source/glsl/generate.cpp

   1 #include <msp/core/hash.h>
   2 #include <msp/core/raii.h>
   3 #include "generate.h"
   4
   5 using namespace std;
   6
   7 namespace Msp {
   8 namespace GL {
   9 namespace SL {
  10
  11 ConstantSpecializer::ConstantSpecializer():
  12         values(0)
  13 { }
  14
  15 void ConstantSpecializer::apply(Stage &stage, const map<string, int> *v)
  16 {
  17         values = v;
  18         stage.content.visit(*this);
  19 }
  20
  21 void ConstantSpecializer::visit(VariableDeclaration &var)
  22 {
  23         bool specializable = false;
  24         if(var.layout)
  25         {
  26                 vector<Layout::Qualifier> &qualifiers = var.layout->qualifiers;
  27                 for(vector<Layout::Qualifier>::iterator i=qualifiers.begin(); i!=qualifiers.end(); ++i)
  28                         if(i->name=="constant_id")
  29                         {
  30                                 specializable = true;
  31                                 if(values)
  32                                         qualifiers.erase(i);
  33                                 else if(i->value==-1)
  34                                         i->value = hash32(var.name)&0x7FFFFFFF;
  35                                 break;
  36                         }
  37
  38                 if(qualifiers.empty())
  39                         var.layout = 0;
  40         }
  41
  42         if(specializable && values)
  43         {
  44                 map<string, int>::const_iterator i = values->find(var.name);
  45                 if(i!=values->end())
  46                 {
  47                         RefPtr<Literal> literal = new Literal;
  48                         if(var.type=="bool")
  49                         {
  50                                 literal->token = (i->second ? "true" : "false");
  51                                 literal->value = static_cast<bool>(i->second);
  52                         }
  53                         else if(var.type=="int")
  54                         {
  55                                 literal->token = lexical_cast<string>(i->second);
  56                                 literal->value = i->second;
  57                         }
  58                         var.init_expression = literal;
  59                 }
  60         }
  61 }
  62
  63
  64 InterfaceGenerator::InterfaceGenerator():
  65         stage(0),
  66         function_scope(false),
  67         copy_block(false),
  68         iface_target_block(0)
  69 { }
  70
  71 string InterfaceGenerator::get_out_prefix(Stage::Type type)
  72 {
  73         if(type==Stage::VERTEX)
  74                 return "_vs_out_";
  75         else if(type==Stage::GEOMETRY)
  76                 return "_gs_out_";
  77         else
  78                 return string();
  79 }
  80
  81 void InterfaceGenerator::apply(Stage &s)
  82 {
  83         stage = &s;
  84         iface_target_block = &stage->content;
  85         if(stage->previous)
  86                 in_prefix = get_out_prefix(stage->previous->type);
  87         out_prefix = get_out_prefix(stage->type);
  88         s.content.visit(*this);
  89         NodeRemover().apply(s, nodes_to_remove);
  90 }
  91
  92 void InterfaceGenerator::visit(Block &block)
  93 {
  94         SetForScope<Block *> set_block(current_block, &block);
  95         for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
  96         {
  97                 assignment_insert_point = i;
  98                 if(&block==&stage->content)
  99                         iface_insert_point = i;
 100
 101                 (*i)->visit(*this);
 102         }
 103 }
 104
 105 string InterfaceGenerator::change_prefix(const string &name, const string &prefix) const
 106 {
 107         unsigned offset = (name.compare(0, in_prefix.size(), in_prefix) ? 0 : in_prefix.size());
 108         return prefix+name.substr(offset);
 109 }
 110
 111 VariableDeclaration *InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 112 {
 113         if(stage->content.variables.count(name))
 114                 return 0;
 115
 116         if(stage->type==Stage::GEOMETRY && !copy_block && var.interface=="out" && var.array)
 117                 return 0;
 118
 119         VariableDeclaration* iface_var = new VariableDeclaration;
 120         iface_var->sampling = var.sampling;
 121         iface_var->interface = iface;
 122         iface_var->type = var.type;
 123         iface_var->name = name;
 124         /* Geometry shader inputs are always arrays.  But if we're bringing in an
 125         entire block, the array is on the block and not individual variables. */
 126         if(stage->type==Stage::GEOMETRY && !copy_block)
 127                 iface_var->array = ((var.array && var.interface!="in") || iface=="in");
 128         else
 129                 iface_var->array = var.array;
 130         if(iface_var->array)
 131                 iface_var->array_size = var.array_size;
 132         if(iface=="in")
 133         {
 134                 iface_var->layout = var.layout;
 135                 iface_var->linked_declaration = &var;
 136                 var.linked_declaration = iface_var;
 137         }
 138
 139         iface_target_block->body.insert(iface_insert_point, iface_var);
 140         iface_target_block->variables.insert(make_pair(name, iface_var));
 141         if(iface_target_block==&stage->content && iface=="in")
 142                 declared_inputs.push_back(iface_var);
 143
 144         return iface_var;
 145 }
 146
 147 InterfaceBlock *InterfaceGenerator::generate_interface(InterfaceBlock &out_block)
 148 {
 149         if(stage->interface_blocks.count("in"+out_block.block_name))
 150                 return 0;
 151
 152         InterfaceBlock *in_block = new InterfaceBlock;
 153         in_block->interface = "in";
 154         in_block->block_name = out_block.block_name;
 155         in_block->members = new Block;
 156         in_block->instance_name = out_block.instance_name;
 157         if(stage->type==Stage::GEOMETRY)
 158                 in_block->array = true;
 159         else
 160                 in_block->array = out_block.array;
 161         in_block->linked_block = &out_block;
 162         out_block.linked_block = in_block;
 163
 164         {
 165                 SetFlag set_copy(copy_block, true);
 166                 SetForScope<Block *> set_target(iface_target_block, in_block->members.get());
 167                 SetForScope<NodeList<Statement>::iterator> set_ins_pt(iface_insert_point, in_block->members->body.end());
 168                 if(out_block.struct_declaration)
 169                         out_block.struct_declaration->members.visit(*this);
 170                 else if(out_block.members)
 171                         out_block.members->visit(*this);
 172         }
 173
 174         iface_target_block->body.insert(iface_insert_point, in_block);
 175         stage->interface_blocks.insert(make_pair("in"+in_block->block_name, in_block));
 176         if(!in_block->instance_name.empty())
 177                 stage->interface_blocks.insert(make_pair("_"+in_block->instance_name, in_block));
 178
 179         SetFlag set_scope(function_scope, false);
 180         SetForScope<Block *> set_block(current_block, &stage->content);
 181         in_block->visit(*this);
 182
 183         return in_block;
 184 }
 185
 186 ExpressionStatement &InterfaceGenerator::insert_assignment(const string &left, Expression *right)
 187 {
 188         Assignment *assign = new Assignment;
 189         VariableReference *ref = new VariableReference;
 190         ref->name = left;
 191         assign->left = ref;
 192         assign->oper = &Operator::get_operator("=", Operator::BINARY);
 193         assign->right = right;
 194
 195         ExpressionStatement *stmt = new ExpressionStatement;
 196         stmt->expression = assign;
 197         current_block->body.insert(assignment_insert_point, stmt);
 198         stmt->visit(*this);
 199
 200         return *stmt;
 201 }
 202
 203 void InterfaceGenerator::visit(VariableReference &var)
 204 {
 205         if(var.declaration || !stage->previous)
 206                 return;
 207         /* Don't pull a variable from previous stage if we just generated an output
 208         interface in this stage */
 209         if(stage->content.variables.count(var.name))
 210                 return;
 211
 212         const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 213         map<string, VariableDeclaration *>::const_iterator i = prev_vars.find(var.name);
 214         if(i==prev_vars.end() || i->second->interface!="out")
 215                 i = prev_vars.find(in_prefix+var.name);
 216         if(i!=prev_vars.end() && i->second->interface=="out")
 217         {
 218                 if(stage->type==Stage::GEOMETRY && i->second->array)
 219                         stage->diagnostics.push_back(Diagnostic(Diagnostic::WARN, var.source, var.line,
 220                                 format("Can't access '%s' through automatic interface because it's an array", var.name)));
 221                 else
 222                 {
 223                         generate_interface(*i->second, "in", i->second->name);
 224                         var.name = i->second->name;
 225                 }
 226                 return;
 227         }
 228
 229         const map<string, InterfaceBlock *> &prev_blocks = stage->previous->interface_blocks;
 230         map<string, InterfaceBlock *>::const_iterator j = prev_blocks.find("_"+var.name);
 231         if(j!=prev_blocks.end() && j->second->interface=="out")
 232         {
 233                 generate_interface(*j->second);
 234                 /* Let VariableResolver convert the variable reference into an interface
 235                 block reference. */
 236                 return;
 237         }
 238
 239         for(j=prev_blocks.begin(); j!=prev_blocks.end(); ++j)
 240                 if(j->second->instance_name.empty() && j->second->struct_declaration)
 241                 {
 242                         const map<string, VariableDeclaration *> &iface_vars = j->second->struct_declaration->members.variables;
 243                         i = iface_vars.find(var.name);
 244                         if(i!=iface_vars.end())
 245                         {
 246                                 generate_interface(*j->second);
 247                                 return;
 248                         }
 249                 }
 250 }
 251
 252 void InterfaceGenerator::visit(VariableDeclaration &var)
 253 {
 254         if(copy_block)
 255                 generate_interface(var, "in", var.name);
 256         else if(var.interface=="out")
 257         {
 258                 /* For output variables in function scope, generate a global interface
 259                 and replace the local declaration with an assignment. */
 260                 VariableDeclaration *out_var = 0;
 261                 if(function_scope && (out_var=generate_interface(var, "out", var.name)))
 262                 {
 263                         out_var->source = var.source;
 264                         out_var->line = var.line;
 265                         nodes_to_remove.insert(&var);
 266                         if(var.init_expression)
 267                         {
 268                                 ExpressionStatement &stmt = insert_assignment(var.name, var.init_expression->clone());
 269                                 stmt.source = var.source;
 270                                 stmt.line = var.line;
 271                                 return;
 272                         }
 273                 }
 274         }
 275         else if(var.interface=="in" && current_block==&stage->content)
 276         {
 277                 if(var.name.compare(0, 3, "gl_"))
 278                         declared_inputs.push_back(&var);
 279
 280                 /* Try to link input variables in global scope with output variables from
 281                 previous stage. */
 282                 if(!var.linked_declaration && stage->previous)
 283                 {
 284                         const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 285                         map<string, VariableDeclaration *>::const_iterator i = prev_vars.find(var.name);
 286                         if(i!=prev_vars.end() && i->second->interface=="out")
 287                         {
 288                                 var.linked_declaration = i->second;
 289                                 i->second->linked_declaration = &var;
 290                         }
 291                 }
 292         }
 293
 294         TraversingVisitor::visit(var);
 295 }
 296
 297 void InterfaceGenerator::visit(InterfaceBlock &iface)
 298 {
 299         if(iface.interface=="in")
 300         {
 301                 /* Try to link input blocks with output blocks sharing the same block
 302                 name from previous stage. */
 303                 if(!iface.linked_block && stage->previous)
 304                 {
 305                         const map<string, InterfaceBlock *> &prev_blocks = stage->previous->interface_blocks;
 306                         map<string, InterfaceBlock *>::const_iterator i = prev_blocks.find("out"+iface.block_name);
 307                         if(i!=prev_blocks.end())
 308                         {
 309                                 iface.linked_block = i->second;
 310                                 i->second->linked_block = &iface;
 311                         }
 312                 }
 313         }
 314
 315         TraversingVisitor::visit(iface);
 316 }
 317
 318 void InterfaceGenerator::visit(FunctionDeclaration &func)
 319 {
 320         SetFlag set_scope(function_scope, true);
 321         // Skip parameters because they're not useful here
 322         func.body.visit(*this);
 323 }
 324
 325 void InterfaceGenerator::visit(Passthrough &pass)
 326 {
 327         // Pass through all input variables declared so far.
 328         vector<VariableDeclaration *> pass_vars = declared_inputs;
 329
 330         if(stage->previous)
 331         {
 332                 const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 333                 for(map<string, VariableDeclaration *>::const_iterator i=prev_vars.begin(); i!=prev_vars.end(); ++i)
 334                 {
 335                         if(i->second->interface!="out")
 336                                 continue;
 337
 338                         /* Pass through output variables from the previous stage, but only
 339                         those which are not already linked to an input here. */
 340                         if(!i->second->linked_declaration && generate_interface(*i->second, "in", i->second->name))
 341                                 pass_vars.push_back(i->second);
 342                 }
 343         }
 344
 345         if(stage->type==Stage::GEOMETRY)
 346         {
 347                 /* Special case for geometry shader: copy gl_Position from input to
 348                 output. */
 349                 InterfaceBlockReference *ref = new InterfaceBlockReference;
 350                 ref->name = "gl_in";
 351
 352                 BinaryExpression *subscript = new BinaryExpression;
 353                 subscript->left = ref;
 354                 subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 355                 subscript->right = pass.subscript;
 356
 357                 MemberAccess *memacc = new MemberAccess;
 358                 memacc->left = subscript;
 359                 memacc->member = "gl_Position";
 360
 361                 insert_assignment("gl_Position", memacc);
 362         }
 363
 364         for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
 365         {
 366                 string out_name = change_prefix((*i)->name, out_prefix);
 367                 generate_interface(**i, "out", out_name);
 368
 369                 VariableReference *ref = new VariableReference;
 370                 ref->name = (*i)->name;
 371                 if(pass.subscript)
 372                 {
 373                         BinaryExpression *subscript = new BinaryExpression;
 374                         subscript->left = ref;
 375                         subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 376                         subscript->right = pass.subscript;
 377                         insert_assignment(out_name, subscript);
 378                 }
 379                 else
 380                         insert_assignment(out_name, ref);
 381         }
 382
 383         nodes_to_remove.insert(&pass);
 384 }
 385
 386 } // namespace SL
 387 } // namespace GL
 388 } // namespace Msp