def METHOD_NAME(curvature, direction, center_x, center_y):
    """
    :param curvature: 1/curvature radius
    :param direction: float, angle in radian
    :param center_x: center of source in image plane
    :param center_y: center of source in image plane
    :return: center_spp_x, center_spp_y
    """
    center_x_spp = center_x - np.cos(direction) / curvature
    center_y_spp = center_y - np.sin(direction) / curvature
    return center_x_spp, center_y_spp