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. This code has

    13  *  NO WARRANTY.

    14  *

    15  * Unless otherwise stated, the rest of PhysicsFS falls under the zlib license.

    16  *  Please see LICENSE.txt in the root of the source tree.

    17  *

    18  * SDL 1.2 falls under the LGPL license. SDL 1.3+ is zlib, like PhysicsFS.

    19  *  You can get SDL at http://www.libsdl.org/

    20  *

    21  *  This file was written by Ryan C. Gordon. (icculus@icculus.org).

    22  */

    23 

    24 #include <stdio.h>  /* used for SEEK_SET, SEEK_CUR, SEEK_END ... */

    25 #include "physfsrwops.h"

    26 

    27 /* SDL's RWOPS interface changed a little in SDL 1.3... */

    28 #if defined(SDL_VERSION_ATLEAST)

    29 #if SDL_VERSION_ATLEAST(1, 3, 0)

    30 #define TARGET_SDL13 1

    31 #endif

    32 #endif

    33 

    34 #if TARGET_SDL13

    35 static long SDLCALL physfsrwops_seek(struct SDL_RWops *rw, long offset, int whence)

    36 #else

    37 static int physfsrwops_seek(SDL_RWops *rw, int offset, int whence)

    38 #endif

    39 {

    40     PHYSFS_File *handle = (PHYSFS_File *) rw->hidden.unknown.data1;

    41     PHYSFS_sint64 pos = 0;

    42 

    43     if (whence == SEEK_SET)

    44         pos = (PHYSFS_sint64) offset;

    45 

    46     else if (whence == SEEK_CUR)

    47     {

    48         const PHYSFS_sint64 current = PHYSFS_tell(handle);

    49         if (current == -1)

    50         {

    51             SDL_SetError("Can't find position in file: %s",

    52                           PHYSFS_getLastError());

    53             return -1;

    54         } /* if */

    55 

    56         if (offset == 0)  /* this is a "tell" call. We're done. */

    57         {

    58             #if TARGET_SDL13

    59             return (long) current;

    60             #else

    61             return (int) current;

    62             #endif

    63         } /* if */

    64 

    65         pos = current + ((PHYSFS_sint64) offset);

    66     } /* else if */

    67 

    68     else if (whence == SEEK_END)

    69     {

    70         const PHYSFS_sint64 len = PHYSFS_fileLength(handle);

    71         if (len == -1)

    72         {

    73             SDL_SetError("Can't find end of file: %s", PHYSFS_getLastError());

    74             return -1;

    75         } /* if */

    76 

    77         pos = len + ((PHYSFS_sint64) offset);

    78     } /* else if */

    79 

    80     else

    81     {

    82         SDL_SetError("Invalid 'whence' parameter.");

    83         return -1;

    84     } /* else */

    85 

    86     if ( pos < 0 )

    87     {

    88         SDL_SetError("Attempt to seek past start of file.");

    89         return -1;

    90     } /* if */

    91     

    92     if (!PHYSFS_seek(handle, (PHYSFS_uint64) pos))

    93     {

    94         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());

    95         return -1;

    96     } /* if */

    97 

    98     #if TARGET_SDL13

    99     return (long) pos;

   100     #else

   101     return (int) pos;

   102     #endif

   103 } /* physfsrwops_seek */

   104 

   105 

   106 #if TARGET_SDL13

   107 static size_t SDLCALL physfsrwops_read(struct SDL_RWops *rw, void *ptr,

   108                                        size_t size, size_t maxnum)

   109 #else

   110 static int physfsrwops_read(SDL_RWops *rw, void *ptr, int size, int maxnum)

   111 #endif

   112 {

   113     PHYSFS_File *handle = (PHYSFS_File *) rw->hidden.unknown.data1;

   114     const PHYSFS_uint64 readlen = (PHYSFS_uint64) (maxnum * size);

   115     const PHYSFS_sint64 rc = PHYSFS_readBytes(handle, ptr, readlen);

   116     if (rc != ((PHYSFS_sint64) readlen))

   117     {

   118         if (!PHYSFS_eof(handle)) /* not EOF? Must be an error. */

   119             SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());

   120     } /* if */

   121 

   122     #if TARGET_SDL13

   123     return (size_t) rc;

   124     #else

   125     return (int) rc;

   126     #endif

   127 } /* physfsrwops_read */

   128 

   129 

   130 #if TARGET_SDL13

   131 static size_t SDLCALL physfsrwops_write(struct SDL_RWops *rw, const void *ptr,

   132                                         size_t size, size_t num)

   133 #else

   134 static int physfsrwops_write(SDL_RWops *rw, const void *ptr, int size, int num)

   135 #endif

   136 {

   137     PHYSFS_File *handle = (PHYSFS_File *) rw->hidden.unknown.data1;

   138     const PHYSFS_uint64 writelen = (PHYSFS_uint64) (num * size);

   139     const PHYSFS_sint64 rc = PHYSFS_writeBytes(handle, ptr, writelen);

   140     if (rc != ((PHYSFS_sint64) writelen))

   141         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());

   142 

   143     #if TARGET_SDL13

   144     return (size_t) rc;

   145     #else

   146     return (int) rc;

   147     #endif

   148 } /* physfsrwops_write */

   149 

   150 

   151 static int physfsrwops_close(SDL_RWops *rw)

   152 {

   153     PHYSFS_File *handle = (PHYSFS_File *) rw->hidden.unknown.data1;

   154     if (!PHYSFS_close(handle))

   155     {

   156         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());

   157         return -1;

   158     } /* if */

   159 

   160     SDL_FreeRW(rw);

   161     return 0;

   162 } /* physfsrwops_close */

   163 

   164 

   165 static SDL_RWops *create_rwops(PHYSFS_File *handle)

   166 {

   167     SDL_RWops *retval = NULL;

   168 

   169     if (handle == NULL)

   170         SDL_SetError("PhysicsFS error: %s", PHYSFS_getLastError());

   171     else

   172     {

   173         retval = SDL_AllocRW();

   174         if (retval != NULL)

   175         {

   176             retval->seek  = physfsrwops_seek;

   177             retval->read  = physfsrwops_read;

   178             retval->write = physfsrwops_write;

   179             retval->close = physfsrwops_close;

   180             retval->hidden.unknown.data1 = handle;

   181         } /* if */

   182     } /* else */

   183 

   184     return retval;

   185 } /* create_rwops */

   186 

   187 

   188 SDL_RWops *PHYSFSRWOPS_makeRWops(PHYSFS_File *handle)

   189 {

   190     SDL_RWops *retval = NULL;

   191     if (handle == NULL)

   192         SDL_SetError("NULL pointer passed to PHYSFSRWOPS_makeRWops().");

   193     else

   194         retval = create_rwops(handle);

   195 

   196     return retval;

   197 } /* PHYSFSRWOPS_makeRWops */

   198 

   199 

   200 SDL_RWops *PHYSFSRWOPS_openRead(const char *fname)

   201 {

   202     return create_rwops(PHYSFS_openRead(fname));

   203 } /* PHYSFSRWOPS_openRead */

   204 

   205 

   206 SDL_RWops *PHYSFSRWOPS_openWrite(const char *fname)

   207 {

   208     return create_rwops(PHYSFS_openWrite(fname));

   209 } /* PHYSFSRWOPS_openWrite */

   210 

   211 

   212 SDL_RWops *PHYSFSRWOPS_openAppend(const char *fname)

   213 {

   214     return create_rwops(PHYSFS_openAppend(fname));

   215 } /* PHYSFSRWOPS_openAppend */

   216 

   217 

   218 /* end of physfsrwops.c ... */

   219