gremlin/libs/glfw/lib/win32/win32_time.c
2011-01-04 18:11:59 +01:00

147 lines
4.4 KiB
C

//========================================================================
// GLFW - An OpenGL framework
// File: win32_time.c
// Platform: Windows
// API version: 2.6
// WWW: http://glfw.sourceforge.net
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Camilla Berglund
//
// 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"
//************************************************************************
//**** GLFW internal functions ****
//************************************************************************
//========================================================================
// _glfwInitTimer() - Initialise timer
//========================================================================
void _glfwInitTimer( void )
{
__int64 freq;
// Check if we have a performance counter
if( QueryPerformanceFrequency( (LARGE_INTEGER *)&freq ) )
{
// Performance counter is available => use it!
_glfwLibrary.Timer.HasPerformanceCounter = GL_TRUE;
// Counter resolution is 1 / counter frequency
_glfwLibrary.Timer.Resolution = 1.0 / (double)freq;
// Set start time for timer
QueryPerformanceCounter( (LARGE_INTEGER *)&_glfwLibrary.Timer.t0_64 );
}
else
{
// No performace counter available => use the tick counter
_glfwLibrary.Timer.HasPerformanceCounter = GL_FALSE;
// Counter resolution is 1 ms
_glfwLibrary.Timer.Resolution = 0.001;
// Set start time for timer
_glfwLibrary.Timer.t0_32 = _glfw_timeGetTime();
}
}
//************************************************************************
//**** Platform implementation functions ****
//************************************************************************
//========================================================================
// Return timer value in seconds
//========================================================================
double _glfwPlatformGetTime( void )
{
double t;
__int64 t_64;
if( _glfwLibrary.Timer.HasPerformanceCounter )
{
QueryPerformanceCounter( (LARGE_INTEGER *)&t_64 );
t = (double)(t_64 - _glfwLibrary.Timer.t0_64);
}
else
{
t = (double)(_glfw_timeGetTime() - _glfwLibrary.Timer.t0_32);
}
// Calculate the current time in seconds
return t * _glfwLibrary.Timer.Resolution;
}
//========================================================================
// Set timer value in seconds
//========================================================================
void _glfwPlatformSetTime( double t )
{
__int64 t_64;
if( _glfwLibrary.Timer.HasPerformanceCounter )
{
QueryPerformanceCounter( (LARGE_INTEGER *)&t_64 );
_glfwLibrary.Timer.t0_64 = t_64 - (__int64)(t/_glfwLibrary.Timer.Resolution);
}
else
{
_glfwLibrary.Timer.t0_32 = _glfw_timeGetTime() - (int)(t*1000.0);
}
}
//========================================================================
// Put a thread to sleep for a specified amount of time
//========================================================================
void _glfwPlatformSleep( double time )
{
DWORD t;
if( time == 0.0 )
{
t = 0;
}
else if( time < 0.001 )
{
t = 1;
}
else if( time > 2147483647.0 )
{
t = 2147483647;
}
else
{
t = (DWORD)(time*1000.0 + 0.5);
}
Sleep( t );
}