static float getAngle(float x, float y) {
		if(x >= 0 && y >= 0) return (float) atan(y/x);
		if(x  < 0 && y >= 0) return (float) (pi - atan(-y/x));
		if(x  < 0 && y  < 0) return (float) (pi + atan(y/x));
		if(x >= 0 && y  < 0) return (float) (2*pi - atan(-y/x));
		return 0;
	}