/*

Simple DirectMedia Layer

Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>

This software is provided 'as-is', without any express or implied

warranty. In no event will the authors be held liable for any damages

arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not

claim that you wrote the original software. If you use this software

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

2. Altered source versions must be plainly marked as such, and must not be

misrepresented as being the original software.

3. This notice may not be removed or altered from any source distribution.

*/

#include "SDL_config.h"

#ifdef SDL_TIMER_WINDOWS

#include "../../core/windows/SDL_windows.h"

#include <mmsystem.h>

#include "SDL_timer.h"

#include "SDL_hints.h"

/* The first (low-resolution) ticks value of the application */

static DWORD start;

#ifndef USE_GETTICKCOUNT

/* Store if a high-resolution performance counter exists on the system */

static BOOL hires_timer_available;

/* The first high-resolution ticks value of the application */

static LARGE_INTEGER hires_start_ticks;

/* The number of ticks per second of the high-resolution performance counter */

static LARGE_INTEGER hires_ticks_per_second;

#endif

static void

timeSetPeriod(UINT uPeriod)

{

static UINT timer_period = 0;

if (uPeriod != timer_period) {

if (timer_period) {

timeEndPeriod(timer_period);

}

timer_period = uPeriod;

if (timer_period) {

timeBeginPeriod(timer_period);

}

}

}

static void

SDL_TimerResolutionChanged(void *userdata, const char *name, const char *oldValue, const char *hint)

{

UINT uPeriod;

/* Unless the hint says otherwise, let's have good sleep precision */

if (hint && *hint) {

uPeriod = SDL_atoi(hint);

} else {

uPeriod = 1;

}

if (uPeriod || oldValue != hint) {

timeSetPeriod(uPeriod);

}

}

void

if (ticks_started) {

return;

}

ticks_started = TRUE;

/* Set first ticks value */

#ifdef USE_GETTICKCOUNT

start = GetTickCount();

#else

/* QueryPerformanceCounter has had problems in the past, but lots of games

use it, so we'll rely on it here.

*/

if (QueryPerformanceFrequency(&hires_ticks_per_second) == TRUE) {

hires_timer_available = TRUE;

QueryPerformanceCounter(&hires_start_ticks);

} else {

hires_timer_available = FALSE;

#ifdef __WINRT__

start = 0; /* the timer failed to start! */

#else

timeSetPeriod(1); /* use 1 ms timer precision */

start = timeGetTime();

}

#endif

SDL_AddHintCallback(SDL_HINT_TIMER_RESOLUTION,

SDL_TimerResolutionChanged, NULL);

}

Uint32

SDL_GetTicks(void)

{

DWORD now;

#ifndef USE_GETTICKCOUNT

LARGE_INTEGER hires_now;

#endif

if (!ticks_started) {

SDL_InitTicks();

}

#ifdef USE_GETTICKCOUNT

now = GetTickCount();

#else

if (hires_timer_available) {

QueryPerformanceCounter(&hires_now);

hires_now.QuadPart -= hires_start_ticks.QuadPart;

hires_now.QuadPart *= 1000;

hires_now.QuadPart /= hires_ticks_per_second.QuadPart;

return (DWORD) hires_now.QuadPart;

} else {

#ifdef __WINRT__

now = 0;

#else

}

#endif

return (now - start);

}

Uint64

SDL_GetPerformanceCounter(void)

{

LARGE_INTEGER counter;

if (!QueryPerformanceCounter(&counter)) {

return SDL_GetTicks();

}

return counter.QuadPart;

}

Uint64

SDL_GetPerformanceFrequency(void)

{

LARGE_INTEGER frequency;

if (!QueryPerformanceFrequency(&frequency)) {

return 1000;

}

return frequency.QuadPart;

}

#ifdef __WINRT__

static void

Sleep(DWORD timeout)

{

static HANDLE mutex = 0;

if ( ! mutex )

{

mutex = CreateEventEx(0, 0, 0, EVENT_ALL_ACCESS);

}

WaitForSingleObjectEx(mutex, timeout, FALSE);

}

#endif

void

SDL_Delay(Uint32 ms)

{

Sleep(ms);

}

#endif /* SDL_TIMER_WINDOWS */

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