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Use of platform specific time functions instead of clock() function to avoid cross-platform problems and for better accuracy

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git-svn-id: https://reactphysics3d.googlecode.com/svn/trunk@440 92aac97c-a6ce-11dd-a772-7fcde58d38e6
This commit is contained in:
chappuis.daniel 2011-09-06 21:37:58 +00:00
parent 94e7153817
commit 10f46956b6
1 changed files with 41 additions and 9 deletions
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50
src/engine/Timer.h
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@ -25,18 +25,31 @@
#ifndef TIMER_H
#define TIMER_H
// TODO : Test this code on Windows platform
// TODO : Test this code on Linux platform
// Libraries
#include <stdexcept>
#include <iostream>
#include <ctime>
#include <cassert>
#if defined(WIN32) || defined(_WIN32) // For Windows platform
#define WINDOWS_TIME
#include <windows.h>
#else // For Mac OS or Linux platform
#include <sys/time.h>
#endif
// Namespace ReactPhysics3D
namespace reactphysics3d {
/* -------------------------------------------------------------------
Class Timer :
This class will take care of the time in the physics engine.
This class will take care of the time in the physics engine. It
uses fuunctions that depend on the current platform to get the
current time.
-------------------------------------------------------------------
*/
class Timer {
@ -64,8 +77,6 @@ class Timer {
double computeInterpolationFactor(); // Compute the interpolation factor
};
// --- Inline functions --- //
// Return the timestep of the physics engine
inline double Timer::getTimeStep() const {
return timeStep;
@ -96,8 +107,20 @@ inline bool Timer::getIsRunning() const {
// Start the timer
inline void Timer::start() {
if (!isRunning) {
#ifdef WINDOWS_TIME
LARGE_INTEGER ticksPerSecond;
LARGE_INTEGER ticks;
QueryPerformanceFrequency(&ticksPerSecond);
QueryPerformanceCounter(&ticks);
lastUpdateTime = double(ticks.QuadPart) / double(ticksPerSecond.QuadPart);
#else
// Initialize the lastUpdateTime with the current time in seconds
lastUpdateTime = std::clock() / double(CLOCKS_PER_SEC);
timeval timeValue;
gettimeofday(&timeValue, NULL);
lastUpdateTime = timeValue.tv_sec + (timeValue.tv_usec / 1000000.0);
#endif
accumulator = 0.0;
isRunning = true;
}
@ -105,9 +128,7 @@ inline void Timer::start() {
// Stop the timer
inline void Timer::stop() {
if (isRunning) {
isRunning = false;
}
isRunning = false;
}
// True if it's possible to take a new step
@ -133,9 +154,20 @@ inline double Timer::computeInterpolationFactor() {
// Compute the time since the last update() call and add it to the accumulator
inline void Timer::update() {
long double currentTime;
#ifdef WINDOWS_TIME
LARGE_INTEGER ticksPerSecond;
LARGE_INTEGER ticks;
QueryPerformanceFrequency(&ticksPerSecond);
QueryPerformanceCounter(&ticks);
currentTime = double(ticks.QuadPart) / double(ticksPerSecond.QuadPart);
#else
// Compute the current time is seconds
long double currentTime = std::clock() / double(CLOCKS_PER_SEC);
timeval timeValue;
gettimeofday(&timeValue, NULL);
currentTime = timeValue.tv_sec + (timeValue.tv_usec / 1000000.0);
#endif
// Compute the delta display time between two display frames
deltaTime = currentTime - lastUpdateTime;