python在图上画出射线及平行线

import math
import numpy as np
import cv2 as cv


def Polar2Cartesian(theata):
    """
    极坐标转直角坐标系
    :return: 斜率
    """
    pi = 3.14
    radian = pi * theata / 180
    return math.tan(radian)

def Painter(ori,theta):
    """
    painter a picture
    :param ori: origin image
    :param theta: θ
    :return: img
    """
    width, height = ori.shape[0], ori.shape[1]
    img = np.zeros((height,width))
    slope = Polar2Cartesian(theta