source/glsl/generate.cpp

   1 #include <msp/core/algorithm.h>
   2 #include <msp/core/hash.h>
   3 #include <msp/core/raii.h>
   4 #include "generate.h"
   5 #include "reflect.h"
   6
   7 using namespace std;
   8
   9 namespace Msp {
  10 namespace GL {
  11 namespace SL {
  12
  13 void ConstantIdAssigner::apply(Module &module, const Features &features)
  14 {
  15         for(Stage &s: module.stages)
  16                 s.content.visit(*this);
  17
  18         for(VariableDeclaration *v: auto_constants)
  19         {
  20                 unsigned id;
  21                 auto j = existing_constants.find(v->name);
  22                 if(j!=existing_constants.end())
  23                         id = j->second;
  24                 else
  25                 {
  26                         id = hash<32>(v->name)%features.constant_id_range;
  27                         while(used_ids.count(id))
  28                                 id = (id+1)%features.constant_id_range;
  29                 }
  30
  31                 auto i = find_member(v->layout->qualifiers, string("constant_id"), &Layout::Qualifier::name);
  32                 if(i!=v->layout->qualifiers.end())
  33                         i->value = id;
  34
  35                 used_ids.insert(id);
  36                 existing_constants[v->name] = id;
  37         }
  38 }
  39
  40 void ConstantIdAssigner::visit(VariableDeclaration &var)
  41 {
  42         if(var.layout)
  43         {
  44                 auto i = find_member(var.layout->qualifiers, string("constant_id"), &Layout::Qualifier::name);
  45                 if(i!=var.layout->qualifiers.end() && i->has_value)
  46                 {
  47                         if(i->value==-1)
  48                                 auto_constants.push_back(&var);
  49                         else
  50                         {
  51                                 existing_constants[var.name] = i->value;
  52                                 used_ids.insert(i->value);
  53                         }
  54                 }
  55         }
  56 }
  57
  58
  59 string InterfaceGenerator::get_out_prefix(Stage::Type type)
  60 {
  61         if(type==Stage::VERTEX)
  62                 return "_vs_out_";
  63         else if(type==Stage::GEOMETRY)
  64                 return "_gs_out_";
  65         else
  66                 return string();
  67 }
  68
  69 void InterfaceGenerator::apply(Stage &s)
  70 {
  71         stage = &s;
  72         iface_target_block = &stage->content;
  73         if(stage->previous)
  74                 in_prefix = get_out_prefix(stage->previous->type);
  75         out_prefix = get_out_prefix(stage->type);
  76         s.content.visit(*this);
  77         NodeRemover().apply(s, nodes_to_remove);
  78 }
  79
  80 void InterfaceGenerator::visit(Block &block)
  81 {
  82         SetForScope<Block *> set_block(current_block, &block);
  83         for(auto i=block.body.begin(); i!=block.body.end(); ++i)
  84         {
  85                 assignment_insert_point = i;
  86                 if(&block==&stage->content)
  87                         iface_insert_point = i;
  88
  89                 (*i)->visit(*this);
  90         }
  91 }
  92
  93 string InterfaceGenerator::change_prefix(const string &name, const string &prefix) const
  94 {
  95         unsigned offset = (name.compare(0, in_prefix.size(), in_prefix) ? 0 : in_prefix.size());
  96         return prefix+name.substr(offset);
  97 }
  98
  99 VariableDeclaration *InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 100 {
 101         if(stage->content.variables.count(name))
 102                 return 0;
 103
 104         if(stage->type==Stage::GEOMETRY && var.interface=="out" && var.array)
 105                 return 0;
 106
 107         VariableDeclaration* iface_var = new VariableDeclaration;
 108         iface_var->sampling = var.sampling;
 109         if(stage->type==Stage::FRAGMENT && iface=="in")
 110                 if(BasicTypeDeclaration *basic = dynamic_cast<BasicTypeDeclaration *>(var.type_declaration))
 111                         if(BasicTypeDeclaration *elem = get_element_type(*basic))
 112                                 if(elem->kind==BasicTypeDeclaration::INT)
 113                                         iface_var->interpolation = "flat";
 114         iface_var->interface = iface;
 115         iface_var->type = var.type;
 116         iface_var->name = name;
 117         // Tessellation and geometry inputs may be arrayed.
 118         if(stage->type==Stage::TESS_CONTROL)
 119                 // VS out -> TCS in: add | TCS in -> TCS out: unchanged | VS out -> TCS out: add
 120                 iface_var->array = (var.array || var.interface!="in");
 121         else if(stage->type==Stage::TESS_EVAL)
 122                 // TCS out -> TES in: unchanged | TES in -> TES out: remove | TCS out -> TES out: remove
 123                 iface_var->array = (var.array && iface=="in");
 124         else if(stage->type==Stage::GEOMETRY)
 125                 // VS/TES out -> GS in: add | GS in -> GS out: remove | VS/TES out -> GS out: unchanged
 126                 iface_var->array = ((var.array && var.interface!="in") || iface=="in");
 127         else
 128                 iface_var->array = var.array;
 129         if(iface_var->array)
 130                 iface_var->array_size = var.array_size;
 131         if(iface=="in")
 132         {
 133                 iface_var->layout = var.layout;
 134                 iface_var->linked_declaration = &var;
 135                 var.linked_declaration = iface_var;
 136         }
 137
 138         if(var.block_declaration)
 139         {
 140                 StructDeclaration *iface_type = var.block_declaration->clone();
 141                 iface_type->name = format("_%s_%s", iface, var.block_declaration->block_name);
 142                 iface_target_block->body.insert(iface_insert_point, iface_type);
 143
 144                 iface_var->type = iface_type->name;
 145                 if(name.empty())
 146                         iface_var->name = format("%s %s", iface, var.block_declaration->block_name);
 147
 148                 stage->interface_blocks.insert(make_pair("in "+var.block_declaration->block_name, iface_var));
 149                 if(!name.empty())
 150                         stage->interface_blocks.insert(make_pair(name, iface_var));
 151         }
 152
 153         iface_target_block->body.insert(iface_insert_point, iface_var);
 154         iface_target_block->variables.insert(make_pair(name, iface_var));
 155         if(iface_target_block==&stage->content && iface=="in")
 156                 declared_inputs.push_back(iface_var);
 157
 158         return iface_var;
 159 }
 160
 161 ExpressionStatement &InterfaceGenerator::insert_assignment(const string &left, Expression *right)
 162 {
 163         Assignment *assign = new Assignment;
 164
 165         string::size_type dot = left.find('.');
 166         VariableReference *ref = new VariableReference;
 167         ref->name = left.substr(0, dot);
 168         assign->left = ref;
 169
 170         while(dot!=string::npos)
 171         {
 172                 string::size_type start = dot+1;
 173                 dot = left.find('.', start);
 174
 175                 MemberAccess *memacc = new MemberAccess;
 176                 memacc->left = assign->left;
 177                 memacc->member = left.substr(start, dot-start);
 178                 assign->left = memacc;
 179         }
 180
 181         assign->oper = &Operator::get_operator("=", Operator::BINARY);
 182         assign->right = right;
 183
 184         ExpressionStatement *stmt = new ExpressionStatement;
 185         stmt->expression = assign;
 186         current_block->body.insert(assignment_insert_point, stmt);
 187         stmt->visit(*this);
 188
 189         return *stmt;
 190 }
 191
 192 void InterfaceGenerator::visit(VariableReference &var)
 193 {
 194         if(var.declaration || !stage->previous)
 195                 return;
 196         /* Don't pull a variable from previous stage if we just generated an output
 197         interface in this stage */
 198         if(stage->content.variables.count(var.name))
 199                 return;
 200
 201         const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 202         auto i = prev_vars.find(var.name);
 203         if(i==prev_vars.end() || i->second->interface!="out")
 204                 i = prev_vars.find(in_prefix+var.name);
 205         if(i!=prev_vars.end() && i->second->interface=="out")
 206         {
 207                 if(stage->type==Stage::GEOMETRY && i->second->array)
 208                         stage->diagnostics.push_back(Diagnostic(Diagnostic::WARN, var.source, var.line,
 209                                 format("Can't access '%s' through automatic interface because it's an array", var.name)));
 210                 else
 211                 {
 212                         generate_interface(*i->second, "in", i->second->name);
 213                         var.name = i->second->name;
 214                 }
 215                 return;
 216         }
 217
 218         for(const auto &kvp: stage->previous->interface_blocks)
 219                 if(kvp.second->name.find(' ')!=string::npos)
 220                 {
 221                         const map<string, VariableDeclaration *> &iface_vars = kvp.second->block_declaration->members.variables;
 222                         i = iface_vars.find(var.name);
 223                         if(i!=iface_vars.end())
 224                         {
 225                                 generate_interface(*kvp.second, "in", string());
 226                                 return;
 227                         }
 228                 }
 229 }
 230
 231 void InterfaceGenerator::visit(VariableDeclaration &var)
 232 {
 233         if(var.interface=="out")
 234         {
 235                 /* For output variables in function scope, generate a global interface
 236                 and replace the local declaration with an assignment. */
 237                 VariableDeclaration *out_var = 0;
 238                 if(function_scope && (out_var=generate_interface(var, "out", var.name)))
 239                 {
 240                         out_var->source = var.source;
 241                         out_var->line = var.line;
 242                         nodes_to_remove.insert(&var);
 243                         if(var.init_expression)
 244                         {
 245                                 ExpressionStatement &stmt = insert_assignment(var.name, var.init_expression->clone());
 246                                 stmt.source = var.source;
 247                                 stmt.line = var.line;
 248                                 return;
 249                         }
 250                 }
 251         }
 252         else if(var.interface=="in" && current_block==&stage->content)
 253         {
 254                 if(var.name.compare(0, 3, "gl_"))
 255                         declared_inputs.push_back(&var);
 256
 257                 /* Try to link input variables in global scope with output variables from
 258                 previous stage. */
 259                 if(!var.linked_declaration && stage->previous)
 260                 {
 261                         const map<string, VariableDeclaration *> *prev_vars;
 262                         string name;
 263                         // Blocks are linked by their block name, not instance name
 264                         if(var.block_declaration)
 265                         {
 266                                 prev_vars = &stage->previous->interface_blocks;
 267                                 name = "out "+var.block_declaration->block_name;
 268                         }
 269                         else
 270                         {
 271                                 prev_vars = &stage->previous->content.variables;
 272                                 name = var.name;
 273                         }
 274
 275                         auto i = prev_vars->find(name);
 276                         if(i!=prev_vars->end() && i->second->interface=="out")
 277                         {
 278                                 var.linked_declaration = i->second;
 279                                 i->second->linked_declaration = &var;
 280                         }
 281                 }
 282         }
 283
 284         TraversingVisitor::visit(var);
 285 }
 286
 287 void InterfaceGenerator::visit(FunctionDeclaration &func)
 288 {
 289         SetFlag set_scope(function_scope, true);
 290         // Skip parameters because they're not useful here
 291         func.body.visit(*this);
 292 }
 293
 294 void InterfaceGenerator::visit(Passthrough &pass)
 295 {
 296         // Pass through all input variables declared so far.
 297         vector<VariableDeclaration *> pass_vars = declared_inputs;
 298
 299         if(stage->previous)
 300         {
 301                 for(const auto &kvp: stage->previous->content.variables)
 302                 {
 303                         if(kvp.second->interface!="out")
 304                                 continue;
 305
 306                         /* Pass through output variables from the previous stage, but only
 307                         those which are not already linked to an input here. */
 308                         if(!kvp.second->linked_declaration && generate_interface(*kvp.second, "in", kvp.second->name))
 309                                 pass_vars.push_back(kvp.second);
 310                 }
 311         }
 312
 313         if(stage->type==Stage::GEOMETRY)
 314         {
 315                 /* Special case for geometry shader: copy gl_Position from input to
 316                 output. */
 317                 VariableReference *ref = new VariableReference;
 318                 ref->name = "gl_in";
 319
 320                 BinaryExpression *subscript = new BinaryExpression;
 321                 subscript->left = ref;
 322                 subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 323                 subscript->right = pass.subscript;
 324
 325                 MemberAccess *memacc = new MemberAccess;
 326                 memacc->left = subscript;
 327                 memacc->member = "gl_Position";
 328
 329                 insert_assignment("out gl_PerVertex.gl_Position", memacc);
 330         }
 331
 332         for(VariableDeclaration *v: pass_vars)
 333         {
 334                 string out_name = change_prefix(v->name, out_prefix);
 335                 generate_interface(*v, "out", out_name);
 336
 337                 VariableReference *ref = new VariableReference;
 338                 ref->name = v->name;
 339                 if(pass.subscript)
 340                 {
 341                         BinaryExpression *subscript = new BinaryExpression;
 342                         subscript->left = ref;
 343                         subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 344                         subscript->right = pass.subscript;
 345                         insert_assignment(out_name, subscript);
 346                 }
 347                 else
 348                         insert_assignment(out_name, ref);
 349         }
 350
 351         nodes_to_remove.insert(&pass);
 352 }
 353
 354
 355 void LayoutDefaulter::apply(Stage &stage)
 356 {
 357         if(stage.type==Stage::TESS_EVAL)
 358         {
 359                 stage.content.visit(*this);
 360                 if((need_winding || need_spacing) && in_iface)
 361                 {
 362                         if(need_winding)
 363                                 in_iface->layout.qualifiers.emplace_back("ccw");
 364                         if(need_spacing)
 365                                 in_iface->layout.qualifiers.emplace_back("equal_spacing");
 366                 }
 367         }
 368 }
 369
 370 void LayoutDefaulter::visit(InterfaceLayout &iface)
 371 {
 372         if(iface.interface=="in")
 373         {
 374                 if(!in_iface)
 375                         in_iface = &iface;
 376                 for(const Layout::Qualifier &q: iface.layout.qualifiers)
 377                 {
 378                         if(q.name=="cw" || q.name=="ccw")
 379                                 need_winding = false;
 380                         else if(q.name=="equal_spacing" || q.name=="fractional_even_spacing" || q.name=="fractional_odd_spacing")
 381                                 need_spacing = false;
 382                 }
 383         }
 384 }
 385
 386
 387 void ArraySizer::apply(Stage &stage)
 388 {
 389         stage.content.visit(*this);
 390         for(const auto &kvp: max_indices)
 391                 if(kvp.first->array && !kvp.first->array_size)
 392                 {
 393                         int size = 0;
 394                         if(stage.type==Stage::GEOMETRY && kvp.first->interface=="in")
 395                                 size = input_size;
 396                         else if(kvp.second>=0)
 397                                 size = kvp.second+1;
 398                         if(!size && !kvp.first->name.compare(0, 3, "gl_"))
 399                                 size = 1;
 400
 401                         if(size>0)
 402                         {
 403                                 Literal *literal_size = new Literal;
 404                                 literal_size->token = lexical_cast<string>(size);
 405                                 literal_size->value = size;
 406                                 kvp.first->array_size = literal_size;
 407                         }
 408                 }
 409 }
 410
 411 void ArraySizer::visit(VariableReference &var)
 412 {
 413         r_declaration = var.declaration;
 414 }
 415
 416 void ArraySizer::visit(MemberAccess &memacc)
 417 {
 418         r_declaration = 0;
 419         TraversingVisitor::visit(memacc);
 420         VariableDeclaration *member_declaration = 0;
 421         if(r_declaration)
 422                 if(StructDeclaration *strct = dynamic_cast<StructDeclaration *>(r_declaration->type_declaration))
 423                 {
 424                         auto i = strct->members.variables.find(memacc.member);
 425                         if(i!=strct->members.variables.end())
 426                                 member_declaration = i->second;
 427                 }
 428         r_declaration = member_declaration;
 429 }
 430
 431 void ArraySizer::visit(Swizzle &swizzle)
 432 {
 433         TraversingVisitor::visit(swizzle);
 434         r_declaration = 0;
 435 }
 436
 437 void ArraySizer::visit(UnaryExpression &unary)
 438 {
 439         TraversingVisitor::visit(unary);
 440         r_declaration = 0;
 441 }
 442
 443 void ArraySizer::visit(BinaryExpression &binary)
 444 {
 445         if(binary.oper->token[0]=='[')
 446                 if(const Literal *literal_index = dynamic_cast<const Literal *>(binary.right.get()))
 447                         if(literal_index->value.check_type<int>())
 448                         {
 449                                 r_declaration = 0;
 450                                 binary.left->visit(*this);
 451                                 if(r_declaration)
 452                                 {
 453                                         max_indices[r_declaration] = literal_index->value.value<int>();
 454                                         return;
 455                                 }
 456                         }
 457
 458         TraversingVisitor::visit(binary);
 459 }
 460
 461 void ArraySizer::visit(TernaryExpression &ternary)
 462 {
 463         TraversingVisitor::visit(ternary);
 464         r_declaration = 0;
 465 }
 466
 467 void ArraySizer::visit(FunctionCall &call)
 468 {
 469         TraversingVisitor::visit(call);
 470         r_declaration = 0;
 471 }
 472
 473 void ArraySizer::visit(InterfaceLayout &layout)
 474 {
 475         if(layout.interface=="in")
 476         {
 477                 for(const Layout::Qualifier &q: layout.layout.qualifiers)
 478                 {
 479                         if(q.name=="points")
 480                                 input_size = 1;
 481                         else if(q.name=="lines")
 482                                 input_size = 2;
 483                         else if(q.name=="triangles")
 484                                 input_size = 3;
 485                         else if(q.name=="lines_adjacency")
 486                                 input_size = 4;
 487                         else if(q.name=="triangles_adjacency")
 488                                 input_size = 6;
 489                 }
 490         }
 491 }
 492
 493 void ArraySizer::visit(VariableDeclaration &var)
 494 {
 495         if(var.array && !var.array_size)
 496                 max_indices[&var] = 0;
 497 }
 498
 499 } // namespace SL
 500 } // namespace GL
 501 } // namespace Msp