def display_heading_line(frame, steering_angle, line_color=(0, 0, 255), line_width=5 ):
    heading_image = np.zeros_like(frame)
    height, width, _ = frame.shape

    # figure out the heading line from steering angle
    # heading line (x1,y1) is always center bottom of the screen
    # (x2, y2) requires a bit of trigonometry

    # Note: the steering angle of:
    # 0-89 degree: turn left
    # 90 degree: going straight
    # 91-180 degree: turn right
    steering_angle_radian = steering_angle / 180.0 * math.pi
    x1 = int(width / 2)
    y1 = height
    x2 = int(x1 - height / 2 / math.tan(steering_angle_radian))
    y2 = int(height / 2)

    cv2.line(heading_image, (x1, y1), (x2, y2), line_color, line_width)
    heading_image = cv2.addWeighted(frame, 0.8, heading_image, 1, 1)

    return heading_image