Godot FSM

This is an example of encapsulating a character's states using a fsm (Finite State Machine) model.

How it works?

First of all let's talk about the structure:

About the Nodes we have:

• Parent KinematicBody2D,
• CollisionShape2D,
• Sprite2D,
• AnimationPlayer,
• Raycast2D,
• CanvasLayer (Just to hold some labels for debug),
• Node for FSM with the character's states as children.

Starting for the FSM Node Script:

• Store a map with the states,
• Store the active state,
• Have a function to change the state,
• The only one with directly access to other States.

Every state's script have his own:

• _enter method (will be executed when entered in this state, like play an animation),
• _update method (will process his behaviours and rules),
• _handle_input method (will process his inputs and methods that the state allows),
• _exit method (will be executed when change from this state to another).

The Kinematic Body script have the _process and _input method, that just access the FSM Node for _update and _handle_input methods from the active state.