上QQ阅读APP看书，第一时间看更新
The game objects
Each game is made of some objects. These can be images, or sounds, but also complex structures, such as a game character and its abilities. In our game, we have a few objects, as follows:
- The cities we have to defend
- The rocket launchers that will fire our rockets
- The rockets themselves
- The bombs that will fall down on our precious cities and try to destroy them
- Explosions that will show up once a rocket bursts into pieces (the particle clouds from these explosions will be the real harm to the bombs; if they collide with an explosion cloud, the bombs will be destroyed)
There are few more elements/objects to the game, such as the game UI (score, background, and so on), but we will concentrate on the ones just listed. Each object will be built with a separate class.