hog: Added support for HOG2 (Descent 3) archives.

icculus · Jun 8, 2019 · a8180f0 · a8180f0
1 parent 9cb45dc
commit a8180f0
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Showing 2 changed files with 67 additions and 11 deletions.
diff --git a/src/physfs.h b/src/physfs.h
@@ -145,7 +145,7 @@
  *   - .ISO (ISO9660 files, CD-ROM images)
  *   - .GRP (Build Engine groupfile archives)
  *   - .PAK (Quake I/II archive format)
- *   - .HOG (Descent I/II HOG file archives)
+ *   - .HOG (Descent I/II/III HOG file archives)
  *   - .MVL (Descent II movielib archives)
  *   - .WAD (DOOM engine archives)
  *   - .VDF (Gothic I/II engine archives)

diff --git a/src/physfs_archiver_hog.c b/src/physfs_archiver_hog.c
@@ -1,9 +1,9 @@
 /*
  * HOG support routines for PhysicsFS.
  *
- * This driver handles Descent I/II HOG archives.
+ * This driver handles Descent I/II/III HOG archives.
  *
- * The format is very simple:
+ * The Descent I/II format is very simple:
  *
  *   The file always starts with the 3-byte signature "DHF" (Descent
  *   HOG file). After that the files of a HOG are just attached after
@@ -23,18 +23,39 @@
  *
  * (That info is from http://www.descent2.com/ddn/specs/hog/)
  *
+ * Descent 3 moved to HOG2 format, which starts with the chars "HOG2",
+ *  then 32-bits for the number of contained files, 32 bits for the offset
+ *  to the first file's data, then 56 bytes of 0xFF (reserved?). Then for
+ *  each file, there's 36 bytes for filename (null-terminated, rest of bytes
+ *  are garbage), 32-bits unknown/reserved (always zero?), 32-bits of length
+ *  of file data, 32-bits of time since Unix epoch. Then immediately following,
+ *  for each file is their uncompressed content, you can find its offset
+ *  by starting at the initial data offset and adding the filesize of each
+ *  prior file.
+ *
+ * This information was found at:
+ *  https://web.archive.org/web/20020213004051/http://descent-3.com/ddn/specs/hog/
+ *
+ *
  * Please see the file LICENSE.txt in the source's root directory.
  *
- *  This file written by Bradley Bell.
- *  Based on grp.c by Ryan C. Gordon.
+ * This file written by Bradley Bell and Ryan C. Gordon.
  */
 
 #define __PHYSICSFS_INTERNAL__
 #include "physfs_internal.h"
 
 #if PHYSFS_SUPPORTS_HOG
 
-static int hogLoadEntries(PHYSFS_Io *io, void *arc)
+static int readui32(PHYSFS_Io *io, PHYSFS_uint32 *val)
+{
+    PHYSFS_uint32 v;
+    BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &v, sizeof (v)), 0);
+    *val = PHYSFS_swapULE32(v);
+    return 1;
+} /* readui32 */
+
+static int hog1LoadEntries(PHYSFS_Io *io, void *arc)
 {
     const PHYSFS_uint64 iolen = io->length(io);
     PHYSFS_uint32 pos = 3;
@@ -45,11 +66,10 @@ static int hogLoadEntries(PHYSFS_Io *io, void *arc)
         char name[13];
 
         BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, name, 13), 0);
-        BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &size, 4), 0);
+        BAIL_IF_ERRPASS(!readui32(io, &size), 0);
         name[12] = '\0';  /* just in case. */
         pos += 13 + 4;
 
-        size = PHYSFS_swapULE32(size);
         BAIL_IF_ERRPASS(!UNPK_addEntry(arc, name, 0, -1, -1, pos, size), 0);
         pos += size;
 
@@ -60,24 +80,60 @@ static int hogLoadEntries(PHYSFS_Io *io, void *arc)
     return 1;
 } /* hogLoadEntries */
 
+static int hog2LoadEntries(PHYSFS_Io *io, void *arc)
+{
+    PHYSFS_uint32 numfiles;
+    PHYSFS_uint32 pos;
+    PHYSFS_uint32 i;
+
+    BAIL_IF_ERRPASS(!readui32(io, &numfiles), 0);
+    BAIL_IF_ERRPASS(!readui32(io, &pos), 0);
+    BAIL_IF_ERRPASS(!io->seek(io, 68), 0);  /* skip to end of header. */
+
+    for (i = 0; i < numfiles; i++) {
+        char name[37];
+        PHYSFS_uint32 reserved;
+        PHYSFS_uint32 size;
+        PHYSFS_uint32 mtime;
+        BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, name, 36), 0);
+        BAIL_IF_ERRPASS(!readui32(io, &reserved), 0);
+        BAIL_IF_ERRPASS(!readui32(io, &size), 0);
+        BAIL_IF_ERRPASS(!readui32(io, &mtime), 0);
+        name[36] = '\0';  /* just in case */
+        BAIL_IF_ERRPASS(!UNPK_addEntry(arc, name, 0, mtime, mtime, pos, size), 0);
+        pos += size;
+    }
+
+    return 1;
+} /* hogLoadEntries */
+
 
 static void *HOG_openArchive(PHYSFS_Io *io, const char *name,
                              int forWriting, int *claimed)
 {
     PHYSFS_uint8 buf[3];
     void *unpkarc = NULL;
+    int hog1 = 0;
 
     assert(io != NULL);  /* shouldn't ever happen. */
     BAIL_IF(forWriting, PHYSFS_ERR_READ_ONLY, NULL);
     BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, buf, 3), NULL);
-    BAIL_IF(memcmp(buf, "DHF", 3) != 0, PHYSFS_ERR_UNSUPPORTED, NULL);
+
+    if (memcmp(buf, "DHF", 3) == 0)
+        hog1 = 1;  /* original HOG (Descent 1 and 2) archive */
+    else
+    {
+        BAIL_IF(memcmp(buf, "HOG", 3) != 0, PHYSFS_ERR_UNSUPPORTED, NULL); /* Not HOG2 */
+        BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, buf, 1), NULL);
+        BAIL_IF(buf[0] != '2', PHYSFS_ERR_UNSUPPORTED, NULL); /* Not HOG2 */
+    } /* else */
 
     *claimed = 1;
 
     unpkarc = UNPK_openArchive(io);
     BAIL_IF_ERRPASS(!unpkarc, NULL);
 
-    if (!hogLoadEntries(io, unpkarc))
+    if (!(hog1 ? hog1LoadEntries(io, unpkarc) : hog2LoadEntries(io, unpkarc)))
     {
         UNPK_abandonArchive(unpkarc);
         return NULL;
@@ -92,7 +148,7 @@ const PHYSFS_Archiver __PHYSFS_Archiver_HOG =
     CURRENT_PHYSFS_ARCHIVER_API_VERSION,
     {
         "HOG",
-        "Descent I/II HOG file format",
+        "Descent I/II/III HOG file format",
         "Bradley Bell <btb@icculus.org>",
         "https://icculus.org/physfs/",
         0,  /* supportsSymlinks */