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