MovementController.cs

using System.Numerics;
using Gondwana.Drawing.Coordinates;
using Gondwana.Physics.Movement.Scripted;
using Gondwana.Scenes;
 
namespace Gondwana.Physics.Movement;

public sealed partial class MovementController : IDisposable
{
    private readonly ISceneLayerCoordinates? _coords;
    private readonly SceneLayer? _sceneLayer;
    private readonly IMovable _mover;
    private MovementState _state;

    public event Action<ScriptedMovement>? ScriptedMovementStarted;

    public event Action<ScriptedMovement>? ScriptedMovementStopped;
 
    // Bind to one target + initial state. Optional layer when you need Grid↔Pixel & wrapping.
    internal MovementController(
        IMovable mover,
        MovementState initial,
        SceneLayer? layer = null)
    {
        _mover = mover;
        _state = initial;
 
        if (layer is not null)
        {
            _sceneLayer = layer;
 
            _coords = layer.CoordinateSystem
                ?? throw new ArgumentException(
                    "SceneLayer must have a CoordinateSystem.",
                    nameof(layer));
        }
    }

    internal bool AdvanceMovement(float dt)
    {
        // Follow owns the frame if engaged.
        if (AdvanceFollow())
            return true;
 
        // Scripted tween/toward runs next.
        if (AdvanceScripted(dt))
            return true;
 
        // Finally, physics integration.
        return AdvanceIntegrated(dt);
    }

    public MovementState MovementState => _state;

    public bool IsFollowing =>
        _followHard ||
        _followPixel is not null ||
        _followGridTarget is not null;

    public bool IsScripted =>
        _state.Script.Type != MovementScriptType.None;

    public bool IsIntegratedActive =>
        !IsFollowing &&
        !IsScripted &&
        _state.HasMotion;

    public bool WrapX { get; set; }

    public bool WrapY { get; set; }

    public void StopAllMovement()
    {
        Unfollow();
 
        _state.Velocity = Vector2.Zero;
        _state.Acceleration = Vector2.Zero;
    }

    public void Dispose()
    {
        _scriptCompleted = null;
 
        ScriptedMovementStarted = null;
        ScriptedMovementStopped = null;
    }
}