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/* |
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SDL - Simple DirectMedia Layer |
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Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga |
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|
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This library is free software; you can redistribute it and/or |
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modify it under the terms of the GNU Library General Public |
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License as published by the Free Software Foundation; either |
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version 2 of the License, or (at your option) any later version. |
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|
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This library is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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Library General Public License for more details. |
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|
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You should have received a copy of the GNU Library General Public |
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License along with this library; if not, write to the Free |
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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|
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Sam Lantinga |
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slouken@devolution.com |
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*/ |
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|
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#ifdef SAVE_RCSID |
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static char rcsid = |
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"@(#) $Id: SDL_timer.h,v 1.4.2.8 2001/02/17 01:45:30 hercules Exp $"; |
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#endif |
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|
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#ifndef _SDL_timer_h |
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#define _SDL_timer_h |
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|
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/* Header for the SDL time management routines */ |
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|
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#include "SDL_main.h" |
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#include "SDL_types.h" |
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|
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#include "begin_code.h" |
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/* Set up for C function definitions, even when using C++ */ |
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#ifdef __cplusplus |
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extern "C" { |
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#endif |
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|
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/* This is the OS scheduler timeslice, in milliseconds */ |
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#define SDL_TIMESLICE 10 |
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|
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/* This is the maximum resolution of the SDL timer on all platforms */ |
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#define TIMER_RESOLUTION 10 /* Experimentally determined */ |
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|
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/* Get the number of milliseconds since the SDL library initialization. |
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* Note that this value wraps if the program runs for more than ~49 days. |
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*/ |
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extern DECLSPEC Uint32 SDL_GetTicks(void); |
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|
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/* Wait a specified number of milliseconds before returning */ |
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extern DECLSPEC void SDL_Delay(Uint32 ms); |
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|
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/* Function prototype for the timer callback function */ |
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typedef Uint32 (*SDL_TimerCallback)(Uint32 interval); |
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|
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/* Set a callback to run after the specified number of milliseconds has |
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* elapsed. The callback function is passed the current timer interval |
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* and returns the next timer interval. If the returned value is the |
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* same as the one passed in, the periodic alarm continues, otherwise a |
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* new alarm is scheduled. If the callback returns 0, the periodic alarm |
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* is cancelled. |
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* |
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* To cancel a currently running timer, call SDL_SetTimer(0, NULL); |
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* |
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* The timer callback function may run in a different thread than your |
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* main code, and so shouldn't call any functions from within itself. |
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* |
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* The maximum resolution of this timer is 10 ms, which means that if |
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* you request a 16 ms timer, your callback will run approximately 20 ms |
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* later on an unloaded system. If you wanted to set a flag signaling |
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* a frame update at 30 frames per second (every 33 ms), you might set a |
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* timer for 30 ms: |
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* SDL_SetTimer((33/10)*10, flag_update); |
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* |
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* If you use this function, you need to pass SDL_INIT_TIMER to SDL_Init(). |
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* |
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* Under UNIX, you should not use raise or use SIGALRM and this function |
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* in the same program, as it is implemented using setitimer(). You also |
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* should not use this function in multi-threaded applications as signals |
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* to multi-threaded apps have undefined behavior in some implementations. |
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*/ |
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extern DECLSPEC int SDL_SetTimer(Uint32 interval, SDL_TimerCallback callback); |
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|
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/* New timer API, supports multiple timers |
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* Written by Stephane Peter <megastep@lokigames.com> |
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*/ |
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|
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/* Function prototype for the new timer callback function. |
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* The callback function is passed the current timer interval and returns |
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* the next timer interval. If the returned value is the same as the one |
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* passed in, the periodic alarm continues, otherwise a new alarm is |
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* scheduled. If the callback returns 0, the periodic alarm is cancelled. |
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*/ |
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typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param); |
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|
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/* Definition of the timer ID type */ |
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typedef struct _SDL_TimerID *SDL_TimerID; |
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|
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/* Add a new timer to the pool of timers already running. |
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Returns a timer ID, or NULL when an error occurs. |
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*/ |
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extern DECLSPEC SDL_TimerID SDL_AddTimer(Uint32 interval, SDL_NewTimerCallback callback, void *param); |
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|
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/* Remove one of the multiple timers knowing its ID. |
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* Returns a boolean value indicating success. |
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*/ |
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extern DECLSPEC SDL_bool SDL_RemoveTimer(SDL_TimerID t); |
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|
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/* Ends C function definitions when using C++ */ |
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#ifdef __cplusplus |
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} |
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#endif |
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#include "close_code.h" |
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|
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#endif /* _SDL_timer_h */ |
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