/*
    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 */
/* vi: set ts=4 sw=4 expandtab: */