view include/SDL_rwops.h @ 1157:baf35853ad54

Date: Mon, 10 Oct 2005 13:09:32 +0300 From: Tommi Kyntola <tommi.kyntola@ray.fi> To: sdl@libsdl.org Subject: [SDL] [RFC] get_ticks broken on linux It uses gettimeofday to calculate the timedifference. Gettimeofday returns current time which is seldom monotonous. This breaks SDL timer subsystem. (time callbacks and all that get borked when the time difference ms is suddenly ~ 2^32) I posted a message about this earlier but got no response. Some thoughts on this matter would be appreciated. (Or even an explanation for the lack of interest.) A patch below would use the posix timers that have been around since posix 93 and do provide a good source of monotonous time on linux boxes (and on few others too). The following patch is also availabe at: http://www.hut.fi/u/tkyntola/SDL-1.2.9-clockfix.patch It's against 1.2.9, but I can easily rediffit against the cvs branch is needed. cheers, Tommi Kyntola tommi.kyntola@ray.fi
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 11 Oct 2005 18:16:12 +0000
parents 02759105b989
children c9b51268668f
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

/* This file provides a general interface for SDL to read and write
   data sources.  It can easily be extended to files, memory, etc.
*/

#ifndef _SDL_RWops_h
#define _SDL_RWops_h

#include <stdio.h>

#include "SDL_types.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/* This is the read/write operation structure -- very basic */

typedef struct SDL_RWops {
	/* Seek to 'offset' relative to whence, one of stdio's whence values:
		SEEK_SET, SEEK_CUR, SEEK_END
	   Returns the final offset in the data source.
	 */
	int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence);

	/* Read up to 'num' objects each of size 'objsize' from the data
	   source to the area pointed at by 'ptr'.
	   Returns the number of objects read, or -1 if the read failed.
	 */
	int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum);

	/* Write exactly 'num' objects each of size 'objsize' from the area
	   pointed at by 'ptr' to data source.
	   Returns 'num', or -1 if the write failed.
	 */
	int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num);

	/* Close and free an allocated SDL_FSops structure */
	int (SDLCALL *close)(struct SDL_RWops *context);

	Uint32 type;
	union {
	    struct {
		int autoclose;
	 	FILE *fp;
	    } stdio;
	    struct {
		Uint8 *base;
	 	Uint8 *here;
		Uint8 *stop;
	    } mem;
	    struct {
		void *data1;
	    } unknown;
	} hidden;

} SDL_RWops;


/* Functions to create SDL_RWops structures from various data sources */

extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode);

extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose);

extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size);
extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size);

extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void);
extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area);

/* Macros to easily read and write from an SDL_RWops structure */
#define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
#define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, SEEK_CUR)
#define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
#define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
#define SDL_RWclose(ctx)		(ctx)->close(ctx)


/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"

#endif /* _SDL_RWops_h */