OpenCV之鼠标操作绘制图形

#coding=utf-8

import cv2
import numpy as np
# 全局变量
drawing = False  # 是否开始绘制
mode = 'none'  # 当前绘制模式
start_x, start_y = -1, -1  # 绘制起点坐标

# 鼠标回调函数
def draw_shape(event, x, y, flags, param):
    global drawing, start_x, start_y, mode

    if (event & cv2.EVENT_LBUTTONDOWN == cv2.EVENT_LBUTTONDOWN):
        drawing = True
        start_x, start_y = x, y

    elif (event & cv2.EVENT_LBUTTONUP &#