Hierarchical Finite State Machine Demo 4.2-31d1c0c Demos 4.2 Featured

Submitted by user Godot Engine; MIT; 2024-03-28

This example shows how to apply the State machine programming pattern in GDscript, including Hierarchical States, and a pushdown automaton.

Why use a state machine:

States are common in games. You can use the pattern to:

1. Separate each behavior and transitions between behaviors, thus make scripts shorter and easier to manage.

2. Respect the Single Responsibility Principle. Each State object represents one action.

3. Improve your code's structure. Look at the scene tree and FileSystem tab: without looking at the code, you'll know what the Player can or cannot do.

You can read more about States in the excellent Game Programming Patterns ebook: https://gameprogrammingpatterns.com/state.html

Language: GDScript

Renderer: Compatibility