Interpreter.cpp

   1 #include "Interpreter.h"
   2
   3 #include "ParsedSource.h"
   4 #include "TypeDescription.h"
   5 #include "../battle/Hero.h"
   6 #include "../battle/Monster.h"
   7 #include "../battle/PartyLayout.h"
   8 #include "../battle/Resources.h"
   9 #include "../common/Ikari.h"
  10 #include "../common/Item.h"
  11 #include "../common/Script.h"
  12 #include "../common/Spell.h"
  13 #include "../common/Stats.h"
  14 #include "../common/TargetingMode.h"
  15 #include "../graphics/ComplexAnimation.h"
  16 #include "../graphics/Font.h"
  17 #include "../graphics/Frame.h"
  18 #include "../graphics/Gauge.h"
  19 #include "../graphics/Menu.h"
  20 #include "../graphics/SimpleAnimation.h"
  21 #include "../graphics/Sprite.h"
  22
  23 #include <algorithm>
  24 #include <cstring>
  25 #include <SDL_image.h>
  26
  27 using battle::Hero;
  28 using battle::Monster;
  29 using battle::PartyLayout;
  30 using common::Ikari;
  31 using common::Item;
  32 using common::Script;
  33 using common::Spell;
  34 using common::Stats;
  35 using common::TargetingMode;
  36 using graphics::Animation;
  37 using graphics::Color;
  38 using graphics::Font;
  39 using graphics::Frame;
  40 using graphics::Gauge;
  41 using graphics::ComplexAnimation;
  42 using graphics::SimpleAnimation;
  43 using graphics::Sprite;
  44 using math::Vector;
  45 using std::make_pair;
  46 using std::set;
  47 using std::string;
  48 using std::vector;
  49
  50 namespace loader {
  51
  52 Interpreter::~Interpreter() {
  53         for (std::map<string, SDL_Surface *>::const_iterator i(imageCache.begin()), end(imageCache.end()); i != end; ++i) {
  54                 SDL_FreeSurface(i->second);
  55         }
  56 }
  57
  58
  59 const Interpreter::ParsedDefinition &Interpreter::GetDefinition(const string &identifier) {
  60         std::map<string, ParsedDefinition>::const_iterator i(parsedDefinitions.find(identifier));
  61         if (i != parsedDefinitions.end()) {
  62                 return i->second;
  63         } else if (source.IsDefined(identifier)) {
  64                 ReadDefinition(source.GetDefinition(identifier));
  65                 return parsedDefinitions.at(identifier);
  66         } else {
  67                 throw Error("access to undefined object " + identifier);
  68         }
  69 }
  70
  71
  72 void *Interpreter::GetObject(int typeId, const std::string &name) {
  73         std::map<string, ParsedDefinition>::const_iterator i(parsedDefinitions.find(name));
  74         if (i != parsedDefinitions.end()) {
  75                 const TypeDescription &requested(TypeDescription::Get(typeId));
  76                 const TypeDescription &actual(TypeDescription::Get(i->second.type));
  77                 if (requested.TypeId() == actual.TypeId()) {
  78                         return values[actual.TypeId()][i->second.id];
  79                 } else if (actual.IsSubtypeOf(requested)) {
  80                         char *sub(reinterpret_cast<char *>(values[actual.TypeId()][i->second.id]));
  81                         std::ptrdiff_t offset(actual.SupertypeOffset(requested));
  82                         return sub - offset;
  83                 } else {
  84                         throw Error("cannot cast " + actual.TypeName() + " to " + requested.TypeName());
  85                 }
  86         } else {
  87                 throw Error("access to undefined object " + name);
  88         }
  89 }
  90
  91
  92 void Interpreter::ReadSource() {
  93         for (set<string>::const_iterator i(source.Exports().begin()), end(source.Exports().end()); i != end; ++i) {
  94                 ReadDefinition(source.GetDefinition(*i));
  95         }
  96 }
  97
  98 void Interpreter::ReadDefinition(const Definition &dfn) {
  99         if (parsedDefinitions.find(dfn.Identifier()) != parsedDefinitions.end()) {
 100                 return;
 101         }
 102         if (dfn.HasLiteralValue()) {
 103                 ReadLiteral(dfn);
 104         } else {
 105                 ReadObject(dfn);
 106         }
 107 }
 108
 109 void Interpreter::ReadLiteral(const Definition &dfn) {
 110         const string &typeName(dfn.GetLiteral()->IsArray() ? "Array" : dfn.GetLiteral()->GetTypeName());
 111         int typeId(TypeDescription::GetTypeId(typeName));
 112         int id(values[typeId].size());
 113         const TypeDescription &td(TypeDescription::Get(typeId));
 114         int size(
 115                         (dfn.GetLiteral()->GetType() == Literal::PATH
 116                                         || dfn.GetLiteral()->GetType() == Literal::STRING)
 117                         ? dfn.GetLiteral()->GetString().size() : td.Size());
 118         char *object(alloc.Alloc(size));
 119         values[typeId].push_back(object);
 120         parsedDefinitions.insert(make_pair(dfn.Identifier(), ParsedDefinition(&dfn, typeId, id)));
 121         if (dfn.GetLiteral()->GetType() == Literal::OBJECT) {
 122                 ReadObject(typeId, id, object, *dfn.GetLiteral()->GetProperties());
 123         } else {
 124                 ReadLiteral(typeId, id, object, *dfn.GetLiteral());
 125         }
 126 }
 127
 128 void Interpreter::ReadLiteral(int typeId, int id, char *object, const Literal &literal) {
 129         switch (literal.GetType()) {
 130                 case Literal::ARRAY_VALUES:
 131                 case Literal::ARRAY_PROPS:
 132                 case Literal::ARRAY_IDENTS:
 133                         throw Error("named arrays are not supported, sorry");
 134                         break;
 135                 case Literal::BOOLEAN:
 136                         new (object) bool(literal.GetBoolean());
 137                         break;
 138                 case Literal::COLOR:
 139                         new (object) Color(literal.GetRed(), literal.GetGreen(), literal.GetBlue(), literal.GetAlpha());
 140                         break;
 141                 case Literal::NUMBER:
 142                         new (object) int(literal.GetNumber());
 143                         break;
 144                 case Literal::PATH:
 145                         std::memcpy(object, literal.GetString().c_str(), literal.GetString().size());
 146                         object[literal.GetString().size()] = '\0';
 147                         break;
 148                 case Literal::SCRIPT:
 149                         new (object) Script;
 150                         ReadScript(literal.GetScript(), reinterpret_cast<Script *>(object));
 151                         break;
 152                 case Literal::STRING:
 153                         std::memcpy(object, literal.GetString().c_str(), literal.GetString().size());
 154                         object[literal.GetString().size()] = '\0';
 155                         break;
 156                 case Literal::VECTOR:
 157                         new (object) Vector<int>(literal.GetX(), literal.GetY());
 158                         break;
 159                 case Literal::OBJECT:
 160                         throw Error("illogical branch: read literal object as non-object literal");
 161         }
 162 }
 163
 164
 165 void *Interpreter::GetObject(int typeId, const Value &v) {
 166         if (v.IsLiteral()) {
 167                 if (v.GetLiteral().IsObject()) {
 168                         int typeId(TypeDescription::GetTypeId(v.GetLiteral().GetTypeName()));
 169                         const TypeDescription &td(TypeDescription::Get(typeId));
 170                         char *object(alloc.Alloc(td.Size()));
 171                         td.Construct(object);
 172                         int id(values[typeId].size());
 173                         values[typeId].push_back(object);
 174                         ReadObject(typeId, id, object, *v.GetLiteral().GetProperties());
 175                         return object;
 176                 } else {
 177                         int typeId(0), id(0);
 178                         switch (v.GetLiteral().GetType()) {
 179                                 case Literal::ARRAY_VALUES:
 180                                 case Literal::ARRAY_PROPS:
 181                                 case Literal::ARRAY_IDENTS:
 182                                         throw Error("cannot copy arrays, sorry");
 183                                         break;
 184                                 case Literal::BOOLEAN:
 185                                         {
 186                                                 typeId = TypeDescription::GetTypeId("Boolean");
 187                                                 id = values[typeId].size();
 188                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 189                                                 char *object(alloc.Alloc(td.Size()));
 190                                                 values[typeId].push_back(new (object) bool(v.GetLiteral().GetBoolean()));
 191                                         }
 192                                         break;
 193                                 case Literal::COLOR:
 194                                         {
 195                                                 typeId = TypeDescription::GetTypeId("Color");
 196                                                 id = values[typeId].size();
 197                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 198                                                 char *object(alloc.Alloc(td.Size()));
 199                                                 values[typeId].push_back(new (object) Color(v.GetLiteral().GetRed(), v.GetLiteral().GetGreen(), v.GetLiteral().GetBlue(), v.GetLiteral().GetAlpha()));
 200                                         }
 201                                         break;
 202                                 case Literal::NUMBER:
 203                                         {
 204                                                 typeId = TypeDescription::GetTypeId("Number");
 205                                                 id = values[typeId].size();
 206                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 207                                                 char *object(alloc.Alloc(td.Size()));
 208                                                 values[typeId].push_back(new (object) int(v.GetLiteral().GetNumber()));
 209                                         }
 210                                         break;
 211                                 case Literal::PATH:
 212                                         {
 213                                                 typeId = TypeDescription::GetTypeId("Path");
 214                                                 id = values[typeId].size();
 215                                                 char *str(alloc.Alloc(v.GetLiteral().GetString().size() + 1));
 216                                                 std::memcpy(str, v.GetLiteral().GetString().c_str(), v.GetLiteral().GetString().size());
 217                                                 str[v.GetLiteral().GetString().size()] = '\0';
 218                                                 values[typeId].push_back(str);
 219                                         }
 220                                         break;
 221                                 case Literal::SCRIPT:
 222                                         {
 223                                                 typeId = TypeDescription::GetTypeId("Script");
 224                                                 char *script(ReadScript(v.GetLiteral().GetScript()));
 225                                                 id = values[typeId].size();
 226                                                 values[typeId].push_back(script);
 227                                         }
 228                                         break;
 229                                 case Literal::STRING:
 230                                         {
 231                                                 typeId = TypeDescription::GetTypeId("String");
 232                                                 id = values[typeId].size();
 233                                                 char *str(alloc.Alloc(v.GetLiteral().GetString().size() + 1));
 234                                                 std::memcpy(str, v.GetLiteral().GetString().c_str(), v.GetLiteral().GetString().size());
 235                                                 str[v.GetLiteral().GetString().size()] = '\0';
 236                                                 values[typeId].push_back(str);
 237                                         }
 238                                         break;
 239                                 case Literal::VECTOR:
 240                                         {
 241                                                 typeId = TypeDescription::GetTypeId("Vector");
 242                                                 id = values[typeId].size();
 243                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 244                                                 char *object(alloc.Alloc(td.Size()));
 245                                                 values[typeId].push_back(new (object) Vector<int>(v.GetLiteral().GetX(), v.GetLiteral().GetY()));
 246                                         }
 247                                         break;
 248                                 case Literal::OBJECT:
 249                                         {
 250                                                 typeId = TypeDescription::GetTypeId(v.GetLiteral().GetTypeName());
 251                                                 const TypeDescription &td(TypeDescription::Get(typeId));
 252                                                 id = values[typeId].size();
 253                                                 char *object(alloc.Alloc(td.Size()));
 254                                                 td.Construct(object);
 255                                                 ReadObject(typeId, id, object, *v.GetLiteral().GetProperties());
 256                                         }
 257                                         break;
 258                         }
 259                         return values[typeId][id];
 260                 }
 261         } else {
 262                 ReadDefinition(source.GetDefinition(v.GetIdentifier()));
 263                 return GetObject(typeId, v.GetIdentifier());
 264         }
 265 }
 266
 267
 268 void Interpreter::ReadObject(const Definition &dfn) {
 269         int typeId(TypeDescription::GetTypeId(dfn.TypeName()));
 270         const TypeDescription &td(TypeDescription::Get(typeId));
 271         int id(values[typeId].size());
 272         char *object(alloc.Alloc(td.Size()));
 273         td.Construct(object);
 274         values[typeId].push_back(object);
 275         parsedDefinitions.insert(make_pair(dfn.Identifier(), ParsedDefinition(&dfn, typeId, id)));
 276         ReadObject(typeId, id, object, *dfn.GetProperties());
 277 }
 278
 279
 280 void Interpreter::ReadObject(int typeId, int id, char *object, const PropertyList &props) {
 281         const TypeDescription &td(TypeDescription::Get(typeId));
 282         for (PropertyList::ConstIterator i(props.Begin()), end(props.End()); i != end; ++i) {
 283                 const FieldDescription &fd(td.GetField(i->first));
 284                 const TypeDescription &fieldType(TypeDescription::Get(fd.TypeId()));
 285                 if (CanLink(*i->second)) {
 286                         char *dest(object + fd.Offset());
 287                         if (fd.IsAggregate()) {
 288                                 int arraySize(i->second->GetLiteral().ArraySize());
 289                                 size_t memberSize = fd.IsReferenced() ? sizeof(char *) : fieldType.Size();
 290                                 char *aggregate = alloc.Alloc(arraySize * memberSize);
 291                                 char *iter = aggregate;
 292                                 if (i->second->GetLiteral().GetType() == Literal::ARRAY_PROPS) {
 293                                         const vector<PropertyList *> &list(i->second->GetLiteral().GetPropertyLists());
 294                                         for (vector<PropertyList *>::const_iterator j(list.begin()), end(list.end());
 295                                                         j != end; ++j, iter += memberSize) {
 296                                                 char *member;
 297                                                 if (fd.IsReferenced()) {
 298                                                         member = alloc.Alloc(fieldType.Size());
 299                                                         *reinterpret_cast<char **>(iter) = member;
 300                                                 } else {
 301                                                         member = iter;
 302                                                 }
 303                                                 fieldType.Construct(member);
 304                                                 ReadObject(fieldType.TypeId(), -1, member, **j);
 305                                         }
 306                                 } else if (i->second->GetLiteral().GetType() == Literal::ARRAY_VALUES) {
 307                                         const vector<Value *> &list(i->second->GetLiteral().GetValues());
 308                                         for (vector<Value *>::const_iterator j(list.begin()), end(list.end());
 309                                                         j != end; ++j, iter += memberSize) {
 310                                                 char *member;
 311                                                 if (fd.IsReferenced()) {
 312                                                         member = alloc.Alloc(fieldType.Size());
 313                                                         *reinterpret_cast<char **>(iter) = member;
 314                                                 } else {
 315                                                         member = iter;
 316                                                 }
 317                                                 fieldType.Construct(member);
 318                                                 ReadLiteral(fieldType.TypeId(), -1, member, (*j)->GetLiteral());
 319                                         }
 320                                 } else {
 321                                         if (!fd.IsReferenced()) {
 322                                                 // TODO: implement inline identifier arrays
 323                                                 throw std::runtime_error("inline identifier arrays not implemented (yet)");
 324                                         }
 325                                         const vector<string> &list(i->second->GetLiteral().GetIdentifiers());
 326                                         for (vector<string>::const_iterator j(list.begin()), end(list.end());
 327                                                         j != end; ++j, iter += memberSize) {
 328                                                 if (source.IsDefined(*j)) {
 329                                                         *reinterpret_cast<void **>(iter)
 330                                                                         = GetObject(fd.TypeId(), *j);
 331                                                 } else {
 332                                                         Postpone(iter, *j, fd.TypeId(), false);
 333                                                 }
 334                                         }
 335                                 }
 336                                 std::memcpy(dest, &aggregate, sizeof(char *));
 337                                 dest += sizeof(char *);
 338                                 std::memcpy(dest, &arraySize, sizeof(int));
 339                         } else if (i->second->IsLiteral() && !fd.IsReferenced()) {
 340                                 // inline literals
 341                                 if (i->second->GetLiteral().IsObject()) {
 342                                         ReadObject(fd.TypeId(), -1, dest, *i->second->GetLiteral().GetProperties());
 343                                 } else {
 344                                         ReadLiteral(fd.TypeId(), -1, dest, i->second->GetLiteral());
 345                                 }
 346                         } else {
 347                                 char *src(reinterpret_cast<char *>(GetObject(fd.TypeId(), *i->second)));
 348                                 if (fd.TypeId() == TypeDescription::GetTypeId("Image")) {
 349                                         src = reinterpret_cast<char *>(GetImage(src));
 350                                 }
 351                                 if (fd.IsReferenced()) {
 352                                         std::memcpy(dest, &src, sizeof(char *));
 353                                 } else {
 354                                         std::memcpy(dest, src, fieldType.Size());
 355                                 }
 356                         }
 357                 } else {
 358                         Postpone(object, i->second->GetIdentifier(), fd.TypeId(), !fd.IsReferenced(), fd.IsAggregate());
 359                 }
 360         }
 361         td.Load(object);
 362 }
 363
 364
 365 void Interpreter::ReadScript(const std::vector<ScriptToken *> &s, Script *script) {
 366         std::map<string, int> labels;
 367         int size(0);
 368         for (vector<ScriptToken *>::const_iterator i(s.begin()), end(s.end()); i != end; ++i) {
 369                 if ((*i)->GetType() == ScriptToken::LABEL) {
 370                         if (labels.count((*i)->Label())) {
 371                                 throw Error("duplicate label " + (*i)->Label());
 372                         } else {
 373                                 labels[(*i)->Label()] = size;
 374                         }
 375                 } else if ((*i)->GetType() != ScriptToken::COMMAND) {
 376                         throw Error("unexpected script token");
 377                 }
 378                 size += sizeof(Script::Code);
 379                 const string &cmd((*i)->CommandName());
 380                 if (cmd == "move") {
 381                         ++i;
 382                         if (i == end) {
 383                                 throw Error("unexpected script end after move");
 384                         }
 385                         const string &reg((*i)->RegisterName());
 386                         if (reg.size() != 2) {
 387                                 throw Error("invalid register name " + reg);
 388                         }
 389                         ++i;
 390                         if (i == end) {
 391                                 throw Error("unexpected script end after move");
 392                         }
 393                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 394                                 switch (reg[0]) {
 395                                         case 'a':
 396                                                 size += sizeof(void *);
 397                                                 break;
 398                                         case 'i':
 399                                                 size += sizeof(int);
 400                                                 break;
 401                                         case 'v':
 402                                                 size += sizeof(Vector<int>);
 403                                                 break;
 404                                         default:
 405                                                 throw Error("unknown register " + reg);
 406                                 }
 407                         }
 408                 } else if (cmd == "add") {
 409                         ++i;
 410                         if (i == end) {
 411                                 throw Error("unexpected script end after add");
 412                         }
 413                         const string &reg((*i)->RegisterName());
 414                         if (reg.size() != 2) {
 415                                 throw Error("invalid register name " + reg);
 416                         }
 417                         ++i;
 418                         if (i == end) {
 419                                 throw Error("unexpected script end after add");
 420                         }
 421                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 422                                 switch (reg[0]) {
 423                                         case 'i':
 424                                                 size += sizeof(int);
 425                                                 break;
 426                                         case 'v':
 427                                                 size += sizeof(Vector<int>);
 428                                                 break;
 429                                         default:
 430                                                 throw Error("expected register after add " + reg);
 431                                 }
 432                         }
 433                 } else if (cmd == "mod") {
 434                         ++i;
 435                         if (i == end) {
 436                                 throw Error("unexpected script end after mod");
 437                         }
 438                         ++i;
 439                         if (i == end) {
 440                                 throw Error("unexpected script end after mod");
 441                         }
 442                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 443                                 size += sizeof(int);
 444                         }
 445                 } else if (cmd == "rand") {
 446                         ++i;
 447                         if (i == end) {
 448                                 throw Error("unexpected script end after rand");
 449                         }
 450                 } else if (cmd == "cmp") {
 451                         ++i;
 452                         if (i == end) {
 453                                 throw Error("unexpected script end after cmp");
 454                         }
 455                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 456                                 size += sizeof(int);
 457                         }
 458                         ++i;
 459                         if (i == end) {
 460                                 throw Error("unexpected script end after cmp");
 461                         }
 462                         if ((*i)->GetType() != ScriptToken::REGISTER) {
 463                                 size += sizeof(int);
 464                         }
 465                 } else if (cmd == "jmp") {
 466                         size += sizeof(int);
 467                         ++i;
 468                         if (i == end) {
 469                                 throw Error("unexpected script end after cmp");
 470                         }
 471                 } else if (cmd == "jeq") {
 472                         size += sizeof(int);
 473                         ++i;
 474                         if (i == end) {
 475                                 throw Error("unexpected script end after cmp");
 476                         }
 477                 } else if (cmd == "jne") {
 478                         size += sizeof(int);
 479                         ++i;
 480                         if (i == end) {
 481                                 throw Error("unexpected script end after cmp");
 482                         }
 483                 } else if (cmd == "jl") {
 484                         size += sizeof(int);
 485                         ++i;
 486                         if (i == end) {
 487                                 throw Error("unexpected script end after cmp");
 488                         }
 489                 } else if (cmd == "jle") {
 490                         size += sizeof(int);
 491                         ++i;
 492                         if (i == end) {
 493                                 throw Error("unexpected script end after cmp");
 494                         }
 495                 } else if (cmd == "jg") {
 496                         size += sizeof(int);
 497                         ++i;
 498                         if (i == end) {
 499                                 throw Error("unexpected script end after cmp");
 500                         }
 501                 } else if (cmd == "jge") {
 502                         size += sizeof(int);
 503                         ++i;
 504                         if (i == end) {
 505                                 throw Error("unexpected script end after cmp");
 506                         }
 507                 } else if (cmd == "sysc") {
 508
 509                 } else {
 510                         throw Error("unknown command " + cmd);
 511                 }
 512         }
 513
 514         char *text(alloc.Alloc(size));
 515         int cursor(0);
 516         for (vector<ScriptToken *>::const_iterator i(s.begin()), end(s.end()); i != end; ++i) {
 517                 if ((*i)->GetType() == ScriptToken::LABEL) {
 518                         continue;
 519                 }
 520                 if ((*i)->GetType() != ScriptToken::COMMAND) {
 521                         throw Error("unexpected script token");
 522                 }
 523                 const string &cmd((*i)->CommandName());
 524                 if (cmd == "move") {
 525                         Script::Code &code(CreateScriptCode(Script::COMMAND_MOVE, text + cursor));
 526                         cursor += sizeof(Script::Code);
 527                         code.numParams = 2;
 528                         ++i;
 529                         const string &reg((*i)->RegisterName());
 530                         switch (reg[0]) {
 531                                 case 'a':
 532                                         code.type = Script::TYPE_ADDRESS;
 533                                         break;
 534                                 case 'i':
 535                                         code.type = Script::TYPE_INTEGER;
 536                                         break;
 537                                 case 'v':
 538                                         code.type = Script::TYPE_VECTOR;
 539                                         break;
 540                                 default:
 541                                         throw Error("invalid register " + reg);
 542                         }
 543                         int regnum(reg[1] - '0');
 544                         if (regnum < 0 || regnum > 6) {
 545                                 throw Error("invalid register " + reg);
 546                         }
 547                         code.reg1 = regnum;
 548                         ++i;
 549
 550                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 551                                 string reg2((*i)->RegisterName());
 552                                 if (reg[0] != reg2[0]) {
 553                                         throw Error("mixed-type commands not allowed");
 554                                 }
 555                                 int reg2num(reg[1] - '0');
 556                                 if (reg2num < 0 || reg2num > 6) {
 557                                         throw Error("invalid register " + reg2);
 558                                 }
 559                                 code.reg2 = reg2num;
 560                         } else {
 561                                 code.reg2 = 7;
 562                                 switch (code.type) {
 563                                         case Script::TYPE_ADDRESS:
 564                                                 ReadScriptAddress(**i, text + cursor);
 565                                                 cursor += sizeof(void *);
 566                                                 break;
 567                                         case Script::TYPE_INTEGER:
 568                                                 ReadScriptInteger(**i, text + cursor);
 569                                                 cursor += sizeof(int);
 570                                                 break;
 571                                         case Script::TYPE_VECTOR:
 572                                                 ReadScriptVector(**i, text + cursor);
 573                                                 cursor += sizeof(Vector<int>);
 574                                                 break;
 575                                 }
 576                         }
 577                 } else if (cmd == "add") {
 578                         Script::Code &code(CreateScriptCode(Script::COMMAND_ADD, text + cursor));
 579                         cursor += sizeof(Script::Code);
 580                         code.numParams = 2;
 581                         ++i;
 582                         const string &reg((*i)->RegisterName());
 583                         switch (reg[0]) {
 584                                 case 'i':
 585                                         code.type = Script::TYPE_INTEGER;
 586                                         break;
 587                                 case 'v':
 588                                         code.type = Script::TYPE_VECTOR;
 589                                         break;
 590                                 default:
 591                                         throw Error("invalid register " + reg);
 592                         }
 593                         int regnum(reg[1] - '0');
 594                         if (regnum < 0 || regnum > 6) {
 595                                 throw Error("invalid register " + reg);
 596                         }
 597                         code.reg1 = regnum;
 598                         ++i;
 599
 600                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 601                                 string reg2((*i)->RegisterName());
 602                                 if (reg[0] != reg2[0]) {
 603                                         throw Error("mixed-type commands not allowed");
 604                                 }
 605                                 int reg2num(reg[1] - '0');
 606                                 if (reg2num < 0 || reg2num > 6) {
 607                                         throw Error("invalid register name " + reg2);
 608                                 }
 609                                 code.reg2 = reg2num;
 610                         } else {
 611                                 code.reg2 = 7;
 612                                 switch (code.type) {
 613                                         case Script::TYPE_INTEGER:
 614                                                 ReadScriptInteger(**i, text + cursor);
 615                                                 cursor += sizeof(int);
 616                                                 break;
 617                                         case Script::TYPE_VECTOR:
 618                                                 ReadScriptVector(**i, text + cursor);
 619                                                 cursor += sizeof(Vector<int>);
 620                                                 break;
 621                                 }
 622                         }
 623                 } else if (cmd == "mod") {
 624                         Script::Code &code(CreateScriptCode(Script::COMMAND_MOD, text + cursor));
 625                         cursor += sizeof(Script::Code);
 626                         code.numParams = 2;
 627                         ++i;
 628                         const string &reg((*i)->RegisterName());
 629                         if (reg[0] != 'i') {
 630                                 throw Error("invalid register " + reg);
 631                         }
 632                         code.type = Script::TYPE_INTEGER;
 633                         int regnum(reg[1] - '0');
 634                         if (regnum < 0 || regnum > 6) {
 635                                 throw Error("invalid register " + reg);
 636                         }
 637                         code.reg1 = regnum;
 638                         ++i;
 639
 640                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 641                                 string reg2((*i)->RegisterName());
 642                                 if (reg[0] != reg2[0]) {
 643                                         throw Error("mixed-type commands not allowed");
 644                                 }
 645                                 int reg2num(reg[1] - '0');
 646                                 if (reg2num < 0 || reg2num > 6) {
 647                                         throw Error("invalid register name " + reg2);
 648                                 }
 649                                 code.reg2 = reg2num;
 650                         } else {
 651                                 code.reg2 = 7;
 652                                 ReadScriptInteger(**i, text + cursor);
 653                                 cursor += sizeof(int);
 654                         }
 655                 } else if (cmd == "rand") {
 656                         Script::Code &code(CreateScriptCode(Script::COMMAND_RAND, text + cursor));
 657                         cursor += sizeof(Script::Code);
 658                         code.numParams = 1;
 659                         ++i;
 660                         const string &reg((*i)->RegisterName());
 661                         if (reg[0] != 'i') {
 662                                 throw Error("invalid register " + reg);
 663                         }
 664                         code.type = Script::TYPE_INTEGER;
 665                         int regnum(reg[1] - '0');
 666                         if (regnum < 0 || regnum > 6) {
 667                                 throw Error("invalid register " + reg);
 668                         }
 669                         code.reg1 = regnum;
 670                 } else if (cmd == "cmp") {
 671                         Script::Code &code(CreateScriptCode(Script::COMMAND_CMP, text + cursor));
 672                         cursor += sizeof(Script::Code);
 673                         code.numParams = 2;
 674                         ++i;
 675                         const string &reg((*i)->RegisterName());
 676                         if (reg[0] != 'i') {
 677                                 throw Error("invalid register " + reg);
 678                         }
 679                         code.type = Script::TYPE_INTEGER;
 680                         int regnum(reg[1] - '0');
 681                         if (regnum < 0 || regnum > 6) {
 682                                 throw Error("invalid register " + reg);
 683                         }
 684                         code.reg1 = regnum;
 685                         ++i;
 686
 687                         if ((*i)->GetType() == ScriptToken::REGISTER) {
 688                                 string reg2((*i)->RegisterName());
 689                                 if (reg[0] != reg2[0]) {
 690                                         throw Error("mixed-type commands not allowed");
 691                                 }
 692                                 int reg2num(reg[1] - '0');
 693                                 if (reg2num < 0 || reg2num > 6) {
 694                                         throw Error("invalid register name " + reg2);
 695                                 }
 696                                 code.reg2 = reg2num;
 697                         } else {
 698                                 code.reg2 = 7;
 699                                 ReadScriptInteger(**i, text + cursor);
 700                                 cursor += sizeof(int);
 701                         }
 702                 } else if (cmd == "jmp") {
 703                         Script::Code &code(CreateScriptCode(Script::COMMAND_JMP, 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 == "jeq") {
 713                         Script::Code &code(CreateScriptCode(Script::COMMAND_JEQ, 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 == "jne") {
 723                         Script::Code &code(CreateScriptCode(Script::COMMAND_JNE, 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 == "jl") {
 733                         Script::Code &code(CreateScriptCode(Script::COMMAND_JL, 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 == "jle") {
 743                         Script::Code &code(CreateScriptCode(Script::COMMAND_JLE, 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 == "jg") {
 753                         Script::Code &code(CreateScriptCode(Script::COMMAND_JG, text + cursor));
 754                         cursor += sizeof(Script::Code);
 755                         code.numParams = 1;
 756                         ++i;
 757                         if (!labels.count((*i)->Identifier())) {
 758                                 throw Error("use of undefined label " + (*i)->Identifier());
 759                         }
 760                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 761                         cursor += sizeof(int);
 762                 } else if (cmd == "jge") {
 763                         Script::Code &code(CreateScriptCode(Script::COMMAND_JGE, text + cursor));
 764                         cursor += sizeof(Script::Code);
 765                         code.numParams = 1;
 766                         ++i;
 767                         if (!labels.count((*i)->Identifier())) {
 768                                 throw Error("use of undefined label " + (*i)->Identifier());
 769                         }
 770                         *reinterpret_cast<int *>(text + cursor) = labels[(*i)->Identifier()];
 771                         cursor += sizeof(int);
 772                 } else if (cmd == "sysc") {
 773                         Script::Code &code(CreateScriptCode(Script::COMMAND_SYSC, text + cursor));
 774                         cursor += sizeof(Script::Code);
 775                         code.numParams = 0;
 776                 } else {
 777                         throw Error("unknown command " + cmd);
 778                 }
 779         }
 780
 781         script->text = text;
 782         script->textlen = size;
 783 }
 784
 785 char *Interpreter::ReadScript(const vector<ScriptToken *> &s) {
 786         char *mem(alloc.Alloc(sizeof(Script)));
 787         new (mem) Script;
 788         Script *script(reinterpret_cast<Script *>(mem));
 789         ReadScript(s, script);
 790         return mem;
 791 }
 792
 793 Script::Code &Interpreter::CreateScriptCode(Script::Command c, char *dest) {
 794         Script::Code &code(*reinterpret_cast<Script::Code *>(dest));
 795         code.command = c;
 796         code.numParams = 0;
 797         code.type = Script::TYPE_NONE;
 798         code.reg1 = 7;
 799         code.reg2 = 7;
 800         return code;
 801 }
 802
 803 void Interpreter::ReadScriptAddress(const ScriptToken &t, char *dest) {
 804         if (t.GetType() != ScriptToken::IDENTIFIER) {
 805                 throw Error("expected identifier for address");
 806         }
 807         if (source.IsDefined(t.Identifier())) {
 808                 const ParsedDefinition &def(GetDefinition(t.Identifier()));
 809                 void *addr(GetObject(def.type, t.Identifier()));
 810                 *reinterpret_cast<void **>(dest) = addr;
 811         } else {
 812                 throw Error("postponing values in scripts not implemented");
 813         }
 814 }
 815
 816 void Interpreter::ReadScriptInteger(const ScriptToken &t, char *dest) {
 817         if (t.GetType() == ScriptToken::IDENTIFIER) {
 818                 if (source.IsDefined(t.Identifier())) {
 819                         void *num(GetObject(TypeDescription::GetTypeId("Number"), t.Identifier()));
 820                         *reinterpret_cast<int *>(dest) = *reinterpret_cast<int *>(num);
 821                 } else {
 822                         throw Error("postponing values in scripts not implemented");
 823                 }
 824         } else if (t.GetType() == ScriptToken::LITERAL) {
 825                 *reinterpret_cast<int *>(dest) = t.GetLiteral()->GetNumber();
 826         } else {
 827                 throw Error("expected identifier or integer literal");
 828         }
 829 }
 830
 831 void Interpreter::ReadScriptVector(const ScriptToken &t, char *dest) {
 832         if (t.GetType() == ScriptToken::IDENTIFIER) {
 833                 if (source.IsDefined(t.Identifier())) {
 834                         void *vec(GetObject(TypeDescription::GetTypeId("Vector"), t.Identifier()));
 835                         *reinterpret_cast<Vector<int> *>(dest) = *reinterpret_cast<Vector<int> *>(vec);
 836                 } else {
 837                         throw Error("postponing values in scripts not implemented");
 838                 }
 839         } else if (t.GetType() == ScriptToken::LITERAL) {
 840                 *reinterpret_cast<Vector<int> *>(dest) = Vector<int>(t.GetLiteral()->GetX(), t.GetLiteral()->GetY());
 841         } else {
 842                 throw Error("expected identifier or vector literal");
 843         }
 844 }
 845
 846
 847 SDL_Surface *Interpreter::GetImage(const string &path) {
 848         std::map<string, SDL_Surface *>::const_iterator result(imageCache.find(path));
 849         if (result != imageCache.end()) {
 850                 return result->second;
 851         } else {
 852                 SDL_Surface *image(IMG_Load(path.c_str()));
 853                 imageCache.insert(make_pair(path, image));
 854                 return image;
 855         }
 856 }
 857
 858
 859 bool Interpreter::CanLink(const Value &v) const {
 860         return v.IsLiteral() || source.IsDefined(v.GetIdentifier());
 861 }
 862
 863 void Interpreter::Postpone(
 864                 char *dest,
 865                 const std::string &identifier,
 866                 int type,
 867                 bool inlined,
 868                 bool aggregate) {
 869         char *str(alloc.Alloc(identifier.size() + 1));
 870         std::memcpy(str, identifier.c_str(), identifier.size());
 871         str[identifier.size()] = '\0';
 872         postponedDefinitions.push_back(
 873                         PostponedDefinition(dest, str, type, inlined, aggregate));
 874 }
 875
 876
 877 void Interpreter::CreateTypeDescriptions() {
 878         {
 879                 TypeDescription &td(TypeDescription::Create(BOOLEAN_ID, "Boolean"));
 880                 td.SetDescription("Logical value which can be either true or false.");
 881                 td.SetSize(sizeof(bool));
 882         }
 883         {
 884                 TypeDescription &td(TypeDescription::Create(COLOR_ID, "Color"));
 885                 td.SetDescription(
 886                                 "A color in RGB format with an optional alpha channel.\n"
 887                                 "Components range from 0 to 255.\n"
 888                                 "Alpha defaults to 255 if omitted.");
 889                 td.SetSize(sizeof(Color));
 890         }
 891         {
 892                 TypeDescription &td(TypeDescription::Create(IMAGE_ID, "Image"));
 893                 td.SetDescription("Path to a PNG file with image data.");
 894                 td.SetSize(sizeof(SDL_Surface));
 895         }
 896         {
 897                 TypeDescription &td(TypeDescription::Create(NUMBER_ID, "Number"));
 898                 td.SetDescription("A signed integer.");
 899                 td.SetSize(sizeof(int));
 900         }
 901         {;
 902                 TypeDescription &td(TypeDescription::Create(PATH_ID, "Path"));
 903                 td.SetDescription("A path in the filesystem which is interpreted relative to the source file's location.");
 904                 td.SetSize(1);
 905                 td.AddSupertype(STRING_ID, 0);
 906         }
 907         {
 908                 TypeDescription &td(TypeDescription::Create(SCRIPT_ID, "Script"));
 909                 td.SetDescription("Collection of commands that define a behaviour.");
 910                 td.SetSize(sizeof(Script));
 911         }
 912         {
 913                 TypeDescription &td(TypeDescription::Create(STRING_ID, "String"));
 914                 td.SetDescription("Some characters.");
 915                 td.SetSize(1);
 916         }
 917         {
 918                 TypeDescription &td(TypeDescription::Create(VECTOR_ID, "Vector"));
 919                 td.SetDescription("A pair of numbers usually describing a 2D translation or offset.");
 920                 td.SetSize(sizeof(Vector<int>));
 921         }
 922 }
 923
 924 }