extras/physfs_rb/physfs/physfsrwops.c
changeset 514 f4e89d934fee
child 654 c0ae01de361d
child 766 3970811e14f4
equal deleted inserted replaced
513:bd18a574bda5 514:f4e89d934fee
       
     1 /*
       
     2  * This code provides a glue layer between PhysicsFS and Simple Directmedia
       
     3  *  Layer's (SDL) RWops i/o abstraction.
       
     4  *
       
     5  * License: this code is public domain. I make no warranty that it is useful,
       
     6  *  correct, harmless, or environmentally safe.
       
     7  *
       
     8  * This particular file may be used however you like, including copying it
       
     9  *  verbatim into a closed-source project, exploiting it commercially, and
       
    10  *  removing any trace of my name from the source (although I hope you won't
       
    11  *  do that). I welcome enhancements and corrections to this file, but I do
       
    12  *  not require you to send me patches if you make changes.
       
    13  *
       
    14  * Unless otherwise stated, the rest of PhysicsFS falls under the GNU Lesser
       
    15  *  General Public License: http://www.gnu.org/licenses/lgpl.txt
       
    16  *
       
    17  * SDL falls under the LGPL, too. You can get SDL at http://www.libsdl.org/
       
    18  *
       
    19  *  This file was written by Ryan C. Gordon. (icculus@clutteredmind.org).
       
    20  */
       
    21 
       
    22 #include <stdio.h>  /* used for SEEK_SET, SEEK_CUR, SEEK_END ... */
       
    23 #include "physfsrwops.h"
       
    24 
       
    25 static int physfsrwops_seek(SDL_RWops *rw, int offset, int whence)
       
    26 {
       
    27     PHYSFS_file *handle = (PHYSFS_file *) rw->hidden.unknown.data1;
       
    28     int pos = 0;
       
    29 
       
    30     if (whence == SEEK_SET)
       
    31     {
       
    32         pos = offset;
       
    33     } /* if */
       
    34 
       
    35     else if (whence == SEEK_CUR)
       
    36     {
       
    37         PHYSFS_sint64 current = PHYSFS_tell(handle);
       
    38         if (current == -1)
       
    39         {
       
    40             SDL_SetError("Can't find position in file: %s",
       
    41                           PHYSFS_getLastError());
       
    42             return(-1);
       
    43         } /* if */
       
    44 
       
    45         pos = (int) current;
       
    46         if ( ((PHYSFS_sint64) pos) != current )
       
    47         {
       
    48             SDL_SetError("Can't fit current file position in an int!");
       
    49             return(-1);
       
    50         } /* if */
       
    51 
       
    52         if (offset == 0)  /* this is a "tell" call. We're done. */
       
    53             return(pos);
       
    54 
       
    55         pos += offset;
       
    56     } /* else if */
       
    57 
       
    58     else if (whence == SEEK_END)
       
    59     {
       
    60         PHYSFS_sint64 len = PHYSFS_fileLength(handle);
       
    61         if (len == -1)
       
    62         {
       
    63             SDL_SetError("Can't find end of file: %s", PHYSFS_getLastError());
       
    64             return(-1);
       
    65         } /* if */
       
    66 
       
    67         pos = (int) len;
       
    68         if ( ((PHYSFS_sint64) pos) != len )
       
    69         {
       
    70             SDL_SetError("Can't fit end-of-file position in an int!");
       
    71             return(-1);
       
    72         } /* if */
       
    73 
       
    74         pos += offset;
       
    75     } /* else if */
       
    76 
       
    77     else
       
    78     {
       
    79         SDL_SetError("Invalid 'whence' parameter.");
       
    80         return(-1);
       
    81     } /* else */
       
    82 
       
    83     if ( pos < 0 )
       
    84     {
       
    85         SDL_SetError("Attempt to seek past start of file.");
       
    86         return(-1);
       
    87     } /* if */
       
    88     
       
    89     if (!PHYSFS_seek(handle, (PHYSFS_uint64) pos))
       
    90     {
       
    91         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());
       
    92         return(-1);
       
    93     } /* if */
       
    94 
       
    95     return(pos);
       
    96 } /* physfsrwops_seek */
       
    97 
       
    98 
       
    99 static int physfsrwops_read(SDL_RWops *rw, void *ptr, int size, int maxnum)
       
   100 {
       
   101     PHYSFS_file *handle = (PHYSFS_file *) rw->hidden.unknown.data1;
       
   102     PHYSFS_sint64 rc = PHYSFS_read(handle, ptr, size, maxnum);
       
   103     if (rc != maxnum)
       
   104     {
       
   105         if (!PHYSFS_eof(handle)) /* not EOF? Must be an error. */
       
   106             SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());
       
   107     } /* if */
       
   108 
       
   109     return((int) rc);
       
   110 } /* physfsrwops_read */
       
   111 
       
   112 
       
   113 static int physfsrwops_write(SDL_RWops *rw, const void *ptr, int size, int num)
       
   114 {
       
   115     PHYSFS_file *handle = (PHYSFS_file *) rw->hidden.unknown.data1;
       
   116     PHYSFS_sint64 rc = PHYSFS_write(handle, ptr, size, num);
       
   117     if (rc != num)
       
   118         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());
       
   119 
       
   120     return((int) rc);
       
   121 } /* physfsrwops_write */
       
   122 
       
   123 
       
   124 static int physfsrwops_close(SDL_RWops *rw)
       
   125 {
       
   126     PHYSFS_file *handle = (PHYSFS_file *) rw->hidden.unknown.data1;
       
   127     if (!PHYSFS_close(handle))
       
   128     {
       
   129         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());
       
   130         return(-1);
       
   131     } /* if */
       
   132 
       
   133     SDL_FreeRW(rw);
       
   134     return(0);
       
   135 } /* physfsrwops_close */
       
   136 
       
   137 
       
   138 static SDL_RWops *create_rwops(PHYSFS_file *handle)
       
   139 {
       
   140     SDL_RWops *retval = NULL;
       
   141 
       
   142     if (handle == NULL)
       
   143         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());
       
   144     else
       
   145     {
       
   146         retval = SDL_AllocRW();
       
   147         if (retval != NULL)
       
   148         {
       
   149             retval->seek  = physfsrwops_seek;
       
   150             retval->read  = physfsrwops_read;
       
   151             retval->write = physfsrwops_write;
       
   152             retval->close = physfsrwops_close;
       
   153             retval->hidden.unknown.data1 = handle;
       
   154         } /* if */
       
   155     } /* else */
       
   156 
       
   157     return(retval);
       
   158 } /* create_rwops */
       
   159 
       
   160 
       
   161 SDL_RWops *PHYSFSRWOPS_makeRWops(PHYSFS_file *handle)
       
   162 {
       
   163     SDL_RWops *retval = NULL;
       
   164     if (handle == NULL)
       
   165         SDL_SetError("NULL pointer passed to PHYSFSRWOPS_makeRWops().");
       
   166     else
       
   167         retval = create_rwops(handle);
       
   168 
       
   169     return(retval);
       
   170 } /* PHYSFSRWOPS_makeRWops */
       
   171 
       
   172 
       
   173 SDL_RWops *PHYSFSRWOPS_openRead(const char *fname)
       
   174 {
       
   175     return(create_rwops(PHYSFS_openRead(fname)));
       
   176 } /* PHYSFSRWOPS_openRead */
       
   177 
       
   178 
       
   179 SDL_RWops *PHYSFSRWOPS_openWrite(const char *fname)
       
   180 {
       
   181     return(create_rwops(PHYSFS_openWrite(fname)));
       
   182 } /* PHYSFSRWOPS_openWrite */
       
   183 
       
   184 
       
   185 SDL_RWops *PHYSFSRWOPS_openAppend(const char *fname)
       
   186 {
       
   187     return(create_rwops(PHYSFS_openAppend(fname)));
       
   188 } /* PHYSFSRWOPS_openAppend */
       
   189 
       
   190 
       
   191 /* end of physfsrwops.c ... */
       
   192