It is a subject that is studied in any degree related to programming, with the book " Design Patterns, Elements of Reusable Object-Oriented Software " by Gamma, Helm, Johnson and Vlissides (the famous Group of Four) being the classic book that started this branch of study.
However, when told in an academic way, design patterns can be difficult to understand and their application is not always clear. This is precisely where Henrique Campos' " Game Development Patterns with Godot 4 " shines.
Campos quite successfully selects 9 of the 23 design patterns enunciated by the Group of Four and explains them in a clear, simple way, rich in examples applied to game development. The patterns chosen by Campos seem to me to be the most useful and the ones with the most immediate application in any game. I have not missed any of the other remaining design patterns because they always seemed too abstract and esoteric to me.
In a very original way, Campos presents his examples based on dialogues or communications between the designer of a fictional game and his programmer. In these communications, the designer demands functionalities focused on enriching specific aspects of a game, while the programmer receives these demands and has to fit them with his objective of creating a scalable and easy-to-maintain code. In each of these examples, a specific design pattern is explained as the best solution to fit the designer's demand with the programmer's objective.
Following this scheme, the author explains the singleton pattern, the observer pattern, the factory, state machines, the command pattern, the strategy pattern, decorators, service locators and event queues. All of this in an order of increasing complexity and based on the previous ones. Along the way, he also explains in a simple but effective way basic principles of development such as those of object-oriented programming or the SOLID principles.
The examples are implemented in GDScript, using Godot 4. I must admit that I was initially a bit wary of the book because I didn't think GDScript was a rich enough language to illustrate these patterns (I admit that I develop in Godot C#). However, the field code is very expressive and GDScript is so concise that the examples end up being read as if they were pseudocode. In the end I didn't miss C#, because the GDScript code managed to convey the idea of the examples in just a few lines, which made them very easy to read and understand.
Therefore, I think it is a highly recommended book that makes a subject that is often repulsive due to the excessively academic treatment it has received in other previous works, enjoyable and fun. If you give it a chance, I think you will enjoy it and it will help you considerably to improve the quality of your code.
