RoomFile.c

   1 #include "RoomFile.h"
   2 #include <stdlib.h>
   3
   4 ssize_t ARF_find_code_start(AF* f, size_t start) {
   5         if(!AF_set_pos(f, start)) return -1;
   6         char buf[4];
   7         unsigned match = 0;
   8         while(1) {
   9                 if(AF_read(f, buf, 1) != 1) break;;
  10                 switch(match) {
  11                         case 0:
  12                                 if(*buf == 'S') match++;
  13                                 else match = 0;
  14                                 break;
  15                         case 1:
  16                                 if(*buf == 'C') match++;
  17                                 else match = 0;
  18                                 break;
  19                         case 2:
  20                                 if(*buf == 'O') match++;
  21                                 else match = 0;
  22                                 break;
  23                         case 3:
  24                                 if(*buf == 'M') return AF_get_pos(f) - 4;
  25                                 else match = 0;
  26                                 break;
  27                         default:
  28                                 assert(0);
  29                 }
  30         }
  31         return -1;
  32 }
  33
  34 static void roomfile_decrypt_text(char *s, int len) {
  35         unsigned i = 0;
  36         while (i < len) {
  37                 *s += "Avis Durgan"[i % 11];
  38                 if (!*s) break;
  39                 ++i; ++s;
  40         }
  41 }
  42
  43 char *RoomFile_extract_source(AF *f, struct RoomFile *r, size_t *sizep) {
  44         *sizep = 0;
  45         off_t pos = r->blockpos[BLOCKTYPE_SCRIPT];
  46         if(!pos || !AF_set_pos(f, pos)) return 0;
  47         int scriptlen = AF_read_int(f);
  48         assert(r->blocklen[BLOCKTYPE_SCRIPT] == scriptlen + 4);
  49         char* out = malloc(scriptlen+1);
  50         if(!out) return out;
  51         if((size_t) -1 == AF_read(f, out, scriptlen)) {
  52                 free(out);
  53                 return 0;
  54         }
  55         *sizep = scriptlen;
  56         roomfile_decrypt_text(out, scriptlen);
  57         out[scriptlen] = 0;
  58         return out;
  59 }
  60
  61
  62 int RoomFile_read(AF *f, struct RoomFile *r) {
  63         if(!AF_set_pos(f, 0)) return 0;
  64         r->version = AF_read_short(f);
  65         while(1) {
  66                 unsigned char blocktype;
  67                 if((size_t) -1 == AF_read(f, &blocktype, 1)) return 0;
  68                 if(blocktype == BLOCKTYPE_EOF) break;
  69                 if(blocktype < BLOCKTYPE_MIN || blocktype > BLOCKTYPE_MAX) return 0;
  70                 int blocklen = AF_read_int(f);
  71                 off_t curr_pos = AF_get_pos(f), next_block = curr_pos + blocklen;
  72                 r->blockpos[blocktype] = curr_pos;
  73                 r->blocklen[blocktype] = blocklen;
  74                 switch(blocktype) {
  75                         case BLOCKTYPE_COMPSCRIPT3:
  76                                 {
  77                                         char sig[4];
  78                                         AF_read(f, sig, 4);
  79                                         assert(!memcmp(sig, "SCOM", 4));
  80                                 }
  81                                 break;
  82                         /* the older script types weren't supported by the released AGS sources ever */
  83                         default:
  84                                 break;
  85                 }
  86                 if(!AF_set_pos(f, next_block)) return 0;
  87         }
  88         return 1;
  89 }