Limit FPS in Libgdx game with Thread.sleep() doesn't work

Question

I am developing a little game for android with libgdx and want to limit the fps to 30 to save battery. The problem is that it doesn\'t work. The fps just drops from 60 to 56

Answer 1

import com.badlogic.gdx.utils.TimeUtils;

public class FPSLimiter {

    private long previousTime = TimeUtils.nanoTime();
    private long currentTime = TimeUtils.nanoTime();
    private long deltaTime = 0;
    private float fps;

    public FPSLimiter(float fps) {
        this.fps = fps;
    }

    public void delay() {
        currentTime = TimeUtils.nanoTime();
        deltaTime += currentTime - previousTime;
        while (deltaTime < 1000000000 / fps) {
            previousTime = currentTime;
            long diff = (long) (1000000000 / fps - deltaTime);
            if (diff / 1000000 > 1) {
                try {
                    Thread.currentThread().sleep(diff / 1000000 - 1);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            currentTime = TimeUtils.nanoTime();
            deltaTime += currentTime - previousTime;
            previousTime = currentTime;
        }
        deltaTime -= 1000000000 / fps;
    }
}