Coordinate pointOnLine(float x1, float y1, float x2, float y2, float distance){
    	float vx = x2 - x1;
    	float vy = y2 - y1;
    	float mag = (float) Math.sqrt(vx*vx + vy*vy);
    	vx /= mag;
    	vy /= mag;
    	
    	float px = (float)x1 + vx * (mag + distance);
    	float py = (float)y1 + vy * (mag + distance);
    	
    	return new Coordinate(px,py);
    }