AIC-Project/Client/Assets/Spine/Runtime/spine-unity/Components/Following/PointFollower.cs

/******************************************************************************
 * Spine Runtimes License Agreement
 * Last updated April 5, 2025. Replaces all prior versions.
 *
 * Copyright (c) 2013-2026, Esoteric Software LLC
 *
 * Integration of the Spine Runtimes into software or otherwise creating
 * derivative works of the Spine Runtimes is permitted under the terms and
 * conditions of Section 2 of the Spine Editor License Agreement:
 * http://esotericsoftware.com/spine-editor-license
 *
 * Otherwise, it is permitted to integrate the Spine Runtimes into software
 * or otherwise create derivative works of the Spine Runtimes (collectively,
 * "Products"), provided that each user of the Products must obtain their own
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 *****************************************************************************/

#if UNITY_2018_3 || UNITY_2019 || UNITY_2018_3_OR_NEWER
#define NEW_PREFAB_SYSTEM
#endif

#if !SPINE_AUTO_UPGRADE_COMPONENTS_OFF
#define AUTO_UPGRADE_TO_43_COMPONENTS
#endif

using UnityEngine;
using UnityEngine.Serialization;

namespace Spine.Unity {

#if NEW_PREFAB_SYSTEM
	[ExecuteAlways]
#else
	[ExecuteInEditMode]
#endif
	[AddComponentMenu("Spine/Point Follower")]
	[HelpURL("https://esotericsoftware.com/spine-unity-utility-components#PointFollower")]
	public class PointFollower : MonoBehaviour, IHasSkeletonRenderer, IHasSkeletonComponent, IUpgradable {

		public SkeletonRenderer skeletonRenderer;
		public ISkeletonRenderer SkeletonRenderer { get { return this.skeletonRenderer; } }
		public ISkeletonRenderer Renderer { get { return this.skeletonRenderer; } }
		public ISkeletonComponent SkeletonComponent { get { return skeletonRenderer as ISkeletonComponent; } }

		[SpineSlot(dataField: "skeletonRenderer", includeNone: true)]
		public string slotName;

		[SpineAttachment(slotField: "slotName", dataField: "skeletonRenderer", fallbackToTextField: true, includeNone: true)]
		public string pointAttachmentName;

		public bool followRotation = true;
		public bool followSkeletonFlip = true;
		public bool followSkeletonZPosition = false;

		Transform skeletonTransform;
		bool skeletonTransformIsParent;
		PointAttachment point;
		Bone bone;
		bool valid;
		public bool IsValid { get { return valid; } }

#if UNITY_EDITOR && AUTO_UPGRADE_TO_43_COMPONENTS
		protected void Awake () {
			if (!Application.isPlaying && !wasUpgradedTo43) {
				UpgradeTo43();
			}
		}
#endif

		public void Initialize () {
			valid = skeletonRenderer != null && skeletonRenderer.valid;
			if (!valid)
				return;

			UpdateReferences();

#if UNITY_EDITOR
			if (Application.isEditor) LateUpdate();
#endif
		}

		private void HandleRebuildRenderer (ISkeletonRenderer skeletonRenderer) {
			Initialize();
		}

		void UpdateReferences () {
			skeletonTransform = skeletonRenderer.transform;
			skeletonRenderer.OnRebuild -= HandleRebuildRenderer;
			skeletonRenderer.OnRebuild += HandleRebuildRenderer;
			skeletonTransformIsParent = Transform.ReferenceEquals(skeletonTransform, transform.parent);

			bone = null;
			point = null;
			if (!string.IsNullOrEmpty(pointAttachmentName)) {
				Skeleton skeleton = skeletonRenderer.Skeleton;

				Slot slot = skeleton.FindSlot(slotName);
				if (slot != null) {
					int slotIndex = slot.Data.Index;
					bone = slot.Bone;
					point = skeleton.GetAttachment(slotIndex, pointAttachmentName) as PointAttachment;
				}
			}
		}

		void OnDestroy () {
			if (skeletonRenderer != null)
				skeletonRenderer.OnRebuild -= HandleRebuildRenderer;
		}

		public void LateUpdate () {
#if UNITY_EDITOR
			if (!Application.isPlaying) skeletonTransformIsParent = Transform.ReferenceEquals(skeletonTransform, transform.parent);
#endif

			if (point == null) {
				if (string.IsNullOrEmpty(pointAttachmentName)) return;
				UpdateReferences();
				if (point == null) return;
			}

			Vector2 worldPos;
			var bonePose = bone.AppliedPose;
			point.ComputeWorldPosition(bonePose, out worldPos.x, out worldPos.y);
			float rotation = point.ComputeWorldRotation(bonePose);

			Transform thisTransform = this.transform;
			if (skeletonTransformIsParent) {
				// Recommended setup: Use local transform properties if Spine GameObject is the immediate parent
				thisTransform.localPosition = new Vector3(worldPos.x, worldPos.y, followSkeletonZPosition ? 0f : thisTransform.localPosition.z);
				if (followRotation) {
					float halfRotation = rotation * 0.5f * Mathf.Deg2Rad;

					Quaternion q = default(Quaternion);
					q.z = Mathf.Sin(halfRotation);
					q.w = Mathf.Cos(halfRotation);
					thisTransform.localRotation = q;
				}
			} else {
				// For special cases: Use transform world properties if transform relationship is complicated
				Vector3 targetWorldPosition = skeletonTransform.TransformPoint(new Vector3(worldPos.x, worldPos.y, 0f));
				if (!followSkeletonZPosition)
					targetWorldPosition.z = thisTransform.position.z;

				Transform transformParent = thisTransform.parent;
				if (transformParent != null) {
					Matrix4x4 m = transformParent.localToWorldMatrix;
					if (m.m00 * m.m11 - m.m01 * m.m10 < 0) // Determinant2D is negative
						rotation = -rotation;
				}

				if (followRotation) {
					Vector3 transformWorldRotation = skeletonTransform.rotation.eulerAngles;
					thisTransform.SetPositionAndRotation(targetWorldPosition, Quaternion.Euler(transformWorldRotation.x, transformWorldRotation.y, transformWorldRotation.z + rotation));
				} else {
					thisTransform.position = targetWorldPosition;
				}
			}

			if (followSkeletonFlip) {
				Vector3 localScale = thisTransform.localScale;
				Skeleton skeleton = skeletonRenderer.Skeleton;
				localScale.y = Mathf.Abs(localScale.y) * Mathf.Sign(skeleton.ScaleX * skeleton.ScaleY);
				thisTransform.localScale = localScale;
			}
		}

		#region Transfer of Deprecated Fields
#if UNITY_EDITOR && AUTO_UPGRADE_TO_43_COMPONENTS
		public virtual void UpgradeTo43 () {
			wasUpgradedTo43 = true;
			if (skeletonRenderer == null) {
				Component previousReference = previousSkeletonRenderer != null ? previousSkeletonRenderer : this;
				skeletonRenderer = previousReference.GetComponent<SkeletonRenderer>();
				if (skeletonRenderer == null)
					Debug.LogError("Please manually re-assign SkeletonRenderer at PointFollower, " +
						"automatic upgrade failed.", this);
			}
		}
		[SerializeField, HideInInspector, FormerlySerializedAs("skeletonRenderer")] Component previousSkeletonRenderer;
		[SerializeField] protected bool wasUpgradedTo43 = false;
#endif
		#endregion
	}
}