include/SDL_rwops.h
author Sam Lantinga <slouken@libsdl.org>
Tue, 21 Feb 2006 08:46:50 +0000
changeset 1402 d910939febfa
parent 1358 c71e05b4dc2e
child 1446 47bf1767c4ca
permissions -rw-r--r--
Use consistent identifiers for the various platforms we support.
Make sure every source file includes SDL_config.h, so the proper system
headers are chosen.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 /* This file provides a general interface for SDL to read and write
    24    data sources.  It can easily be extended to files, memory, etc.
    25 */
    26 
    27 #ifndef _SDL_rwops_h
    28 #define _SDL_rwops_h
    29 
    30 #include "SDL_stdinc.h"
    31 #include "SDL_error.h"
    32 
    33 #include "begin_code.h"
    34 /* Set up for C function definitions, even when using C++ */
    35 #ifdef __cplusplus
    36 extern "C" {
    37 #endif
    38 
    39 /* This is the read/write operation structure -- very basic */
    40 
    41 typedef struct SDL_RWops {
    42 	/* Seek to 'offset' relative to whence, one of stdio's whence values:
    43 		SEEK_SET, SEEK_CUR, SEEK_END
    44 	   Returns the final offset in the data source.
    45 	 */
    46 	int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence);
    47 
    48 	/* Read up to 'num' objects each of size 'objsize' from the data
    49 	   source to the area pointed at by 'ptr'.
    50 	   Returns the number of objects read, or -1 if the read failed.
    51 	 */
    52 	int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum);
    53 
    54 	/* Write exactly 'num' objects each of size 'objsize' from the area
    55 	   pointed at by 'ptr' to data source.
    56 	   Returns 'num', or -1 if the write failed.
    57 	 */
    58 	int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num);
    59 
    60 	/* Close and free an allocated SDL_FSops structure */
    61 	int (SDLCALL *close)(struct SDL_RWops *context);
    62 
    63 	Uint32 type;
    64 	union {
    65 #ifdef HAVE_STDIO_H
    66 	    struct {
    67 		int autoclose;
    68 	 	FILE *fp;
    69 	    } stdio;
    70 #endif
    71 	    struct {
    72 		Uint8 *base;
    73 	 	Uint8 *here;
    74 		Uint8 *stop;
    75 	    } mem;
    76 	    struct {
    77 		void *data1;
    78 	    } unknown;
    79 	} hidden;
    80 
    81 } SDL_RWops;
    82 
    83 
    84 /* Functions to create SDL_RWops structures from various data sources */
    85 
    86 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode);
    87 
    88 #ifdef HAVE_STDIO_H
    89 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose);
    90 #endif
    91 
    92 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size);
    93 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size);
    94 
    95 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void);
    96 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area);
    97 
    98 #define RW_SEEK_SET	0	/* Seek from the beginning of data */
    99 #define RW_SEEK_CUR	1	/* Seek relative to current read point */
   100 #define RW_SEEK_END	2	/* Seek relative to the end of data */
   101 
   102 /* Macros to easily read and write from an SDL_RWops structure */
   103 #define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
   104 #define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, RW_SEEK_CUR)
   105 #define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
   106 #define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
   107 #define SDL_RWclose(ctx)		(ctx)->close(ctx)
   108 
   109 
   110 /* Read an item of the specified endianness and return in native format */
   111 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src);
   112 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src);
   113 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src);
   114 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src);
   115 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src);
   116 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src);
   117 
   118 /* Write an item of native format to the specified endianness */
   119 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value);
   120 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value);
   121 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value);
   122 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value);
   123 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value);
   124 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value);
   125 
   126 
   127 /* Ends C function definitions when using C++ */
   128 #ifdef __cplusplus
   129 }
   130 #endif
   131 #include "close_code.h"
   132 
   133 #endif /* _SDL_rwops_h */