Book Image

Game Development Patterns and Best Practices

By : John P. Doran, Matt Casanova
Book Image

Game Development Patterns and Best Practices

By: John P. Doran, Matt Casanova

Overview of this book

You’ve learned how to program, and you’ve probably created some simple games at some point, but now you want to build larger projects and find out how to resolve your problems. So instead of a coder, you might now want to think like a game developer or software engineer. To organize your code well, you need certain tools to do so, and that’s what this book is all about. You will learn techniques to code quickly and correctly, while ensuring your code is modular and easily understandable. To begin, we will start with the core game programming patterns, but not the usual way. We will take the use case strategy with this book. We will take an AAA standard game and show you the hurdles at multiple stages of development. Similarly, various use cases are used to showcase other patterns such as the adapter pattern, prototype pattern, flyweight pattern, and observer pattern. Lastly, we’ll go over some tips and tricks on how to refactor your code to remove common code smells and make it easier for others to work with you. By the end of the book you will be proficient in using the most popular and frequently used patterns with the best practices.
Table of Contents (19 chapters)
Title Page
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
4
Artificial Intelligence Using the State Pattern

The Factory method pattern


The Factory method pattern is exactly the design pattern we need to solve our problem. The purpose of this pattern is to have a way of creating the derived class that we want without needed to specify the concreate class in our high-level module. This is done by defining an interface for creating objects, but letting subclasses decide which class to instantiate.

In our case, we will create a StageFactory interface with a method called Build that will return a Stage*. We can then create subclasses such as Level2Factory to instantiate our derived classes. Our StageManager class now only needs to know about the Stage and StageFactory abstractions:

Creating a Stage Factory

//StageManager.cpp 
void StageManager::Update() 
{ 
Stage* pStage = m_stageFactory->Build();

pStage->Init(); 

  while(currentStage == nextStage) 
    pStage->Update(); 

pStage->Shutdown(); 
m_StageFactory->Destroy(pStage);//stage must be destroyed
} 

Notice that we have moved the call...