chameleon/Assets/Scripts/PlayerPoseController.cs

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Animations;
using UnityEngine.Playables;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

/// <summary>
/// Sits next to the <see cref="PlayerCharacterController"/> and holds a list of <see cref="PlayerPose"/>s
/// plus the active index. The active pose is held continuously — while idle, walking, and sprinting
/// alike — so cycling to the next pose, or the sprint reset to the default pose, shows up
/// immediately instead of only once the player comes to a stop. One key cycles to the next pose
/// (wrapping), and sprinting in any state (ground, air, wall, ceiling) snaps the selection back to the default pose.
///
/// The pose clip is played through a tiny <see cref="PlayableGraph"/> (an
/// <see cref="AnimationClipPlayable"/> on an <see cref="AnimationPlayableOutput"/>) that overrides
/// the Animator Controller's run/idle animation for as long as a pose is selected (it only hands the
/// rig back when the list is empty / the clip is null). The per-pose ceiling y-offset is routed
/// through the controller (the single writer of the model-offset transform) so it composes with the
/// wall-lean instead of fighting it.
/// </summary>
[RequireComponent(typeof(PlayerCharacterController))]
[DisallowMultipleComponent]
// Run after PlayerCharacterController (default order 0) so the ceiling / sprint state polled below is
// this frame's, and the ceiling offset resolves without a one-frame seam.
[DefaultExecutionOrder(100)]
public partial class PlayerPoseController : MonoBehaviour
{
    [Header("Poses")]
    [Tooltip("Selectable poses. Index 0 is the default pose that sprinting resets to.")]
    [SerializeField] private List<PlayerPose> poses = new();

    [Tooltip("Index the selection resets to while sprinting in any state (the default/standard pose).")]
    [Min(0)]
    [SerializeField] private int defaultPoseIndex = 0;

    [Header("Input")]
#if ENABLE_INPUT_SYSTEM
    [Tooltip("Key that cycles to the next pose (wraps at the end of the list).")]
    [SerializeField] private Key cycleKey = Key.C;
#else
    [Tooltip("Key that cycles to the next pose (wraps at the end of the list).")]
    [SerializeField] private KeyCode cycleKey = KeyCode.C;
#endif

    private PlayerCharacterController _player;
    private Animator _animator;
    private string _graphName; // cached so building the graph allocates no string from the Update path

    private int _currentIndex;

    // Playables: a held clip that overrides the Animator Controller while idle.
    private PlayableGraph _graph;
    private AnimationPlayableOutput _output;
    private AnimationClipPlayable _clipPlayable;
    private AnimationClip _activeClip;
    private bool _posePlaying;

    // Rest pose snapshot of the whole Animator subtree, taken in Awake before the Animator first
    // evaluates. An AnimationClipPlayable only writes the bones its curves cover, so a clip that
    // doesn't key a bone (an empty clip like the T-pose, or a partial one) would otherwise leave that
    // bone frozen on the previous animation. Restoring this before each pose start makes every pose
    // define the full body. meshOffsetTarget is an ancestor of the Animator, so it is never in this
    // set and the controller's lean/ceiling offset stays untouched.
    private Transform[] _restBones;
    private Vector3[] _restPos;
    private Quaternion[] _restRot;
    private Vector3[] _restScale;

    /// <summary>Index of the currently selected pose.</summary>
    public int CurrentIndex => _currentIndex;

    void Awake()
    {
        _player = GetComponent<PlayerCharacterController>();
        _animator = _player ? _player.animator : null;
        _graphName = $"{name}-Pose";
        if (_animator)
            CaptureRestPose();
        else
            Debug.LogWarning("[PlayerPoseController] No Animator on the PlayerCharacterController; poses cannot play.", this);
    }

    void Update()
    {
        if (CycleKeyPressed())
            NextPose();

        // Sprinting in any state (ground, air, wall, ceiling) snaps the selection back to the default
        // pose. Held continuously below, so the reset shows up immediately, not only once back on the floor.
        if (_player.IsSprinting)
            _currentIndex = WrapIndex(defaultPoseIndex);

        PlayerPose pose = ActivePose();

        // Hold the pose continuously — idle, walking, and sprinting alike — so a selection change
        // (cycling, or the sprint reset to the default pose above) shows immediately instead of only
        // once the player stops. PlayPose hands the rig back to the controller only when there is no
        // clip to play (empty list / null clip).
        PlayPose(pose ? pose.Clip : null);

        // Tell the controller the pose graph owns the Animator output so it stops poking the run-bool
        // (moot while overridden, and it would warn every frame). Read next frame, when this matches
        // the bound-graph state (both only change here).
        _player.AnimatorOverridden = _posePlaying;

        // Ceiling y-offset: only while stuck to the ceiling, routed through the controller so it
        // shares the wall-lean's single write of the model transform.
        float ceilingOffset = (pose && _player.IsOnCeiling) ? pose.CeilingYOffset : 0f;
        _player.SetPoseLocalYOffset(ceilingOffset);
    }

    void OnDisable()
    {
        // Hand the rig back to the Animator Controller and never leak a graph; rebuilt lazily on the
        // next idle frame. Also clear any ceiling offset we were holding.
        ReleasePose();
        if (_player)
        {
            _player.SetPoseLocalYOffset(0f);
            _player.AnimatorOverridden = false;
        }
    }

    /// <summary>Advances to the next pose, wrapping at the end of the list.</summary>
    public void NextPose() => SetPoseIndex(_currentIndex + 1);

    /// <summary>Steps back to the previous pose, wrapping at the start of the list.</summary>
    public void PreviousPose() => SetPoseIndex(_currentIndex - 1);

    /// <summary>Selects a pose by index, wrapping into range so cycling never goes out of bounds.</summary>
    public void SetPoseIndex(int index) => _currentIndex = WrapIndex(index);

    private int WrapIndex(int index)
    {
        int count = poses.Count;
        if (count == 0) return 0;
        return ((index % count) + count) % count;
    }

    private PlayerPose ActivePose()
    {
        if (poses.Count == 0) return null;
        return poses[Mathf.Clamp(_currentIndex, 0, poses.Count - 1)];
    }

    private bool CycleKeyPressed()
    {
#if ENABLE_INPUT_SYSTEM
        var keyboard = Keyboard.current;
        return keyboard != null && keyboard[cycleKey].wasPressedThisFrame;
#else
        return Input.GetKeyDown(cycleKey);
#endif
    }

    /// <summary>
    /// Plays and holds the given clip through the Playables graph, overriding the Animator
    /// Controller. No-op while the same clip is already held, so idle re-apply never restarts it.
    /// A null clip (or no animator) releases back to the controller.
    /// </summary>
    private void PlayPose(AnimationClip clip)
    {
        if (!clip || !_animator)
        {
            ReleasePose();
            return;
        }
        if (_posePlaying && _activeClip == clip)
            return;

        if (!_graph.IsValid())
        {
            _graph = PlayableGraph.Create(_graphName);
            _graph.SetTimeUpdateMode(DirectorUpdateMode.GameTime);
            _output = AnimationPlayableOutput.Create(_graph, "Pose", _animator);
        }
        if (_clipPlayable.IsValid())
            _graph.DestroyPlayable(_clipPlayable);

        // Snap un-keyed bones to rest first, so a partial or empty clip (e.g. the T-pose) defines the
        // whole body instead of inheriting the previous animation's pose. The clip then overrides the
        // bones it does key when the graph evaluates later this frame.
        ResetToRestPose();

        _clipPlayable = AnimationClipPlayable.Create(_graph, clip);
        _output.SetSourcePlayable(_clipPlayable);
        if (!_graph.IsPlaying())
            _graph.Play();

        _activeClip = clip;
        _posePlaying = true;
    }

    /// <summary>
    /// Snapshots every transform a pose clip can address (the Animator's whole subtree) in its
    /// authored rest pose. Taken in Awake before the Animator first evaluates, so it captures the rig
    /// at rest (the paintman rig's rest pose is its T-pose).
    /// </summary>
    private void CaptureRestPose()
    {
        _restBones = _animator.transform.GetComponentsInChildren<Transform>(true);
        int n = _restBones.Length;
        _restPos = new Vector3[n];
        _restRot = new Quaternion[n];
        _restScale = new Vector3[n];
        for (int i = 0; i < n; i++)
        {
            Transform t = _restBones[i];
            _restPos[i] = t.localPosition;
            _restRot[i] = t.localRotation;
            _restScale[i] = t.localScale;
        }
    }

    /// <summary>Restores the captured rest pose so an empty or partial pose clip fully defines the body.</summary>
    private void ResetToRestPose()
    {
        if (_restBones == null)
            return;
        for (int i = 0; i < _restBones.Length; i++)
        {
            Transform t = _restBones[i];
            if (!t)
                continue;
            t.localPosition = _restPos[i];
            t.localRotation = _restRot[i];
            t.localScale = _restScale[i];
        }
    }

    /// <summary>Destroys the graph so the Animator Controller (run/idle) drives the rig again.</summary>
    private void ReleasePose()
    {
        if (!_posePlaying)
            return;
        if (_graph.IsValid())
            _graph.Destroy();
        _graph = default;
        _output = default;
        _clipPlayable = default;
        _activeClip = null;
        _posePlaying = false;
    }
}