From aac707d187febd36e6a805ea8ba592b767c56ccc Mon Sep 17 00:00:00 2001
From: Takayuki Matsuoka <matsutaka@pixiv.co.jp>
Date: Wed, 7 Sep 2022 16:56:46 +0900
Subject: [PATCH] Optimize UniHumanoid.BoneLimit.ToHumanBoneName

This change optimizes the following points:

(1) Replace linear search for "cashedHumanTraitBoneName" with Dictionary.
(2) Avoid GC alloc in the inner loop.
(2a) Do b.ToString() at the outside of the loop.
(2b) Do x.Replace(" ", "") at once in the static constructor of BoneLimit.
---
 .../Runtime/UniHumanoid/AvatarDescription.cs  | 22 +++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/Assets/UniGLTF/Runtime/UniHumanoid/AvatarDescription.cs b/Assets/UniGLTF/Runtime/UniHumanoid/AvatarDescription.cs
index 05a3abd6e..d9ac4c47b 100644
--- a/Assets/UniGLTF/Runtime/UniHumanoid/AvatarDescription.cs
+++ b/Assets/UniGLTF/Runtime/UniHumanoid/AvatarDescription.cs
@@ -20,6 +20,19 @@ namespace UniHumanoid
         public Vector3 center;
         public float axisLength;
         private static string[] cashedHumanTraitBoneName = null;
+        private static readonly Dictionary<HumanBodyBones, string> cachedHumanBodyBonesToBoneNameMap =
+            new Dictionary<HumanBodyBones, string>();
+
+        static BoneLimit()
+        {
+            // 呼び出し毎にGCが発生するのでキャッシュする
+            string[] boneNames = HumanTrait.BoneName;
+            cashedHumanTraitBoneName = new string[boneNames.Length];
+            for (var i = 0; i < boneNames.Length; i++)
+            {
+                cashedHumanTraitBoneName[i] = boneNames[i].Replace(" ", "");
+            }
+        }
 
         public static BoneLimit From(HumanBone bone)
         {
@@ -37,16 +50,17 @@ namespace UniHumanoid
 
         public static String ToHumanBoneName(HumanBodyBones b)
         {
-            // 呼び出し毎にGCが発生するのでキャッシュする
-            if (cashedHumanTraitBoneName == null)
+            if (cachedHumanBodyBonesToBoneNameMap.TryGetValue(b, out string result))
             {
-                cashedHumanTraitBoneName = HumanTrait.BoneName;
+                return result;
             }
 
+            var bs = b.ToString();
             foreach (var x in cashedHumanTraitBoneName)
             {
-                if (x.Replace(" ", "") == b.ToString())
+                if (x == bs)
                 {
+                    cachedHumanBodyBonesToBoneNameMap[b] = x;
                     return x;
                 }
             }