include/SDL_rwops.h
author Sam Lantinga <slouken@libsdl.org>
Mon, 27 Feb 2006 03:48:48 +0000
changeset 1446 47bf1767c4ca
parent 1402 d910939febfa
child 1447 515df0086eb7
permissions -rw-r--r--
Date: Mon, 27 Feb 2006 02:17:29 +0100
From: "William Petiot [exoide]"
Subject: Re: [SDL] cvs version: questions regarding HAVE_STDIO_H in standard w

I managed to get a first implementation of it, which I tested for "simple" use
with tests sample apps, they work ok. I think this needs more tests.

Here is the diff against CVS/SDL12, attached.
     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 
    66 #ifdef HAVE_STDIO_H 
    67 	    struct {
    68 		int autoclose;
    69 	 	FILE *fp;
    70 	    } stdio;
    71 #else
    72 #ifdef __WIN32__
    73 		struct {
    74 			void*  h;
    75 			int    autoclose;
    76 			int    append;
    77 		} win32io;
    78 #endif
    79 #endif
    80 	    struct {
    81 		Uint8 *base;
    82 	 	Uint8 *here;
    83 		Uint8 *stop;
    84 	    } mem;
    85 	    struct {
    86 		void *data1;
    87 	    } unknown;
    88 	} hidden;
    89 
    90 } SDL_RWops;
    91 
    92 
    93 /* Functions to create SDL_RWops structures from various data sources */
    94 
    95 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode);
    96 
    97 #ifdef HAVE_STDIO_H
    98 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose);
    99 #endif
   100 
   101 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size);
   102 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size);
   103 
   104 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void);
   105 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area);
   106 
   107 #define RW_SEEK_SET	0	/* Seek from the beginning of data */
   108 #define RW_SEEK_CUR	1	/* Seek relative to current read point */
   109 #define RW_SEEK_END	2	/* Seek relative to the end of data */
   110 
   111 /* Macros to easily read and write from an SDL_RWops structure */
   112 #define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
   113 #define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, RW_SEEK_CUR)
   114 #define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
   115 #define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
   116 #define SDL_RWclose(ctx)		(ctx)->close(ctx)
   117 
   118 
   119 /* Read an item of the specified endianness and return in native format */
   120 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src);
   121 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src);
   122 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src);
   123 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src);
   124 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src);
   125 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src);
   126 
   127 /* Write an item of native format to the specified endianness */
   128 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value);
   129 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value);
   130 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value);
   131 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value);
   132 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value);
   133 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value);
   134 
   135 
   136 /* Ends C function definitions when using C++ */
   137 #ifdef __cplusplus
   138 }
   139 #endif
   140 #include "close_code.h"
   141 
   142 #endif /* _SDL_rwops_h */