text: /*
   * WAD support routines for PhysicsFS.
   *
   * This driver handles DOOM engine archives ("wads"). 
   * This format (but not this driver) was designed by id Software for use
   *  with the DOOM engine.
   * The specs of the format are from the unofficial doom specs v1.666
   * found here: http://www.gamers.org/dhs/helpdocs/dmsp1666.html
   * The format of the archive: (from the specs)
   *
   *  A WAD file has three parts:
   *  (1) a twelve-byte header
   *  (2) one or more "lumps"
   *  (3) a directory or "info table" that contains the names, offsets, and
   *      sizes of all the lumps in the WAD
   *
   *  The header consists of three four-byte parts:
   *    (a) an ASCII string which must be either "IWAD" or "PWAD"
   *    (b) a uint32 which is the number of lumps in the wad
   *    (c) a uint32 which is the file offset to the start of
   *    the directory
   *
   *  The directory has one 16-byte entry for every lump. Each entry consists
   *  of three parts:
   *
   *    (a) a uint32, the file offset to the start of the lump
   *    (b) a uint32, the size of the lump in bytes
   *    (c) an 8-byte ASCII string, the name of the lump, padded with zeros.
   *        For example, the "DEMO1" entry in hexadecimal would be
   *        (44 45 4D 4F 31 00 00 00)
   * 
   * Note that there is no way to tell if an opened WAD archive is a
   *  IWAD or PWAD with this archiver.
   * I couldn't think of a way to provide that information, without being too
   *  hacky.
   * I don't think it's really that important though.
   *
   *
   * Please see the file LICENSE.txt in the source's root directory.
   *
   * This file written by Travis Wells, based on the GRP archiver by
   *  Ryan C. Gordon.
   */
  
  #define __PHYSICSFS_INTERNAL__
  #include "physfs_internal.h"
  
  #if PHYSFS_SUPPORTS_WAD
  
  static int wadLoadEntries(PHYSFS_Io *io, const PHYSFS_uint32 count, void *arc)
  {
      PHYSFS_uint32 i;
      for (i = 0; i < count; i++)
      {
          PHYSFS_uint32 pos;
          PHYSFS_uint32 size;
          char name[9];
  
          BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &pos, 4), 0);
          BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &size, 4), 0);
          BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, name, 8), 0);
  
          name[8] = '\0'; /* name might not be null-terminated in file. */
          size = PHYSFS_swapULE32(size);
          pos = PHYSFS_swapULE32(pos);
          BAIL_IF_ERRPASS(!UNPK_addEntry(arc, name, 0, -1, -1, pos, size), 0);
      } /* for */
  
      return 1;
  } /* wadLoadEntries */
  
  #pragma clang diagnostic push
  #pragma clang diagnostic ignored "-Wunused-parameter"
  static void *WAD_openArchive(PHYSFS_Io *io, const char *name,
                               int forWriting, int *claimed)
  {
      PHYSFS_uint8 buf[4];
      PHYSFS_uint32 count;
      PHYSFS_uint32 directoryOffset;
      void *unpkarc;
  
      assert(io != NULL);  /* shouldn't ever happen. */
  
      BAIL_IF(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
      BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, buf, sizeof (buf)), NULL);
      if ((memcmp(buf, "IWAD", 4) != 0) && (memcmp(buf, "PWAD", 4) != 0))
          BAIL(PHYSFS_ERR_UNSUPPORTED, NULL);
  
      *claimed = 1;
  
      BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &count, sizeof (count)), NULL);
      count = PHYSFS_swapULE32(count);
  
      BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &directoryOffset, 4), 0);
      directoryOffset = PHYSFS_swapULE32(directoryOffset);
  
      BAIL_IF_ERRPASS(!io->seek(io, directoryOffset), 0);
  
      unpkarc = UNPK_openArchive(io);
      BAIL_IF_ERRPASS(!unpkarc, NULL);
  
      if (!wadLoadEntries(io, count, unpkarc))
      {
          UNPK_abandonArchive(unpkarc);
          return NULL;
      } /* if */
  
      return unpkarc;
  } /* WAD_openArchive */
  #pragma clang diagnostic pop
  
  const PHYSFS_Archiver __PHYSFS_Archiver_WAD =
  {
      CURRENT_PHYSFS_ARCHIVER_API_VERSION,
      {
          "WAD",
          "DOOM engine format",
          "Travis Wells <traviswells@mchsi.com>",
          "http://www.3dmm2.com/doom/",
          0,  /* supportsSymlinks */
      },
      WAD_openArchive,
      UNPK_enumerate,
      UNPK_openRead,
      UNPK_openWrite,
      UNPK_openAppend,
      UNPK_remove,
      UNPK_mkdir,
      UNPK_stat,
      UNPK_closeArchive
  };
  
  #endif  /* defined PHYSFS_SUPPORTS_WAD */
  
  /* end of physfs_archiver_wad.c ... */
  
  