新增回声扩散特效

unity/Assets/eco/EchoSystem.cs

@@ -50,16 +50,38 @@ namespace IndianOceanAssets.Engine2_5D
         [Tooltip("描边颜色（默认白色，可自定义）")]
         [SerializeField] private Color outlineColor = Color.white;
 
+        [Header("红圈视觉")]
+        [Tooltip("红圈颜色")]
+        [SerializeField] private Color ringColor = new Color(1f, 0.15f, 0.1f, 1f);
+
+        [Tooltip("红圈宽度（世界单位）")]
+        [SerializeField] private float ringVisualWidth = 2.5f;
+
+        [Tooltip("红圈离地高度（避免Z-fighting）")]
+        [SerializeField] private float ringYOffset = 0.1f;
+
+        [Tooltip("红圈渐隐总时间（秒）。从释放瞬间开始线性渐隐，到 0 后隐藏。默认 4 秒")]
+        [SerializeField] private float ringFadeTime = 4f;
+
+        [Tooltip("红圈扩散速度（世界单位/秒），独立于波纹扩散速度")]
+        [SerializeField] private float ringExpandSpeed = 15f;
+
         [Header("冷却")]
         [Tooltip("回声冷却时间（秒）")]
         [SerializeField] private float cooldown = 3f;
 
+        // 红圈视觉
+        private GameObject _ringVisual;
+        private Material _ringMaterial;
+
         // 全局 shader 属性 ID（通过 Shader.SetGlobalX 设置，所有描边精灵共享）
         private static readonly int EchoCenterID           = Shader.PropertyToID("_EchoCenter");
         private static readonly int EchoRadiusID           = Shader.PropertyToID("_EchoRadius");
         private static readonly int EchoWidthID            = Shader.PropertyToID("_EchoWidth");
         private static readonly int EchoOutlineIntensityID = Shader.PropertyToID("_EchoOutlineIntensity");
         private static readonly int EchoOutlineColorID    = Shader.PropertyToID("_EchoOutlineColor");
+        private static readonly int EchoRingAlphaID       = Shader.PropertyToID("_EchoRingAlpha");
+        private static readonly int EchoRingRadiusID      = Shader.PropertyToID("_EchoRingRadius");
 
         private enum State { Idle, Expanding, Sustaining, Fading }
 
@@ -69,6 +91,8 @@ namespace IndianOceanAssets.Engine2_5D
         private float _stateTimer;
         private Vector2 _center;
         private float _lastEchoTime = -999f;
+        private float _ringAlpha = 0f;
+        private float _ringRadius = 0f;
 
         private void Start()
         {
@@ -76,12 +100,58 @@ namespace IndianOceanAssets.Engine2_5D
             Shader.SetGlobalFloat(EchoOutlineIntensityID, 0f);
             Shader.SetGlobalColor(EchoOutlineColorID, outlineColor);
             Shader.SetGlobalFloat(EchoWidthID, ringWidth);
+            Shader.SetGlobalFloat(EchoRingAlphaID, 0f);
+
+            CreateRingVisual();
+        }
+
+        /// <summary>
+        /// 创建红圈视觉：一个平铺在地面上的 Quad，使用 EchoRing shader。
+        /// shader 通过全局 _EchoCenter / _EchoRadius 自动计算圆环位置，
+        /// 无需每帧更新 Mesh —— 只需在释放时移动 Quad 到回声中心即可。
+        /// </summary>
+        private void CreateRingVisual()
+        {
+            _ringVisual = GameObject.CreatePrimitive(PrimitiveType.Quad);
+            _ringVisual.name = "EchoRing_Visual";
+
+            // 移除不需要的碰撞体
+            var col = _ringVisual.GetComponent<Collider>();
+            if (col != null) Destroy(col);
+
+            // 平铺在地面：绕 X 轴旋转 90°
+            _ringVisual.transform.rotation = Quaternion.Euler(90f, 0f, 0f);
+
+            // 缩放：覆盖 maxRadius * 2 的范围
+            float size = maxRadius * 2f;
+            _ringVisual.transform.localScale = new Vector3(size, size, 1f);
+            // 不挂载到玩家下——回声中心固定，不跟随玩家移动
+
+            // 创建材质（运行时）
+            var shader = Shader.Find("IndianOcean/EchoRing");
+            if (shader != null)
+            {
+                _ringMaterial = new Material(shader);
+                _ringMaterial.SetColor("_RingColor", ringColor);
+                _ringMaterial.SetFloat("_RingWidth", ringVisualWidth);
+                // 确保渲染在黑暗遮罩之上（黑暗遮罩 sortingOrder=9999, renderQueue=3100）
+                _ringMaterial.renderQueue = 3250;
+                var renderer = _ringVisual.GetComponent<MeshRenderer>();
+                renderer.sortingOrder = 10001;
+                renderer.material = _ringMaterial;
+            }
+            else
+            {
+                Debug.LogError("[EchoSystem] 找不到 IndianOcean/EchoRing shader！");
+            }
+
+            _ringVisual.SetActive(false);
         }
 
         private void Update()
         {
-            // 触发
-            if (Input.GetKeyDown(echoKey) && _state == State.Idle && Time.time > _lastEchoTime + cooldown)
+            // 触发：CD 好即可释放，无需等状态机结束（StartEcho 会重置所有状态）
+            if (Input.GetKeyDown(echoKey) && Time.time > _lastEchoTime + cooldown)
             {
                 StartEcho();
             }
@@ -100,12 +170,19 @@ namespace IndianOceanAssets.Engine2_5D
             Shader.SetGlobalFloat(EchoWidthID, ringWidth);
             Shader.SetGlobalFloat(EchoOutlineIntensityID, _intensity);
             Shader.SetGlobalColor(EchoOutlineColorID, outlineColor);
+
+            // 红圈独立渐隐与扩散
+            UpdateRingAlpha();
+            UpdateRingRadius();
+            Shader.SetGlobalFloat(EchoRingAlphaID, _ringAlpha);
+            Shader.SetGlobalFloat(EchoRingRadiusID, _ringRadius);
         }
 
         private void StartEcho()
         {
             _state = State.Expanding;
             _radius = 0f;
+            _ringRadius = 0f;
             _intensity = 1f;
             _stateTimer = 0f;
             _lastEchoTime = Time.time;
@@ -118,6 +195,13 @@ namespace IndianOceanAssets.Engine2_5D
             Vector3 p = transform.position;
             _center = new Vector2(p.x, p.z);
 
+            // 显示红圈：移动到回声中心位置
+            if (_ringVisual != null)
+            {
+                _ringVisual.transform.position = new Vector3(p.x, ringYOffset, p.z);
+                _ringVisual.SetActive(true);
+            }
+
             // 通知订阅者（敌人聆听等）
             OnEchoReleased?.Invoke(p);
         }
@@ -156,6 +240,42 @@ namespace IndianOceanAssets.Engine2_5D
             }
         }
 
+        /// <summary>
+        /// 红圈独立渐隐逻辑：
+        /// 从释放瞬间开始线性渐隐（1 → 0），ringFadeTime 秒后完全消失。
+        /// </summary>
+        private void UpdateRingAlpha()
+        {
+            if (_state == State.Idle)
+            {
+                _ringAlpha = 0f;
+                return;
+            }
+
+            float elapsed = Time.time - _lastEchoTime;
+            _ringAlpha = Mathf.Clamp01(1f - elapsed / Mathf.Max(0.001f, ringFadeTime));
+
+            // 渐隐完成后隐藏红圈物体（节省渲染开销）
+            if (_ringAlpha <= 0f && _ringVisual != null)
+                _ringVisual.SetActive(false);
+        }
+
+        /// <summary>
+        /// 红圈独立扩散：按 ringExpandSpeed 扩散，封顶 maxRadius。
+        /// </summary>
+        private void UpdateRingRadius()
+        {
+            if (_state == State.Idle)
+            {
+                _ringRadius = 0f;
+                return;
+            }
+
+            _ringRadius += ringExpandSpeed * Time.deltaTime;
+            if (_ringRadius > maxRadius)
+                _ringRadius = maxRadius;
+        }
+
         /// <summary>
         /// 外部调用：强制停止回声
         /// </summary>
@@ -163,7 +283,12 @@ namespace IndianOceanAssets.Engine2_5D
         {
             _state = State.Idle;
             _intensity = 0f;
+            _ringAlpha = 0f;
+            _ringRadius = 0f;
             Shader.SetGlobalFloat(EchoOutlineIntensityID, 0f);
+            Shader.SetGlobalFloat(EchoRingAlphaID, 0f);
+            if (_ringVisual != null)
+                _ringVisual.SetActive(false);
         }
 
         public bool IsActive => _state != State.Idle;