velocity.py 文件源码

def get_points(event, x, y, flags, param):
    global lpnts, mode, counter, which_intersect

    if event == cv2.EVENT_LBUTTONDOWN:
        lpnts = np.append(lpnts, np.array([[x, y]]), axis=0)
        cv2.polylines(img, [lpnts], False, (0, 0, 255))
        if lpnts.size > 2:
            if mode == 0:

                #check(l1, lpnts[-1], lpnts[-2])
                if check(l1, lpnts[-1], lpnts[-2]):
                    which_intersect = 0
                    mode = 1
                #check(l2, lpnts[-1], lpnts[-2])
                if check(l2, lpnts[-1], lpnts[-2]):
                    which_intersect = 1
                    mode = 1

            elif mode == 1:

                counter += 1
                if check(lines[(which_intersect + 1) % 2], lpnts[-1], lpnts[-2]):
                    mode = 3
                    print counter


# check if the new point crosses a line