From b5e23f0096a6438659f362bce115a00101bb80d5 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Thu, 15 Feb 2024 11:46:17 +0100
Subject: [PATCH] Improve JsonAssetReference

---
 Source/Engine/AI/BehaviorKnowledgeSelector.cs |  4 +-
 Source/Engine/Content/JsonAssetReference.cs   | 38 ++++++++++++++++---
 Source/Engine/Content/JsonAssetReference.h    |  9 +++++
 3 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/Source/Engine/AI/BehaviorKnowledgeSelector.cs b/Source/Engine/AI/BehaviorKnowledgeSelector.cs
index 5c642e92a..cdcaf6c40 100644
--- a/Source/Engine/AI/BehaviorKnowledgeSelector.cs
+++ b/Source/Engine/AI/BehaviorKnowledgeSelector.cs
@@ -146,7 +146,7 @@ namespace FlaxEngine
         public string Path;
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="BehaviorKnowledgeSelectorAny"/> structure.
+        /// Initializes a new instance of the <see cref="BehaviorKnowledgeSelector{T}"/> structure.
         /// </summary>
         /// <param name="path">The selector path.</param>
         public BehaviorKnowledgeSelector(string path)
@@ -155,7 +155,7 @@ namespace FlaxEngine
         }
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="BehaviorKnowledgeSelectorAny"/> structure.
+        /// Initializes a new instance of the <see cref="BehaviorKnowledgeSelector{T}"/> structure.
         /// </summary>
         /// <param name="other">The other selector.</param>
         public BehaviorKnowledgeSelector(BehaviorKnowledgeSelectorAny other)
diff --git a/Source/Engine/Content/JsonAssetReference.cs b/Source/Engine/Content/JsonAssetReference.cs
index adfaa5179..7c8a8902f 100644
--- a/Source/Engine/Content/JsonAssetReference.cs
+++ b/Source/Engine/Content/JsonAssetReference.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2012-2023 Wojciech Figat. All rights reserved.
 
 using System;
+using System.Runtime.CompilerServices;
 
 namespace FlaxEngine
 {
@@ -19,13 +20,9 @@ namespace FlaxEngine
         public JsonAsset Asset;
 
         /// <summary>
-        /// Gets the instance of the Json Asset. Null if unset.
+        /// Gets the instance of the serialized object from the json asset data. Cached internally.
         /// </summary>
-        /// <returns>instance of the Json Asset or null if unset.</returns>
-        public T Get()
-        {
-            return (T)Asset?.Instance;
-        }
+        public T Instance => (T)Asset?.Instance;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="JsonAssetReference{T}"/> structure.
@@ -68,6 +65,35 @@ namespace FlaxEngine
             return new JsonAssetReference<T>(Object.FromUnmanagedPtr(valuePtr) as JsonAsset);
         }
 
+        /// <summary>
+        /// Checks if the object exists (reference is not null and the unmanaged object pointer is valid).
+        /// </summary>
+        /// <param name="obj">The object to check.</param>
+        /// <returns>True if object is valid, otherwise false.</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static implicit operator bool(JsonAssetReference<T> obj)
+        {
+            return obj.Asset;
+        }
+
+        /// <summary>
+        /// Checks whether the two objects are equal.
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool operator ==(JsonAssetReference<T> left, JsonAssetReference<T> right)
+        {
+            return left.Asset == right.Asset;
+        }
+
+        /// <summary>
+        /// Checks whether the two objects are not equal.
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool operator !=(JsonAssetReference<T> left, JsonAssetReference<T> right)
+        {
+            return left.Asset != right.Asset;
+        }
+
         /// <inheritdoc />
         public override string ToString()
         {
diff --git a/Source/Engine/Content/JsonAssetReference.h b/Source/Engine/Content/JsonAssetReference.h
index 82fbe47f1..d84c44926 100644
--- a/Source/Engine/Content/JsonAssetReference.h
+++ b/Source/Engine/Content/JsonAssetReference.h
@@ -12,6 +12,15 @@
 template<typename T>
 API_STRUCT(NoDefault, Template, MarshalAs=JsonAsset*) struct JsonAssetReference : AssetReference<JsonAsset>
 {
+    /// <summary>
+    /// Gets the deserialized native object instance of the given type. Returns null if asset is not loaded or loaded object has different type.
+    /// </summary>
+    /// <returns>The asset instance object or null.</returns>
+    FORCE_INLINE T* GetInstance() const
+    {
+        return _asset ? Get()->GetInstance<T>() : nullptr;
+    }
+
     JsonAssetReference& operator=(JsonAsset* asset) noexcept
     {
         OnSet(asset);