowed_features_.multisampling) {
    459     bool ext_has_multisample =
    460         extensions.Contains("GL_EXT_framebuffer_multisample");
    461     if (!workarounds_.disable_angle_framebuffer_multisample) {
    462       ext_has_multisample |=
    463          extensions.Contains("GL_ANGLE_framebuffer_multisample");
    464     }
    465     if (ext_has_multisample) {
    466       feature_flags_.chromium_framebuffer_multisample = true;
    467       validators_.frame_buffer_target.AddValue(GL_READ_FRAMEBUFFER_EXT);
    468       validators_.frame_buffer_target.AddValue(GL_DRAW_FRAMEBUFFER_EXT);
    469       validators_.g_l_state.AddValue(GL_READ_FRAMEBUFFER_BINDING_EXT);
    470       validators_.g_l_state.AddValue(GL_MAX_SAMPLES_EXT);
    471       validators_.render_buffer_parameter.AddValue(GL_RENDERBUFFER_SAMPLES_EXT);
    472       AddExtensionString("GL_CHROMIUM_framebuffer_multisample");
    473     } else {
    474       if (extensions.Contains("GL_EXT_multisampled_render_to_texture")) {
    475         feature_flags_.multisampled_render_to_texture = true;
    476       } else if (extensions.Contains("GL_IMG_multisampled_render_to_texture")) {
    477         feature_flags_.multisampled_render_to_texture = true;
    478         feature_flags_.use_img_for_multisampled_render_to_texture = true;
    479       }
    480       if (feature_flags_.multisampled_render_to_texture) {
    481         validators_.render_buffer_parameter.AddValue(
    482             GL_RENDERBUFFER_SAMPLES_EXT);
    483         validators_.g_l_state.AddValue(GL_MAX_SAMPLES_EXT);
    484         validators_.frame_buffer_parameter.AddValue(
    485             GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_SAMPLES_EXT);
    486         AddExtensionString("GL_EXT_multisampled_render_to_texture");
    487       }
    488     }
    489   }
    490 
    491   if (extensions.Contains("GL_OES_depth24") || gfx::HasDesktopGLFeatures()) {
    492     AddExtensionString("GL_OES_depth24");
    493     validators_.render_buffer_format.AddValue(GL_DEPTH_COMPONENT24);
    494   }
    495 
    496   if (!workarounds_.disable_oes_standard_derivatives &&
    497       (extensions.Contains("GL_OES_standard_derivatives") ||
    498        gfx::HasDesktopGLFeatures())) {
    499     AddExtensionString("GL_OES_standard_derivatives");
    500     feature_flags_.oes_standard_derivatives = true;
    501     validators_.hint_target.AddValue(GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
    502     validators_.g_l_state.AddValue(GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
    503   }
    504 
    505   if (extensions.Contains("GL_OES_EGL_image_external")) {
    506     AddExtensionString("GL_OES_EGL_image_external");
    507     feature_flags_.oes_egl_image_external = true;
    508     validators_.texture_bind_target.AddValue(GL_TEXTURE_EXTERNAL_OES);
    509     validators_.get_tex_param_target.AddValue(GL_TEXTURE_EXTERNAL_OES);
    510     validators_.texture_parameter.AddValue(GL_REQUIRED_TEXTURE_IMAGE_UNITS_OES);
    511     validators_.g_l_state.AddValue(GL_TEXTURE_BINDING_EXTERNAL_OES);
    512   }
    513 
    514   if (extensions.Contains("GL_OES_compressed_ETC1_RGB8_texture")) {
    515     AddExtensionString("GL_OES_compressed_ETC1_RGB8_texture");
    516     validators_.compressed_texture_format.AddValue(GL_ETC1_RGB8_OES);
    517   }
    518 
    519   // Ideally we would only expose this extension on Mac OS X, to
    520   // support GL_CHROMIUM_iosurface and the compositor. We don't want
    521   // applications to start using it; they should use ordinary non-
    522   // power-of-two textures. However, for unit testing purposes we
    523   // expose it on all supported platforms.
    524   if (extensions.Contains("GL_ARB_texture_rectangle")) {
    525     AddExtensionString("GL_ARB_texture_rectangle");
    526     feature_flags_.arb_texture_rectangle = true;
    527     validators_.texture_bind_target.AddValue(GL_TEXTURE_RECTANGLE_ARB);
    528     // For the moment we don't add this enum to the texture_target
    529     // validator. This implies that the only way to get image data into a
    530     // rectangular texture is via glTexImageIOSurface2DCHROMIUM, which is
    531     // just fine since again we don't want applications depending on this
    532     // extension.
    533     validators_.get_tex_param_target.AddValue(GL_TEXTURE_RECTANGLE_ARB);
    534     validators_.g_l_state.AddValue(GL_TEXTURE_BINDING_RECTANGLE_ARB);
    535   }
    536 
    537 #if defined(OS_MACOSX)
    538   if (IOSurfaceSupport::Initialize()) {
    539     AddExtensionString("GL_CHROMIUM_iosurface");
    540   }
    541 #endif
    542 
    543   // TODO(gman): Add support for these extensions.
    544   //     GL_OES_depth32
    545 
    546   feature_flags_.enable_texture_float_linear |= enable_texture_float_linear;
    547   feature_flags_.enable_texture_half_float_linear |=
    548       enable_texture_half_float_linear;
    549   feature_flags_.npot_ok |= npot_ok;
    550 
    551   if (extensions.Contains("GL_ANGLE_pack_reverse_row_order")) {
    552     AddExtensionString("GL_ANGLE_pack_reverse_row_order");
    553     feature_flags_.angle_pack_reverse_row_order = true;
    554     validators_.pixel_store.AddValue(GL_PACK_REVERSE_ROW_ORDER_ANGLE);
    555     validators_.g_l_state.AddValue(GL_PACK_REVERSE_ROW_ORDER_ANGLE);
    556   }
    557 
    558   if (extensions.Contains("GL_ANGLE_texture_usage")) {
    559     AddExtensionString("GL_ANGLE_texture_usage");
    560     validators_.texture_parameter.AddValue(GL_TEXTURE_USAGE_ANGLE);
    561   }
    562 
    563   if (extensions.Contains("GL_EXT_texture_storage")) {
    564     AddExtensionString("GL_EXT_texture_storage");
    565     validators_.texture_parameter.AddValue(GL_TEXTURE_IMMUTABLE_FORMAT_EXT);
    566     if (enable_texture_format_bgra8888)
    567         validators_.texture_internal_format_storage.AddValue(GL_BGRA8_EXT);
    568     if (enable_texture_float) {
    569         validators_.texture_internal_format_storage.AddValue(GL_RGBA32F_EXT);
    570         validators_.texture_internal_format_storage.AddValue(GL_RGB32F_EXT);
    571         validators_.texture_internal_format_storage.AddValue(GL_ALPHA32F_EXT);
    572         validators_.texture_internal_format_storage.AddValue(
    573             GL_LUMINANCE32F_EXT);
    574         validators_.texture_internal_format_storage.AddValue(
    575             GL_LUMINANCE_ALPHA32F_EXT);
    576     }
    577     if (enable_texture_half_float) {
    578         validators_.texture_internal_format_storage.AddValue(GL_RGBA16F_EXT);
    579         validators_.texture_internal_format_storage.AddValue(GL_RGB16F_EXT);
    580         validators_.texture_internal_format_storage.AddValue(GL_ALPHA16F_EXT);
    581         validators_.texture_internal_format_storage.AddValue(
    582             GL_LUMINANCE16F_EXT);
    583         validators_.texture_internal_format_storage.AddValue(
    584             GL_LUMINANCE_ALPHA16F_EXT);
    585     }
    586   }
    587 
    588   bool have_ext_occlusion_query_boolean =
    589       extensions.Contains("GL_EXT_occlusion_query_boolean");
    590   bool have_arb_occlusion_query2 =
    591       extensions.Contains("GL_ARB_occlusion_query2");
    592   bool have_arb_occlusion_query =
    593       extensions.Contains("GL_ARB_occlusion_query");
    594 
    595   if (!workarounds_.disable_ext_occlusion_query &&
    596       (have_ext_occlusion_query_boolean ||
    597        have_arb_occlusion_query2 ||
    598        have_arb_occlusion_query)) {
    599     AddExtensionString("GL_EXT_occlusion_query_boolean");
    600     feature_flags_.occlusion_query_boolean = true;
    601     feature_flags_.use_arb_occlusion_query2_for_occlusion_query_boolean =
    602         !have_ext_occlusion_query_boolean && have_arb_occlusion_query2;
    603     feature_flags_.use_arb_occlusion_query_for_occlusion_query_boolean =
    604         !have_ext_occlusion_query_boolean && have_arb_occlusion_query &&
    605         !have_arb_occlusion_query2;
    606   }
    607 
    608   if (!workarounds_.disable_angle_instanced_arrays &&
    609       (extensions.Contains("GL_ANGLE_instanced_arrays") ||
    610        (extensions.Contains("GL_ARB_instanced_arrays") &&
    611         extensions.Contains("GL_ARB_draw_instanced")))) {
    612     AddExtensionString("GL_ANGLE_instanced_arrays");
    613     feature_flags_.angle_instanced_arrays = true;
    614     validators_.vertex_attribute.AddValue(GL_VERTEX_ATTRIB_ARRAY_DIVISOR_ANGLE);
    615   }
    616 
    617   if (!workarounds_.disable_ext_draw_buffers &&
    618       (extensions.Contains("GL_ARB_draw_buffers") ||
    619        extensions.Contains("GL_EXT_draw_buffers"))) {
    620     AddExtensionString("GL_EXT_draw_buffers");
    621     feature_flags_.ext_draw_buffers = true;
    622 
    623     GLint max_color_attachments = 0;
    624     glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS_EXT, &max_color_attachments);
    625     for (GLenum i = GL_COLOR_ATTACHMENT1_EXT;
    626          i < static_cast<GLenum>(GL_COLOR_ATTACHMENT0 + max_color_attachments);
    627          ++i) {
    628       validators_.attachment.AddValue(i);
    629     }
    630 
    631     validators_.g_l_state.AddValue(GL_MAX_COLOR_ATTACHMENTS_EXT);
    632     validators_.g_l_state.AddValue(GL_MAX_DRAW_BUFFERS_ARB);
    633     GLint max_draw_buffers = 0;
    634     glGetIntegerv(GL_MAX_DRAW_BUFFERS_ARB, &max_draw_buffers);
    635     for (GLenum i = GL_DRAW_BUFFER0_ARB;
    636          i < static_cast<GLenum>(GL_DRAW_BUFFER0_ARB + max_draw_buffers);
    637          ++i) {
    638       validators_.g_l_state.AddValue(i);
    639     }
    640   }
    641 
    642   if (extensions.Contains("GL_EXT_frag_depth") || gfx::HasDesktopGLFeatures()) {
    643     AddExtensionString("GL_EXT_frag_depth");
    644     feature_flags_.ext_frag_depth = true;
    645   }
    646 
    647   bool ui_gl_fence_works =
    648       extensions.Contains("GL_NV_fence") ||
    649       extensions.Contains("GL_ARB_sync");
    650 
    651   if (ui_gl_fence_works &&
    652       extensions.Contains("GL_ARB_pixel_buffer_object") &&
    653       !workarounds_.disable_async_readpixels) {
    654     feature_flags_.use_async_readpixels = true;
    655   }
    656 
    657   if (!disallowed_features_.swap_buffer_complete_callback)
    658     AddExtensionString("GL_CHROMIUM_swapbuffers_complete_callback");
    659 
    660   bool is_es3 = false;
    661   const char* str = reinterpret_cast<const char*>(glGetString(GL_VERSION));
    662   if (str) {
    663     std::string lstr(StringToLowerASCII(std::string(str)));
    664     is_es3 = (lstr.substr(0, 12) == "opengl es 3.");
    665   }
    666 
    667   if (is_es3 || extensions.Contains("GL_ARB_sampler_objects")) {
    668     feature_flags_.enable_samplers = true;
    669     // TODO(dsinclair): Add AddExtensionString("GL_CHROMIUM_sampler_objects")
    670     // when available.
    671   }
    672 }
    673 
    674 void FeatureInfo::AddExtensionString(const std::string& str) {
    675   if (extensions_.find(str) == std::string::npos) {
    676     extensions_ += (extensions_.empty() ? "" : " ") + str;
    677   }
    678 }
    679 
    680 FeatureInfo::~FeatureInfo() {
    681 }
    682 
    683 }  // namespace gles2
    684 }  // namespace gpu
    685