122 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			122 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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| * Copyright (c) 2011 Erin Catto http://box2d.org
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| *
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| * This software is provided 'as-is', without any express or implied
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| * warranty.  In no event will the authors be held liable for any damages
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| * arising from the use of this software.
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| * Permission is granted to anyone to use this software for any purpose,
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| * including commercial applications, and to alter it and redistribute it
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| * freely, subject to the following restrictions:
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| * 1. The origin of this software must not be misrepresented; you must not
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| * claim that you wrote the original software. If you use this software
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| * in a product, an acknowledgment in the product documentation would be
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| * appreciated but is not required.
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| * 2. Altered source versions must be plainly marked as such, and must not be
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| * misrepresented as being the original software.
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| * 3. This notice may not be removed or altered from any source distribution.
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| */
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| 
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| #include "Box2D/Common/b2Timer.h"
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| 
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| #if defined(_WIN32)
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| 
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| float64 b2Timer::s_invFrequency = 0.0f;
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| 
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| #ifndef WIN32_LEAN_AND_MEAN
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| #define WIN32_LEAN_AND_MEAN
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| #endif
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| 
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| #include <windows.h>
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| 
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| b2Timer::b2Timer()
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| {
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| 	LARGE_INTEGER largeInteger;
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| 
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| 	if (s_invFrequency == 0.0f)
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| 	{
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| 		QueryPerformanceFrequency(&largeInteger);
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| 		s_invFrequency = float64(largeInteger.QuadPart);
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| 		if (s_invFrequency > 0.0f)
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| 		{
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| 			s_invFrequency = 1000.0f / s_invFrequency;
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| 		}
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| 	}
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| 
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| 	QueryPerformanceCounter(&largeInteger);
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| 	m_start = float64(largeInteger.QuadPart);
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| }
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| 
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| void b2Timer::Reset()
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| {
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| 	LARGE_INTEGER largeInteger;
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| 	QueryPerformanceCounter(&largeInteger);
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| 	m_start = float64(largeInteger.QuadPart);
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| }
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| 
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| float32 b2Timer::GetMilliseconds() const
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| {
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| 	LARGE_INTEGER largeInteger;
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| 	QueryPerformanceCounter(&largeInteger);
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| 	float64 count = float64(largeInteger.QuadPart);
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| 	float32 ms = float32(s_invFrequency * (count - m_start));
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| 	return ms;
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| }
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| 
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| #elif defined(__linux__) || defined (__APPLE__)
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| 
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| #include <sys/time.h>
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| 
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| b2Timer::b2Timer()
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| {
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|     Reset();
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| }
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| 
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| void b2Timer::Reset()
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| {
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|     timeval t;
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|     gettimeofday(&t, 0);
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|     m_start_sec = t.tv_sec;
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|     m_start_usec = t.tv_usec;
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| }
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| 
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| float32 b2Timer::GetMilliseconds() const
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| {
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|     timeval t;
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|     gettimeofday(&t, 0);
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| 	time_t start_sec = m_start_sec;
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| 	suseconds_t start_usec = m_start_usec;
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| 	
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| 	// http://www.gnu.org/software/libc/manual/html_node/Elapsed-Time.html
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| 	if (t.tv_usec < start_usec)
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| 	{
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| 		int nsec = (start_usec - t.tv_usec) / 1000000 + 1;
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| 		start_usec -= 1000000 * nsec;
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| 		start_sec += nsec;
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| 	}
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| 	
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| 	if (t.tv_usec - start_usec > 1000000)
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| 	{
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| 		int nsec = (t.tv_usec - start_usec) / 1000000;
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| 		start_usec += 1000000 * nsec;
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| 		start_sec -= nsec;
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| 	}
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| 	return 1000.0f * (t.tv_sec - start_sec) + 0.001f * (t.tv_usec - start_usec);
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| }
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| 
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| #else
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| 
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| b2Timer::b2Timer()
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| {
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| }
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| 
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| void b2Timer::Reset()
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| {
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| }
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| 
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| float32 b2Timer::GetMilliseconds() const
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| {
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| 	return 0.0f;
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| }
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| 
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| #endif
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