优化一些动画效果

Signed-off-by: TRADER_FOER <lhf190@outlook.com>

Assets/Scripts/UI/SongSelection/SongDotAnimationUI.cs

@@ -0,0 +1,167 @@
+using System.Collections.Generic;
+using Ichni.Menu;
+using UnityEngine;
+
+public class SongDotAnimationUI : MonoBehaviour
+{
+    [Header("引用")]
+    public SongListControllerUI controllerUI;
+
+    [Header("预制体")]
+    public GameObject DotPfab;
+
+    [Header("布局参数")]
+    [SerializeField] private float innerOffset = 400f;
+    [SerializeField] private float outerOffset = 600f;
+    [SerializeField] [Min(1f)] private float visibleSongRadius = 2f;
+    [SerializeField] [Min(1)] private int visibleDotCount = 5;
+    [SerializeField] [Range(0f, 1f)] private float outerScale = 0f;
+    [SerializeField] [Range(0f, 1f)] private float midScale = 0.2f;
+    [SerializeField] [Range(0f, 1f)] private float outerAlpha = 0f;
+    [SerializeField] [Range(0f, 1f)] private float midAlpha = 0.45f;
+
+    private readonly List<RectTransform> dots = new();
+    private readonly List<CanvasGroup> dotCanvasGroups = new();
+    private int displayedCount = -1;
+
+    public int Count => controllerUI != null ? controllerUI.SongCount : 0;
+    public float ScrollProgress => controllerUI != null ? controllerUI.ScrollProgress : 0f;
+
+    void Start()
+    {
+        RebuildDotsIfNeeded();
+    }
+
+    void LateUpdate()
+    {
+        RebuildDotsIfNeeded();
+
+        if (controllerUI == null || dots.Count == 0)
+        {
+            return;
+        }
+
+        float centerIndex = controllerUI.ContinuousSongIndex;
+        int firstVisibleSongIndex = Mathf.FloorToInt(centerIndex) - visibleDotCount / 2;
+        for (int i = 0; i < dots.Count; i++)
+        {
+            RectTransform dot = dots[i];
+            int songIndex = firstVisibleSongIndex + i;
+            if (songIndex < 0 || songIndex >= Count)
+            {
+                SetDotVisible(i, false);
+                continue;
+            }
+
+            float relativeIndex = songIndex - centerIndex;
+            float absoluteRelativeIndex = Mathf.Abs(relativeIndex);
+            bool isVisible = absoluteRelativeIndex <= visibleSongRadius;
+
+            SetDotVisible(i, isVisible);
+            if (!isVisible)
+            {
+                continue;
+            }
+
+            float y = GetDotY(relativeIndex);
+            dots[i].anchoredPosition = new Vector2(0f, y);
+
+            float scale = GetDotScale(absoluteRelativeIndex);
+            dots[i].localScale = Vector3.one * Mathf.Clamp01(scale);
+
+            if (i < dotCanvasGroups.Count && dotCanvasGroups[i] != null)
+            {
+                dotCanvasGroups[i].alpha = GetDotAlpha(absoluteRelativeIndex);
+            }
+        }
+    }
+
+    private void RebuildDotsIfNeeded()
+    {
+        int targetCount = Mathf.Min(Count, visibleDotCount);
+        if (displayedCount == targetCount)
+        {
+            return;
+        }
+
+        for (int i = dots.Count - 1; i >= 0; i--)
+        {
+            if (dots[i] != null)
+            {
+                Destroy(dots[i].gameObject);
+            }
+        }
+
+        dots.Clear();
+        dotCanvasGroups.Clear();
+
+        if (DotPfab == null)
+        {
+            displayedCount = -1;
+            return;
+        }
+
+        for (int i = 0; i < targetCount; i++)
+        {
+            GameObject go = Instantiate(DotPfab, transform);
+            dots.Add(go.GetComponent<RectTransform>());
+
+            CanvasGroup canvasGroup = go.GetComponent<CanvasGroup>();
+            if (canvasGroup == null)
+            {
+                canvasGroup = go.AddComponent<CanvasGroup>();
+            }
+
+            dotCanvasGroups.Add(canvasGroup);
+        }
+
+        displayedCount = targetCount;
+    }
+
+    private void SetDotVisible(int dotIndex, bool isVisible)
+    {
+        RectTransform dot = dots[dotIndex];
+        if (dot.gameObject.activeSelf != isVisible)
+        {
+            dot.gameObject.SetActive(isVisible);
+        }
+    }
+
+    private float GetDotY(float relativeIndex)
+    {
+        float absRelativeIndex = Mathf.Abs(relativeIndex);
+        if (absRelativeIndex <= 1f)
+        {
+            return -relativeIndex * innerOffset;
+        }
+
+        float scaleRange = Mathf.Max(visibleSongRadius - 1f, 0.0001f);
+        float outerT = Mathf.Clamp01((absRelativeIndex - 1f) / scaleRange);
+        float distance = Mathf.Lerp(innerOffset, outerOffset, outerT);
+        return -Mathf.Sign(relativeIndex) * distance;
+    }
+
+    private float GetDotScale(float absoluteRelativeIndex)
+    {
+        if (absoluteRelativeIndex <= 1f)
+        {
+            return Mathf.Lerp(1f, midScale, absoluteRelativeIndex);
+        }
+
+        float scaleRange = Mathf.Max(visibleSongRadius - 1f, 0.0001f);
+        float outerT = Mathf.Clamp01((absoluteRelativeIndex - 1f) / scaleRange);
+        return Mathf.Lerp(midScale, outerScale, outerT);
+    }
+
+    private float GetDotAlpha(float absoluteRelativeIndex)
+    {
+        if (absoluteRelativeIndex <= 1f)
+        {
+            return Mathf.Lerp(1f, midAlpha, absoluteRelativeIndex);
+        }
+
+        float scaleRange = Mathf.Max(visibleSongRadius - 1f, 0.0001f);
+        float outerT = Mathf.Clamp01((absoluteRelativeIndex - 1f) / scaleRange);
+        return Mathf.Lerp(midAlpha, outerAlpha, outerT);
+    }
+}