src/timer/macos/SDL_systimer.c
author Sam Lantinga <slouken@libsdl.org>
Mon, 29 May 2006 04:04:35 +0000
branchSDL-1.3
changeset 1668 4da1ee79c9af
parent 1662 782fd950bd46
permissions -rw-r--r--
more tweaking indent options

/*
    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_MACOS

#include <Types.h>
#include <Timer.h>
#include <OSUtils.h>
#include <Gestalt.h>
#include <Processes.h>

#include <LowMem.h>

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

#include "FastTimes.h"

#if TARGET_API_MAC_CARBON
#define NewTimerProc NewTimerUPP
#endif

#define MS_PER_TICK	(1000.0/60.0)   /* MacOS tick = 1/60 second */


#define kTwoPower32     (4294967296.0)  /* 2^32 */

static double start_tick;
static int is_fast_inited = 0;

void
SDL_StartTicks(void)
{
    if (!is_fast_inited)        // important to check or FastTime may hang machine!
        SDL_SYS_TimerInit();

    start_tick = FastMicroseconds();
}

Uint32
SDL_GetTicks(void)
{

    if (!is_fast_inited)
        SDL_SYS_TimerInit();

    return FastMilliseconds();
}

void
SDL_Delay(Uint32 ms)
{
    Uint32 stop, now;

    stop = SDL_GetTicks() + ms;
    do {
#if TARGET_API_MAC_CARBON
        MPYield();
#else
        SystemTask();
#endif

        now = SDL_GetTicks();

    }
    while (stop > now);
}

/*
void SDL_StartTicks(void)
{
	// FIXME: Should we implement a wrapping algorithm, like Win32? 
}

Uint32 SDL_GetTicks(void)
{
	UnsignedWide ms;
	
	Microseconds (&ms);
	
	return ( ms.lo / 1000 );
}

void SDL_Delay(Uint32 ms)
{
	
	UnsignedWide microsecs;
	UInt32       stop;
	
	Microseconds (&microsecs);
	
	stop = microsecs.lo + (ms * 1000);
	
	while ( stop > microsecs.lo ) {
	
	   SystemTask ();
	   
	   Microseconds (&microsecs);
	}

}*/

/* Data to handle a single periodic alarm */
typedef struct _ExtendedTimerRec
{
    TMTask tmTask;
    ProcessSerialNumber taskPSN;
} ExtendedTimerRec, *ExtendedTimerPtr;

static ExtendedTimerRec gExtendedTimerRec;


int
SDL_SYS_TimerInit(void)
{
    FastInitialize();
    is_fast_inited = 1;

    return (0);
}

void
SDL_SYS_TimerQuit(void)
{
    /* We don't need a cleanup? */
    return;
}

/* Our Stub routine to set up and then call the real routine. */
pascal void
TimerCallbackProc(TMTaskPtr tmTaskPtr)
{
    Uint32 ms;

    WakeUpProcess(&((ExtendedTimerPtr) tmTaskPtr)->taskPSN);

    ms = SDL_alarm_callback(SDL_alarm_interval);
    if (ms) {
        SDL_alarm_interval = ROUND_RESOLUTION(ms);
        PrimeTime((QElemPtr) & gExtendedTimerRec.tmTask, SDL_alarm_interval);
    } else {
        SDL_alarm_interval = 0;
    }
}

int
SDL_SYS_StartTimer(void)
{
    /*
     * Configure the global structure that stores the timing information.
     */
    gExtendedTimerRec.tmTask.qLink = NULL;
    gExtendedTimerRec.tmTask.qType = 0;
    gExtendedTimerRec.tmTask.tmAddr = NewTimerProc(TimerCallbackProc);
    gExtendedTimerRec.tmTask.tmCount = 0;
    gExtendedTimerRec.tmTask.tmWakeUp = 0;
    gExtendedTimerRec.tmTask.tmReserved = 0;
    GetCurrentProcess(&gExtendedTimerRec.taskPSN);

    /* Install the task record */
    InsXTime((QElemPtr) & gExtendedTimerRec.tmTask);

    /* Go! */
    PrimeTime((QElemPtr) & gExtendedTimerRec.tmTask, SDL_alarm_interval);
    return (0);
}

void
SDL_SYS_StopTimer(void)
{
    RmvTime((QElemPtr) & gExtendedTimerRec.tmTask);
}

#endif /* SDL_TIMER_MACOS */
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