src/loader/Interpreter.cpp

   1 /*
   2  * Interpreter.cpp
   3  *
   4  *  Created on: Aug 26, 2012
   5  *      Author: holy
   6  */
   7
   8 #include "Interpreter.h"
   9
  10 #include "ParsedSource.h"
  11 #include "../battle/Hero.h"
  12 #include "../battle/Monster.h"
  13 #include "../battle/PartyLayout.h"
  14 #include "../battle/Resources.h"
  15 #include "../common/Ikari.h"
  16 #include "../common/Item.h"
  17 #include "../common/Script.h"
  18 #include "../common/Spell.h"
  19 #include "../common/Stats.h"
  20 #include "../common/TargetingMode.h"
  21 #include "../graphics/ComplexAnimation.h"
  22 #include "../graphics/Font.h"
  23 #include "../graphics/Frame.h"
  24 #include "../graphics/Gauge.h"
  25 #include "../graphics/Menu.h"
  26 #include "../graphics/SimpleAnimation.h"
  27 #include "../graphics/Sprite.h"
  28
  29 #include <algorithm>
  30 #include <cstring>
  31 #include <SDL_image.h>
  32
  33 using battle::Hero;
  34 using battle::Monster;
  35 using battle::PartyLayout;
  36 using common::Ikari;
  37 using common::Item;
  38 using common::Script;
  39 using common::Spell;
  40 using common::Stats;
  41 using common::TargetingMode;
  42 using graphics::Animation;
  43 using graphics::Color;
  44 using graphics::Font;
  45 using graphics::Frame;
  46 using graphics::Gauge;
  47 using graphics::ComplexAnimation;
  48 using graphics::SimpleAnimation;
  49 using graphics::Sprite;
  50 using geometry::Vector;
  51 using std::make_pair;
  52 using std::set;
  53 using std::string;
  54 using std::vector;
  55
  56 namespace loader {
  57
  58 Interpreter::~Interpreter() {
  59         for (std::map<string, SDL_Surface *>::const_iterator i(imageCache.begin()), end(imageCache.end()); i != end; ++i) {
  60                 SDL_FreeSurface(i->second);
  61         }
  62 }
  63
  64
  65 const Interpreter::ParsedDefinition &Interpreter::GetDefinition(const string &identifier) {
  66         std::map<string, ParsedDefinition>::const_iterator i(parsedDefinitions.find(identifier));
  67         if (i != parsedDefinitions.end()) {
  68                 return i->second;
  69         } else if (source.IsDefined(identifier)) {
  70                 ReadDefinition(source.GetDefinition(identifier));
  71                 return parsedDefinitions.at(identifier);
  72         } else {
  73                 throw Error("access to undefined object " + identifier);
  74         }
  75 }
  76
  77
  78 void *Interpreter::GetObject(int typeId, const std::string &name) {
  79         std::map<string, ParsedDefinition>::const_iterator i(parsedDefinitions.find(name));
  80         if (i != parsedDefinitions.end()) {
  81                 const TypeDescription &requested(TypeDescription::Get(typeId));
  82                 const TypeDescription &actual(TypeDescription::Get(i->second.type));
  83                 if (requested.TypeId() == actual.TypeId()) {
  84                         return values[actual.TypeId()][i->second.id];
  85                 } else if (actual.IsSubtypeOf(requested)) {
  86                         char *sub(reinterpret_cast<char *>(values[actual.TypeId()][i->second.id]));
  87                         std::ptrdiff_t offset(actual.SupertypeOffset(requested));
  88                         return sub - offset;
  89                 } else {
  90                         throw Error("cannot cast " + actual.TypeName() + " to " + requested.TypeName());
  91                 }
  92         } else {
  93                 throw Error("access to undefined object " + name);
  94         }
  95 }
  96
  97
  98 void Interpreter::ReadSource() {
  99         for (set<string>::const_iterator i(source.Exports().begin()), end(source.Exports().end()); i != end; ++i) {
 100                 ReadDefinition(source.GetDefinition(*i));
 101         }
 102 }
 103
 104 void Interpreter::ReadDefinition(const Definition &dfn) {
 105         if (parsedDefinitions.find(dfn.Identifier()) != parsedDefinitions.end()) {
 106                 return;
 107         }
 108         if (dfn.HasLiteralValue()) {
 109                 ReadLiteral(dfn);
 110         } else {
 111                 ReadObject(dfn);
 112         }
 113 }
 114
 115 void Interpreter::ReadLiteral(const Definition &dfn) {
 116         const string &typeName(dfn.GetLiteral()->IsArray() ? "Array" : dfn.GetLiteral()->GetTypeName());
 117         int typeId(TypeDescription::GetTypeId(typeName));
 118         int id(values[typeId].size());
 119         const TypeDescription &td(TypeDescription::Get(typeId));
 120         int size(
 121                         (dfn.GetLiteral()->GetType() == Literal::PATH
 122                                         || dfn.GetLiteral()->GetType() == Literal::STRING)
 123                         ? dfn.GetLiteral()->GetString().size() : td.Size());
 124         char *object(alloc.Alloc(size));
 125         values[typeId].push_back(object);
 126         parsedDefinitions.insert(make_pair(dfn.Identifier(), ParsedDefinition(&dfn, typeId, id)));
 127         if (dfn.GetLiteral()->GetType() == Literal::OBJECT) {
 128                 ReadObject(typeId, id, object, *dfn.GetLiteral()->GetProperties());
 129         } else {
 130                 ReadLiteral(typeId, id, object, *dfn.GetLiteral());
 131         }
 132 }
 133
 134 void Interpreter::ReadLiteral(int typeId, int id, char *object, const Literal &literal) {
 135         switch (literal.GetType()) {
 136                 case Literal::ARRAY_VALUES:
 137                         throw Error("named value arrays are not supported, sorry");
 138                         break;
 139                 case Literal::ARRAY_PROPS:
 140                         throw Error("named property list arrays are not supported, sorry");
 141                         break;
 142                 case Literal::BOOLEAN:
 143                         new (object) bool(literal.GetBoolean());
 144                         break;
 145                 case Literal::COLOR:
 146                         new (object) Color(literal.GetRed(), literal.GetGreen(), literal.GetBlue(), literal.GetAlpha());
 147                         break;
 148                 case Literal::NUMBER:
 149                         new (object) int(literal.GetNumber());
 150                         break;
 151                 case Literal::PATH:
 152                         std::memcpy(object, literal.GetString().c_str(), literal.GetString().size());
 153                         object[literal.GetString().size()] = '\0';
 154                         break;
 155                 case Literal::SCRIPT:
 156                         new (object) Script;
 157                         ReadScript(literal.GetScript(), reinterpret_cast<Script *>(object));
 158                         break;
 159                 case Literal::STRING:
 160                         std::memcpy(object, literal.GetString().c_str(), literal.GetString().size());
 161                         object[literal.GetString().size()] = '\0';
 162                         break;
 163                 case Literal::VECTOR:
 164                         new (object) Vector<int>(literal.GetX(), literal.GetY());
 165                         break;
 166                 case Literal::OBJECT:
 167                         throw Error("illogical branch: read literal object as non-object literal");
 168         }
 169 }
 170
 171
 172 void *Interpreter::GetObject(int typeId, const Value &v) {
 173         if (v.IsLiteral()) {
 174                 if (v.GetLiteral().IsObject()) {
 175                         int typeId(TypeDescription::GetTypeId(v.GetLiteral().GetTypeName()));
 176                         const TypeDescription &td(TypeDescription::Get(typeId));
 177                         char *object(alloc.Alloc(td.Size()));
 178                         td.Construct(object);
 179                         int id(values[typeId].size());
 180                         values[typeId].push_back(object);
 181                         ReadObject(typeId, id, object, *v.GetLiteral().GetProperties());
 182                         return object;
 183                 } else {
 184                         int typeId(0), id(0);
 185                         switch (v.GetLiteral().GetType()) {
 186                                 case Literal::ARRAY_VALUES:
 187                                         throw Error("cannot copy value arrays, sorry");
 188                                         break;
 189                                 case Literal::ARRAY_PROPS:
 190                                         throw Error("cannot copy property list arrays, sorry");
 191                                         break;
 192                                 case Literal::BOOLEAN:
 193                                         {
 194                                                 typeId = TypeDescription::GetTypeId("Boolean");
 195                                                 id = values[typeId].size();
 196                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 197                                                 char *object(alloc.Alloc(td.Size()));
 198                                                 values[typeId].push_back(new (object) bool(v.GetLiteral().GetBoolean()));
 199                                         }
 200                                         break;
 201                                 case Literal::COLOR:
 202                                         {
 203                                                 typeId = TypeDescription::GetTypeId("Color");
 204                                                 id = values[typeId].size();
 205                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 206                                                 char *object(alloc.Alloc(td.Size()));
 207                                                 values[typeId].push_back(new (object) Color(v.GetLiteral().GetRed(), v.GetLiteral().GetGreen(), v.GetLiteral().GetBlue(), v.GetLiteral().GetAlpha()));
 208                                         }
 209                                         break;
 210                                 case Literal::NUMBER:
 211                                         {
 212                                                 typeId = TypeDescription::GetTypeId("Number");
 213                                                 id = values[typeId].size();
 214                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 215                                                 char *object(alloc.Alloc(td.Size()));
 216                                                 values[typeId].push_back(new (object) int(v.GetLiteral().GetNumber()));
 217                                         }
 218                                         break;
 219                                 case Literal::PATH:
 220                                         {
 221                                                 typeId = TypeDescription::GetTypeId("Path");
 222                                                 id = values[typeId].size();
 223                                                 char *str(alloc.Alloc(v.GetLiteral().GetString().size() + 1));
 224                                                 std::memcpy(str, v.GetLiteral().GetString().c_str(), v.GetLiteral().GetString().size());
 225                                                 str[v.GetLiteral().GetString().size()] = '\0';
 226                                                 values[typeId].push_back(str);
 227                                         }
 228                                         break;
 229                                 case Literal::SCRIPT:
 230                                         {
 231                                                 typeId = TypeDescription::GetTypeId("Script");
 232                                                 char *script(ReadScript(v.GetLiteral().GetScript()));
 233                                                 id = values[typeId].size();
 234                                                 values[typeId].push_back(script);
 235                                         }
 236                                         break;
 237                                 case Literal::STRING:
 238                                         {
 239                                                 typeId = TypeDescription::GetTypeId("String");
 240                                                 id = values[typeId].size();
 241                                                 char *str(alloc.Alloc(v.GetLiteral().GetString().size() + 1));
 242                                                 std::memcpy(str, v.GetLiteral().GetString().c_str(), v.GetLiteral().GetString().size());
 243                                                 str[v.GetLiteral().GetString().size()] = '\0';
 244                                                 values[typeId].push_back(str);
 245                                         }
 246                                         break;
 247                                 case Literal::VECTOR:
 248                                         {
 249                                                 typeId = TypeDescription::GetTypeId("Vector");
 250                                                 id = values[typeId].size();
 251                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 252                                                 char *object(alloc.Alloc(td.Size()));
 253                                                 values[typeId].push_back(new (object) Vector<int>(v.GetLiteral().GetX(), v.GetLiteral().GetY()));
 254                                         }
 255                                         break;
 256                                 case Literal::OBJECT:
 257                                         {
 258                                                 typeId = TypeDescription::GetTypeId(v.GetLiteral().GetTypeName());
 259                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 260                                                 id = values[typeId].size();
 261                                                 char *object(alloc.Alloc(td.Size()));
 262                                                 td.Construct(object);
 263                                                 ReadObject(typeId, id, object, *v.GetLiteral().GetProperties());
 264                                         }
 265                                         break;
 266                         }
 267                         return values[typeId][id];
 268                 }
 269         } else {
 270                 ReadDefinition(source.GetDefinition(v.GetIdentifier()));
 271                 return GetObject(typeId, v.GetIdentifier());
 272         }
 273 }
 274
 275
 276 void Interpreter::ReadObject(const Definition &dfn) {
 277         int typeId(TypeDescription::GetTypeId(dfn.TypeName()));
 278         const TypeDescription &td(TypeDescription::Get(typeId));
 279         int id(values[typeId].size());
 280         char *object(alloc.Alloc(td.Size()));
 281         td.Construct(object);
 282         values[typeId].push_back(object);
 283         parsedDefinitions.insert(make_pair(dfn.Identifier(), ParsedDefinition(&dfn, typeId, id)));
 284         ReadObject(typeId, id, object, *dfn.GetProperties());
 285 }
 286
 287
 288 void Interpreter::ReadObject(int typeId, int id, char *object, const PropertyList &props) {
 289         const TypeDescription &td(TypeDescription::Get(typeId));
 290         for (PropertyList::ConstIterator i(props.Begin()), end(props.End()); i != end; ++i) {
 291                 const FieldDescription &fd(td.GetField(i->first));
 292                 const TypeDescription &fieldType(TypeDescription::Get(fd.TypeId()));
 293                 if (CanLink(*i->second)) {
 294                         char *dest(object + fd.Offset());
 295                         if (fd.IsAggregate()) {
 296                                 int arraySize(i->second->GetLiteral().ArraySize());
 297                                 char *aggregate(alloc.Alloc(fieldType.Size() * arraySize));
 298                                 char *iter(aggregate);
 299                                 if (i->second->GetLiteral().GetType() == Literal::ARRAY_PROPS) {
 300                                         const vector<PropertyList *> &list(i->second->GetLiteral().GetPropertyLists());
 301                                         for (vector<PropertyList *>::const_iterator j(list.begin()), end(list.end()); j != end; ++j, iter += fieldType.Size()) {
 302                                                 fieldType.Construct(iter);
 303                                                 ReadObject(fieldType.TypeId(), -1, iter, **j);
 304                                         }
 305                                 } else {
 306                                         const vector<Value *> &list(i->second->GetLiteral().GetValues());
 307                                         for (vector<Value *>::const_iterator j(list.begin()), end(list.end()); j != end; ++j, iter += fieldType.Size()) {
 308                                                 fieldType.Construct(iter);
 309                                                 ReadLiteral(fieldType.TypeId(), -1, iter, (*j)->GetLiteral());
 310                                         }
 311                                 }
 312                                 if (fd.IsReferenced()) {
 313                                         std::memcpy(dest, &aggregate, sizeof(char *));
 314                                         dest += sizeof(char *);
 315                                         std::memcpy(dest, &arraySize, sizeof(int));
 316                                 } else {
 317                                         throw Error("aggregate type fields must be referenced");
 318                                 }
 319                         } else if (i->second->IsLiteral() && !fd.IsReferenced()) {
 320                                 // inline literals
 321                                 if (i->second->GetLiteral().IsObject()) {
 322                                         ReadObject(fd.TypeId(), -1, dest, *i->second->GetLiteral().GetProperties());
 323                                 } else {
 324                                         ReadLiteral(fd.TypeId(), -1, dest, i->second->GetLiteral());
 325                                 }
 326                         } else {
 327                                 char *src(reinterpret_cast<char *>(GetObject(fd.TypeId(), *i->second)));
 328                                 if (fd.TypeId() == TypeDescription::GetTypeId("Image")) {
 329                                         src = reinterpret_cast<char *>(GetImage(src));
 330                                 }
 331                                 if (fd.IsReferenced()) {
 332                                         std::memcpy(dest, &src, sizeof(char *));
 333                                 } else {
 334                                         std::memcpy(dest, src, fieldType.Size());
 335                                 }
 336                         }
 337                 } else {
 338                         Postpone(typeId, id, fd.Offset(), i->second->GetIdentifier(), fd.TypeId(), !fd.IsReferenced());
 339                 }
 340         }
 341         td.Load(object);
 342 }
 343
 344
 345 void Interpreter::ReadScript(const std::vector<ScriptToken *> &s, Script *script) {
 346         std::map<string, int> labels;
 347         int size(0);
 348         for (vector<ScriptToken *>::const_iterator i(s.begin()), end(s.end()); i != end; ++i) {
 349                 if ((*i)->GetType() == ScriptToken::LABEL) {
 350                         if (labels.count((*i)->Label())) {
 351                                 throw Error("duplicate label " + (*i)->Label());
 352                         } else {
 353                                 labels[(*i)->Label()] = size;
 354                         }
 355                 } else if ((*i)->GetType() != ScriptToken::COMMAND) {
 356                         throw Error("unexpected script token");
 357                 }
 358                 size += sizeof(Script::Code);
 359                 const string &cmd((*i)->CommandName());
 360                 if (cmd == "move") {
 361                         ++i;
 362                         if (i == end) {
 363                                 throw Error("unexpected script end after move");
 364                         }
 365                         const string &reg((*i)->RegisterName());
 366                         if (reg.size() != 2) {
 367                                 throw Error("invalid register name " + reg);
 368                         }
 369                         ++i;
 370                         if (i == end) {
 371                                 throw Error("unexpected script end after move");
 372                         }
 373                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 374                                 switch (reg[0]) {
 375                                         case 'a':
 376                                                 size += sizeof(void *);
 377                                                 break;
 378                                         case 'i':
 379                                                 size += sizeof(int);
 380                                                 break;
 381                                         case 'v':
 382                                                 size += sizeof(Vector<int>);
 383                                                 break;
 384                                         default:
 385                                                 throw Error("unknown register " + reg);
 386                                 }
 387                         }
 388                 } else if (cmd == "add") {
 389                         ++i;
 390                         if (i == end) {
 391                                 throw Error("unexpected script end after add");
 392                         }
 393                         const string &reg((*i)->RegisterName());
 394                         if (reg.size() != 2) {
 395                                 throw Error("invalid register name " + reg);
 396                         }
 397                         ++i;
 398                         if (i == end) {
 399                                 throw Error("unexpected script end after add");
 400                         }
 401                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 402                                 switch (reg[0]) {
 403                                         case 'i':
 404                                                 size += sizeof(int);
 405                                                 break;
 406                                         case 'v':
 407                                                 size += sizeof(Vector<int>);
 408                                                 break;
 409                                         default:
 410                                                 throw Error("expected register after add " + reg);
 411                                 }
 412                         }
 413                 } else if (cmd == "mod") {
 414                         ++i;
 415                         if (i == end) {
 416                                 throw Error("unexpected script end after mod");
 417                         }
 418                         ++i;
 419                         if (i == end) {
 420                                 throw Error("unexpected script end after mod");
 421                         }
 422                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 423                                 size += sizeof(int);
 424                         }
 425                 } else if (cmd == "rand") {
 426                         ++i;
 427                         if (i == end) {
 428                                 throw Error("unexpected script end after rand");
 429                         }
 430                 } else if (cmd == "cmp") {
 431                         ++i;
 432                         if (i == end) {
 433                                 throw Error("unexpected script end after cmp");
 434                         }
 435                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 436                                 size += sizeof(int);
 437                         }
 438                         ++i;
 439                         if (i == end) {
 440                                 throw Error("unexpected script end after cmp");
 441                         }
 442                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 443                                 size += sizeof(int);
 444                         }
 445                 } else if (cmd == "jmp") {
 446                         size += sizeof(int);
 447                         ++i;
 448                         if (i == end) {
 449                                 throw Error("unexpected script end after cmp");
 450                         }
 451                 } else if (cmd == "jeq") {
 452                         size += sizeof(int);
 453                         ++i;
 454                         if (i == end) {
 455                                 throw Error("unexpected script end after cmp");
 456                         }
 457                 } else if (cmd == "jne") {
 458                         size += sizeof(int);
 459                         ++i;
 460                         if (i == end) {
 461                                 throw Error("unexpected script end after cmp");
 462                         }
 463                 } else if (cmd == "jl") {
 464                         size += sizeof(int);
 465                         ++i;
 466                         if (i == end) {
 467                                 throw Error("unexpected script end after cmp");
 468                         }
 469                 } else if (cmd == "jle") {
 470                         size += sizeof(int);
 471                         ++i;
 472                         if (i == end) {
 473                                 throw Error("unexpected script end after cmp");
 474                         }
 475                 } else if (cmd == "jg") {
 476                         size += sizeof(int);
 477                         ++i;
 478                         if (i == end) {
 479                                 throw Error("unexpected script end after cmp");
 480                         }
 481                 } else if (cmd == "jge") {
 482                         size += sizeof(int);
 483                         ++i;
 484                         if (i == end) {
 485                                 throw Error("unexpected script end after cmp");
 486                         }
 487                 } else if (cmd == "sysc") {
 488
 489                 } else {
 490                         throw Error("unknown command " + cmd);
 491                 }
 492         }
 493
 494         char *text(alloc.Alloc(size));
 495         int cursor(0);
 496         for (vector<ScriptToken *>::const_iterator i(s.begin()), end(s.end()); i != end; ++i) {
 497                 if ((*i)->GetType() == ScriptToken::LABEL) {
 498                         continue;
 499                 }
 500                 if ((*i)->GetType() != ScriptToken::COMMAND) {
 501                         throw Error("unexpected script token");
 502                 }
 503                 const string &cmd((*i)->CommandName());
 504                 if (cmd == "move") {
 505                         Script::Code &code(CreateScriptCode(Script::COMMAND_MOVE, text + cursor));
 506                         cursor += sizeof(Script::Code);
 507                         code.numParams = 2;
 508                         ++i;
 509                         const string &reg((*i)->RegisterName());
 510                         switch (reg[0]) {
 511                                 case 'a':
 512                                         code.type = Script::TYPE_ADDRESS;
 513                                         break;
 514                                 case 'i':
 515                                         code.type = Script::TYPE_INTEGER;
 516                                         break;
 517                                 case 'v':
 518                                         code.type = Script::TYPE_VECTOR;
 519                                         break;
 520                                 default:
 521                                         throw Error("invalid register " + reg);
 522                         }
 523                         int regnum(reg[1] - '0');
 524                         if (regnum < 0 || regnum > 6) {
 525                                 throw Error("invalid register " + reg);
 526                         }
 527                         code.reg1 = regnum;
 528                         ++i;
 529
 530                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 531                                 string reg2((*i)->RegisterName());
 532                                 if (reg[0] != reg2[0]) {
 533                                         throw Error("mixed-type commands not allowed");
 534                                 }
 535                                 int reg2num(reg[1] - '0');
 536                                 if (reg2num < 0 || reg2num > 6) {
 537                                         throw Error("invalid register " + reg2);
 538                                 }
 539                                 code.reg2 = reg2num;
 540                         } else {
 541                                 code.reg2 = 7;
 542                                 switch (code.type) {
 543                                         case Script::TYPE_ADDRESS:
 544                                                 ReadScriptAddress(**i, text + cursor);
 545                                                 cursor += sizeof(void *);
 546                                                 break;
 547                                         case Script::TYPE_INTEGER:
 548                                                 ReadScriptInteger(**i, text + cursor);
 549                                                 cursor += sizeof(int);
 550                                                 break;
 551                                         case Script::TYPE_VECTOR:
 552                                                 ReadScriptVector(**i, text + cursor);
 553                                                 cursor += sizeof(Vector<int>);
 554                                                 break;
 555                                 }
 556                         }
 557                 } else if (cmd == "add") {
 558                         Script::Code &code(CreateScriptCode(Script::COMMAND_ADD, text + cursor));
 559                         cursor += sizeof(Script::Code);
 560                         code.numParams = 2;
 561                         ++i;
 562                         const string &reg((*i)->RegisterName());
 563                         switch (reg[0]) {
 564                                 case 'i':
 565                                         code.type = Script::TYPE_INTEGER;
 566                                         break;
 567                                 case 'v':
 568                                         code.type = Script::TYPE_VECTOR;
 569                                         break;
 570                                 default:
 571                                         throw Error("invalid register " + reg);
 572                         }
 573                         int regnum(reg[1] - '0');
 574                         if (regnum < 0 || regnum > 6) {
 575                                 throw Error("invalid register " + reg);
 576                         }
 577                         code.reg1 = regnum;
 578                         ++i;
 579
 580                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 581                                 string reg2((*i)->RegisterName());
 582                                 if (reg[0] != reg2[0]) {
 583                                         throw Error("mixed-type commands not allowed");
 584                                 }
 585                                 int reg2num(reg[1] - '0');
 586                                 if (reg2num < 0 || reg2num > 6) {
 587                                         throw Error("invalid register name " + reg2);
 588                                 }
 589                                 code.reg2 = reg2num;
 590                         } else {
 591                                 code.reg2 = 7;
 592                                 switch (code.type) {
 593                                         case Script::TYPE_INTEGER:
 594                                                 ReadScriptInteger(**i, text + cursor);
 595                                                 cursor += sizeof(int);
 596                                                 break;
 597                                         case Script::TYPE_VECTOR:
 598                                                 ReadScriptVector(**i, text + cursor);
 599                                                 cursor += sizeof(Vector<int>);
 600                                                 break;
 601                                 }
 602                         }
 603                 } else if (cmd == "mod") {
 604                         Script::Code &code(CreateScriptCode(Script::COMMAND_MOD, text + cursor));
 605                         cursor += sizeof(Script::Code);
 606                         code.numParams = 2;
 607                         ++i;
 608                         const string &reg((*i)->RegisterName());
 609                         if (reg[0] != 'i') {
 610                                 throw Error("invalid register " + reg);
 611                         }
 612                         code.type = Script::TYPE_INTEGER;
 613                         int regnum(reg[1] - '0');
 614                         if (regnum < 0 || regnum > 6) {
 615                                 throw Error("invalid register " + reg);
 616                         }
 617                         code.reg1 = regnum;
 618                         ++i;
 619
 620                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 621                                 string reg2((*i)->RegisterName());
 622                                 if (reg[0] != reg2[0]) {
 623                                         throw Error("mixed-type commands not allowed");
 624                                 }
 625                                 int reg2num(reg[1] - '0');
 626                                 if (reg2num < 0 || reg2num > 6) {
 627                                         throw Error("invalid register name " + reg2);
 628                                 }
 629                                 code.reg2 = reg2num;
 630                         } else {
 631                                 code.reg2 = 7;
 632                                 ReadScriptInteger(**i, text + cursor);
 633                                 cursor += sizeof(int);
 634                         }
 635                 } else if (cmd == "rand") {
 636                         Script::Code &code(CreateScriptCode(Script::COMMAND_RAND, text + cursor));
 637                         cursor += sizeof(Script::Code);
 638                         code.numParams = 1;
 639                         ++i;
 640                         const string &reg((*i)->RegisterName());
 641                         if (reg[0] != 'i') {
 642                                 throw Error("invalid register " + reg);
 643                         }
 644                         code.type = Script::TYPE_INTEGER;
 645                         int regnum(reg[1] - '0');
 646                         if (regnum < 0 || regnum > 6) {
 647                                 throw Error("invalid register " + reg);
 648                         }
 649                         code.reg1 = regnum;
 650                 } else if (cmd == "cmp") {
 651                         Script::Code &code(CreateScriptCode(Script::COMMAND_CMP, text + cursor));
 652                         cursor += sizeof(Script::Code);
 653                         code.numParams = 2;
 654                         ++i;
 655                         const string &reg((*i)->RegisterName());
 656                         if (reg[0] != 'i') {
 657                                 throw Error("invalid register " + reg);
 658                         }
 659                         code.type = Script::TYPE_INTEGER;
 660                         int regnum(reg[1] - '0');
 661                         if (regnum < 0 || regnum > 6) {
 662                                 throw Error("invalid register " + reg);
 663                         }
 664                         code.reg1 = regnum;
 665                         ++i;
 666
 667                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 668                                 string reg2((*i)->RegisterName());
 669                                 if (reg[0] != reg2[0]) {
 670                                         throw Error("mixed-type commands not allowed");
 671                                 }
 672                                 int reg2num(reg[1] - '0');
 673                                 if (reg2num < 0 || reg2num > 6) {
 674                                         throw Error("invalid register name " + reg2);
 675                                 }
 676                                 code.reg2 = reg2num;
 677                         } else {
 678                                 code.reg2 = 7;
 679                                 ReadScriptInteger(**i, text + cursor);
 680                                 cursor += sizeof(int);
 681                         }
 682                 } else if (cmd == "jmp") {
 683                         Script::Code &code(CreateScriptCode(Script::COMMAND_JMP, text + cursor));
 684                         cursor += sizeof(Script::Code);
 685                         code.numParams = 1;
 686                         ++i;
 687                         if (!labels.count((*i)->Identifier())) {
 688                                 throw Error("use of undefined label " + (*i)->Identifier());
 689                         }
 690                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 691                         cursor += sizeof(int);
 692                 } else if (cmd == "jeq") {
 693                         Script::Code &code(CreateScriptCode(Script::COMMAND_JEQ, text + cursor));
 694                         cursor += sizeof(Script::Code);
 695                         code.numParams = 1;
 696                         ++i;
 697                         if (!labels.count((*i)->Identifier())) {
 698                                 throw Error("use of undefined label " + (*i)->Identifier());
 699                         }
 700                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 701                         cursor += sizeof(int);
 702                 } else if (cmd == "jne") {
 703                         Script::Code &code(CreateScriptCode(Script::COMMAND_JNE, text + cursor));
 704                         cursor += sizeof(Script::Code);
 705                         code.numParams = 1;
 706                         ++i;
 707                         if (!labels.count((*i)->Identifier())) {
 708                                 throw Error("use of undefined label " + (*i)->Identifier());
 709                         }
 710                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 711                         cursor += sizeof(int);
 712                 } else if (cmd == "jl") {
 713                         Script::Code &code(CreateScriptCode(Script::COMMAND_JL, text + cursor));
 714                         cursor += sizeof(Script::Code);
 715                         code.numParams = 1;
 716                         ++i;
 717                         if (!labels.count((*i)->Identifier())) {
 718                                 throw Error("use of undefined label " + (*i)->Identifier());
 719                         }
 720                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 721                         cursor += sizeof(int);
 722                 } else if (cmd == "jle") {
 723                         Script::Code &code(CreateScriptCode(Script::COMMAND_JLE, text + cursor));
 724                         cursor += sizeof(Script::Code);
 725                         code.numParams = 1;
 726                         ++i;
 727                         if (!labels.count((*i)->Identifier())) {
 728                                 throw Error("use of undefined label " + (*i)->Identifier());
 729                         }
 730                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 731                         cursor += sizeof(int);
 732                 } else if (cmd == "jg") {
 733                         Script::Code &code(CreateScriptCode(Script::COMMAND_JG, text + cursor));
 734                         cursor += sizeof(Script::Code);
 735                         code.numParams = 1;
 736                         ++i;
 737                         if (!labels.count((*i)->Identifier())) {
 738                                 throw Error("use of undefined label " + (*i)->Identifier());
 739                         }
 740                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 741                         cursor += sizeof(int);
 742                 } else if (cmd == "jge") {
 743                         Script::Code &code(CreateScriptCode(Script::COMMAND_JGE, text + cursor));
 744                         cursor += sizeof(Script::Code);
 745                         code.numParams = 1;
 746                         ++i;
 747                         if (!labels.count((*i)->Identifier())) {
 748                                 throw Error("use of undefined label " + (*i)->Identifier());
 749                         }
 750                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 751                         cursor += sizeof(int);
 752                 } else if (cmd == "sysc") {
 753                         Script::Code &code(CreateScriptCode(Script::COMMAND_SYSC, text + cursor));
 754                         cursor += sizeof(Script::Code);
 755                         code.numParams = 0;
 756                 } else {
 757                         throw Error("unknown command " + cmd);
 758                 }
 759         }
 760
 761         script->text = text;
 762         script->textlen = size;
 763 }
 764
 765 char *Interpreter::ReadScript(const vector<ScriptToken *> &s) {
 766         char *mem(alloc.Alloc(sizeof(Script)));
 767         new (mem) Script;
 768         Script *script(reinterpret_cast<Script *>(mem));
 769         ReadScript(s, script);
 770         return mem;
 771 }
 772
 773 Script::Code &Interpreter::CreateScriptCode(Script::Command c, char *dest) {
 774         Script::Code &code(*reinterpret_cast<Script::Code *>(dest));
 775         code.command = c;
 776         code.numParams = 0;
 777         code.type = Script::TYPE_NONE;
 778         code.reg1 = 7;
 779         code.reg2 = 7;
 780         return code;
 781 }
 782
 783 void Interpreter::ReadScriptAddress(const ScriptToken &t, char *dest) {
 784         if (t.GetType() != ScriptToken::IDENTIFIER) {
 785                 throw Error("expected identifier for address");
 786         }
 787         if (source.IsDefined(t.Identifier())) {
 788                 const ParsedDefinition &def(GetDefinition(t.Identifier()));
 789                 void *addr(GetObject(def.type, t.Identifier()));
 790                 *reinterpret_cast<void **>(dest) = addr;
 791         } else {
 792                 throw Error("postponing values in scripts not implemented");
 793         }
 794 }
 795
 796 void Interpreter::ReadScriptInteger(const ScriptToken &t, char *dest) {
 797         if (t.GetType() == ScriptToken::IDENTIFIER) {
 798                 if (source.IsDefined(t.Identifier())) {
 799                         void *num(GetObject(TypeDescription::GetTypeId("Number"), t.Identifier()));
 800                         *reinterpret_cast<int *>(dest) = *reinterpret_cast<int *>(num);
 801                 } else {
 802                         throw Error("postponing values in scripts not implemented");
 803                 }
 804         } else if (t.GetType() == ScriptToken::LITERAL) {
 805                 *reinterpret_cast<int *>(dest) = t.GetLiteral()->GetNumber();
 806         } else {
 807                 throw Error("expected identifier or integer literal");
 808         }
 809 }
 810
 811 void Interpreter::ReadScriptVector(const ScriptToken &t, char *dest) {
 812         if (t.GetType() == ScriptToken::IDENTIFIER) {
 813                 if (source.IsDefined(t.Identifier())) {
 814                         void *vec(GetObject(TypeDescription::GetTypeId("Vector"), t.Identifier()));
 815                         *reinterpret_cast<Vector<int> *>(dest) = *reinterpret_cast<Vector<int> *>(vec);
 816                 } else {
 817                         throw Error("postponing values in scripts not implemented");
 818                 }
 819         } else if (t.GetType() == ScriptToken::LITERAL) {
 820                 *reinterpret_cast<Vector<int> *>(dest) = Vector<int>(t.GetLiteral()->GetX(), t.GetLiteral()->GetY());
 821         } else {
 822                 throw Error("expected identifier or vector literal");
 823         }
 824 }
 825
 826
 827 SDL_Surface *Interpreter::GetImage(const string &path) {
 828         std::map<string, SDL_Surface *>::const_iterator result(imageCache.find(path));
 829         if (result != imageCache.end()) {
 830                 return result->second;
 831         } else {
 832                 SDL_Surface *image(IMG_Load(path.c_str()));
 833                 imageCache.insert(make_pair(path, image));
 834                 return image;
 835         }
 836 }
 837
 838
 839 bool Interpreter::CanLink(const Value &v) const {
 840         return v.IsLiteral() || source.IsDefined(v.GetIdentifier());
 841 }
 842
 843 void Interpreter::Postpone(int type, int id, std::ptrdiff_t offset, const std::string &identifier, int linkedType, bool inlined) {
 844         char *str(alloc.Alloc(identifier.size() + 1));
 845         std::memcpy(str, identifier.c_str(), identifier.size());
 846         str[identifier.size()] = '\0';
 847         postponedDefinitions.push_back(PostponedDefinition(type, id, offset, str, linkedType, inlined));
 848 }
 849
 850
 851 void Interpreter::CreateTypeDescriptions() {
 852         {
 853                 TypeDescription &td(TypeDescription::Create(BOOLEAN_ID, "Boolean"));
 854                 td.SetDescription("Logical value which can be either true or false.");
 855                 td.SetSize(sizeof(bool));
 856         }
 857         {
 858                 TypeDescription &td(TypeDescription::Create(COLOR_ID, "Color"));
 859                 td.SetDescription(
 860                                 "A color in RGB format with an optional alpha channel.\n"
 861                                 "Components range from 0 to 255.\n"
 862                                 "Alpha defaults to 255 if omitted.");
 863                 td.SetSize(sizeof(Color));
 864         }
 865         {
 866                 TypeDescription &td(TypeDescription::Create(IMAGE_ID, "Image"));
 867                 td.SetDescription("Path to a PNG file with image data.");
 868                 td.SetSize(sizeof(SDL_Surface));
 869         }
 870         {
 871                 TypeDescription &td(TypeDescription::Create(NUMBER_ID, "Number"));
 872                 td.SetDescription("A signed integer.");
 873                 td.SetSize(sizeof(int));
 874         }
 875         {;
 876                 TypeDescription &td(TypeDescription::Create(PATH_ID, "Path"));
 877                 td.SetDescription("A path in the filesystem which is interpreted relative to the source file's location.");
 878                 td.SetSize(1);
 879                 td.AddSupertype(STRING_ID, 0);
 880         }
 881         {
 882                 TypeDescription &td(TypeDescription::Create(SCRIPT_ID, "Script"));
 883                 td.SetDescription("Collection of commands that define a behaviour.");
 884                 td.SetSize(sizeof(Script));
 885         }
 886         {
 887                 TypeDescription &td(TypeDescription::Create(STRING_ID, "String"));
 888                 td.SetDescription("Some characters.");
 889                 td.SetSize(1);
 890         }
 891         {
 892                 TypeDescription &td(TypeDescription::Create(VECTOR_ID, "Vector"));
 893                 td.SetDescription("A pair of numbers usually describing a 2D translation or offset.");
 894                 td.SetSize(sizeof(Vector<int>));
 895         }
 896 }
 897
 898 }