source/glsl/finalize.cpp

   1 #include <msp/core/algorithm.h>
   2 #include <msp/core/hash.h>
   3 #include <msp/core/raii.h>
   4 #include <msp/strings/lexicalcast.h>
   5 #include "finalize.h"
   6 #include "glsl_error.h"
   7 #include "reflect.h"
   8
   9 using namespace std;
  10
  11 namespace Msp {
  12 namespace GL {
  13 namespace SL {
  14
  15 void StructOrganizer::visit(StructDeclaration &strct)
  16 {
  17         SetForScope<int> set_offset(offset, 0);
  18         TraversingVisitor::visit(strct);
  19 }
  20
  21 void StructOrganizer::visit(VariableDeclaration &var)
  22 {
  23         if(offset>=0)
  24         {
  25                 int *layout_offset = 0;
  26                 bool has_matrix_order = false;
  27                 if(var.layout)
  28                 {
  29                         for(Layout::Qualifier &q: var.layout->qualifiers)
  30                         {
  31                                 if(q.name=="offset" && q.has_value)
  32                                 {
  33                                         layout_offset = &q.value;
  34                                         if(q.value>=offset)
  35                                                 offset = q.value;
  36                                 }
  37                                 else if(q.name=="column_major" || q.name=="row_major")
  38                                         has_matrix_order = true;
  39                         }
  40                 }
  41
  42                 MemoryRequirementsCalculator::Result mem_reqs = MemoryRequirementsCalculator().apply(var);
  43                 offset += mem_reqs.alignment-1;
  44                 offset -= offset%mem_reqs.alignment;
  45
  46                 if(layout_offset)
  47                         *layout_offset = offset;
  48                 else
  49                         add_layout_qualifier(var.layout, Layout::Qualifier("offset", offset));
  50
  51                 if(!has_matrix_order)
  52                 {
  53                         const BasicTypeDeclaration *basic = dynamic_cast<const BasicTypeDeclaration *>(var.type_declaration);
  54                         while(basic && basic->kind==BasicTypeDeclaration::ARRAY)
  55                                 basic = dynamic_cast<const BasicTypeDeclaration *>(basic->base_type);
  56                         if(basic && basic->kind==BasicTypeDeclaration::MATRIX)
  57                                 add_layout_qualifier(var.layout, Layout::Qualifier("column_major"));
  58                 }
  59
  60                 offset += mem_reqs.size;
  61         }
  62 }
  63
  64
  65 void LocationAllocator::apply(Module &module, const Features &f, bool a)
  66 {
  67         features = f;
  68         alloc_new = a;
  69         for(Stage &s: module.stages)
  70                 apply(s);
  71
  72         if(features.target_api!=VULKAN)
  73                 allocate_locations("uniform");
  74
  75         for(VariableDeclaration *b: unbound_blocks)
  76                 bind_uniform(b->layout, b->block_declaration->block_name, features.uniform_binding_range);
  77         for(VariableDeclaration *t: unbound_textures)
  78                 bind_uniform(t->layout, t->name, features.texture_binding_range);
  79 }
  80
  81 void LocationAllocator::apply(Stage &stage)
  82 {
  83         swap(used_locations["in"], used_locations["out"]);
  84         used_locations["out"].clear();
  85
  86         stage.content.visit(*this);
  87
  88         allocate_locations("in");
  89         allocate_locations("out");
  90 }
  91
  92 void LocationAllocator::allocate_locations(const string &iface)
  93 {
  94         auto write = unplaced_variables.begin();
  95         unsigned next = 0;
  96         for(auto i=unplaced_variables.begin(); i!=unplaced_variables.end(); ++i)
  97         {
  98                 if((*i)->interface!=iface)
  99                 {
 100                         if(write!=i)
 101                                 *write = *i;
 102                         ++write;
 103                         continue;
 104                 }
 105
 106                 if((*i)->interface=="uniform")
 107                 {
 108                         auto j = uniforms.find((*i)->name);
 109                         if(j!=uniforms.end() && j->second.location>=0)
 110                         {
 111                                 add_layout_qualifier((*i)->layout, Layout::Qualifier("location", j->second.location));
 112                                 continue;
 113                         }
 114                 }
 115
 116                 if(!alloc_new)
 117                         continue;
 118
 119                 set<unsigned> &used = used_locations[(*i)->interface];
 120
 121                 unsigned size = LocationCounter().apply(**i);
 122                 while(1)
 123                 {
 124                         int blocking = -1;
 125                         for(unsigned j=0; j<size; ++j)
 126                                 if(used.count(next+j))
 127                                         blocking = next+j;
 128                         if(blocking<0)
 129                                 break;
 130                         next = blocking+1;
 131                 }
 132
 133                 add_layout_qualifier((*i)->layout, Layout::Qualifier("location", next));
 134                 if((*i)->interface=="uniform")
 135                         uniforms[(*i)->name].location = next;
 136
 137                 for(unsigned j=0; j<size; ++j)
 138                         used.insert(next+j);
 139                 next += size;
 140         }
 141
 142         unplaced_variables.erase(write, unplaced_variables.end());
 143 }
 144
 145 void LocationAllocator::bind_uniform(RefPtr<Layout> &layout, const string &name, unsigned range)
 146 {
 147         auto i = uniforms.find(name);
 148
 149         int desc_set = (i!=uniforms.end() ? i->second.desc_set : 0);
 150         if(features.target_api==VULKAN && get_layout_value(layout.get(), "set")<0)
 151                 add_layout_qualifier(layout, Layout::Qualifier("set", desc_set));
 152
 153         if(i!=uniforms.end() && i->second.bind_point>=0)
 154                 add_layout_qualifier(layout, Layout::Qualifier("binding", i->second.bind_point));
 155         else if(alloc_new)
 156         {
 157                 set<unsigned> &used = used_bindings[desc_set];
 158
 159                 unsigned bind_point = hash_fold<32>(hash<64>(name))%range;
 160                 while(used.count(bind_point))
 161                         bind_point = (bind_point+1)%range;
 162
 163                 add_layout_qualifier(layout, Layout::Qualifier("binding", bind_point));
 164                 uniforms[name].bind_point = bind_point;
 165                 used.insert(bind_point);
 166         }
 167 }
 168
 169 bool LocationAllocator::visit_uniform(const string &name, RefPtr<Layout> &layout)
 170 {
 171         int desc_set = 0;
 172         int bind_point = get_layout_value(layout.get(), "binding");
 173
 174         if(features.target_api==VULKAN)
 175         {
 176                 desc_set = get_layout_value(layout.get(), "set");
 177                 if(desc_set<0 && bind_point>=0)
 178                 {
 179                         desc_set = 0;
 180                         add_layout_qualifier(layout, Layout::Qualifier("set", desc_set));
 181                 }
 182
 183                 if(desc_set>=0)
 184                         uniforms[name].desc_set = desc_set;
 185         }
 186
 187         if(bind_point>=0)
 188         {
 189                 used_bindings[desc_set].insert(bind_point);
 190                 uniforms[name].bind_point = bind_point;
 191         }
 192
 193         return bind_point>=0;
 194 }
 195
 196 void LocationAllocator::visit(VariableDeclaration &var)
 197 {
 198         if(!var.name.compare(0, 3, "gl_"))
 199                 return;
 200
 201         if(!var.interface.empty() && !var.block_declaration)
 202         {
 203                 int location = get_layout_value(var.layout.get(), "location");
 204
 205                 if(location<0 && var.linked_declaration && var.linked_declaration->layout)
 206                 {
 207                         location = get_layout_value(var.linked_declaration->layout.get(), "location");
 208                         if(location>=0)
 209                                 add_layout_qualifier(var.layout, Layout::Qualifier("location", location));
 210                 }
 211
 212                 if(location>=0)
 213                 {
 214                         unsigned size = LocationCounter().apply(var);
 215                         for(unsigned i=0; i<size; ++i)
 216                                 used_locations[var.interface].insert(location+i);
 217                         if(var.interface=="uniform")
 218                                 uniforms[var.name].location = location;
 219                 }
 220                 else
 221                         unplaced_variables.push_back(&var);
 222         }
 223
 224         if(var.interface=="uniform")
 225         {
 226                 if(var.block_declaration)
 227                 {
 228                         bool push_constant = has_layout_qualifier(var.layout.get(), "push_constant");
 229                         if(!push_constant && !visit_uniform(var.block_declaration->block_name, var.layout))
 230                                 unbound_blocks.push_back(&var);
 231                 }
 232                 else
 233                 {
 234                         const TypeDeclaration *base_type = get_ultimate_base_type(var.type_declaration);
 235                         if(dynamic_cast<const ImageTypeDeclaration *>(base_type) && !visit_uniform(var.name, var.layout))
 236                                 unbound_textures.push_back(&var);
 237                 }
 238         }
 239 }
 240
 241
 242 void DepthRangeConverter::apply(Stage &stage, const Features &features)
 243 {
 244         if(stage.type!=Stage::VERTEX || features.target_api==VULKAN)
 245                 return;
 246
 247         stage.content.visit(*this);
 248 }
 249
 250 void DepthRangeConverter::visit(FunctionDeclaration &func)
 251 {
 252         if(func.definition==&func && func.name=="main")
 253         {
 254                 VariableReference *position = new VariableReference;
 255                 position->name = "gl_Position";
 256
 257                 MemberAccess *z = new MemberAccess;
 258                 z->left = position;
 259                 z->member = "z";
 260
 261                 Literal *scale = new Literal;
 262                 scale->token = "2.0";
 263                 scale->value = 2.0f;
 264
 265                 BinaryExpression *multiply = new BinaryExpression;
 266                 multiply->oper = &Operator::get_operator("*", Operator::BINARY);
 267                 multiply->left = z;
 268                 multiply->right = scale;
 269
 270                 MemberAccess *w = new MemberAccess;
 271                 w->left = position->clone();
 272                 w->member = "w";
 273
 274                 BinaryExpression *subtract = new BinaryExpression;
 275                 subtract->oper = &Operator::get_operator("-", Operator::BINARY);
 276                 subtract->left = multiply;
 277                 subtract->right = w;
 278
 279                 Assignment *assign = new Assignment;
 280                 assign->oper = &Operator::get_operator("=", Operator::BINARY);
 281                 assign->left = z->clone();
 282                 assign->right = subtract;
 283
 284                 ExpressionStatement *statement = new ExpressionStatement;
 285                 statement->expression = assign;
 286
 287                 func.body.body.push_back(statement);
 288         }
 289 }
 290
 291
 292 void PrecisionConverter::apply(Stage &s)
 293 {
 294         stage = &s;
 295         s.content.visit(*this);
 296         NodeRemover().apply(s, nodes_to_remove);
 297 }
 298
 299 void PrecisionConverter::visit(Block &block)
 300 {
 301         for(auto i=block.body.begin(); i!=block.body.end(); ++i)
 302         {
 303                 if(&block==&stage->content)
 304                         insert_point = i;
 305                 (*i)->visit(*this);
 306         }
 307 }
 308
 309 void PrecisionConverter::visit(Precision &prec)
 310 {
 311         if(stage->required_features.target_api==OPENGL_ES)
 312                 have_default.insert(prec.type);
 313         else
 314                 nodes_to_remove.insert(&prec);
 315 }
 316
 317 void PrecisionConverter::visit(VariableDeclaration &var)
 318 {
 319         if(stage->required_features.target_api!=OPENGL_ES)
 320         {
 321                 var.precision.clear();
 322                 return;
 323         }
 324
 325         const char *default_prec = (stage->type==Stage::FRAGMENT ? "mediump" : "highp");
 326         const TypeDeclaration *type = var.type_declaration;
 327         while(type)
 328         {
 329                 if(dynamic_cast<const ImageTypeDeclaration *>(type))
 330                 {
 331                         default_prec = "lowp";
 332                         break;
 333                 }
 334                 else if(const BasicTypeDeclaration *basic = dynamic_cast<const BasicTypeDeclaration *>(type))
 335                 {
 336                         if(basic->kind==BasicTypeDeclaration::INT || basic->kind==BasicTypeDeclaration::FLOAT)
 337                                 break;
 338                         type = basic->base_type;
 339                 }
 340                 else
 341                         return;
 342         }
 343         if(!type)
 344                 return;
 345
 346         if(!have_default.count(type->name))
 347         {
 348                 Precision *prec = new Precision;
 349                 prec->precision = default_prec;
 350                 prec->type = type->name;
 351                 stage->content.body.insert(insert_point, prec);
 352
 353                 have_default.insert(type->name);
 354         }
 355 }
 356
 357
 358 void FeatureConverter::apply(Stage &s, const Features &feat)
 359 {
 360         stage = &s;
 361         features = feat;
 362
 363         if(!stage->required_features.glsl_version)
 364                 stage->required_features.glsl_version = Version(1, (stage->required_features.target_api==OPENGL_ES ? 0 : 10));
 365
 366         apply();
 367 }
 368
 369 void FeatureConverter::unsupported(const string &reason)
 370 {
 371         Diagnostic diagnostic;
 372         diagnostic.severity = Diagnostic::ERR;
 373         diagnostic.source = GENERATED_SOURCE;
 374         diagnostic.line = 0;
 375         diagnostic.message = reason;
 376         stage->diagnostics.push_back(diagnostic);
 377 }
 378
 379 bool FeatureConverter::check_version(const Version &feature_version) const
 380 {
 381         if(features.glsl_version<feature_version)
 382                 return false;
 383         else if(stage->required_features.glsl_version<feature_version)
 384                 stage->required_features.glsl_version = feature_version;
 385
 386         return true;
 387 }
 388
 389 bool FeatureConverter::check_extension(bool Features::*extension) const
 390 {
 391         if(!(features.*extension))
 392                 return false;
 393
 394         stage->required_features.*extension = true;
 395
 396         return true;
 397 }
 398
 399
 400 void StructuralFeatureConverter::apply()
 401 {
 402         if(supports_stage(stage->type))
 403         {
 404                 stage->content.visit(*this);
 405                 NodeRemover().apply(*stage, nodes_to_remove);
 406         }
 407         else
 408                 unsupported(format("Stage %s is not supported", Stage::get_stage_name(stage->type)));
 409 }
 410
 411 void StructuralFeatureConverter::visit(Block &block)
 412 {
 413         for(auto i=block.body.begin(); i!=block.body.end(); ++i)
 414         {
 415                 if(&block==&stage->content)
 416                         uniform_insert_point = i;
 417                 (*i)->visit(*this);
 418         }
 419 }
 420
 421 void StructuralFeatureConverter::visit(RefPtr<Expression> &expr)
 422 {
 423         r_replaced_reference = 0;
 424         expr->visit(*this);
 425         if(r_replaced_reference)
 426                 expr = r_replaced_reference;
 427         r_replaced_reference = 0;
 428 }
 429
 430 bool StructuralFeatureConverter::supports_stage(Stage::Type st) const
 431 {
 432         if(st==Stage::GEOMETRY)
 433         {
 434                 if(features.target_api==VULKAN)
 435                         return true;
 436                 else if(features.target_api==OPENGL_ES)
 437                         return check_version(Version(3, 20));
 438                 else
 439                         return check_version(Version(1, 50));
 440         }
 441         else
 442                 return true;
 443 }
 444
 445 bool StructuralFeatureConverter::supports_unified_interface_syntax() const
 446 {
 447         if(features.target_api==VULKAN)
 448                 return true;
 449         else if(features.target_api==OPENGL_ES)
 450                 return check_version(Version(3, 0));
 451         else
 452                 return check_version(Version(1, 30));
 453 }
 454
 455 void StructuralFeatureConverter::visit(VariableReference &var)
 456 {
 457         if(var.declaration==frag_out && !supports_unified_interface_syntax())
 458         {
 459                 var.name = "gl_FragColor";
 460                 var.declaration = 0;
 461         }
 462
 463         r_flattened_interface = nodes_to_remove.count(var.declaration);
 464 }
 465
 466 void StructuralFeatureConverter::visit(MemberAccess &memacc)
 467 {
 468         r_flattened_interface = false;
 469         visit(memacc.left);
 470         if(r_flattened_interface)
 471         {
 472                 VariableReference *var = new VariableReference;
 473                 var->name = memacc.member;
 474                 r_replaced_reference = var;
 475         }
 476 }
 477
 478 void StructuralFeatureConverter::visit(Assignment &assign)
 479 {
 480         TraversingVisitor::visit(assign);
 481         if(assign.target.declaration==frag_out && !supports_unified_interface_syntax())
 482                 assign.target.declaration = 0;
 483 }
 484
 485 bool StructuralFeatureConverter::supports_unified_sampling_functions() const
 486 {
 487         if(features.target_api==VULKAN)
 488                 return true;
 489         else if(features.target_api==OPENGL_ES)
 490                 return check_version(Version(3, 0));
 491         else
 492                 return check_version(Version(1, 30));
 493 }
 494
 495 void StructuralFeatureConverter::visit(FunctionCall &call)
 496 {
 497         if(call.declaration && call.declaration->source==BUILTIN_SOURCE)
 498         {
 499                 if(!call.name.compare(0, 7, "texture") && call.arguments.size()>=1)
 500                 {
 501                         const ImageTypeDeclaration *arg_image = dynamic_cast<const ImageTypeDeclaration *>(call.arguments.front()->type);
 502                         if(arg_image && !supports_unified_sampling_functions())
 503                         {
 504                                 string suffix = call.name.substr(7);
 505                                 call.name = (arg_image->shadow ? "shadow" : "texture");
 506
 507                                 switch(arg_image->dimensions)
 508                                 {
 509                                 case ImageTypeDeclaration::ONE: call.name += "1D"; break;
 510                                 case ImageTypeDeclaration::TWO: call.name += "2D"; break;
 511                                 case ImageTypeDeclaration::THREE: call.name += "3D"; break;
 512                                 case ImageTypeDeclaration::CUBE: call.name += "Cube"; break;
 513                                 }
 514
 515                                 if(arg_image->array)
 516                                 {
 517                                         /* Array textures and the unified sampling function name were
 518                                         both introduced in GLSL 1.30. */
 519                                         if(arg_image->dimensions==ImageTypeDeclaration::ONE || arg_image->dimensions==ImageTypeDeclaration::TWO)
 520                                                 check_extension(&Features::ext_texture_array);
 521                                         call.name += "Array";
 522                                 }
 523
 524                                 call.name += suffix;
 525                         }
 526                 }
 527         }
 528
 529         TraversingVisitor::visit(call);
 530 }
 531
 532 bool StructuralFeatureConverter::supports_interface_blocks(const string &iface) const
 533 {
 534         if(features.target_api==VULKAN)
 535                 return true;
 536         else if(features.target_api==OPENGL_ES)
 537         {
 538                 if(iface=="uniform")
 539                         return check_version(Version(3, 0));
 540                 else
 541                         return check_version(Version(3, 20));
 542         }
 543         else if(check_version(Version(1, 50)))
 544                 return true;
 545         else if(iface=="uniform")
 546                 return check_extension(&Features::arb_uniform_buffer_object);
 547         else
 548                 return false;
 549 }
 550
 551 void StructuralFeatureConverter::visit(VariableDeclaration &var)
 552 {
 553         if(var.block_declaration)
 554         {
 555                 bool push_constant = has_layout_qualifier(var.layout.get(), "push_constant");
 556                 if(!supports_interface_blocks(var.interface) || (push_constant && features.target_api!=VULKAN))
 557                 {
 558                         if(var.name.find(' ')==string::npos)
 559                                 unsupported("ARB_uniform_buffer_object required for interface block instances");
 560                         else
 561                         {
 562                                 for(const RefPtr<Statement> &s: var.block_declaration->members.body)
 563                                         if(VariableDeclaration *mem = dynamic_cast<VariableDeclaration *>(s.get()))
 564                                                 mem->interface = var.interface;
 565                                 stage->content.body.splice(uniform_insert_point, var.block_declaration->members.body);
 566                                 nodes_to_remove.insert(&var);
 567                                 nodes_to_remove.insert(var.block_declaration);
 568                         }
 569                 }
 570         }
 571
 572         if((var.interface=="in" || var.interface=="out") && !supports_unified_interface_syntax())
 573                 if(stage->type==Stage::FRAGMENT && var.interface=="out")
 574                 {
 575                         frag_out = &var;
 576                         nodes_to_remove.insert(&var);
 577                 }
 578
 579         TraversingVisitor::visit(var);
 580 }
 581
 582
 583 void QualifierConverter::apply()
 584 {
 585         stage->content.visit(*this);
 586 }
 587
 588 bool QualifierConverter::supports_interface_layouts() const
 589 {
 590         if(features.target_api==VULKAN)
 591                 return true;
 592         else if(features.target_api==OPENGL_ES)
 593                 return check_version(Version(3, 0));
 594         else if(check_version(Version(3, 30)))
 595                 return true;
 596         else if(check_version(Version(1, 30)))
 597                 return check_extension(&Features::arb_explicit_attrib_location);
 598         else
 599                 return false;
 600 }
 601
 602 bool QualifierConverter::supports_stage_interface_layouts() const
 603 {
 604         if(features.target_api==VULKAN)
 605                 return true;
 606         else if(features.target_api==OPENGL_ES)
 607                 return check_version(Version(3, 10));
 608         else if(check_version(Version(4, 10)))
 609                 return true;
 610         else
 611                 return check_extension(&Features::arb_separate_shader_objects);
 612 }
 613
 614 bool QualifierConverter::supports_centroid_sampling() const
 615 {
 616         if(features.target_api==VULKAN)
 617                 return true;
 618         else if(features.target_api==OPENGL_ES)
 619                 return check_version(Version(3, 0));
 620         else if(check_version(Version(1, 20)))
 621                 return true;
 622         else
 623                 return check_extension(&Features::ext_gpu_shader4);
 624 }
 625
 626 bool QualifierConverter::supports_sample_sampling() const
 627 {
 628         if(features.target_api==VULKAN)
 629                 return true;
 630         else if(features.target_api==OPENGL_ES)
 631                 return check_version(Version(3, 20));
 632         else if(check_version(Version(4, 0)))
 633                 return true;
 634         else
 635                 return check_extension(&Features::arb_gpu_shader5);
 636 }
 637
 638 bool QualifierConverter::supports_uniform_location() const
 639 {
 640         if(features.target_api==VULKAN)
 641                 return false;
 642         else if(features.target_api==OPENGL_ES)
 643                 return check_version(Version(3, 10));
 644         else if(check_version(Version(4, 30)))
 645                 return true;
 646         else
 647                 return check_extension(&Features::arb_explicit_uniform_location);
 648 }
 649
 650 bool QualifierConverter::supports_binding() const
 651 {
 652         if(features.target_api==VULKAN)
 653                 return true;
 654         else if(features.target_api==OPENGL_ES)
 655                 return check_version(Version(3, 10));
 656         else
 657                 return check_version(Version(4, 20));
 658 }
 659
 660 bool QualifierConverter::supports_interface_block_location() const
 661 {
 662         if(features.target_api==VULKAN)
 663                 return true;
 664         else if(features.target_api==OPENGL_ES)
 665                 return check_version(Version(3, 20));
 666         else if(check_version(Version(4, 40)))
 667                 return true;
 668         else
 669                 return check_extension(&Features::arb_enhanced_layouts);
 670 }
 671
 672 void QualifierConverter::visit(VariableDeclaration &var)
 673 {
 674         if(var.layout)
 675         {
 676                 for(auto i=var.layout->qualifiers.begin(); i!=var.layout->qualifiers.end(); )
 677                 {
 678                         if(i->name=="location")
 679                         {
 680                                 bool supported = true;
 681                                 bool external = false;
 682                                 if(var.block_declaration)
 683                                         supported = supports_interface_block_location();
 684                                 else if(var.interface=="in")
 685                                 {
 686                                         external = (stage->type==Stage::VERTEX);
 687                                         supported = (external ? supports_interface_layouts() : supports_stage_interface_layouts());
 688                                 }
 689                                 else if(var.interface=="out")
 690                                 {
 691                                         external = (stage->type==Stage::FRAGMENT);
 692                                         supported = (external ? supports_interface_layouts() : supports_stage_interface_layouts());
 693                                         if(external && !supported && !check_extension(&Features::ext_gpu_shader4))
 694                                         {
 695                                                 external = false;
 696                                                 if(i->value!=0)
 697                                                         unsupported("EXT_gpu_shader4 required for multiple fragment shader outputs");
 698                                         }
 699                                 }
 700                                 else if(var.interface=="uniform")
 701                                         supported = supports_uniform_location();
 702
 703                                 if(!supported)
 704                                 {
 705                                         if(external)
 706                                                 stage->locations[var.name] = i->value;
 707                                         i = var.layout->qualifiers.erase(i);
 708                                 }
 709                                 else
 710                                         ++i;
 711                         }
 712                         else if(i->name=="binding" && !supports_binding())
 713                         {
 714                                 if(var.block_declaration)
 715                                         stage->uniform_block_bindings[var.block_declaration->block_name] = i->value;
 716                                 else if(dynamic_cast<const ImageTypeDeclaration *>(get_ultimate_base_type(var.type_declaration)))
 717                                         stage->texture_bindings[var.name] = i->value;
 718
 719                                 i = var.layout->qualifiers.erase(i);
 720                         }
 721                         else
 722                                 ++i;
 723                 }
 724
 725                 if(var.layout->qualifiers.empty())
 726                         var.layout = 0;
 727         }
 728
 729         if(var.sampling=="centroid")
 730         {
 731                 if(!supports_centroid_sampling())
 732                         var.sampling = string();
 733         }
 734         else if(var.sampling=="sample")
 735         {
 736                 if(!supports_sample_sampling())
 737                         var.sampling = string();
 738         }
 739
 740         if(var.name=="gl_ClipDistance")
 741                 if(const Literal *literal_size = dynamic_cast<const Literal *>(var.array_size.get()))
 742                         stage->n_clip_distances = literal_size->value.value<int>();
 743
 744         TraversingVisitor::visit(var);
 745 }
 746
 747 } // namespace SL
 748 } // namespace GL
 749 } // namespace Msp