include/SDL_timer.h

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2011 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifndef _SDL_timer_h
#define _SDL_timer_h

/**
 *  \file SDL_timer.h
 *  
 *  Header for the SDL time management routines.
 */

#include "SDL_stdinc.h"
#include "SDL_error.h"

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

/**
 * \brief Get the number of milliseconds since the SDL library initialization.
 *  
 * \note This value wraps if the program runs for more than ~49 days.
 */
extern DECLSPEC Uint32 SDLCALL SDL_GetTicks(void);

/**
 * \brief Get the current value of the high resolution counter
 */
extern DECLSPEC Uint64 SDLCALL SDL_GetPerformanceCounter(void);

/**
 * \brief Get the count per second of the high resolution counter
 */
extern DECLSPEC Uint64 SDLCALL SDL_GetPerformanceFrequency(void);

/**
 * \brief Wait a specified number of milliseconds before returning.
 */
extern DECLSPEC void SDLCALL SDL_Delay(Uint32 ms);

/**
 *  Function prototype for the 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_TimerCallback) (Uint32 interval, void *param);

/**
 * Definition of the timer ID type.
 */
typedef int SDL_TimerID;

/**
 * \brief Add a new timer to the pool of timers already running.
 *
 * \return A timer ID, or NULL when an error occurs.
 */
extern DECLSPEC SDL_TimerID SDLCALL SDL_AddTimer(Uint32 interval,
                                                 SDL_TimerCallback callback,
                                                 void *param);

/**
 * \brief Remove a timer knowing its ID.
 *
 * \return A boolean value indicating success or failure.
 *
 * \warning It is not safe to remove a timer multiple times.
 */
extern DECLSPEC SDL_bool SDLCALL SDL_RemoveTimer(SDL_TimerID t);


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

#endif /* _SDL_timer_h */

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