libsegl/fpsmanager.cpp

#include "fpsmanager.h"

namespace segl {

FPSManager::FPSManager(int _fps) {
	setFPS(_fps);
	frames = 0;
	framerate = 0;
	lastticks = SDL_GetTicks();
}

void FPSManager::setFPS(int _fps) {
	if(_fps<1 || _fps > 500)
		return;
	tickrate = 1000.0f/(float)_fps;
}

void FPSManager::delay() {
	frames++;
	
	Uint32 now    = SDL_GetTicks();
	Uint32 target = lastticks + (Uint32)(tickrate * (float)frames);
	
	if(now <= target) {
		SDL_Delay(target-now);
	} else {
		framerate = frames/((now-lastticks)/1000.0f);
		frames = 0;
		lastticks = SDL_GetTicks();
	}
}

float FPSManager::getFPS() {
	return framerate;
}

} // namespace segl