SDL_MPWtimer.c
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SDL - Simple DirectMedia Layer
Copyright (C) 1997-2006 Sam Lantinga
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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.
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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.
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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
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Sam Lantinga
slouken@libsdl.org
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*/
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#include "SDL_config.h"
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#ifdef SDL_TIMER_MACOS
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#include <Types.h>
#include <Timer.h>
#include <OSUtils.h>
#include <Gestalt.h>
#include <Processes.h>
#include <LowMem.h>
#include "SDL_timer.h"
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#include "../SDL_timer_c.h"
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#define MS_PER_TICK (1000/60) /* MacOS tick = 1/60 second */
/* Note: This is only a step above the original 1/60s implementation.
* For a good implementation, see FastTimes.[ch], by Matt Slot.
*/
#define USE_MICROSECONDS
#define WideTo64bit(w) (*(UInt64 *) &(w))
UInt64 start;
void SDL_StartTicks(void)
{
#ifdef USE_MICROSECONDS
UnsignedWide now;
Microseconds(&now);
start = WideTo64bit(now);
#else
/* FIXME: Should we implement a wrapping algorithm, like Win32? */
#endif
}
Uint32 SDL_GetTicks(void)
{
#ifdef USE_MICROSECONDS
UnsignedWide now;
Microseconds(&now);
return (Uint32)((WideTo64bit(now)-start)/1000);
#else
return(LMGetTicks()*MS_PER_TICK);
#endif
}
void SDL_Delay(Uint32 ms)
{
#ifdef USE_MICROSECONDS
Uint32 end_ms;
end_ms = SDL_GetTicks() + ms;
do {
/* FIXME: Yield CPU? */ ;
} while ( SDL_GetTicks() < end_ms );
#else
UInt32 unused; /* MJS */
Delay(ms/MS_PER_TICK, &unused);
#endif
}
/* Data to handle a single periodic alarm */
typedef struct _ExtendedTimerRec
{
TMTask tmTask;
ProcessSerialNumber taskPSN;
} ExtendedTimerRec, *ExtendedTimerPtr;
static ExtendedTimerRec gExtendedTimerRec;
int SDL_SYS_TimerInit(void)
{
/* We don't need a setup? */
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 = NewTimerUPP(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);
}
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#endif /* SDL_TIMER_MACOS */