Pulling It All Together

All of these components are used to compose and display what amounts to a single image on the screen. Each time the game renders to the screen, it is said to have rendered a frame. Frames are similar to a strip of developed movie film. Figure 2.2 analyzes each one of these frames over a short segment of a game.

Figure 2.2: Transitions from frame to frame in a game.

You can see an illusion of movement is created by making subtle and small movements as each frame progresses. Interactive entertainment capitalizes on this measure of control. The illusion of movement in a game is based on the rapid display of each frame. Interactivity comes from the fact that a game passes through a set of rules that determines how the game looks each time you pass through the game loop. Because games tend to use all the resources that a given machine may have, there are differing philosophies regarding how to present the frames in a game. Should frames be shown as frequently as possible, or should they be limited in some regard?