Game design patterns are reusable solutions to common problems that arise in game development. They help you structure your code, organize your assets, and implement your gameplay features. In this article, we will explore some of the most popular game design patterns for mobile games, and how they can benefit your projects.
MVC stands for Model-View-Controller, and it is a widely used pattern for separating the data, logic, and presentation of your game. The model is responsible for storing and manipulating the game state, the view is responsible for rendering the graphics and sound, and the controller is responsible for handling the user input and game events. By using MVC, you can make your code more modular, testable, and maintainable, as well as avoid tight coupling between different components.
I love design patterns and MVC might be a great way of separating layers of abstraction and handling communication in larger UI systems in i.e. mobile games but what I always say is to not do it for art's sake. You should definitely think about that or MVVC/MVP (model view presenter) but calculate if it's really fit your needs and time constraints. Not all game engines UI systems architecture and available components will perfectly fit with these patterns. Some of these require usage of interfaces and depending on how flexible you would like your UI views to be (i.e. made in code as well as in blueprints) you may come across some engine-specific issues. Still it's definitely worth giving it a try for sake of maintaining a good architecture!
Sometimes this is overkill and doesn't jive well with standard (and more direct) development methods inside Unity, but for sure a controller should be separate from game object data when there is a one to many relationship, i.e. a lot of objects of the same class.
A finite state machine is a pattern that allows you to define the behavior of your game objects based on their current state and the transitions between them. For example, a character can have states such as idle, walking, jumping, and attacking, and switch between them based on input or triggers. A finite state machine can help you simplify your code, avoid complex if-else statements, and create more dynamic and responsive gameplay.
Using polymorphism in an object oriented programming language, you can create an elegant finite state machine instead of using switch statements with an array.
The observer pattern is a pattern that allows you to create a communication system between your game objects without direct references. The idea is that you have one or more subjects that broadcast messages or events, and one or more observers that subscribe to those messages or events and react accordingly. For example, you can have a subject that emits a score update event, and an observer that displays the score on the screen. The observer pattern can help you decouple your game objects, reduce dependencies, and increase flexibility.
The singleton pattern is a pattern that ensures that you have only one instance of a class or object in your game. This can be useful for managing global variables, settings, or resources that need to be accessed from anywhere in your game. For example, you can have a singleton that stores the game manager, the audio manager, or the save system. The singleton pattern can help you avoid creating multiple copies of the same object, simplify your code, and improve performance.
An important thing about Singleton Pattern is that you should really know where you can't use it. It is really useful for manager classes and easy to implement. For this reason unexperienced developers mostly make this mistake. But if you use it too much and don't handle the dependencies with other classes, objects and scenes/maps etc. your code can become a "sphagetti monster god" really quick. Most of the senior game programmers trying to use singleton at minimum.
The factory pattern is a pattern that allows you to create objects without specifying their exact class or type. Instead, you use a factory class or method that returns an object based on some parameters or conditions. For example, you can have a factory that creates enemies of different types based on the level or difficulty of your game. The factory pattern can help you abstract the creation process, reduce hard-coded values, and support polymorphism.
The decorator pattern is a pattern that allows you to add new functionality or behavior to an existing object without modifying its original class or structure. Instead, you wrap the object with another object that implements the same interface or inherits from the same class, and add the extra functionality in the wrapper. For example, you can have a decorator that adds a shield effect to a character, or a power-up effect to a weapon. The decorator pattern can help you extend your objects, avoid subclassing, and follow the open-closed principle.