uisimulator/sdl/timer.c

   1 /***************************************************************************
   2 *             __________               __   ___.
   3 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7 *                     \/            \/     \/    \/            \/
   8 * $Id: timer.h 13806 2007-07-06 21:36:32Z jethead71 $
   9 *
  10 * Copyright (C) 2005 Kévin Ferrare
  11 *
  12 * This program is free software; you can redistribute it and/or
  13 * modify it under the terms of the GNU General Public License
  14 * as published by the Free Software Foundation; either version 2
  15 * of the License, or (at your option) any later version.
  16 *
  17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18 * KIND, either express or implied.
  19 *
  20 ****************************************************************************/
  21
  22 #include "timer.h"
  23 #include <SDL_timer.h>
  24
  25 static int timer_prio = -1;
  26 void (*global_timer_callback)(void);
  27 SDL_TimerID timerId;
  28
  29 Uint32 SDL_timer_callback(Uint32 interval, void *param){
  30     (void)param;
  31     global_timer_callback();
  32     return(interval);
  33 }
  34
  35 #define cycles_to_miliseconds(cycles) \
  36     ((int)((1000*cycles)/TIMER_FREQ))
  37
  38 bool timer_register(int reg_prio, void (*unregister_callback)(void),
  39                     long cycles, int int_prio, void (*timer_callback)(void))
  40 {
  41     (void)int_prio;/* interrupt priority not used */
  42     (void)unregister_callback;
  43     if (reg_prio <= timer_prio || cycles == 0)
  44         return false;
  45     timer_prio=reg_prio;
  46     global_timer_callback=timer_callback;
  47     timerId=SDL_AddTimer(cycles_to_miliseconds(cycles), SDL_timer_callback, 0);
  48     return true;
  49 }
  50
  51 bool timer_set_period(long cycles)
  52 {
  53     SDL_RemoveTimer (timerId);
  54     timerId=SDL_AddTimer(cycles_to_miliseconds(cycles), SDL_timer_callback, 0);
  55     return true;
  56 }
  57
  58 void timer_unregister(void)
  59 {
  60     SDL_RemoveTimer (timerId);
  61     timer_prio = -1;
  62 }