SDL_timer.h
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上传用户:sun1608
上传日期:2007-02-02
资源大小:6116k
文件大小:4k
源码类别:
流媒体/Mpeg4/MP4
开发平台:
Visual C++
- /*
- SDL - Simple DirectMedia Layer
- Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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: SDL_timer.h,v 1.4 2002/04/22 21:38:01 wmay Exp $";
- #endif
- #ifndef _SDL_timer_h
- #define _SDL_timer_h
- /* Header for the SDL time management routines */
- #include "SDL_main.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 OS scheduler timeslice, in milliseconds */
- #define SDL_TIMESLICE 10
- /* This is the maximum resolution of the SDL timer on all platforms */
- #define TIMER_RESOLUTION 10 /* Experimentally determined */
- /* Get the number of milliseconds since the SDL library initialization.
- * Note that this value wraps if the program runs for more than ~49 days.
- */
- extern DECLSPEC Uint32 SDLCALL SDL_GetTicks(void);
- /* Wait a specified number of milliseconds before returning */
- extern DECLSPEC void SDLCALL SDL_Delay(Uint32 ms);
- /* Function prototype for the timer callback function */
- typedef Uint32 (SDLCALL *SDL_TimerCallback)(Uint32 interval);
- /* Set a callback to run after the specified number of milliseconds has
- * elapsed. The callback function is passed the current timer interval
- * and returns the next timer interval. If the returned value is the
- * same as the one passed in, the periodic alarm continues, otherwise a
- * new alarm is scheduled. If the callback returns 0, the periodic alarm
- * is cancelled.
- *
- * To cancel a currently running timer, call SDL_SetTimer(0, NULL);
- *
- * The timer callback function may run in a different thread than your
- * main code, and so shouldn't call any functions from within itself.
- *
- * The maximum resolution of this timer is 10 ms, which means that if
- * you request a 16 ms timer, your callback will run approximately 20 ms
- * later on an unloaded system. If you wanted to set a flag signaling
- * a frame update at 30 frames per second (every 33 ms), you might set a
- * timer for 30 ms:
- * SDL_SetTimer((33/10)*10, flag_update);
- *
- * If you use this function, you need to pass SDL_INIT_TIMER to SDL_Init().
- *
- * Under UNIX, you should not use raise or use SIGALRM and this function
- * in the same program, as it is implemented using setitimer(). You also
- * should not use this function in multi-threaded applications as signals
- * to multi-threaded apps have undefined behavior in some implementations.
- */
- extern DECLSPEC int SDLCALL SDL_SetTimer(Uint32 interval, SDL_TimerCallback callback);
- /* New timer API, supports multiple timers
- * Written by Stephane Peter <megastep@lokigames.com>
- */
- /* Function prototype for the new timer callback function.
- * The callback function is passed the current timer interval and returns
- * the next timer interval. If the returned value is the same as the one
- * passed in, the periodic alarm continues, otherwise a new alarm is
- * scheduled. If the callback returns 0, the periodic alarm is cancelled.
- */
- typedef Uint32 (SDLCALL *SDL_NewTimerCallback)(Uint32 interval, void *param);
- /* Definition of the timer ID type */
- typedef struct _SDL_TimerID *SDL_TimerID;
- /* Add a new timer to the pool of timers already running.
- Returns a timer ID, or NULL when an error occurs.
- */
- extern DECLSPEC SDL_TimerID SDLCALL SDL_AddTimer(Uint32 interval, SDL_NewTimerCallback callback, void *param);
- /* Remove one of the multiple timers knowing its ID.
- * Returns a boolean value indicating success.
- */
- extern DECLSPEC SDL_bool SDLCALL SDL_RemoveTimer(SDL_TimerID t);
- /* Ends C function definitions when using C++ */
- #ifdef __cplusplus
- }
- #endif
- #include "close_code.h"
- #endif /* _SDL_timer_h */