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 * All files in this archive are subject to the GNU General Public License.
  13 * See the file COPYING in the source tree root for full license agreement.
  14 *
  15 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16 * KIND, either express or implied.
  17 *
  18 ****************************************************************************/
  19
  20 #include "timer.h"
  21 #include <SDL_timer.h>
  22
  23 static int timer_prio = -1;
  24 void (*global_timer_callback)(void);
  25 SDL_TimerID timerId;
  26
  27 Uint32 SDL_timer_callback(Uint32 interval, void *param){
  28     (void)param;
  29     global_timer_callback();
  30     return(interval);
  31 }
  32
  33 #define cycles_to_miliseconds(cycles) \
  34     ((int)((1000*cycles)/TIMER_FREQ))
  35
  36 bool timer_register(int reg_prio, void (*unregister_callback)(void),
  37                     long cycles, int int_prio, void (*timer_callback)(void))
  38 {
  39     (void)int_prio;/* interrupt priority not used */
  40     (void)unregister_callback;
  41     if (reg_prio <= timer_prio || cycles == 0)
  42         return false;
  43     timer_prio=reg_prio;
  44     global_timer_callback=timer_callback;
  45     timerId=SDL_AddTimer(cycles_to_miliseconds(cycles), SDL_timer_callback, 0);
  46     return true;
  47 }
  48
  49 bool timer_set_period(long cycles)
  50 {
  51     SDL_RemoveTimer (timerId);
  52     timerId=SDL_AddTimer(cycles_to_miliseconds(cycles), SDL_timer_callback, 0);
  53     return true;
  54 }
  55
  56 void timer_unregister(void)
  57 {
  58     SDL_RemoveTimer (timerId);
  59     timer_prio = -1;
  60 }