m_time.cpp

C++课程大学作业的一次任务

////////////////////////////////
//       M_TIME.CPP
// CLASS M_Time
// 	IN-GAME	TIME SIGNAL GENERATOR
//
// PROJECT: Ultra Pac Man
// LAST UPDATE: Nov. 12th 2001
// PROGRAMER: Mal
////////////////////////////////

#include "m_time.h"

//Pre-defined Global pointer
M_Time* thisTimer;

unsigned breakflag;
long clockticks;
millisec MillisecTimer;

M_Time::M_Time()
{
	lFrameCounter = 0;
	lNextFrameTime = 0;
	fMaxFPS = DEFAULTMAXFPS;
	fFPS = fMaxFPS;
	//calculates how long does a frame take if runs under desired MaxFPS
	fFrameTime = 1000/fMaxFPS;
}

void M_Time::Reset()
{
	clockticks = 0;
	lFrameCounter = 0;
	lNextFrameTime = 0;
}

long M_Time::GetFrameCounter()
{
 return lFrameCounter;
}

float M_Time::GetMaxFPS()
{
 return fMaxFPS;
}

float M_Time::GetFPS()
{
 return fFPS;
}

bool M_Time::SetMaxFPS(float DesiredFPS)
{
	if(DesiredFPS>0 && DesiredFPS<1001)
	{
		fMaxFPS = DesiredFPS;
		fFrameTime = 1000/fMaxFPS;
		return M_NORMAL;
	}
 return M_ERR_MAXFPS_SETTING;
}

long M_Time::CreateSnapshot()
{
	lCurTime = clockticks;//Get current clockticks
	lNextFrameTime = lCurTime + fFrameTime;

 return (++lFrameCounter);
}

void M_Time::FPSDelay()
{
	if(clockticks<lNextFrameTime)
	{
		//Calculate actual FPS
		fFPS = fMaxFPS;

		while(clockticks<lNextFrameTime);
	}
	else
	{
		fFPS = 1000/(clockticks-lCurTime);
	}
}