impl Update_extensionsUsed

Assets/UniGLTF/Runtime/UniGLTF/IO/GltfJsonUtil.cs

@@ -1,15 +1,99 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+using UniJSON;
+using UnityEngine;
+
 namespace UniGLTF
 {
     public static class GltfJsonUtil
     {
+        public static IEnumerable<object[]> TraverseJsonPath(JsonNode node, List<object> path)
+        {
+            if (path == null)
+            {
+                path = new List<object>();
+            }
+            yield return path.ToArray();
+
+            if (node.IsArray())
+            {
+                int i = 0;
+                foreach (var child in node.ArrayItems())
+                {
+                    path.Add(i);
+                    foreach (var x in TraverseJsonPath(child, path))
+                    {
+                        yield return x;
+                    }
+                    path.RemoveAt(path.Count - 1);
+                    ++i;
+                }
+            }
+            else if (node.IsMap())
+            {
+                foreach (var kv in node.ObjectItems())
+                {
+                    path.Add(kv.Key.GetString());
+                    foreach (var x in TraverseJsonPath(kv.Value, path))
+                    {
+                        yield return x;
+                    }
+                    path.RemoveAt(path.Count - 1);
+                }
+            }
+        }
+
+        static string DoubleQuote(string src)
+        {
+            return $"\"{src}\"";
+        }
+
         /// <summary>
         /// https://github.com/KhronosGroup/glTF/blob/main/specification/2.0/schema/glTF.schema.json
+        /// 
+        /// extensionUsed の更新を各拡張自身にやらせるのは無駄だし、手動でコントロールするのも間違いの元である。
+        /// 完成品の JSON から後付けで作ることにした。
+        /// 
+        /// * Exporter しか使わない処理なので、GC, 処理速度は気にしてない
+        /// 
         /// </summary>
         /// <param name="src"></param>
         /// <returns></returns>
         public static string Update_extensionsUsed(string src)
         {
+            var used = new HashSet<string>();
+            var parsed = src.ParseAsJson();
+            foreach (var path in TraverseJsonPath(parsed, null))
+            {
+                if (path.Length >= 2)
+                {
+                    if (path[path.Length - 2] is string x)
+                    {
+                        if (x == "extensions")
+                        {
+                            used.Add(path[path.Length - 1] as string);
+                        }
+                    }
+                }
+            }
+
+            var values = "\"extensionUsed\":[" + string.Join(",", used.Select(x => DoubleQuote(x))) + "]";
+            Debug.Log(values);
+            if (parsed.ContainsKey("extensionUsed"))
+            {
+                // replace
+                src = Regex.Replace(src, @"""extensionUsed""\s*:\s*\[[^\]]+\]", values);
+            }
+            else
+            {
+                // add
+                var close = src.LastIndexOf("}");
+                src = src.Substring(0, close) + "," + values + "}";
+            }
+
             return src;
         }
     }
-}
+}

Assets/UniGLTF/Tests/UniGLTF/GltfJsonUtilTests.cs

@@ -1,5 +1,6 @@
 using NUnit.Framework;
 using UniJSON;
+using System.Linq;
 
 namespace UniGLTF
 {
@@ -34,15 +35,58 @@ namespace UniGLTF
             },
             ""name"": ""Red"",
             ""extensions"": {
-                ""KHR_materials_unlit"", {}
+                ""KHR_materials_unlit"": {}
             }
         }
-    ],
+    ]
 }");
 
             var parsed = dst.ParseAsJson();
 
-            Assert.AreEqual("[\"KHR_materials_unlit\"]", parsed["extensionUsed"].ToString());
+            Assert.AreEqual(new string[] { "KHR_materials_unlit" },
+            parsed["extensionUsed"].ArrayItems().Select(x => x.GetString()).ToArray());
+        }
+
+        [Test]
+        public void Replace_extensionUsed()
+        {
+            var dst = GltfJsonUtil.Update_extensionsUsed(@"{
+    ""asset"": {
+        ""generator"": ""COLLADA2GLTF"",
+        ""version"": ""2.0""
+    },
+    ""scene"": 0,
+    ""scenes"": [
+        {
+            ""nodes"": [
+                0
+            ]
+    }
+    ],
+    ""extensionUsed"": [""dummy""],
+    ""materials"": [
+        {
+            ""pbrMetallicRoughness"": {
+                ""baseColorFactor"": [
+                    0.800000011920929,
+                    0.0,
+                    0.0,
+                    1.0
+                ],
+                ""metallicFactor"": 0.0
+            },
+            ""name"": ""Red"",
+            ""extensions"": {
+                ""KHR_materials_unlit"": {}
+            }
+        }
+    ]
+}");
+
+            var parsed = dst.ParseAsJson();
+
+            Assert.AreEqual(new string[] { "KHR_materials_unlit" },
+            parsed["extensionUsed"].ArrayItems().Select(x => x.GetString()).ToArray());
         }
     }
 }