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 4-byte (long) integer which is the number of lumps in the wad

    20  *    (c) a long integer 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 long integer, the file offset to the start of the lump

    27  *    (b) a long integer, 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 UNPKentry *wadLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 fileCount)

    51 {

    52     PHYSFS_uint32 directoryOffset;

    53     UNPKentry *entries = NULL;

    54     UNPKentry *entry = NULL;

    55 

    56     BAIL_IF_MACRO(!__PHYSFS_readAll(io, &directoryOffset, 4), ERRPASS, 0);

    57     directoryOffset = PHYSFS_swapULE32(directoryOffset);

    58 

    59     BAIL_IF_MACRO(!io->seek(io, directoryOffset), ERRPASS, 0);

    60 

    61     entries = (UNPKentry *) allocator.Malloc(sizeof (UNPKentry) * fileCount);

    62     BAIL_IF_MACRO(!entries, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    63 

    64     for (entry = entries; fileCount > 0; fileCount--, entry++)

    65     {

    66         if (!__PHYSFS_readAll(io, &entry->startPos, 4)) goto failed;

    67         if (!__PHYSFS_readAll(io, &entry->size, 4)) goto failed;

    68         if (!__PHYSFS_readAll(io, &entry->name, 8)) goto failed;

    69 

    70         entry->name[8] = '\0'; /* name might not be null-terminated in file. */

    71         entry->size = PHYSFS_swapULE32(entry->size);

    72         entry->startPos = PHYSFS_swapULE32(entry->startPos);

    73     } /* for */

    74 

    75     return entries;

    76 

    77 failed:

    78     allocator.Free(entries);

    79     return NULL;

    80 } /* wadLoadEntries */

    81 

    82 

    83 static void *WAD_openArchive(PHYSFS_Io *io, const char *name, int forWriting)

    84 {

    85     PHYSFS_uint8 buf[4];

    86     UNPKentry *entries = NULL;

    87     PHYSFS_uint32 count = 0;

    88 

    89     assert(io != NULL);  /* shouldn't ever happen. */

    90 

    91     BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);

    92     BAIL_IF_MACRO(!__PHYSFS_readAll(io, buf, sizeof (buf)), ERRPASS, NULL);

    93     if ((memcmp(buf, "IWAD", 4) != 0) && (memcmp(buf, "PWAD", 4) != 0))

    94         BAIL_MACRO(PHYSFS_ERR_UNSUPPORTED, NULL);

    95 

    96     BAIL_IF_MACRO(!__PHYSFS_readAll(io, &count, sizeof (count)), ERRPASS, NULL);

    97     count = PHYSFS_swapULE32(count);

    98 

    99     entries = wadLoadEntries(io, count);

   100     BAIL_IF_MACRO(!entries, ERRPASS, NULL);

   101     return UNPK_openArchive(io, entries, count);

   102 } /* WAD_openArchive */

   103 

   104 

   105 const PHYSFS_Archiver __PHYSFS_Archiver_WAD =

   106 {

   107     CURRENT_PHYSFS_ARCHIVER_API_VERSION,

   108     {

   109         "WAD",

   110         "DOOM engine format",

   111         "Travis Wells <traviswells@mchsi.com>",

   112         "http://www.3dmm2.com/doom/",

   113         0,  /* supportsSymlinks */

   114     },

   115     WAD_openArchive,

   116     UNPK_enumerateFiles,

   117     UNPK_openRead,

   118     UNPK_openWrite,

   119     UNPK_openAppend,

   120     UNPK_remove,

   121     UNPK_mkdir,

   122     UNPK_stat,

   123     UNPK_closeArchive

   124 };

   125 

   126 #endif  /* defined PHYSFS_SUPPORTS_WAD */

   127 

   128 /* end of archiver_wad.c ... */

   129