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Input Layers

Input layers let you control which part of your game receives input first. When a dialog is open, it should consume input before the game logic sees it.

Quick Start

public class GameScene : Scene
{
    private readonly InputLayerManager _layerManager;

    public GameScene(InputLayerManager layerManager)
    {
        _layerManager = layerManager;
    }

    protected override void OnEnter()
    {
        var uiLayer = _layerManager.CreateLayer(""UI"", priority: 1000);
        var gameLayer = _layerManager.CreateLayer(""Game"", priority: 0);
    }

    protected override void OnUpdate(GameTime gameTime)
    {
        _layerManager.ProcessInput();

        if (!_layerManager.KeyboardConsumed)
        {
            HandleGameKeyboard();
        }

        if (!_layerManager.MouseConsumed)
        {
            HandleGameMouse();
        }
    }
}

How It Works

  1. Layers are processed by priority — highest first
  2. A layer can consume input — returning true blocks lower layers
  3. Check consumption flags — KeyboardConsumed, MouseConsumed

Typical priorities:

Layer Priority Purpose
Dialog/Modal 2000 Critical UI
Normal UI 1000 Menus, HUD
Game 0 Player input
Background -1000 Ambient input

Best Practices

  1. Always call ProcessInput() first in OnUpdate
  2. Check consumption flags before handling game input
  3. Return true from layer handlers to consume input
  4. Unregister layers in OnExit or OnUnloadAsync
protected override void OnUpdate(GameTime gameTime)
{
    _layerManager.ProcessInput(); // Always first!

    if (!_layerManager.KeyboardConsumed && Input.IsKeyDown(Key.W))
    {
        MovePlayer();
    }
}

Next Steps