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
50static 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
73static 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, 0, 1);
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
111const 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