OPGL绘制的地球 显示一个网球体，定义裁剪平面，对球体进行裁剪，设置键盘控制参数，使网球体旋转，以便从不同的角度观察裁剪情况。-The OPGL draw the Earth a tennis body, defined clipping plane, the sphere cutting, to set keyboard control parameters, the tennis body rotation, in order to cut from different angles.

打乒乓球的小游戏，点击开始按钮即可开始游戏，用鼠标点击并拖拽下边的正方形即可接球，游戏过程中先取得11分即为获胜方，同时游戏结束。-Table tennis game, click the Start button to start the game, use the mouse to click and drag the bottom of the square to the ball during the game to score 11 points first is the winner