private void drawArrow(Graphics g, int x1, int y1, int x2, int y2) {
			if (x1 == x2 && y1 == y2) {

			} else {
				g.drawLine(x1, y1, x2, y2);

				double directionCorrection = 1;
				if (x2 > x1) {
					directionCorrection = -1;
				}
				double alpha = Math.atan((double) (y2 - y1) / (double) (x2 - x1));
				double theta1 = alpha + Math.PI / 8d;
				double theta2 = alpha - Math.PI / 8d;
				int r = (int) Math.ceil(0.5 * _fieldScaleFactor);
				double linie1x = x2 + (r * Math.cos(theta1)) * directionCorrection;
				double linie1y = y2 + (r * Math.sin(theta1)) * directionCorrection;
				double linie2x = x2 + (r * Math.cos(theta2)) * directionCorrection;
				double linie2y = y2 + (r * Math.sin(theta2)) * directionCorrection;
				g.drawLine(x2, y2, (int) linie1x, (int) linie1y);
				g.drawLine(x2, y2, (int) linie2x, (int) linie2y);
			}
		}