InputSystem

Attribute-driven input binding framework built on top of Unity's Input System package. Provides a declarative, reflection-based approach to connecting input actions to handler methods — subclass InputActionMapBinding, mark methods with [InputActionCallback], and the system auto-discovers and wires up bindings with automatic type conversion.

Architecture

Data Flow

Key Concepts

Concept	Description
InputActionScheme	MonoBehaviour that holds a Unity InputActionAsset and its binding handlers. The root entry point.
InputActionMapBinding	Abstract base class — subclass to define input handlers for one action map. Methods marked with [InputActionCallback] are auto-discovered.
InputActionCallback	Delegate wrapper that auto-converts between method signatures (Action, Action<CallbackContext>, Action<T>) for Unity's input callback system.
InputActionCallbackAttribute	Method attribute specifying which input action and phase a handler responds to.
InputActionPhase	Enum mapping to Unity's input phases: STARTED, PERFORMED, CANCELLED.

Quick Start

1. Create a binding class

using Paragon.Core.InputSystem;
using UnityEngine;

[Serializable]
public class PlayerMovementBinding : InputActionMapBinding
{
    [InputActionCallback("Move")]
    private void OnMove(Vector2 moveInput)
    {
        // moveInput is auto-extracted from CallbackContext.ReadValue<Vector2>()
        Debug.Log($"Moving: {moveInput}");
    }

    [InputActionCallback("Jump", InputActionPhase.STARTED)]
    private void OnJump()
    {
        // No parameters — CallbackContext is ignored
        Debug.Log("Jump!");
    }

    [InputActionCallback("Sprint", InputActionPhase.CANCELLED)]
    private void OnSprintReleased()
    {
        Debug.Log("Sprint released");
    }
}

2. Assign in the Inspector

Attach an InputActionScheme component to a GameObject, assign a Unity InputActionAsset, and the system will create binding slots for each action map. Assign your PlayerMovementBinding to the corresponding action map slot.

3. Enable at runtime

inputScheme.Enable();  // Enables all action maps and binds all handlers

Supported Callback Signatures

Signature	Behavior
void Method()	Called on input; CallbackContext is discarded
void Method(InputAction.CallbackContext ctx)	Called with full context — no wrapping needed
void Method(Vector2 value)	Auto-extracts via ctx.ReadValue<Vector2>()
void Method(float value)	Auto-extracts via ctx.ReadValue<float>()
Any void Method(T value) where T : struct	Auto-extracts via ctx.ReadValue<T>()

Classes

Class	Description
InputActionScheme	MonoBehaviour root — holds the InputActionAsset and manages bindings
InputActionMapBinding	Abstract base for declaring input handlers via attributes
InputActionCallback	Delegate wrapper with automatic type conversion
InputActionCallbackAttribute	Method attribute for declaring input action handlers
InputActionPhase	Enum for input action phases

See Also

• Paragon Core — parent framework