参考资料： 《HTML5 Canvas 开发详解》- 莫振杰 《HTML5 Canvas 核心技术》 [https://www.runoob.com/w3cnote/html5-canvas-intro.html](https://www.runoob.com/w3cnote/html5-canvas-intro.html) [https://www.imooc.com/search/?type=course&words=canvas](https://www.imooc.com/search/?type=course&words=canvas)