Learning XNA 3.0

Chapter 4. Applying Some Object-Oriented Design

Congratulations! You built the beginnings of a rudimentary game at the end of the previous chapter. You're making some real progress here. However, the way that we've done things thus far, while good for educational purposes, is very inefficient from a design standpoint. A sound design will always increase development efficiency.

You probably noticed how painful it was to add a new sprite object to your project. Especially if you need to add an object that will animate, use collision detection, and move, there are a lot of variables and other code that must be duplicated, and as a result your code is becoming quite a mess. If you continue down this path, things will quickly get out of hand. So, let's take a few minutes to apply some sound object-oriented design to your system—this will make things a lot easier for you down the road.

Designing Your Classes

If you were doing serious game development, you'd want to expand further on the design in this chapter and fine-tune it to meet your needs. We don't have time to tweak your design to how you'd want it for a commercial-quality application, but there are some changes you can make that will result in a huge improvement over what you have thus far.

First things first, let's look at your objects. The basic visual object in a 2D game is a sprite. Based on the code you put together in previous chapters, you have two different types of objects: objects that are controlled by the player, and objects ...