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/* ptwinmm.c -- portable timer implementation for win32 */


#include "porttime.h"
#include "windows.h"
#include "time.h"


TIMECAPS caps;

static long time_offset = 0;
static int time_started_flag = FALSE;
static long time_resolution;
static MMRESULT timer_id;
static PtCallback *time_callback;

void CALLBACK winmm_time_callback(UINT uID, UINT uMsg, DWORD_PTR dwUser,
									DWORD_PTR dw1, DWORD_PTR dw2)
{
	(*time_callback)(Pt_Time(), (void *) dwUser);
}


PMEXPORT PtError Pt_Start(int resolution, PtCallback *callback, void *userData)
{
	if (time_started_flag) return ptAlreadyStarted;
	timeBeginPeriod(resolution);
	time_resolution = resolution;
	time_offset = timeGetTime();
	time_started_flag = TRUE;
	time_callback = callback;
	if (callback) {
		timer_id = timeSetEvent(resolution, 1, winmm_time_callback,
			(DWORD_PTR) userData, TIME_PERIODIC | TIME_CALLBACK_FUNCTION);
		if (!timer_id) return ptHostError;
	}
	return ptNoError;
}


PMEXPORT PtError Pt_Stop()
{
	if (!time_started_flag) return ptAlreadyStopped;
	if (time_callback && timer_id) {
		timeKillEvent(timer_id);
		time_callback = NULL;
		timer_id = 0;
	}
	time_started_flag = FALSE;
	timeEndPeriod(time_resolution);
	return ptNoError;
}


PMEXPORT int Pt_Started()
{
	return time_started_flag;
}


PMEXPORT PtTimestamp Pt_Time()
{
	return timeGetTime() - time_offset;
}


PMEXPORT void Pt_Sleep(int32_t duration)
{
	Sleep(duration);
}