102 lines
4.0 KiB
C#
102 lines
4.0 KiB
C#
// UICustomBoundsFade.cs
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// 挂在使用 UI/Default-Gama shader 的 Graphic 对象上。
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// 指定一个目标 RectTransform，每帧将其世界坐标四角范围同步到 _CustomFadeRect。
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// 当前 Graphic 会在该范围内渐变，边缘外完全透明。
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using UnityEngine;
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using UnityEngine.UI;
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#if UNITY_EDITOR
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using UnityEditor;
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#endif
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namespace NLD.UI
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{
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[RequireComponent(typeof(Graphic))]
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[DisallowMultipleComponent]
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public class UICustomBoundsFade : MonoBehaviour
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{
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[Tooltip("使用 UI-Default-Gama shader 的基础材质（必须指定，否则脚本不生效）")]
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[SerializeField] private Material _baseMaterial;
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[Tooltip("目标 GameObject 的 RectTransform，渐变范围以其世界坐标四角为准")]
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public RectTransform targetRect;
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[Tooltip("渐变过渡宽度（UV 分数）：0 = 硬切边界，0.5 = 渐变延伸到 bounds 中心。与 bounds 物理尺寸无关")]
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[Range(0f, 0.5f)]
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public float softness = 0.1f;
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[Tooltip("渐变曲线指数，1 = 线性，>1 慢起快收，<1 快起慢收")]
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[Range(0.1f, 5f)]
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public float curve = 1f;
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// ── 内部状态 ──────────────────────────────────────────────────
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private Graphic _graphic;
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private Material _materialInstance;
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private static readonly int _propRect = Shader.PropertyToID("_CustomFadeRect");
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private static readonly int _propSoftness = Shader.PropertyToID("_CustomFadeSoftness");
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private static readonly int _propCurve = Shader.PropertyToID("_CustomFadeCurve");
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private const string _keyword = "USE_CUSTOM_BOUNDS_FADE";
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// ── 生命周期 ──────────────────────────────────────────────────
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private void OnEnable()
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{
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_graphic = GetComponent<Graphic>();
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if (_graphic == null) return;
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// 优先使用指定的 Gama 基础材质，否则回退到 Graphic 当前材质
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Material original = _baseMaterial != null ? _baseMaterial : _graphic.material;
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_materialInstance = new Material(original)
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{
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name = original.name + "_CustomBoundsFade"
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};
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_materialInstance.EnableKeyword(_keyword);
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_graphic.material = _materialInstance;
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SyncToMaterial();
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}
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private void OnDisable()
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{
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if (_graphic != null)
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_graphic.material = null; // 置 null 即回退到 defaultMaterial
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if (_materialInstance != null)
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{
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DestroyImmediate(_materialInstance);
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_materialInstance = null;
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}
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}
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private void LateUpdate() => SyncToMaterial();
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// ── 核心同步 ──────────────────────────────────────────────────
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private void SyncToMaterial()
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{
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if (_materialInstance == null || targetRect == null) return;
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// GetWorldCorners: [0]=BL [1]=TL [2]=TR [3]=BR
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var corners = new Vector3[4];
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targetRect.GetWorldCorners(corners);
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float xMin = corners[0].x;
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float yMin = corners[0].y;
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float xMax = corners[2].x;
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float yMax = corners[2].y;
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_materialInstance.SetVector(_propRect, new Vector4(xMin, yMin, xMax, yMax));
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_materialInstance.SetFloat (_propSoftness, softness);
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_materialInstance.SetFloat (_propCurve, curve);
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}
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#if UNITY_EDITOR
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// Editor 下实时预览（OnValidate 在 inspector 改值时调用）
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private void OnValidate()
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{
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if (!Application.isPlaying && _materialInstance != null)
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SyncToMaterial();
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}
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#endif
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}
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}
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