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 = get_layout_value(layout.get(), "set");
 172         int bind_point = get_layout_value(layout.get(), "binding");
 173
 174         if(features.target_api==VULKAN)
 175         {
 176                 if(desc_set<0 && bind_point>=0)
 177                 {
 178                         desc_set = 0;
 179                         add_layout_qualifier(layout, Layout::Qualifier("set", desc_set));
 180                 }
 181
 182                 if(desc_set>=0)
 183                         uniforms[name].desc_set = desc_set;
 184         }
 185         else if(desc_set>=0 && bind_point<0)
 186         {
 187                 auto i = find_member(layout->qualifiers, string("set"), &Layout::Qualifier::name);
 188                 layout->qualifiers.erase(i);
 189         }
 190
 191         if(bind_point>=0)
 192         {
 193                 used_bindings[desc_set].insert(bind_point);
 194                 uniforms[name].bind_point = bind_point;
 195         }
 196
 197         return bind_point>=0;
 198 }
 199
 200 void LocationAllocator::visit(VariableDeclaration &var)
 201 {
 202         if(!var.name.compare(0, 3, "gl_"))
 203                 return;
 204
 205         if(!var.interface.empty() && !var.block_declaration)
 206         {
 207                 int location = get_layout_value(var.layout.get(), "location");
 208
 209                 if(location<0 && var.linked_declaration && var.linked_declaration->layout)
 210                 {
 211                         location = get_layout_value(var.linked_declaration->layout.get(), "location");
 212                         if(location>=0)
 213                                 add_layout_qualifier(var.layout, Layout::Qualifier("location", location));
 214                 }
 215
 216                 if(location>=0)
 217                 {
 218                         unsigned size = LocationCounter().apply(var);
 219                         for(unsigned i=0; i<size; ++i)
 220                                 used_locations[var.interface].insert(location+i);
 221                         if(var.interface=="uniform")
 222                                 uniforms[var.name].location = location;
 223                 }
 224                 else
 225                         unplaced_variables.push_back(&var);
 226         }
 227
 228         if(var.interface=="uniform")
 229         {
 230                 if(var.block_declaration)
 231                 {
 232                         bool push_constant = has_layout_qualifier(var.layout.get(), "push_constant");
 233                         if(!push_constant && !visit_uniform(var.block_declaration->block_name, var.layout))
 234                                 unbound_blocks.push_back(&var);
 235                 }
 236                 else
 237                 {
 238                         const TypeDeclaration *base_type = get_ultimate_base_type(var.type_declaration);
 239                         if(dynamic_cast<const ImageTypeDeclaration *>(base_type) && !visit_uniform(var.name, var.layout))
 240                                 unbound_textures.push_back(&var);
 241                 }
 242         }
 243 }
 244
 245
 246 void DepthRangeConverter::apply(Stage &stage, const Features &features)
 247 {
 248         if(stage.type!=Stage::VERTEX || features.target_api==VULKAN)
 249                 return;
 250
 251         stage.content.visit(*this);
 252 }
 253
 254 void DepthRangeConverter::visit(FunctionDeclaration &func)
 255 {
 256         if(func.definition==&func && func.name=="main")
 257         {
 258                 VariableReference *position = new VariableReference;
 259                 position->name = "gl_Position";
 260
 261                 MemberAccess *z = new MemberAccess;
 262                 z->left = position;
 263                 z->member = "z";
 264
 265                 Literal *scale = new Literal;
 266                 scale->token = "2.0";
 267                 scale->value = 2.0f;
 268
 269                 BinaryExpression *multiply = new BinaryExpression;
 270                 multiply->oper = &Operator::get_operator("*", Operator::BINARY);
 271                 multiply->left = z;
 272                 multiply->right = scale;
 273
 274                 MemberAccess *w = new MemberAccess;
 275                 w->left = position->clone();
 276                 w->member = "w";
 277
 278                 BinaryExpression *subtract = new BinaryExpression;
 279                 subtract->oper = &Operator::get_operator("-", Operator::BINARY);
 280                 subtract->left = multiply;
 281                 subtract->right = w;
 282
 283                 Assignment *assign = new Assignment;
 284                 assign->oper = &Operator::get_operator("=", Operator::BINARY);
 285                 assign->left = z->clone();
 286                 assign->right = subtract;
 287
 288                 ExpressionStatement *statement = new ExpressionStatement;
 289                 statement->expression = assign;
 290
 291                 func.body.body.push_back(statement);
 292         }
 293 }
 294
 295
 296 void PrecisionConverter::apply(Stage &s)
 297 {
 298         stage = &s;
 299         s.content.visit(*this);
 300         NodeRemover().apply(s, nodes_to_remove);
 301 }
 302
 303 void PrecisionConverter::visit(Block &block)
 304 {
 305         for(auto i=block.body.begin(); i!=block.body.end(); ++i)
 306         {
 307                 if(&block==&stage->content)
 308                         insert_point = i;
 309                 (*i)->visit(*this);
 310         }
 311 }
 312
 313 void PrecisionConverter::visit(Precision &prec)
 314 {
 315         if(stage->required_features.target_api==OPENGL_ES)
 316                 have_default.insert(prec.type);
 317         else
 318                 nodes_to_remove.insert(&prec);
 319 }
 320
 321 void PrecisionConverter::visit(VariableDeclaration &var)
 322 {
 323         if(stage->required_features.target_api!=OPENGL_ES)
 324         {
 325                 var.precision.clear();
 326                 return;
 327         }
 328
 329         const char *default_prec = (stage->type==Stage::FRAGMENT ? "mediump" : "highp");
 330         const TypeDeclaration *type = var.type_declaration;
 331         while(type)
 332         {
 333                 if(dynamic_cast<const ImageTypeDeclaration *>(type))
 334                 {
 335                         default_prec = "lowp";
 336                         break;
 337                 }
 338                 else if(const BasicTypeDeclaration *basic = dynamic_cast<const BasicTypeDeclaration *>(type))
 339                 {
 340                         if(basic->kind==BasicTypeDeclaration::INT || basic->kind==BasicTypeDeclaration::FLOAT)
 341                                 break;
 342                         type = basic->base_type;
 343                 }
 344                 else
 345                         return;
 346         }
 347         if(!type)
 348                 return;
 349
 350         if(!have_default.count(type->name))
 351         {
 352                 Precision *prec = new Precision;
 353                 prec->precision = default_prec;
 354                 prec->type = type->name;
 355                 stage->content.body.insert(insert_point, prec);
 356
 357                 have_default.insert(type->name);
 358         }
 359 }
 360
 361
 362 void FeatureConverter::apply(Stage &s, const Features &feat)
 363 {
 364         stage = &s;
 365         features = feat;
 366
 367         if(!stage->required_features.glsl_version)
 368                 stage->required_features.glsl_version = Version(1, (stage->required_features.target_api==OPENGL_ES ? 0 : 10));
 369
 370         apply();
 371 }
 372
 373 void FeatureConverter::unsupported(const string &reason)
 374 {
 375         Diagnostic diagnostic;
 376         diagnostic.severity = Diagnostic::ERR;
 377         diagnostic.source = GENERATED_SOURCE;
 378         diagnostic.line = 0;
 379         diagnostic.message = reason;
 380         stage->diagnostics.push_back(diagnostic);
 381 }
 382
 383 bool FeatureConverter::check_version(const Version &feature_version) const
 384 {
 385         if(features.glsl_version<feature_version)
 386                 return false;
 387         else if(stage->required_features.glsl_version<feature_version)
 388                 stage->required_features.glsl_version = feature_version;
 389
 390         return true;
 391 }
 392
 393 bool FeatureConverter::check_extension(bool Features::*extension) const
 394 {
 395         if(!(features.*extension))
 396                 return false;
 397
 398         stage->required_features.*extension = true;
 399
 400         return true;
 401 }
 402
 403
 404 void StructuralFeatureConverter::apply()
 405 {
 406         if(supports_stage(stage->type))
 407         {
 408                 stage->content.visit(*this);
 409                 NodeRemover().apply(*stage, nodes_to_remove);
 410         }
 411         else
 412                 unsupported(format("Stage %s is not supported", Stage::get_stage_name(stage->type)));
 413 }
 414
 415 void StructuralFeatureConverter::visit(Block &block)
 416 {
 417         for(auto i=block.body.begin(); i!=block.body.end(); ++i)
 418         {
 419                 if(&block==&stage->content)
 420                         uniform_insert_point = i;
 421                 (*i)->visit(*this);
 422         }
 423 }
 424
 425 void StructuralFeatureConverter::visit(RefPtr<Expression> &expr)
 426 {
 427         r_replaced_reference = 0;
 428         expr->visit(*this);
 429         if(r_replaced_reference)
 430                 expr = r_replaced_reference;
 431         r_replaced_reference = 0;
 432 }
 433
 434 bool StructuralFeatureConverter::supports_stage(Stage::Type st) const
 435 {
 436         if(st==Stage::GEOMETRY)
 437         {
 438                 if(features.target_api==VULKAN)
 439                         return true;
 440                 else if(features.target_api==OPENGL_ES)
 441                         return check_version(Version(3, 20));
 442                 else
 443                         return check_version(Version(1, 50));
 444         }
 445         else
 446                 return true;
 447 }
 448
 449 bool StructuralFeatureConverter::supports_unified_interface_syntax() const
 450 {
 451         if(features.target_api==VULKAN)
 452                 return true;
 453         else if(features.target_api==OPENGL_ES)
 454                 return check_version(Version(3, 0));
 455         else
 456                 return check_version(Version(1, 30));
 457 }
 458
 459 void StructuralFeatureConverter::visit(VariableReference &var)
 460 {
 461         if(var.declaration==frag_out && !supports_unified_interface_syntax())
 462         {
 463                 var.name = "gl_FragColor";
 464                 var.declaration = 0;
 465         }
 466
 467         r_flattened_interface = nodes_to_remove.count(var.declaration);
 468 }
 469
 470 void StructuralFeatureConverter::visit(MemberAccess &memacc)
 471 {
 472         r_flattened_interface = false;
 473         visit(memacc.left);
 474         if(r_flattened_interface)
 475         {
 476                 VariableReference *var = new VariableReference;
 477                 var->name = memacc.member;
 478                 r_replaced_reference = var;
 479         }
 480 }
 481
 482 void StructuralFeatureConverter::visit(Assignment &assign)
 483 {
 484         TraversingVisitor::visit(assign);
 485         if(assign.target.declaration==frag_out && !supports_unified_interface_syntax())
 486                 assign.target.declaration = 0;
 487 }
 488
 489 bool StructuralFeatureConverter::supports_unified_sampling_functions() const
 490 {
 491         if(features.target_api==VULKAN)
 492                 return true;
 493         else if(features.target_api==OPENGL_ES)
 494                 return check_version(Version(3, 0));
 495         else
 496                 return check_version(Version(1, 30));
 497 }
 498
 499 void StructuralFeatureConverter::visit(FunctionCall &call)
 500 {
 501         if(call.declaration && call.declaration->source==BUILTIN_SOURCE)
 502         {
 503                 if(!call.name.compare(0, 7, "texture") && call.arguments.size()>=1)
 504                 {
 505                         const ImageTypeDeclaration *arg_image = dynamic_cast<const ImageTypeDeclaration *>(call.arguments.front()->type);
 506                         if(arg_image && !supports_unified_sampling_functions())
 507                         {
 508                                 string suffix = call.name.substr(7);
 509                                 call.name = (arg_image->shadow ? "shadow" : "texture");
 510
 511                                 switch(arg_image->dimensions)
 512                                 {
 513                                 case ImageTypeDeclaration::ONE: call.name += "1D"; break;
 514                                 case ImageTypeDeclaration::TWO: call.name += "2D"; break;
 515                                 case ImageTypeDeclaration::THREE: call.name += "3D"; break;
 516                                 case ImageTypeDeclaration::CUBE: call.name += "Cube"; break;
 517                                 }
 518
 519                                 if(arg_image->array)
 520                                 {
 521                                         /* Array textures and the unified sampling function name were
 522                                         both introduced in GLSL 1.30. */
 523                                         if(arg_image->dimensions==ImageTypeDeclaration::ONE || arg_image->dimensions==ImageTypeDeclaration::TWO)
 524                                                 check_extension(&Features::ext_texture_array);
 525                                         call.name += "Array";
 526                                 }
 527
 528                                 call.name += suffix;
 529                         }
 530                 }
 531         }
 532
 533         TraversingVisitor::visit(call);
 534 }
 535
 536 bool StructuralFeatureConverter::supports_interface_blocks(const string &iface) const
 537 {
 538         if(features.target_api==VULKAN)
 539                 return true;
 540         else if(features.target_api==OPENGL_ES)
 541         {
 542                 if(iface=="uniform")
 543                         return check_version(Version(3, 0));
 544                 else
 545                         return check_version(Version(3, 20));
 546         }
 547         else if(check_version(Version(1, 50)))
 548                 return true;
 549         else if(iface=="uniform")
 550                 return check_extension(&Features::arb_uniform_buffer_object);
 551         else
 552                 return false;
 553 }
 554
 555 void StructuralFeatureConverter::visit(VariableDeclaration &var)
 556 {
 557         if(var.block_declaration)
 558         {
 559                 bool push_constant = has_layout_qualifier(var.layout.get(), "push_constant");
 560                 if(!supports_interface_blocks(var.interface) || (push_constant && features.target_api!=VULKAN))
 561                 {
 562                         if(var.name.find(' ')==string::npos)
 563                                 unsupported("ARB_uniform_buffer_object required for interface block instances");
 564                         else
 565                         {
 566                                 for(const RefPtr<Statement> &s: var.block_declaration->members.body)
 567                                         if(VariableDeclaration *mem = dynamic_cast<VariableDeclaration *>(s.get()))
 568                                                 mem->interface = var.interface;
 569                                 stage->content.body.splice(uniform_insert_point, var.block_declaration->members.body);
 570                                 nodes_to_remove.insert(&var);
 571                                 nodes_to_remove.insert(var.block_declaration);
 572                         }
 573                 }
 574         }
 575
 576         if((var.interface=="in" || var.interface=="out") && !supports_unified_interface_syntax())
 577                 if(stage->type==Stage::FRAGMENT && var.interface=="out")
 578                 {
 579                         frag_out = &var;
 580                         nodes_to_remove.insert(&var);
 581                 }
 582
 583         TraversingVisitor::visit(var);
 584 }
 585
 586
 587 void QualifierConverter::apply()
 588 {
 589         stage->content.visit(*this);
 590 }
 591
 592 bool QualifierConverter::supports_interface_layouts() const
 593 {
 594         if(features.target_api==VULKAN)
 595                 return true;
 596         else if(features.target_api==OPENGL_ES)
 597                 return check_version(Version(3, 0));
 598         else if(check_version(Version(3, 30)))
 599                 return true;
 600         else if(check_version(Version(1, 30)))
 601                 return check_extension(&Features::arb_explicit_attrib_location);
 602         else
 603                 return false;
 604 }
 605
 606 bool QualifierConverter::supports_stage_interface_layouts() const
 607 {
 608         if(features.target_api==VULKAN)
 609                 return true;
 610         else if(features.target_api==OPENGL_ES)
 611                 return check_version(Version(3, 10));
 612         else if(check_version(Version(4, 10)))
 613                 return true;
 614         else
 615                 return check_extension(&Features::arb_separate_shader_objects);
 616 }
 617
 618 bool QualifierConverter::supports_centroid_sampling() const
 619 {
 620         if(features.target_api==VULKAN)
 621                 return true;
 622         else if(features.target_api==OPENGL_ES)
 623                 return check_version(Version(3, 0));
 624         else if(check_version(Version(1, 20)))
 625                 return true;
 626         else
 627                 return check_extension(&Features::ext_gpu_shader4);
 628 }
 629
 630 bool QualifierConverter::supports_sample_sampling() const
 631 {
 632         if(features.target_api==VULKAN)
 633                 return true;
 634         else if(features.target_api==OPENGL_ES)
 635                 return check_version(Version(3, 20));
 636         else if(check_version(Version(4, 0)))
 637                 return true;
 638         else
 639                 return check_extension(&Features::arb_gpu_shader5);
 640 }
 641
 642 bool QualifierConverter::supports_uniform_location() const
 643 {
 644         if(features.target_api==VULKAN)
 645                 return false;
 646         else if(features.target_api==OPENGL_ES)
 647                 return check_version(Version(3, 10));
 648         else if(check_version(Version(4, 30)))
 649                 return true;
 650         else
 651                 return check_extension(&Features::arb_explicit_uniform_location);
 652 }
 653
 654 bool QualifierConverter::supports_binding() const
 655 {
 656         if(features.target_api==VULKAN)
 657                 return true;
 658         else if(features.target_api==OPENGL_ES)
 659                 return check_version(Version(3, 10));
 660         else
 661                 return check_version(Version(4, 20));
 662 }
 663
 664 bool QualifierConverter::supports_interface_block_location() const
 665 {
 666         if(features.target_api==VULKAN)
 667                 return true;
 668         else if(features.target_api==OPENGL_ES)
 669                 return check_version(Version(3, 20));
 670         else if(check_version(Version(4, 40)))
 671                 return true;
 672         else
 673                 return check_extension(&Features::arb_enhanced_layouts);
 674 }
 675
 676 void QualifierConverter::visit(VariableDeclaration &var)
 677 {
 678         if(var.layout)
 679         {
 680                 for(auto i=var.layout->qualifiers.begin(); i!=var.layout->qualifiers.end(); )
 681                 {
 682                         if(i->name=="location")
 683                         {
 684                                 bool supported = true;
 685                                 bool external = false;
 686                                 if(var.block_declaration)
 687                                         supported = supports_interface_block_location();
 688                                 else if(var.interface=="in")
 689                                 {
 690                                         external = (stage->type==Stage::VERTEX);
 691                                         supported = (external ? supports_interface_layouts() : supports_stage_interface_layouts());
 692                                 }
 693                                 else if(var.interface=="out")
 694                                 {
 695                                         external = (stage->type==Stage::FRAGMENT);
 696                                         supported = (external ? supports_interface_layouts() : supports_stage_interface_layouts());
 697                                         if(external && !supported && !check_extension(&Features::ext_gpu_shader4))
 698                                         {
 699                                                 external = false;
 700                                                 if(i->value!=0)
 701                                                         unsupported("EXT_gpu_shader4 required for multiple fragment shader outputs");
 702                                         }
 703                                 }
 704                                 else if(var.interface=="uniform")
 705                                         supported = supports_uniform_location();
 706
 707                                 if(!supported)
 708                                 {
 709                                         if(external)
 710                                                 stage->locations[var.name] = i->value;
 711                                         i = var.layout->qualifiers.erase(i);
 712                                 }
 713                                 else
 714                                         ++i;
 715                         }
 716                         else if(i->name=="binding" && !supports_binding())
 717                         {
 718                                 if(var.block_declaration)
 719                                         stage->uniform_block_bindings[var.block_declaration->block_name] = i->value;
 720                                 else if(dynamic_cast<const ImageTypeDeclaration *>(get_ultimate_base_type(var.type_declaration)))
 721                                         stage->texture_bindings[var.name] = i->value;
 722
 723                                 i = var.layout->qualifiers.erase(i);
 724                         }
 725                         else
 726                                 ++i;
 727                 }
 728
 729                 if(var.layout->qualifiers.empty())
 730                         var.layout = 0;
 731         }
 732
 733         if(var.sampling=="centroid")
 734         {
 735                 if(!supports_centroid_sampling())
 736                         var.sampling = string();
 737         }
 738         else if(var.sampling=="sample")
 739         {
 740                 if(!supports_sample_sampling())
 741                         var.sampling = string();
 742         }
 743
 744         if(var.name=="gl_ClipDistance")
 745                 if(const Literal *literal_size = dynamic_cast<const Literal *>(var.array_size.get()))
 746                         stage->n_clip_distances = literal_size->value.value<int>();
 747
 748         TraversingVisitor::visit(var);
 749 }
 750
 751 } // namespace SL
 752 } // namespace GL
 753 } // namespace Msp