python实战篇(四)---Python+OpenCV画动态时钟

# 1. 新建一个画板并填充成白色
img = np.zeros((450, 450, 3), np.uint8)
img[:] = (255, 255, 255)
# 2. 画出圆盘
cv2.circle(img, center, radius, (0, 0, 0), thickness=5)

# 3. 画出60条秒和分钟的刻线
for i in range(60):
    # 最外部圆，计算A点
    x1 = center_x + (radius - margin) * math.cos(i * 6 * np.pi / 180.0)
    y1 = center_y + (radius - margin) * math.sin(i * 6 * np.pi / 180.0)
    pt1.append((int(x1), int(y1)))
    # 同心小圆，计算B点
    x2 = center_x + (radius - 15) * math.cos(i * 6 * np.pi / 180.0)
    y2 = center_y + (radius - 15) * math.sin(i * 6 * np.pi / 180.0)
    cv2.line(img, pt1[i], (int(x2), int(y2)), (255, 0, 0), thickness=2)

while (1):
    # 不断拷贝表盘图，才能更新绘制，不然会重叠在一起
    temp = np.copy(img)
    # 5. 获取系统时间，画出动态的时-分-秒三条刻线
    now_time = datetime.datetime.now()
    hour, minute, second = now_time.hour, now_time.minute, now_time.second
    # 画秒刻线
    # OpenCV中的角度是顺时针计算的，所以需要转换下
    sec_angle = second * 6 + 270 if second <= 15 else (second - 15) * 6
    sec_x = center_x + (radius - margin) * math.cos(sec_angle * np.pi / 180.0)
    sec_y = center_y + (radius - margin) * math.sin(sec_angle * np.pi / 180.0)
    cv2.line(temp, center, (int(sec_x), int(sec_y)), (203, 255, 166), 2)
    # 画分刻线
    min_angle = minute * 6 + 270 if minute <= 15 else (minute - 15) * 6
    min_x = center_x + (radius - 35) * math.cos(min_angle * np.pi / 180.0)
    min_y = center_y + (radius - 35) * math.sin(min_angle * np.pi / 180.0)
    cv2.line(temp, center, (int(min_x), int(min_y)), (186, 199, 255), 8)
    # 画时刻线
    hour_angle = hour * 30 + 270 if hour <= 3 else (hour - 3) * 30
    hour_x = center_x + (radius - 65) * math.cos(hour_angle * np.pi / 180.0)
    hour_y = center_y + (radius - 65) * math.sin(hour_angle * np.pi / 180.0)
    cv2.line(temp, center, (int(hour_x), int(hour_y)), (255, 198, 26), 15)