一个类似坦克游戏的demo程序

使用Direction类来进行方向控制

使用Dot类来计算距离

用上Direction类和Dot类之后，这个demo程序变得异常简单额。。

也没什么好说，主要透过这个例子，让大家类熟悉Direction类和Dot类的使用方法

不懂的可以在后面跟帖提问，高手如果看到什么有错误的地方，请指正出来，多谢指教

-A similar tank game demo program using the Direction class to carry out the direction of controlling the use of Dot class to calculate the distance to spend Direction class and Dot classes later, the demo program becomes extremely simple and the amount. . Also there' s really nothing, primarily through example, so that everyone familiar with the Direction class class class and Dot do not understand, you can use behind the thread to ask questions, expert If you see something is wrong place, please correct me out, thank Zhijiao