source/libs/zziplib/zziplib-0.13.62/SDL/SDL_rwops_zzip.c

   1 /*
   2  *      Copyright (c) 2001 Guido Draheim <guidod@gmx.de>
   3  *      Use freely under the restrictions of the ZLIB License
   4  *
   5  *      (this example uses errno which might not be multithreaded everywhere)
   6  */
   7
   8 #include <SDL_rwops_zzip.h>
   9 #include <zzip/zzip.h>
  10 #include <string.h> /* strchr */
  11
  12 /* MSVC can not take a casted variable as an lvalue ! */
  13 #define SDL_RWOPS_ZZIP_DATA(_context) \
  14              ((_context)->hidden.unknown.data1)
  15 #define SDL_RWOPS_ZZIP_FILE(_context)  (ZZIP_FILE*) \
  16              ((_context)->hidden.unknown.data1)
  17
  18 static int _zzip_seek(SDL_RWops *context, int offset, int whence)
  19 {
  20     return zzip_seek(SDL_RWOPS_ZZIP_FILE(context), offset, whence);
  21 }
  22
  23 static int _zzip_read(SDL_RWops *context, void *ptr, int size, int maxnum)
  24 {
  25     return zzip_read(SDL_RWOPS_ZZIP_FILE(context), ptr, size*maxnum) / size;
  26 }
  27
  28 static int _zzip_write(SDL_RWops *context, const void *ptr, int size, int num)
  29 {
  30     return 0; /* ignored */
  31 }
  32
  33 static int _zzip_close(SDL_RWops *context)
  34 {
  35     if (! context) return 0; /* may be SDL_RWclose is called by atexit */
  36
  37     zzip_close (SDL_RWOPS_ZZIP_FILE(context));
  38     SDL_FreeRW (context);
  39     return 0;
  40 }
  41
  42 SDL_RWops *SDL_RWFromZZIP(const char* file, const char* mode)
  43 {
  44     register SDL_RWops* rwops;
  45     register ZZIP_FILE* zzip_file;
  46
  47     if (! strchr (mode, 'r'))
  48         return SDL_RWFromFile(file, mode);
  49
  50     zzip_file = zzip_fopen (file, mode);
  51     if (! zzip_file) return 0;
  52
  53     rwops = SDL_AllocRW ();
  54     if (! rwops) { errno=ENOMEM; zzip_close (zzip_file); return 0; }
  55
  56     SDL_RWOPS_ZZIP_DATA(rwops) = zzip_file;
  57     rwops->read = _zzip_read;
  58     rwops->write = _zzip_write;
  59     rwops->seek = _zzip_seek;
  60     rwops->close = _zzip_close;
  61     return rwops;
  62 }