| /* |
| SDL - Simple DirectMedia Layer |
| Copyright (C) 1997-2009 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 |
| 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: |
| * @code SDL_SetTimer((33/10)*10, flag_update); @endcode |
| * |
| * 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. |
| * |
| * This function returns 0 if successful, or -1 if there was an error. |
| */ |
| extern DECLSPEC int SDLCALL SDL_SetTimer(Uint32 interval, SDL_TimerCallback callback); |
| |
| /** @name New timer API |
| * 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 */ |