gfx/gl/GLContextFeatures.cpp

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "GLContext.h"
   7 #include "nsPrintfCString.h"
   8
   9 namespace mozilla {
  10 namespace gl {
  11
  12 const size_t kMAX_EXTENSION_GROUP_SIZE = 5;
  13
  14 enum class GLVersion : uint32_t {
  15   NONE = 0,  // Feature is not supported natively by GL
  16   GL1_2 = 120,
  17   GL1_3 = 130,
  18   GL2 = 200,
  19   GL2_1 = 210,
  20   GL3 = 300,
  21   GL3_1 = 310,
  22   GL3_2 = 320,
  23   GL3_3 = 330,
  24   GL4 = 400,
  25   GL4_1 = 410,
  26   GL4_2 = 420,
  27   GL4_3 = 430,
  28 };
  29
  30 enum class GLESVersion : uint32_t {
  31   NONE = 0,  // Feature is not support natively by GL ES
  32   ES2 = 200,
  33   ES3 = 300,
  34   ES3_1 = 310,
  35   ES3_2 = 320,
  36 };
  37
  38 // ARB_ES2_compatibility is natively supported in OpenGL 4.1.
  39 static const GLVersion kGLCoreVersionForES2Compat = GLVersion::GL4_1;
  40
  41 // ARB_ES3_compatibility is natively supported in OpenGL 4.3.
  42 static const GLVersion kGLCoreVersionForES3Compat = GLVersion::GL4_3;
  43
  44 struct FeatureInfo {
  45   const char* mName;
  46
  47   /* The (desktop) OpenGL version that provides this feature */
  48   GLVersion mOpenGLVersion;
  49
  50   /* The OpenGL ES version that provides this feature */
  51   GLESVersion mOpenGLESVersion;
  52
  53   /* If there is an ARB extension, and its function symbols are
  54    * not decorated with an ARB suffix, then its extension ID should go
  55    * here, and NOT in mExtensions.  For example, ARB_vertex_array_object
  56    * functions do not have an ARB suffix, because it is an extension that
  57    * was created to match core GL functionality and will never differ.
  58    * Some ARB extensions do have a suffix, if they were created before
  59    * a core version of the functionality existed.
  60    *
  61    * If there is no such ARB extension, pass 0 (GLContext::Extension_None)
  62    */
  63   GLContext::GLExtensions mARBExtensionWithoutARBSuffix;
  64
  65   /* Extensions that also provide this feature */
  66   GLContext::GLExtensions mExtensions[kMAX_EXTENSION_GROUP_SIZE];
  67 };
  68
  69 static const FeatureInfo sFeatureInfoArr[] = {
  70     {"bind_buffer_offset",
  71      GLVersion::NONE,
  72      GLESVersion::NONE,
  73      GLContext::Extension_None,
  74      {
  75
  76          GLContext::EXT_transform_feedback, GLContext::NV_transform_feedback2,
  77          GLContext::Extensions_End}},
  78     {"blend_minmax",
  79      GLVersion::GL2,
  80      GLESVersion::ES3,
  81      GLContext::Extension_None,
  82      {GLContext::EXT_blend_minmax, GLContext::Extensions_End}},
  83     {"clear_buffers",
  84      GLVersion::GL3,
  85      GLESVersion::ES3,
  86      GLContext::Extension_None,
  87      {GLContext::Extensions_End}},
  88     {"copy_buffer",
  89      GLVersion::GL3_1,
  90      GLESVersion::ES3,
  91      GLContext::ARB_copy_buffer,
  92      {GLContext::Extensions_End}},
  93     {"depth_texture",
  94      GLVersion::GL2,
  95      GLESVersion::ES3,
  96      GLContext::Extension_None,
  97      {GLContext::ARB_depth_texture, GLContext::OES_depth_texture,
  98       // Intentionally avoid putting ANGLE_depth_texture here,
  99       // it does not offer quite the same functionality.
 100       GLContext::Extensions_End}},
 101     {"draw_buffers",
 102      GLVersion::GL2,
 103      GLESVersion::ES3,
 104      GLContext::Extension_None,
 105      {GLContext::ARB_draw_buffers, GLContext::EXT_draw_buffers,
 106       GLContext::Extensions_End}},
 107     {"draw_buffers_indexed",
 108      GLVersion::GL3,
 109      GLESVersion::ES3_2,
 110      GLContext::Extension_None,
 111      {GLContext::OES_draw_buffers_indexed, GLContext::Extensions_End}},
 112     {"draw_instanced",
 113      GLVersion::GL3_1,
 114      GLESVersion::ES3,
 115      GLContext::Extension_None,
 116      {GLContext::ARB_draw_instanced, GLContext::EXT_draw_instanced,
 117       GLContext::NV_draw_instanced, GLContext::ANGLE_instanced_arrays,
 118       GLContext::Extensions_End}},
 119     {"element_index_uint",
 120      GLVersion::GL2,
 121      GLESVersion::ES3,
 122      GLContext::Extension_None,
 123      {GLContext::OES_element_index_uint, GLContext::Extensions_End}},
 124     {"ES2_compatibility",
 125      kGLCoreVersionForES2Compat,
 126      GLESVersion::ES2,                  // OpenGL ES version
 127      GLContext::ARB_ES2_compatibility,  // no suffix on ARB extension
 128      {GLContext::Extensions_End}},
 129     {"ES3_compatibility",
 130      kGLCoreVersionForES3Compat,
 131      GLESVersion::ES3,                  // OpenGL ES version
 132      GLContext::ARB_ES3_compatibility,  // no suffix on ARB extension
 133      {GLContext::Extensions_End}},
 134     {"EXT_color_buffer_float",
 135      GLVersion::GL3,
 136      GLESVersion::ES3_2,
 137      GLContext::Extension_None,
 138      {GLContext::EXT_color_buffer_float, GLContext::Extensions_End}},
 139     {// Removes clamping for float color outputs from frag shaders.
 140      "frag_color_float",
 141      GLVersion::GL3,
 142      GLESVersion::ES3,
 143      GLContext::Extension_None,
 144      {GLContext::ARB_color_buffer_float, GLContext::EXT_color_buffer_float,
 145       GLContext::EXT_color_buffer_half_float,
 146       GLContext::CHROMIUM_color_buffer_float_rgba, GLContext::Extensions_End}},
 147     {"frag_depth",
 148      GLVersion::GL2,
 149      GLESVersion::ES3,
 150      GLContext::Extension_None,
 151      {GLContext::EXT_frag_depth, GLContext::Extensions_End}},
 152     {// Check for just the blit framebuffer blit part of
 153      // ARB_framebuffer_object
 154      "framebuffer_blit",
 155      GLVersion::GL3,
 156      GLESVersion::ES3,
 157      GLContext::ARB_framebuffer_object,
 158      {GLContext::ANGLE_framebuffer_blit, GLContext::EXT_framebuffer_blit,
 159       GLContext::NV_framebuffer_blit, GLContext::Extensions_End}},
 160     {// Check for just the multisample renderbuffer part of
 161      // ARB_framebuffer_object
 162      "framebuffer_multisample",
 163      GLVersion::GL3,
 164      GLESVersion::ES3,
 165      GLContext::ARB_framebuffer_object,
 166      {GLContext::ANGLE_framebuffer_multisample,
 167       GLContext::APPLE_framebuffer_multisample,
 168       GLContext::EXT_framebuffer_multisample,
 169       GLContext::EXT_multisampled_render_to_texture,
 170       GLContext::Extensions_End}},
 171     {// ARB_framebuffer_object support
 172      "framebuffer_object",
 173      GLVersion::GL3,
 174      GLESVersion::ES3,
 175      GLContext::ARB_framebuffer_object,
 176      {GLContext::Extensions_End}},
 177     {// EXT_framebuffer_object/OES_framebuffer_object support
 178      "framebuffer_object_EXT_OES",
 179      GLVersion::GL3,
 180      GLESVersion::ES2,
 181      GLContext::Extension_None,
 182      {GLContext::EXT_framebuffer_object, GLContext::OES_framebuffer_object,
 183       GLContext::Extensions_End}},
 184     {"get_integer_indexed",
 185      GLVersion::GL3,
 186      GLESVersion::ES3,
 187      GLContext::Extension_None,
 188      {GLContext::EXT_draw_buffers2, GLContext::Extensions_End}},
 189     {"get_integer64_indexed",
 190      GLVersion::GL3_2,
 191      GLESVersion::ES3,
 192      GLContext::Extension_None,
 193      {GLContext::Extensions_End}},
 194     {"get_query_object_i64v",
 195      GLVersion::GL3_3,
 196      GLESVersion::NONE,
 197      GLContext::ARB_timer_query,
 198      {GLContext::ANGLE_timer_query, GLContext::EXT_disjoint_timer_query,
 199       GLContext::EXT_timer_query, GLContext::Extensions_End}},
 200     {
 201         "get_query_object_iv",
 202         GLVersion::GL2,
 203         GLESVersion::NONE,
 204         GLContext::Extension_None,
 205         {GLContext::Extensions_End}
 206         /*
 207          * XXX_get_query_object_iv only provide GetQueryObjectiv provided by
 208          * ARB_occlusion_query (added by OpenGL 2.0).
 209          */
 210     },
 211     {"gpu_shader4",
 212      GLVersion::GL3,
 213      GLESVersion::ES3,
 214      GLContext::Extension_None,
 215      {GLContext::EXT_gpu_shader4, GLContext::Extensions_End}},
 216     {"instanced_arrays",
 217      GLVersion::GL3_3,
 218      GLESVersion::ES3,
 219      GLContext::Extension_None,
 220      {GLContext::ARB_instanced_arrays, GLContext::NV_instanced_arrays,
 221       GLContext::ANGLE_instanced_arrays, GLContext::Extensions_End}},
 222     {
 223         "instanced_non_arrays",
 224         GLVersion::GL3_3,
 225         GLESVersion::ES3,
 226         GLContext::Extension_None,
 227         {GLContext::ARB_instanced_arrays, GLContext::Extensions_End}
 228         /* This is an expanded version of `instanced_arrays` that allows for all
 229          * enabled active attrib arrays to have non-zero divisors.
 230          * ANGLE_instanced_arrays and NV_instanced_arrays forbid this, but GLES3
 231          * has no such restriction.
 232          */
 233     },
 234     {"internalformat_query",
 235      GLVersion::GL4_2,
 236      GLESVersion::ES3,
 237      GLContext::ARB_internalformat_query,
 238      {GLContext::Extensions_End}},
 239     {"invalidate_framebuffer",
 240      GLVersion::GL4_3,
 241      GLESVersion::ES3,
 242      GLContext::ARB_invalidate_subdata,
 243      {GLContext::Extensions_End}},
 244     {"map_buffer_range",
 245      GLVersion::GL3,
 246      GLESVersion::ES3,
 247      GLContext::ARB_map_buffer_range,
 248      {GLContext::EXT_map_buffer_range, GLContext::Extensions_End}},
 249     {"multiview",
 250      GLVersion::NONE,
 251      GLESVersion::NONE,
 252      GLContext::Extension_None,
 253      {GLContext::ANGLE_multiview, GLContext::OVR_multiview2,
 254       GLContext::Extensions_End}},
 255     {
 256         "occlusion_query",
 257         GLVersion::GL2,
 258         GLESVersion::NONE,
 259         GLContext::Extension_None,
 260         {GLContext::Extensions_End}
 261         // XXX_occlusion_query depend on ARB_occlusion_query (added in
 262         // OpenGL 2.0)
 263     },
 264     {
 265         "occlusion_query_boolean",
 266         kGLCoreVersionForES3Compat,
 267         GLESVersion::ES3,
 268         GLContext::ARB_ES3_compatibility,
 269         {GLContext::EXT_occlusion_query_boolean, GLContext::Extensions_End}
 270         /*
 271          * XXX_occlusion_query_boolean provide ANY_SAMPLES_PASSED_CONSERVATIVE,
 272          * but EXT_occlusion_query_boolean is only a OpenGL ES extension. But
 273          * it is supported on desktop if ARB_ES3_compatibility because
 274          * EXT_occlusion_query_boolean (added in OpenGL ES 3.0).
 275          */
 276     },
 277     {
 278         "occlusion_query2",
 279         GLVersion::GL3_3,
 280         GLESVersion::ES3,
 281         GLContext::Extension_None,
 282         {GLContext::ARB_occlusion_query2, GLContext::ARB_ES3_compatibility,
 283          GLContext::EXT_occlusion_query_boolean, GLContext::Extensions_End}
 284         /*
 285          * XXX_occlusion_query2 (add in OpenGL 3.3) provide ANY_SAMPLES_PASSED,
 286          * which is provided by ARB_occlusion_query2,
 287          * EXT_occlusion_query_boolean (added in OpenGL ES 3.0) and
 288          * ARB_ES3_compatibility
 289          */
 290     },
 291     {"packed_depth_stencil",
 292      GLVersion::GL3,
 293      GLESVersion::ES3,
 294      GLContext::Extension_None,
 295      {GLContext::EXT_packed_depth_stencil, GLContext::OES_packed_depth_stencil,
 296       GLContext::Extensions_End}},
 297     {"prim_restart",
 298      GLVersion::GL3_1,
 299      GLESVersion::NONE,
 300      GLContext::Extension_None,
 301      {// GLContext::NV_primitive_restart, // Has different enum values.
 302       GLContext::Extensions_End}},
 303     {"prim_restart_fixed",
 304      kGLCoreVersionForES3Compat,
 305      GLESVersion::ES3,
 306      GLContext::ARB_ES3_compatibility,
 307      {GLContext::Extensions_End}},
 308     {"provoking_vertex",
 309      GLVersion::GL3_2,
 310      GLESVersion::NONE,
 311      GLContext::ARB_provoking_vertex,
 312      {GLContext::ANGLE_provoking_vertex, GLContext::EXT_provoking_vertex,
 313       GLContext::Extensions_End}},
 314     {"query_counter",
 315      GLVersion::GL3_3,
 316      GLESVersion::NONE,
 317      GLContext::ARB_timer_query,
 318      {GLContext::ANGLE_timer_query, GLContext::EXT_disjoint_timer_query,
 319       // EXT_timer_query does NOT support GL_TIMESTAMP retrieval with
 320       // QueryCounter.
 321       GLContext::Extensions_End}},
 322     {
 323         "query_objects",
 324         GLVersion::GL2,
 325         GLESVersion::ES3,
 326         GLContext::Extension_None,
 327         {GLContext::ANGLE_timer_query, GLContext::EXT_disjoint_timer_query,
 328          GLContext::EXT_occlusion_query_boolean, GLContext::Extensions_End}
 329         /*
 330          * XXX_query_objects only provide entry points commonly supported by
 331          * ARB_occlusion_query (added in OpenGL 2.0),
 332          * EXT_occlusion_query_boolean (added in OpenGL ES 3.0), and
 333          * ARB_timer_query (added in OpenGL 3.3)
 334          */
 335     },
 336     {"query_time_elapsed",
 337      GLVersion::GL3_3,
 338      GLESVersion::NONE,
 339      GLContext::ARB_timer_query,
 340      {GLContext::ANGLE_timer_query, GLContext::EXT_disjoint_timer_query,
 341       GLContext::EXT_timer_query, GLContext::Extensions_End}},
 342     {"read_buffer",
 343      GLVersion::GL2,
 344      GLESVersion::ES3,
 345      GLContext::Extension_None,
 346      {GLContext::Extensions_End}},
 347     {"renderbuffer_color_float",
 348      GLVersion::GL3,
 349      GLESVersion::ES3_2,
 350      GLContext::Extension_None,
 351      {GLContext::ARB_texture_float, GLContext::EXT_color_buffer_float,
 352       GLContext::CHROMIUM_color_buffer_float_rgba, GLContext::Extensions_End}},
 353     {"renderbuffer_color_half_float",
 354      GLVersion::GL3,
 355      GLESVersion::ES3_2,
 356      GLContext::Extension_None,
 357      {GLContext::ARB_texture_float, GLContext::EXT_color_buffer_float,
 358       GLContext::EXT_color_buffer_half_float, GLContext::Extensions_End}},
 359     {"robust_buffer_access_behavior",
 360      GLVersion::NONE,
 361      GLESVersion::NONE,
 362      GLContext::Extension_None,
 363      {GLContext::ARB_robust_buffer_access_behavior,
 364       GLContext::KHR_robust_buffer_access_behavior, GLContext::Extensions_End}},
 365     {"robustness",
 366      GLVersion::NONE,
 367      GLESVersion::NONE,
 368      GLContext::Extension_None,
 369      {GLContext::ARB_robustness, GLContext::EXT_robustness,
 370       GLContext::KHR_robustness, GLContext::Extensions_End}},
 371     {"sRGB",
 372      GLVersion::GL3,
 373      GLESVersion::ES3,
 374      GLContext::ARB_framebuffer_sRGB,
 375      {GLContext::EXT_sRGB, GLContext::EXT_framebuffer_sRGB,
 376       GLContext::Extensions_End}},
 377     {"sampler_objects",
 378      GLVersion::GL3_3,
 379      GLESVersion::ES3,
 380      GLContext::ARB_sampler_objects,
 381      {GLContext::Extensions_End}},
 382     {"seamless_cube_map_opt_in",
 383      GLVersion::GL3_2,
 384      GLESVersion::NONE,
 385      GLContext::ARB_seamless_cube_map,
 386      {GLContext::Extensions_End}},
 387     {"shader_texture_lod",
 388      GLVersion::GL3,
 389      GLESVersion::ES3,
 390      GLContext::Extension_None,
 391      {GLContext::ARB_shader_texture_lod, GLContext::EXT_shader_texture_lod,
 392       GLContext::Extensions_End}},
 393     {// Do we have separate DRAW and READ framebuffer bind points?
 394      "split_framebuffer",
 395      GLVersion::GL3,
 396      GLESVersion::ES3,
 397      GLContext::ARB_framebuffer_object,
 398      {GLContext::ANGLE_framebuffer_blit,
 399       GLContext::APPLE_framebuffer_multisample, GLContext::EXT_framebuffer_blit,
 400       GLContext::NV_framebuffer_blit, GLContext::Extensions_End}},
 401     {"standard_derivatives",
 402      GLVersion::GL2,
 403      GLESVersion::ES3,
 404      GLContext::Extension_None,
 405      {GLContext::OES_standard_derivatives, GLContext::Extensions_End}},
 406     {"sync",
 407      GLVersion::GL3_2,
 408      GLESVersion::ES3,
 409      GLContext::Extension_None,
 410      {GLContext::ARB_sync, GLContext::APPLE_sync, GLContext::Extensions_End}},
 411     {"texture_3D",
 412      GLVersion::GL1_2,
 413      GLESVersion::ES3,
 414      GLContext::Extension_None,
 415      {GLContext::OES_texture_3D, GLContext::Extensions_End}},
 416     {"texture_3D_compressed",
 417      GLVersion::GL1_3,
 418      GLESVersion::ES3,
 419      GLContext::Extension_None,
 420      {GLContext::ARB_texture_compression, GLContext::OES_texture_3D,
 421       GLContext::Extensions_End}},
 422     {"texture_3D_copy",
 423      GLVersion::GL1_2,
 424      GLESVersion::ES3,
 425      GLContext::Extension_None,
 426      {GLContext::EXT_copy_texture, GLContext::OES_texture_3D,
 427       GLContext::Extensions_End}},
 428     {"texture_compression_bptc",
 429      GLVersion::GL4_2,
 430      GLESVersion::NONE,
 431      GLContext::Extension_None,
 432      {GLContext::ARB_texture_compression_bptc,
 433       GLContext::EXT_texture_compression_bptc, GLContext::Extensions_End}},
 434     {"texture_compression_rgtc",
 435      GLVersion::GL3,
 436      GLESVersion::NONE,
 437      GLContext::Extension_None,
 438      {GLContext::ARB_texture_compression_rgtc,
 439       GLContext::EXT_texture_compression_rgtc, GLContext::Extensions_End}},
 440     {"texture_float",
 441      GLVersion::GL3,
 442      GLESVersion::ES3,
 443      GLContext::Extension_None,
 444      {GLContext::ARB_texture_float, GLContext::OES_texture_float,
 445       GLContext::Extensions_End}},
 446     {"texture_float_linear",
 447      GLVersion::GL3_1,
 448      GLESVersion::NONE,
 449      GLContext::Extension_None,
 450      {GLContext::ARB_texture_float, GLContext::OES_texture_float_linear,
 451       GLContext::Extensions_End}},
 452     {
 453         "texture_half_float",
 454         GLVersion::GL3,
 455         GLESVersion::ES3,
 456         GLContext::Extension_None,
 457         {GLContext::ARB_half_float_pixel, GLContext::ARB_texture_float,
 458          GLContext::NV_half_float, GLContext::Extensions_End}
 459         /**
 460          * We are not including OES_texture_half_float in this feature, because:
 461          *   GL_HALF_FLOAT     = 0x140B
 462          *   GL_HALF_FLOAT_ARB = 0x140B == GL_HALF_FLOAT
 463          *   GL_HALF_FLOAT_NV  = 0x140B == GL_HALF_FLOAT
 464          *   GL_HALF_FLOAT_OES = 0x8D61 != GL_HALF_FLOAT
 465          * WebGL handles this specifically with an OES_texture_half_float check.
 466          */
 467     },
 468     {"texture_half_float_linear",
 469      GLVersion::GL3_1,
 470      GLESVersion::ES3,
 471      GLContext::Extension_None,
 472      {GLContext::ARB_half_float_pixel, GLContext::ARB_texture_float,
 473       GLContext::NV_half_float, GLContext::OES_texture_half_float_linear,
 474       GLContext::Extensions_End}},
 475     {"texture_non_power_of_two",
 476      GLVersion::GL2,
 477      GLESVersion::ES3,
 478      GLContext::Extension_None,
 479      {GLContext::ARB_texture_non_power_of_two, GLContext::OES_texture_npot,
 480       GLContext::Extensions_End}},
 481     {"texture_norm16",
 482      GLVersion::GL3_1,
 483      GLESVersion::ES3_1,
 484      GLContext::EXT_texture_norm16,
 485      {GLContext::Extensions_End}},
 486     {"texture_rg",
 487      GLVersion::GL3,
 488      GLESVersion::ES3,
 489      GLContext::ARB_texture_rg,
 490      {GLContext::Extensions_End}},
 491     {"texture_storage",
 492      GLVersion::GL4_2,
 493      GLESVersion::ES3,
 494      GLContext::ARB_texture_storage,
 495      {/*
 496        * Not including GL_EXT_texture_storage here because it
 497        * doesn't guarantee glTexStorage3D, which is required for
 498        * WebGL 2.
 499        */
 500       GLContext::Extensions_End}},
 501     {"texture_swizzle",
 502      GLVersion::GL3_3,
 503      GLESVersion::ES3,
 504      GLContext::ARB_texture_swizzle,
 505      {GLContext::Extensions_End}},
 506     {"transform_feedback2",
 507      GLVersion::GL4,
 508      GLESVersion::ES3,
 509      GLContext::ARB_transform_feedback2,
 510      {GLContext::NV_transform_feedback2, GLContext::Extensions_End}},
 511     {"uniform_buffer_object",
 512      GLVersion::GL3_1,
 513      GLESVersion::ES3,
 514      GLContext::ARB_uniform_buffer_object,
 515      {GLContext::Extensions_End}},
 516     {"uniform_matrix_nonsquare",
 517      GLVersion::GL2_1,
 518      GLESVersion::ES3,
 519      GLContext::Extension_None,
 520      {GLContext::Extensions_End}},
 521     {"vertex_array_object",
 522      GLVersion::GL3,
 523      GLESVersion::ES3,
 524      GLContext::ARB_vertex_array_object,  // ARB extension
 525      {GLContext::OES_vertex_array_object, GLContext::APPLE_vertex_array_object,
 526       GLContext::Extensions_End}}};
 527
 528 static inline const FeatureInfo& GetFeatureInfo(GLFeature feature) {
 529   static_assert(MOZ_ARRAY_LENGTH(sFeatureInfoArr) == size_t(GLFeature::EnumMax),
 530                 "Mismatched lengths for sFeatureInfoInfos and GLFeature enums");
 531
 532   MOZ_ASSERT(feature < GLFeature::EnumMax,
 533              "GLContext::GetFeatureInfoInfo : unknown <feature>");
 534
 535   return sFeatureInfoArr[size_t(feature)];
 536 }
 537
 538 static inline uint32_t ProfileVersionForFeature(GLFeature feature,
 539                                                 ContextProfile profile) {
 540   MOZ_ASSERT(profile != ContextProfile::Unknown,
 541              "GLContext::ProfileVersionForFeature : unknown <profile>");
 542
 543   const FeatureInfo& featureInfo = GetFeatureInfo(feature);
 544
 545   if (profile == ContextProfile::OpenGLES)
 546     return (uint32_t)featureInfo.mOpenGLESVersion;
 547
 548   return (uint32_t)featureInfo.mOpenGLVersion;
 549 }
 550
 551 static bool IsFeaturePartOfProfileVersion(GLFeature feature,
 552                                           ContextProfile profile,
 553                                           unsigned int version) {
 554   unsigned int profileVersion = ProfileVersionForFeature(feature, profile);
 555
 556   /**
 557    * if `profileVersion` is zero, it means that no version of the profile
 558    * added support for the feature.
 559    */
 560   return profileVersion && version >= profileVersion;
 561 }
 562
 563 bool GLContext::IsFeatureProvidedByCoreSymbols(GLFeature feature) {
 564   if (IsFeaturePartOfProfileVersion(feature, mProfile, mVersion)) return true;
 565
 566   if (IsExtensionSupported(
 567           GetFeatureInfo(feature).mARBExtensionWithoutARBSuffix))
 568     return true;
 569
 570   return false;
 571 }
 572
 573 const char* GLContext::GetFeatureName(GLFeature feature) {
 574   return GetFeatureInfo(feature).mName;
 575 }
 576
 577 void GLContext::InitFeatures() {
 578   for (size_t featureId = 0; featureId < size_t(GLFeature::EnumMax);
 579        featureId++) {
 580     GLFeature feature = GLFeature(featureId);
 581
 582     if (IsFeaturePartOfProfileVersion(feature, mProfile, mVersion)) {
 583       mAvailableFeatures[featureId] = true;
 584       continue;
 585     }
 586
 587     mAvailableFeatures[featureId] = false;
 588
 589     const FeatureInfo& featureInfo = GetFeatureInfo(feature);
 590
 591     if (IsExtensionSupported(featureInfo.mARBExtensionWithoutARBSuffix)) {
 592       mAvailableFeatures[featureId] = true;
 593       continue;
 594     }
 595
 596     for (size_t j = 0; true; j++) {
 597       MOZ_ASSERT(j < kMAX_EXTENSION_GROUP_SIZE,
 598                  "kMAX_EXTENSION_GROUP_SIZE too small");
 599
 600       if (featureInfo.mExtensions[j] == GLContext::Extensions_End) break;
 601
 602       if (IsExtensionSupported(featureInfo.mExtensions[j])) {
 603         mAvailableFeatures[featureId] = true;
 604         break;
 605       }
 606     }
 607   }
 608
 609   if (ShouldDumpExts()) {
 610     for (size_t featureId = 0; featureId < size_t(GLFeature::EnumMax);
 611          featureId++) {
 612       GLFeature feature = GLFeature(featureId);
 613       printf_stderr("[%s] Feature::%s\n",
 614                     IsSupported(feature) ? "enabled" : "disabled",
 615                     GetFeatureName(feature));
 616     }
 617   }
 618 }
 619
 620 void GLContext::MarkUnsupported(GLFeature feature) {
 621   mAvailableFeatures[size_t(feature)] = false;
 622
 623   const FeatureInfo& featureInfo = GetFeatureInfo(feature);
 624
 625   for (size_t i = 0; true; i++) {
 626     MOZ_ASSERT(i < kMAX_EXTENSION_GROUP_SIZE,
 627                "kMAX_EXTENSION_GROUP_SIZE too small");
 628
 629     if (featureInfo.mExtensions[i] == GLContext::Extensions_End) break;
 630
 631     MarkExtensionUnsupported(featureInfo.mExtensions[i]);
 632   }
 633
 634   MOZ_ASSERT(!IsSupported(feature), "GLContext::MarkUnsupported has failed!");
 635
 636   NS_WARNING(
 637       nsPrintfCString("%s marked as unsupported", GetFeatureName(feature))
 638           .get());
 639 }
 640
 641 } /* namespace gl */
 642 } /* namespace mozilla */