将一条直线朝着划线方向进行偏移

 写了一个将一条link朝着划线方向偏移一定的距离。供参考。

def cal_poi(geom1,geom2,dis):
    """
    将一条直线link朝着划线方向偏移
    :param geom1:
    :param geom2:
    :param dis:
    :return:
    """
    dis = int(dis)
    angle = cal_angle(LineString([geom1,geom2]))
    x_sum = 0
    y_sum = 0
    if angle == 0 or angle == 360:
        x_sum = 0
        y_sum = dis
    elif angle < 90:
        x_sum = dis*abs(math.sin(angle))
        y_sum = dis*abs(math.cos(angle))
    elif angle == 90:
        x_sum = dis
        y_sum = 0
    elif angle < 180:
        x_sum = dis*abs(math.sin(180 - angle))
        y_sum = -dis*abs(math.sin(180 - angle))
    elif angle == 180:
        x_sum = 0
        y_sum = -dis
    elif angle < 270:
        x_sum = -dis*abs(math.sin(270 - angle))
        y_sum = -dis*abs(math.sin(270 - angle))
    elif angle == 270:
        x_sum = -5
        y_sum = 0
    elif angle < 360:
        x_sum = -dis*abs(math.sin(360 - angle))
        y_sum = dis*abs(math.sin(360 - angle))
    x = geom2.x + x_sum
    y = geom2.y + y_sum
    return LineString([geom1,Point(x, y)])