view src/timer/dc/SDL_systimer.c @ 3880:74e828c64315 SDL-1.2

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:45:37 +0000
parents 92947e3a18db
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 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
*/
#include "SDL_config.h"

#ifdef SDL_TIMER_DC

#include <kos.h>

#include "SDL_thread.h"
#include "SDL_timer.h"
#include "../SDL_timer_c.h"

static unsigned start;

/* 
	jif =  ms * HZ /1000
	ms  = jif * 1000/HZ
*/

void SDL_StartTicks(void)
{
	/* Set first ticks value */
	start = jiffies;
}

Uint32 SDL_GetTicks(void)
{
	return((jiffies-start)*1000/HZ);
}

void SDL_Delay(Uint32 ms)
{
	thd_sleep(ms);
}

/* Data to handle a single periodic alarm */
static int timer_alive = 0;
static SDL_Thread *timer = NULL;

static int RunTimer(void *unused)
{
	while ( timer_alive ) {
		if ( SDL_timer_running ) {
			SDL_ThreadedTimerCheck();
		}
		SDL_Delay(10);
	}
	return(0);
}

/* This is only called if the event thread is not running */
int SDL_SYS_TimerInit(void)
{
	timer_alive = 1;
	timer = SDL_CreateThread(RunTimer, NULL);
	if ( timer == NULL )
		return(-1);
	return(SDL_SetTimerThreaded(1));
}

void SDL_SYS_TimerQuit(void)
{
	timer_alive = 0;
	if ( timer ) {
		SDL_WaitThread(timer, NULL);
		timer = NULL;
	}
}

int SDL_SYS_StartTimer(void)
{
	SDL_SetError("Internal logic error: DC uses threaded timer");
	return(-1);
}

void SDL_SYS_StopTimer(void)
{
	return;
}

#endif /* SDL_TIMER_DC */