GodotComponentTest/entities/Workbench.cs

using System.Diagnostics;
using Godot;

public class Workbench : Entity {
    public bool IsMouseOver;

    private MeshInstance _geometry;

    [Signal]
    public delegate void EntityClicked(Entity entity);

    // Called when the node enters the scene tree for the first time.
    public override void _Ready() {
        _geometry = GetNode<MeshInstance>("Geometry/workbench");
        Debug.Assert(_geometry != null);

        Connect("input_event", this, nameof(OnAreaInputEvent));
        Connect("mouse_entered", this, nameof(OnAreaMouseEntered));
        Connect("mouse_exited", this, nameof(OnAreaMouseExited));
    }

    public void OnAreaInputEvent(Node camera, InputEvent inputEvent, Vector3 position, Vector3 normal,
        int shapeIndex) {
        if (IsMouseOver && inputEvent is InputEventMouseButton) {
            InputEventMouseButton mouseButtonEvent = (InputEventMouseButton)inputEvent;
            if (mouseButtonEvent.ButtonIndex == 1 && mouseButtonEvent.Pressed) {
                EmitSignal("EntityClicked", this);
            }
        }
    }

    public void OnAreaMouseEntered() {
        IsMouseOver = true;
        SpatialMaterial overrideMaterial = new();
        overrideMaterial.AlbedoColor = new Color(1, 0, 0);
        _geometry.MaterialOverride = overrideMaterial;
    }

    public void OnAreaMouseExited() {
        IsMouseOver = false;
        _geometry.MaterialOverride = null;
    }

//  // Called every frame. 'delta' is the elapsed time since the previous frame.
//  public override void _Process(float delta)
//  {
//      
//  }
}