利用opengl写的炮弹发射小界面，能连续发射子弹，抛物线轨迹等。-Use opengl write shells fired small interface, continuous firing bullets, parabolic trajectory.

展示一个小球的平抛轨迹，并增加小球撞击地面的形变。-It shows a small ball of flat parabolic trajectory, and to increase the ball hits the ground deformation.