js文档工具：
jsdoc3
示例： 两种模式：full stack 和 side-by-side
The World is now an infinite plain extending in all directions as far as you need, with 0,0 being the centre of the world. The Camera now roams within this endless world, which you can resize dynamically. This gives you some powerful new features - for example you can now rotate the world around its axis, for truly different sorts of games. You can extend it vertically for a scrolling shoot-em-up or in all directions for an 8-way scroller. It's a whole lot more powerful and we made a new example game Tanks to show it off.