//=============================================================================

#include <SDL/SDL.h>

#include "Framerate.h"

namespace ATCsim { // Project ATCsim namespace.

namespace Framerate {

// These variables are only visible from inside this namespace.

// They cannot be accessed from outside with FPS::oldTime for example.

// They are initialized at startup and keep their values between function calls.

unsigned int oldTime(0);

unsigned int lastTime(0);

float speedFactor(0);

unsigned int frames(0);

unsigned int nFrames(50);

// Not initialized to zero or we'll get infinite speed.

void compute() {

// Compute framerate (aka FPS).

++frames;

if (oldTime + 1000 < SDL_GetTicks()) {

oldTime = SDL_GetTicks();

nFrames = frames;

frames = 0;

}

// Compute speed factor.

speedFactor = ( float(SDL_GetTicks() - lastTime) / 1000.0f ); // * 32.0f;

lastTime = SDL_GetTicks();

}

//----------------------------------------------------------------------------

unsigned int getFPS() {

return nFrames;

}

//----------------------------------------------------------------------------

float getSpeedFactor() {

return speedFactor;

}

}

} // End of project ATCsim namespace.