apps/plugins/zxbox/sptiming.c

   1 /*
   2  * Copyright (C) 1996-1998 Szeredi Miklos 2006 Anton Romanov
   3  * Email: mszeredi@inf.bme.hu
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version. See the file COPYING.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  */
  20
  21 #include "zxconfig.h"
  22
  23 #include "sptiming.h"
  24 #include "interf.h"
  25 /* not precise but .... anyway this is used only when not playing
  26  * sound ... */
  27 long shouldbe_tick;
  28
  29 void spti_init(void){
  30         spti_reset();
  31 }
  32 void spti_sleep(unsigned long usecs){
  33 /*      unsigned long now,need;
  34         now = *rb->current_tick;
  35         need = now + usecs;
  36         rb -> sleep ( need - now );*/
  37     rb->sleep ( usecs );
  38 }
  39 void spti_reset(void){
  40         shouldbe_tick = *rb -> current_tick;
  41 }
  42 void spti_wait(void){
  43         long rem;
  44         long now;
  45
  46         now = *rb -> current_tick;
  47     shouldbe_tick+=SKIPTICKS;
  48         rem = shouldbe_tick - now;
  49
  50         if(rem > 0) {
  51                 if(rem > SKIPTICKS) rem = SKIPTICKS;
  52                         spti_sleep((unsigned long) rem);
  53         }
  54     if(rem == SKIPTICKS || rem < -10 * SKIPTIME) spti_reset();
  55 }