Improve the StateMachine to Support Parameters in Transitions

[rluders]

📌 Description

The StateMachine currently handles state transitions well but does not allow additional information to be passed between states. We need to improve this functionality to allow parameters to be included.

🎯 Goals

• Add parameter support for state transitions.
• Improve state-to-state communication.
• Create unit tests to ensure transitions work correctly.

📂 Related Files

• state_machine/state_machine.gd
• state_machine/state.gd

✅ Acceptance Criteria

• States can receive parameters upon transition.
• The StateMachine can store the last state.
• A method exists to query the current state and its parameters.

[rluders]

I think that I already implemented this partially.

[amitnos123]

Not sure, if the right place to ask.
Why are the StateMachine and State extending from Node, not object?

[rluders]

Not sure, if the right place to ask.
Why are the StateMachine and State extending from Node, not object?

That’s a good question!

The StateMachine and State extend from Node instead of Object mainly because they need to be part of the scene tree. This allows them to take advantage of Godot’s built-in lifecycle methods (_ready, _process, _physics_process, etc.) and enables the StateMachine to detect and manage child State nodes dynamically.

If they were just Objects, we would have to manually manage their lifecycle and interactions, making integration with the scene tree more cumbersome. By using Node, states can be defined in the scene hierarchy, allowing for a more flexible and visual approach to state composition.

[amitnos123]

I remember reading in Godot's manual about not using everything as a node. Sharing the link here
When and how to avoid using nodes for everything

[rluders]

Cool. But I don't mind. Unless Objects can also be drag a dropped to the scene and have its properties accessible by the inspector.

[rluders]

BTW, the state machine here is just a "plus". There is other well known FSM that can be easily used with the framework. This is basically the main reason why I don't care much.