source/glsl/generate.cpp

   1 #include <msp/core/hash.h>
   2 #include <msp/core/raii.h>
   3 #include <msp/strings/lexicalcast.h>
   4 #include "builtin.h"
   5 #include "generate.h"
   6
   7 using namespace std;
   8
   9 namespace Msp {
  10 namespace GL {
  11 namespace SL {
  12
  13 void DeclarationCombiner::apply(Stage &stage)
  14 {
  15         stage.content.visit(*this);
  16         NodeRemover().apply(stage, nodes_to_remove);
  17 }
  18
  19 void DeclarationCombiner::visit(Block &block)
  20 {
  21         if(current_block)
  22                 return;
  23
  24         TraversingVisitor::visit(block);
  25 }
  26
  27 void DeclarationCombiner::visit(VariableDeclaration &var)
  28 {
  29         VariableDeclaration *&ptr = variables[var.name];
  30         if(ptr)
  31         {
  32                 ptr->type = var.type;
  33                 if(var.init_expression)
  34                         ptr->init_expression = var.init_expression;
  35                 if(var.layout)
  36                 {
  37                         if(ptr->layout)
  38                         {
  39                                 for(vector<Layout::Qualifier>::iterator i=var.layout->qualifiers.begin(); i!=var.layout->qualifiers.end(); ++i)
  40                                 {
  41                                         bool found = false;
  42                                         for(vector<Layout::Qualifier>::iterator j=ptr->layout->qualifiers.begin(); (!found && j!=ptr->layout->qualifiers.end()); ++j)
  43                                                 if(j->name==i->name)
  44                                                 {
  45                                                         j->has_value = i->value;
  46                                                         j->value = i->value;
  47                                                         found = true;
  48                                                 }
  49
  50                                         if(!found)
  51                                                 ptr->layout->qualifiers.push_back(*i);
  52                                 }
  53                         }
  54                         else
  55                                 ptr->layout = var.layout;
  56                 }
  57                 nodes_to_remove.insert(&var);
  58         }
  59         else
  60                 ptr = &var;
  61 }
  62
  63
  64 ConstantSpecializer::ConstantSpecializer():
  65         values(0)
  66 { }
  67
  68 void ConstantSpecializer::apply(Stage &stage, const map<string, int> *v)
  69 {
  70         values = v;
  71         stage.content.visit(*this);
  72 }
  73
  74 void ConstantSpecializer::visit(VariableDeclaration &var)
  75 {
  76         bool specializable = false;
  77         if(var.layout)
  78         {
  79                 vector<Layout::Qualifier> &qualifiers = var.layout->qualifiers;
  80                 for(vector<Layout::Qualifier>::iterator i=qualifiers.begin(); i!=qualifiers.end(); ++i)
  81                         if(i->name=="constant_id")
  82                         {
  83                                 specializable = true;
  84                                 if(values)
  85                                         qualifiers.erase(i);
  86                                 else if(i->value==-1)
  87                                         i->value = hash32(var.name)&0x7FFFFFFF;
  88                                 break;
  89                         }
  90
  91                 if(qualifiers.empty())
  92                         var.layout = 0;
  93         }
  94
  95         if(specializable && values)
  96         {
  97                 map<string, int>::const_iterator i = values->find(var.name);
  98                 if(i!=values->end())
  99                 {
 100                         RefPtr<Literal> literal = new Literal;
 101                         if(var.type=="bool")
 102                                 literal->token = (i->second ? "true" : "false");
 103                         else if(var.type=="int")
 104                                 literal->token = lexical_cast<string>(i->second);
 105                         var.init_expression = literal;
 106                 }
 107         }
 108 }
 109
 110
 111 void BlockHierarchyResolver::enter(Block &block)
 112 {
 113         block.parent = current_block;
 114 }
 115
 116
 117 TypeResolver::TypeResolver():
 118         stage(0)
 119 { }
 120
 121 void TypeResolver::apply(Stage &s)
 122 {
 123         stage = &s;
 124         s.types.clear();
 125         s.content.visit(*this);
 126 }
 127
 128 void TypeResolver::visit(BasicTypeDeclaration &type)
 129 {
 130         map<string, TypeDeclaration *>::iterator i = stage->types.find(type.base);
 131         type.base_type = (i!=stage->types.end() ? i->second : 0);
 132
 133         if(type.kind==BasicTypeDeclaration::VECTOR && type.base_type)
 134                 if(BasicTypeDeclaration *basic_base = dynamic_cast<BasicTypeDeclaration *>(type.base_type))
 135                         if(basic_base->kind==BasicTypeDeclaration::VECTOR)
 136                         {
 137                                 type.kind = BasicTypeDeclaration::MATRIX;
 138                                 type.size |= basic_base->size<<16;
 139                         }
 140
 141         stage->types.insert(make_pair(type.name, &type));
 142 }
 143
 144 void TypeResolver::visit(ImageTypeDeclaration &type)
 145 {
 146         map<string, TypeDeclaration *>::iterator i = stage->types.find(type.base);
 147         type.base_type = (i!=stage->types.end() ? i->second : 0);
 148
 149         stage->types.insert(make_pair(type.name, &type));
 150 }
 151
 152 void TypeResolver::visit(StructDeclaration &strct)
 153 {
 154         stage->types.insert(make_pair(strct.name, &strct));
 155         TraversingVisitor::visit(strct);
 156 }
 157
 158 void TypeResolver::visit(VariableDeclaration &var)
 159 {
 160         map<string, TypeDeclaration *>::iterator i = stage->types.find(var.type);
 161         if(i!=stage->types.end())
 162                 var.type_declaration = i->second;
 163 }
 164
 165 void TypeResolver::visit(FunctionDeclaration &func)
 166 {
 167         map<string, TypeDeclaration *>::iterator i = stage->types.find(func.return_type);
 168         func.return_type_declaration = (i!=stage->types.end() ? i->second : 0);
 169         TraversingVisitor::visit(func);
 170 }
 171
 172
 173 VariableResolver::VariableResolver():
 174         stage(0),
 175         r_members(0),
 176         record_target(false),
 177         r_self_referencing(false),
 178         r_assignment_target(0)
 179 { }
 180
 181 void VariableResolver::apply(Stage &s)
 182 {
 183         stage = &s;
 184         s.interface_blocks.clear();
 185         s.content.visit(*this);
 186 }
 187
 188 void VariableResolver::enter(Block &block)
 189 {
 190         block.variables.clear();
 191 }
 192
 193 void VariableResolver::visit(VariableReference &var)
 194 {
 195         var.declaration = 0;
 196         r_members = 0;
 197         /* Look for variable declarations in the block hierarchy first.  Interface
 198         blocks are always defined in the top level so we can't accidentally skip
 199         one. */
 200         for(Block *block=current_block; (!var.declaration && block); block=block->parent)
 201         {
 202                 map<string, VariableDeclaration *>::iterator i = block->variables.find(var.name);
 203                 if(i!=block->variables.end())
 204                         var.declaration = i->second;
 205         }
 206
 207         if(!var.declaration)
 208         {
 209                 const map<string, InterfaceBlock *> &blocks = stage->interface_blocks;
 210                 map<string, InterfaceBlock *>::const_iterator i = blocks.find("_"+var.name);
 211                 if(i!=blocks.end())
 212                 {
 213                         /* The name refers to an interface block with an instance name rather
 214                         than a variable.  Prepare a new syntax tree node accordingly. */
 215                         r_iface_ref = new InterfaceBlockReference;
 216                         r_iface_ref->source = var.source;
 217                         r_iface_ref->line = var.line;
 218                         r_iface_ref->name = var.name;
 219                         r_iface_ref->declaration = i->second;
 220                         r_members = &i->second->members.variables;
 221                 }
 222                 else
 223                 {
 224                         // Look for the variable in anonymous interface blocks.
 225                         for(i=blocks.begin(); (!var.declaration && i!=blocks.end()); ++i)
 226                                 if(i->second->instance_name.empty())
 227                                 {
 228                                         map<string, VariableDeclaration *>::iterator j = i->second->members.variables.find(var.name);
 229                                         if(j!=i->second->members.variables.end())
 230                                                 var.declaration = j->second;
 231                                 }
 232                 }
 233         }
 234
 235         if(var.declaration)
 236                 if(StructDeclaration *strct = dynamic_cast<StructDeclaration *>(var.declaration->type_declaration))
 237                         r_members = &strct->members.variables;
 238
 239         if(record_target)
 240         {
 241                 if(r_assignment_target)
 242                 {
 243                         /* More than one variable reference found in assignment target.
 244                         Unable to determine what the primary target is. */
 245                         record_target = false;
 246                         r_assignment_target = 0;
 247                 }
 248                 else
 249                         r_assignment_target = var.declaration;
 250         }
 251         else if(var.declaration && var.declaration==r_assignment_target)
 252                 r_self_referencing = true;
 253 }
 254
 255 void VariableResolver::visit(InterfaceBlockReference &iface)
 256 {
 257         iface.declaration = 0;
 258         for(Block *block=current_block; block; block=block->parent)
 259         {
 260                 map<string, InterfaceBlock *>::iterator i = stage->interface_blocks.find("_"+iface.name);
 261                 if(i!=stage->interface_blocks.end())
 262                 {
 263                         iface.declaration = i->second;
 264                         r_members = &i->second->members.variables;
 265                         break;
 266                 }
 267         }
 268 }
 269
 270 void VariableResolver::visit(MemberAccess &memacc)
 271 {
 272         r_members = 0;
 273         r_iface_ref = 0;
 274         memacc.left->visit(*this);
 275
 276         if(r_iface_ref)
 277                 memacc.left = r_iface_ref;
 278         r_iface_ref = 0;
 279
 280         memacc.declaration = 0;
 281         if(r_members)
 282         {
 283                 map<string, VariableDeclaration *>::iterator i = r_members->find(memacc.member);
 284                 if(i!=r_members->end())
 285                 {
 286                         memacc.declaration = i->second;
 287                         if(StructDeclaration *strct = dynamic_cast<StructDeclaration *>(i->second->type_declaration))
 288                                 r_members = &strct->members.variables;
 289                 }
 290                 else
 291                         r_members = 0;
 292         }
 293 }
 294
 295 void VariableResolver::visit(UnaryExpression &unary)
 296 {
 297         TraversingVisitor::visit(unary);
 298         r_members = 0;
 299         r_iface_ref = 0;
 300 }
 301
 302 void VariableResolver::visit(BinaryExpression &binary)
 303 {
 304         if(binary.oper->token[0]=='[')
 305         {
 306                 {
 307                         /* The subscript expression is not a part of the primary assignment
 308                         target. */
 309                         SetFlag set(record_target, false);
 310                         binary.right->visit(*this);
 311                 }
 312                 r_members = 0;
 313                 r_iface_ref = 0;
 314                 binary.left->visit(*this);
 315                 if(r_iface_ref)
 316                         binary.left = r_iface_ref;
 317         }
 318         else
 319         {
 320                 TraversingVisitor::visit(binary);
 321                 r_members = 0;
 322         }
 323
 324         r_iface_ref = 0;
 325 }
 326
 327 void VariableResolver::visit(Assignment &assign)
 328 {
 329         {
 330                 SetFlag set(record_target);
 331                 r_assignment_target = 0;
 332                 assign.left->visit(*this);
 333                 assign.target_declaration = r_assignment_target;
 334         }
 335
 336         r_self_referencing = false;
 337         assign.right->visit(*this);
 338         assign.self_referencing = (r_self_referencing || assign.oper->token[0]!='=');
 339
 340         r_members = 0;
 341         r_iface_ref = 0;
 342 }
 343
 344 void VariableResolver::visit(FunctionCall &call)
 345 {
 346         TraversingVisitor::visit(call);
 347         r_members = 0;
 348         r_iface_ref = 0;
 349 }
 350
 351 void VariableResolver::visit(VariableDeclaration &var)
 352 {
 353         if(!block_interface.empty() && var.interface.empty())
 354                 var.interface = block_interface;
 355
 356         TraversingVisitor::visit(var);
 357         current_block->variables.insert(make_pair(var.name, &var));
 358 }
 359
 360 void VariableResolver::visit(InterfaceBlock &iface)
 361 {
 362         /* Block names can be reused in different interfaces.  Prefix the name with
 363         the first character of the interface to avoid conflicts. */
 364         stage->interface_blocks.insert(make_pair(iface.interface+iface.name, &iface));
 365         if(!iface.instance_name.empty())
 366                 stage->interface_blocks.insert(make_pair("_"+iface.instance_name, &iface));
 367
 368         SetForScope<string> set_iface(block_interface, iface.interface);
 369         TraversingVisitor::visit(iface);
 370 }
 371
 372
 373 void FunctionResolver::apply(Stage &s)
 374 {
 375         stage = &s;
 376         s.functions.clear();
 377         s.content.visit(*this);
 378 }
 379
 380 void FunctionResolver::visit(FunctionCall &call)
 381 {
 382         map<string, FunctionDeclaration *>::iterator i = stage->functions.find(call.name);
 383         if(i!=stage->functions.end())
 384                 call.declaration = i->second;
 385
 386         TraversingVisitor::visit(call);
 387 }
 388
 389 void FunctionResolver::visit(FunctionDeclaration &func)
 390 {
 391         FunctionDeclaration *&stage_decl = stage->functions[func.name];
 392         vector<FunctionDeclaration *> &decls = declarations[func.name];
 393         if(func.definition==&func)
 394         {
 395                 stage_decl = &func;
 396
 397                 // Set all previous declarations to use this definition.
 398                 for(vector<FunctionDeclaration *>::iterator i=decls.begin(); i!=decls.end(); ++i)
 399                 {
 400                         (*i)->definition = func.definition;
 401                         (*i)->body.body.clear();
 402                 }
 403         }
 404         else
 405         {
 406                 func.definition = 0;
 407                 if(!stage_decl)
 408                         stage_decl = &func;
 409                 else
 410                         func.definition = stage_decl->definition;
 411         }
 412         decls.push_back(&func);
 413
 414         TraversingVisitor::visit(func);
 415 }
 416
 417
 418 InterfaceGenerator::InterfaceGenerator():
 419         stage(0),
 420         function_scope(false),
 421         iface_block(0),
 422         copy_block(false),
 423         iface_target_block(0)
 424 { }
 425
 426 string InterfaceGenerator::get_out_prefix(Stage::Type type)
 427 {
 428         if(type==Stage::VERTEX)
 429                 return "_vs_out_";
 430         else if(type==Stage::GEOMETRY)
 431                 return "_gs_out_";
 432         else
 433                 return string();
 434 }
 435
 436 void InterfaceGenerator::apply(Stage &s)
 437 {
 438         stage = &s;
 439         iface_target_block = &stage->content;
 440         if(stage->previous)
 441                 in_prefix = get_out_prefix(stage->previous->type);
 442         out_prefix = get_out_prefix(stage->type);
 443         s.content.visit(*this);
 444         NodeRemover().apply(s, nodes_to_remove);
 445 }
 446
 447 void InterfaceGenerator::visit(Block &block)
 448 {
 449         SetForScope<Block *> set_block(current_block, &block);
 450         for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 451         {
 452                 assignment_insert_point = i;
 453                 if(&block==&stage->content)
 454                         iface_insert_point = i;
 455
 456                 (*i)->visit(*this);
 457         }
 458 }
 459
 460 string InterfaceGenerator::change_prefix(const string &name, const string &prefix) const
 461 {
 462         unsigned offset = (name.compare(0, in_prefix.size(), in_prefix) ? 0 : in_prefix.size());
 463         return prefix+name.substr(offset);
 464 }
 465
 466 VariableDeclaration *InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 467 {
 468         if(stage->content.variables.count(name))
 469                 return 0;
 470
 471         VariableDeclaration* iface_var = new VariableDeclaration;
 472         iface_var->sampling = var.sampling;
 473         iface_var->interface = iface;
 474         iface_var->type = var.type;
 475         iface_var->name = name;
 476         /* Geometry shader inputs are always arrays.  But if we're bringing in an
 477         entire block, the array is on the block and not individual variables. */
 478         if(stage->type==Stage::GEOMETRY && !copy_block)
 479                 iface_var->array = ((var.array && var.interface!="in") || iface=="in");
 480         else
 481                 iface_var->array = var.array;
 482         if(iface_var->array)
 483                 iface_var->array_size = var.array_size;
 484         if(iface=="in")
 485         {
 486                 iface_var->layout = var.layout;
 487                 iface_var->linked_declaration = &var;
 488                 var.linked_declaration = iface_var;
 489         }
 490
 491         iface_target_block->body.insert(iface_insert_point, iface_var);
 492         iface_target_block->variables.insert(make_pair(name, iface_var));
 493
 494         return iface_var;
 495 }
 496
 497 InterfaceBlock *InterfaceGenerator::generate_interface(InterfaceBlock &out_block)
 498 {
 499         if(stage->interface_blocks.count("in"+out_block.name))
 500                 return 0;
 501
 502         InterfaceBlock *in_block = new InterfaceBlock;
 503         in_block->interface = "in";
 504         in_block->name = out_block.name;
 505         in_block->instance_name = out_block.instance_name;
 506         if(stage->type==Stage::GEOMETRY)
 507                 in_block->array = true;
 508         else
 509                 in_block->array = out_block.array;
 510         in_block->linked_block = &out_block;
 511         out_block.linked_block = in_block;
 512
 513         {
 514                 SetFlag set_copy(copy_block, true);
 515                 SetForScope<Block *> set_target(iface_target_block, &in_block->members);
 516                 SetForScope<NodeList<Statement>::iterator> set_ins_pt(iface_insert_point, in_block->members.body.end());
 517                 out_block.members.visit(*this);
 518         }
 519
 520         iface_target_block->body.insert(iface_insert_point, in_block);
 521         stage->interface_blocks.insert(make_pair("in"+in_block->name, in_block));
 522         if(!in_block->instance_name.empty())
 523                 stage->interface_blocks.insert(make_pair("_"+in_block->instance_name, in_block));
 524
 525         SetFlag set_scope(function_scope, false);
 526         SetForScope<Block *> set_block(current_block, &stage->content);
 527         in_block->visit(*this);
 528
 529         return in_block;
 530 }
 531
 532 ExpressionStatement &InterfaceGenerator::insert_assignment(const string &left, Expression *right)
 533 {
 534         Assignment *assign = new Assignment;
 535         VariableReference *ref = new VariableReference;
 536         ref->name = left;
 537         assign->left = ref;
 538         assign->oper = &Operator::get_operator("=", Operator::BINARY);
 539         assign->right = right;
 540
 541         ExpressionStatement *stmt = new ExpressionStatement;
 542         stmt->expression = assign;
 543         current_block->body.insert(assignment_insert_point, stmt);
 544         stmt->visit(*this);
 545
 546         return *stmt;
 547 }
 548
 549 void InterfaceGenerator::visit(VariableReference &var)
 550 {
 551         if(var.declaration || !stage->previous)
 552                 return;
 553         /* Don't pull a variable from previous stage if we just generated an output
 554         interface in this stage */
 555         if(stage->content.variables.count(var.name))
 556                 return;
 557
 558         const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 559         map<string, VariableDeclaration *>::const_iterator i = prev_vars.find(var.name);
 560         if(i==prev_vars.end() || i->second->interface!="out")
 561                 i = prev_vars.find(in_prefix+var.name);
 562         if(i!=prev_vars.end() && i->second->interface=="out")
 563         {
 564                 generate_interface(*i->second, "in", i->second->name);
 565                 var.name = i->second->name;
 566                 return;
 567         }
 568
 569         const map<string, InterfaceBlock *> &prev_blocks = stage->previous->interface_blocks;
 570         map<string, InterfaceBlock *>::const_iterator j = prev_blocks.find("_"+var.name);
 571         if(j!=prev_blocks.end() && j->second->interface=="out")
 572         {
 573                 generate_interface(*j->second);
 574                 /* Let VariableResolver convert the variable reference into an interface
 575                 block reference. */
 576                 return;
 577         }
 578
 579         for(j=prev_blocks.begin(); j!=prev_blocks.end(); ++j)
 580                 if(j->second->instance_name.empty())
 581                 {
 582                         i = j->second->members.variables.find(var.name);
 583                         if(i!=j->second->members.variables.end())
 584                         {
 585                                 generate_interface(*j->second);
 586                                 return;
 587                         }
 588                 }
 589 }
 590
 591 void InterfaceGenerator::visit(VariableDeclaration &var)
 592 {
 593         if(copy_block)
 594         {
 595                 generate_interface(var, "in", var.name);
 596                 return;
 597         }
 598
 599         if(iface_block)
 600         {
 601                 if(iface_block->linked_block)
 602                 {
 603                         // Link all variables to their counterparts in the linked block.
 604                         const map<string, VariableDeclaration *> &linked_vars = iface_block->linked_block->members.variables;
 605                         map<string, VariableDeclaration *>::const_iterator i = linked_vars.find(var.name);
 606                         if(i!=linked_vars.end())
 607                         {
 608                                 var.linked_declaration = i->second;
 609                                 var.linked_declaration->linked_declaration = &var;
 610                         }
 611                 }
 612                 return;
 613         }
 614
 615         if(var.interface=="out")
 616         {
 617                 /* For output variables in function scope, generate a global interface
 618                 and replace the local declaration with an assignment. */
 619                 VariableDeclaration *out_var = 0;
 620                 if(function_scope && (out_var=generate_interface(var, "out", var.name)))
 621                 {
 622                         out_var->source = var.source;
 623                         out_var->line = var.line;
 624                         nodes_to_remove.insert(&var);
 625                         if(var.init_expression)
 626                         {
 627                                 ExpressionStatement &stmt = insert_assignment(var.name, var.init_expression->clone());
 628                                 stmt.source = var.source;
 629                                 stmt.line = var.line;
 630                                 return;
 631                         }
 632                 }
 633         }
 634         else if(var.interface=="in")
 635         {
 636                 /* Try to link input variables in global scope with output variables from
 637                 previous stage. */
 638                 if(current_block==&stage->content && !var.linked_declaration && stage->previous)
 639                 {
 640                         const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 641                         map<string, VariableDeclaration *>::const_iterator i = prev_vars.find(var.name);
 642                         if(i!=prev_vars.end() && i->second->interface=="out")
 643                         {
 644                                 var.linked_declaration = i->second;
 645                                 i->second->linked_declaration = &var;
 646                         }
 647                 }
 648         }
 649
 650         TraversingVisitor::visit(var);
 651 }
 652
 653 void InterfaceGenerator::visit(InterfaceBlock &iface)
 654 {
 655         if(iface.interface=="in")
 656         {
 657                 /* Try to link input blocks with output blocks sharing the same block
 658                 name from previous stage. */
 659                 if(!iface.linked_block && stage->previous)
 660                 {
 661                         const map<string, InterfaceBlock *> &prev_blocks = stage->previous->interface_blocks;
 662                         map<string, InterfaceBlock *>::const_iterator i = prev_blocks.find("out"+iface.name);
 663                         if(i!=prev_blocks.end())
 664                         {
 665                                 iface.linked_block = i->second;
 666                                 i->second->linked_block = &iface;
 667                         }
 668                 }
 669         }
 670
 671         SetForScope<InterfaceBlock *> set_iface(iface_block, &iface);
 672         TraversingVisitor::visit(iface);
 673 }
 674
 675 void InterfaceGenerator::visit(FunctionDeclaration &func)
 676 {
 677         SetFlag set_scope(function_scope, true);
 678         // Skip parameters because they're not useful here
 679         func.body.visit(*this);
 680 }
 681
 682 void InterfaceGenerator::visit(Passthrough &pass)
 683 {
 684         vector<VariableDeclaration *> pass_vars;
 685
 686         // Pass through all input variables of this stage.
 687         for(map<string, VariableDeclaration *>::const_iterator i=stage->content.variables.begin(); i!=stage->content.variables.end(); ++i)
 688                 if(i->second->interface=="in")
 689                         pass_vars.push_back(i->second);
 690
 691         if(stage->previous)
 692         {
 693                 const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 694                 for(map<string, VariableDeclaration *>::const_iterator i=prev_vars.begin(); i!=prev_vars.end(); ++i)
 695                 {
 696                         if(i->second->interface!="out")
 697                                 continue;
 698
 699                         /* Pass through output variables from the previous stage, but only
 700                         those which are not already linked to an input here. */
 701                         if(!i->second->linked_declaration && generate_interface(*i->second, "in", i->second->name))
 702                                 pass_vars.push_back(i->second);
 703                 }
 704         }
 705
 706         if(stage->type==Stage::GEOMETRY)
 707         {
 708                 /* Special case for geometry shader: copy gl_Position from input to
 709                 output. */
 710                 InterfaceBlockReference *ref = new InterfaceBlockReference;
 711                 ref->name = "gl_in";
 712
 713                 BinaryExpression *subscript = new BinaryExpression;
 714                 subscript->left = ref;
 715                 subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 716                 subscript->right = pass.subscript;
 717
 718                 MemberAccess *memacc = new MemberAccess;
 719                 memacc->left = subscript;
 720                 memacc->member = "gl_Position";
 721
 722                 insert_assignment("gl_Position", memacc);
 723         }
 724
 725         for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
 726         {
 727                 string out_name = change_prefix((*i)->name, out_prefix);
 728                 generate_interface(**i, "out", out_name);
 729
 730                 VariableReference *ref = new VariableReference;
 731                 ref->name = (*i)->name;
 732                 if(pass.subscript)
 733                 {
 734                         BinaryExpression *subscript = new BinaryExpression;
 735                         subscript->left = ref;
 736                         subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 737                         subscript->right = pass.subscript;
 738                         insert_assignment(out_name, subscript);
 739                 }
 740                 else
 741                         insert_assignment(out_name, ref);
 742         }
 743
 744         nodes_to_remove.insert(&pass);
 745 }
 746
 747 } // namespace SL
 748 } // namespace GL
 749 } // namespace Msp