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  1. /*
  2.  * WAD support routines for PhysicsFS.
  3.  *
  4.  * This driver handles DOOM engine archives ("wads").
  5.  * This format (but not this driver) was designed by id Software for use
  6.  *  with the DOOM engine.
  7.  * The specs of the format are from the unofficial doom specs v1.666
  8.  * found here: http://www.gamers.org/dhs/helpdocs/dmsp1666.html
  9.  * The format of the archive: (from the specs)
  10.  *
  11.  *  A WAD file has three parts:
  12.  *  (1) a twelve-byte header
  13.  *  (2) one or more "lumps"
  14.  *  (3) a directory or "info table" that contains the names, offsets, and
  15.  *      sizes of all the lumps in the WAD
  16.  *
  17.  *  The header consists of three four-byte parts:
  18.  *    (a) an ASCII string which must be either "IWAD" or "PWAD"
  19.  *    (b) a uint32 which is the number of lumps in the wad
  20.  *    (c) a uint32 which is the file offset to the start of
  21.  *    the directory
  22.  *
  23.  *  The directory has one 16-byte entry for every lump. Each entry consists
  24.  *  of three parts:
  25.  *
  26.  *    (a) a uint32, the file offset to the start of the lump
  27.  *    (b) a uint32, the size of the lump in bytes
  28.  *    (c) an 8-byte ASCII string, the name of the lump, padded with zeros.
  29.  *        For example, the "DEMO1" entry in hexadecimal would be
  30.  *        (44 45 4D 4F 31 00 00 00)
  31.  *
  32.  * Note that there is no way to tell if an opened WAD archive is a
  33.  *  IWAD or PWAD with this archiver.
  34.  * I couldn't think of a way to provide that information, without being too
  35.  *  hacky.
  36.  * I don't think it's really that important though.
  37.  *
  38.  *
  39.  * Please see the file LICENSE.txt in the source's root directory.
  40.  *
  41.  * This file written by Travis Wells, based on the GRP archiver by
  42.  *  Ryan C. Gordon.
  43.  */
  44.  
  45. #define __PHYSICSFS_INTERNAL__
  46. #include "physfs_internal.h"
  47.  
  48. #if PHYSFS_SUPPORTS_WAD
  49.  
  50. static int wadLoadEntries(PHYSFS_Io *io, const PHYSFS_uint32 count, void *arc)
  51. {
  52.     PHYSFS_uint32 i;
  53.     for (i = 0; i < count; i++)
  54.     {
  55.         PHYSFS_uint32 pos;
  56.         PHYSFS_uint32 size;
  57.         char name[9];
  58.  
  59.         BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &pos, 4), 0);
  60.         BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &size, 4), 0);
  61.         BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, name, 8), 0);
  62.  
  63.         name[8] = '\0'; /* name might not be null-terminated in file. */
  64.         size = PHYSFS_swapULE32(size);
  65.         pos = PHYSFS_swapULE32(pos);
  66.         BAIL_IF_ERRPASS(!UNPK_addEntry(arc, name, 0, -1, -1, pos, size), 0);
  67.     } /* for */
  68.  
  69.     return 1;
  70. } /* wadLoadEntries */
  71.  
  72.  
  73. static void *WAD_openArchive(PHYSFS_Io *io, const char *name,
  74.                              int forWriting, int *claimed)
  75. {
  76.     PHYSFS_uint8 buf[4];
  77.     PHYSFS_uint32 count;
  78.     PHYSFS_uint32 directoryOffset;
  79.     void *unpkarc;
  80.  
  81.     assert(io != NULL);  /* shouldn't ever happen. */
  82.  
  83.     BAIL_IF(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
  84.     BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, buf, sizeof (buf)), NULL);
  85.     if ((memcmp(buf, "IWAD", 4) != 0) && (memcmp(buf, "PWAD", 4) != 0))
  86.         BAIL(PHYSFS_ERR_UNSUPPORTED, NULL);
  87.  
  88.     *claimed = 1;
  89.  
  90.     BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &count, sizeof (count)), NULL);
  91.     count = PHYSFS_swapULE32(count);
  92.  
  93.     BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &directoryOffset, 4), 0);
  94.     directoryOffset = PHYSFS_swapULE32(directoryOffset);
  95.  
  96.     BAIL_IF_ERRPASS(!io->seek(io, directoryOffset), 0);
  97.  
  98.     unpkarc = UNPK_openArchive(io);
  99.     BAIL_IF_ERRPASS(!unpkarc, NULL);
  100.  
  101.     if (!wadLoadEntries(io, count, unpkarc))
  102.     {
  103.         UNPK_abandonArchive(unpkarc);
  104.         return NULL;
  105.     } /* if */
  106.  
  107.     return unpkarc;
  108. } /* WAD_openArchive */
  109.  
  110.  
  111. const PHYSFS_Archiver __PHYSFS_Archiver_WAD =
  112. {
  113.     CURRENT_PHYSFS_ARCHIVER_API_VERSION,
  114.     {
  115.         "WAD",
  116.         "DOOM engine format",
  117.         "Travis Wells <traviswells@mchsi.com>",
  118.         "http://www.3dmm2.com/doom/",
  119.         0,  /* supportsSymlinks */
  120.     },
  121.     WAD_openArchive,
  122.     UNPK_enumerate,
  123.     UNPK_openRead,
  124.     UNPK_openWrite,
  125.     UNPK_openAppend,
  126.     UNPK_remove,
  127.     UNPK_mkdir,
  128.     UNPK_stat,
  129.     UNPK_closeArchive
  130. };
  131.  
  132. #endif  /* defined PHYSFS_SUPPORTS_WAD */
  133.  
  134. /* end of physfs_archiver_wad.c ... */
  135.  
  136.