timer.h

小型的3D游戏引擎

/////////////////////////////////////////////////////
//                     TIMER.H                     //
//    This is the timer class used mostly to get   //
//     a constante movement speed independet on    //
//           FPS and to calculate the FPS          //
//            Based on NeHe's timer code           //
/////////////////////////////////////////////////////


#ifndef TIMERH
#define TIMERH

#include <windows.h>

class GcTimer
{
public:

	// Cponstructor / Destructor
	GcTimer();
	~GcTimer();

	// Returns the time since the program started
	float GetTime();

	// Return the FPS (as a string)
	char *FPS();

	// The timing function, StartTimer is caled 
	// before the main loop and DoTimer inside the loop
	void  StartTimer();
	void  DoTimer();

	// Return the movements constante (for constant movement speed on all computers)
	float CalcMove(float desDistance) { return desDistance * secsPerFrame; }


private:
	__int64			frequency;					// Timer Frequency
	float			resolution;					// Timer Resolution
	unsigned long	mm_timer_start;				// Multimedia Timer Start Value
	unsigned long	mm_timer_elapsed;			// Multimedia Timer Elapsed Time
	bool			performance_timer;			// Using The Performance Timer?
	__int64			performance_timer_start;	// Performance Timer Start Value
	__int64			performance_timer_elapsed;	// Performance Timer Elapsed Time

	float time;			// Used to check the current time
	float timeDiff;		// Used to determine the time elapsed
	float secsPerFrame; // Used to hold the value for how many seconds have elapsed between frames
	float lastTime;		// Used to see if it's time to update the FPS
	char  buffer[20];	// Used for printing
};

#endif