摄像机区域的优化

Assets/_Game/Scripts/Camera/CameraAdaptiveLookaheadExtension.cs

@@ -0,0 +1,105 @@
+using UnityEngine;
+using Unity.Cinemachine;
+
+namespace BaseGames.Camera
+{
+    /// <summary>
+    /// 速度自适应 Lookahead 扩展。
+    ///
+    /// 玩家水平速度越快，Lookahead.Time 越接近 CameraArea 配置的最大值；
+    /// 静止时衰减至最大值的 <see cref="_restScale"/> 倍，避免静止时镜头无谓偏移。
+    ///
+    /// 挂载位置：Persistent 场景中的 VCamA / VCamB GameObject。
+    /// <see cref="CameraStateController.ConfigureSlot"/> 在每次切换区域时调用
+    /// <see cref="SetConfiguredMax"/> 传入该区域的 LookaheadTime。
+    /// </summary>
+    [AddComponentMenu("Cinemachine/Extensions/Camera Adaptive Lookahead")]
+    [DisallowMultipleComponent]
+    public class CameraAdaptiveLookaheadExtension : CinemachineExtension
+    {
+        [Tooltip("静止时 Lookahead 缩减比例（0~1）。\n" +
+                 "0 = 静止时完全无 Lookahead；0.25 = 静止时使用配置值的 25%。\n" +
+                 "推荐 0.2~0.3。")]
+        [Range(0f, 1f)]
+        [SerializeField] private float _restScale = 0.25f;
+
+        [Tooltip("达到最大 Lookahead 所需的水平速度（世界单位/秒）。\n" +
+                 "玩家以此速度奔跑时 Lookahead.Time = 100% 配置值。推荐 10~15。")]
+        [SerializeField] private float _speedAtFullLookahead = 12f;
+
+        [Tooltip("水平速度估算的平滑强度。越大响应越快。推荐 4~6。")]
+        [SerializeField] private float _speedSmoothing = 5f;
+
+        // ── 内部状态 ──────────────────────────────────────────────────────────
+
+        private float _configuredMaxTime = -1f;   // -1 = ConfigureSlot 尚未调用
+        private float _estimatedSpeedX;
+        private float _lastFollowX;
+        private bool  _trackingInitialized;
+
+        // ── 公开 API ──────────────────────────────────────────────────────────
+
+        /// <summary>
+        /// 由 <see cref="CameraStateController.ConfigureSlot"/> 调用，
+        /// 传入当前 CameraArea 配置的最大 Lookahead 时长。
+        /// </summary>
+        public void SetConfiguredMax(float maxTime) => _configuredMaxTime = maxTime;
+
+        // ── Extension ─────────────────────────────────────────────────────────
+
+        protected override void PostPipelineStageCallback(
+            CinemachineVirtualCameraBase vcam,
+            CinemachineCore.Stage stage,
+            ref CameraState state,
+            float deltaTime)
+        {
+            if (stage != CinemachineCore.Stage.Body) return;
+
+            // 编辑器预览时不运行
+            if (deltaTime <= 0f)
+            {
+                _trackingInitialized = false;
+                return;
+            }
+
+            // ConfigureSlot 尚未调用时跳过（避免覆盖默认值）
+            if (_configuredMaxTime < 0f) return;
+
+            // ── 估算玩家水平速度 ──────────────────────────────────────────────
+            Transform follow = vcam.Follow;
+            if (follow != null)
+            {
+                if (!_trackingInitialized)
+                {
+                    _lastFollowX         = follow.position.x;
+                    _trackingInitialized = true;
+                }
+
+                float rawSpeedX  = Mathf.Abs(follow.position.x - _lastFollowX) / deltaTime;
+                _lastFollowX     = follow.position.x;
+                _estimatedSpeedX = Mathf.Lerp(_estimatedSpeedX, rawSpeedX, deltaTime * _speedSmoothing);
+            }
+
+            // ── 速度映射 → Lookahead 时长 ─────────────────────────────────────
+            float fraction   = Mathf.Clamp01(_estimatedSpeedX / _speedAtFullLookahead);
+            float scaledTime = Mathf.Lerp(_configuredMaxTime * _restScale, _configuredMaxTime, fraction);
+
+            var composer = vcam.GetComponent<CinemachinePositionComposer>();
+            if (composer == null) return;
+
+            var lah  = composer.Lookahead;
+            lah.Time = scaledTime;
+            composer.Lookahead = lah;
+        }
+
+        /// <summary>
+        /// 重置速度估算状态。在相机硬切时由 CameraStateController 调用，
+        /// 避免上一区域的奔跑速度影响新区域的初始 Lookahead 量。
+        /// </summary>
+        public void ResetState()
+        {
+            _estimatedSpeedX     = 0f;
+            _trackingInitialized = false;
+        }
+    }
+}