glfw/src/win32_time.c
2014-04-08 17:47:38 +02:00

87 lines
2.7 KiB
C

//========================================================================
// GLFW 3.1 Win32 - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2010 Camilla Berglund <elmindreda@elmindreda.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 "internal.h"
// Return raw time
//
static unsigned __int64 getRawTime(void)
{
if (_glfw.win32_time.hasPC)
{
unsigned __int64 time;
QueryPerformanceCounter((LARGE_INTEGER*) &time);
return time;
}
else
return (unsigned __int64) _glfw_timeGetTime();
}
//////////////////////////////////////////////////////////////////////////
////// GLFW internal API //////
//////////////////////////////////////////////////////////////////////////
// Initialise timer
//
void _glfwInitTimer(void)
{
unsigned __int64 frequency;
if (QueryPerformanceFrequency((LARGE_INTEGER*) &frequency))
{
_glfw.win32_time.hasPC = GL_TRUE;
_glfw.win32_time.resolution = 1.0 / (double) frequency;
}
else
{
_glfw.win32_time.hasPC = GL_FALSE;
_glfw.win32_time.resolution = 0.001; // winmm resolution is 1 ms
}
_glfw.win32_time.base = getRawTime();
}
//////////////////////////////////////////////////////////////////////////
////// GLFW platform API //////
//////////////////////////////////////////////////////////////////////////
double _glfwPlatformGetTime(void)
{
return (double) (getRawTime() - _glfw.win32_time.base) *
_glfw.win32_time.resolution;
}
void _glfwPlatformSetTime(double time)
{
_glfw.win32_time.base = getRawTime() -
(unsigned __int64) (time / _glfw.win32_time.resolution);
}