[Assets] Allow some assets to be non-referenceable (asset name collis…

…ion is allowed in this case because they exist only at compile-time). This is used for scripts, otherwise they can't have same name as an asset.

sources/assets/Xenko.Core.Assets/Analysis/AssetCollision.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 
 using Xenko.Core.IO;
 using Xenko.Core.Serialization.Contents;
@@ -66,8 +67,11 @@ public static void Clean(Package package, ICollection<AssetItem> inputItems, ICo
                     changed = true;
                 }
 
-                UFile newLocation;
-                if (assetResolver.RegisterLocation(item.Location, out newLocation))
+                // Note: we ignore name collisions if asset is not referenceable
+                var referenceable = item.Asset.GetType().GetCustomAttribute<AssetDescriptionAttribute>()?.Referenceable ?? true;
+
+                UFile newLocation = null;
+                if (referenceable && assetResolver.RegisterLocation(item.Location, out newLocation))
                 {
                     changed = true;
                 }

sources/assets/Xenko.Core.Assets/AssetDescriptionAttribute.cs

@@ -30,6 +30,12 @@ public AssetDescriptionAttribute(string fileExtensions)
         /// </summary>
         public bool AllowArchetype { get; set; } = true;
 
+        /// <summary>
+        /// Defines if an asset is referenceable through an <see cref="AssetReference"/>.
+        /// Asset name collision is allowed in this case because they exist only at compile-time.
+        /// </summary>
+        public bool Referenceable { get; set; } = true;
+
         /// <summary>
         /// Always mark this asset type as root.
         /// </summary>

sources/assets/Xenko.Core.Assets/PackageAssetCollection.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Diagnostics;
+using System.Reflection;
 using System.Threading;
 using Xenko.Core;
 using Xenko.Core.Diagnostics;
@@ -132,8 +133,12 @@ public void Add(AssetItem item)
             var asset = item.Asset;
             asset.IsIdLocked = true;
 
+            // Note: we ignore name collisions if asset is not referenceable
+            var referenceable = item.Asset.GetType().GetCustomAttribute<AssetDescriptionAttribute>()?.Referenceable ?? true;
+
             // Maintain all internal maps
-            mapPathToId.Add(item.Location, item.Id);
+            if (referenceable)
+                mapPathToId.Add(item.Location, item.Id);
             mapIdToPath.Add(item.Id, item.Location);
             mapIdToAsset.Add(item.Id, item);
             registeredItems.Add(item);
@@ -204,7 +209,11 @@ public bool Remove(AssetItem item)
                 registeredItems.Remove(item);
                 mapIdToAsset.Remove(item.Id);
                 mapIdToPath.Remove(item.Id);
-                mapPathToId.Remove(item.Location);
+
+                // Note: we ignore name collisions if asset is not referenceable
+                var referenceable = item.Asset.GetType().GetCustomAttribute<AssetDescriptionAttribute>()?.Referenceable ?? true;
+                if (referenceable)
+                    mapPathToId.Remove(item.Location);
 
                 RemoveInternal(item);
 
@@ -328,8 +337,11 @@ public void CheckCanAdd(AssetItem item)
                 throw new ArgumentException("Cannot add an asset that is already added to another package", "item");
             }
 
+            // Note: we ignore name collisions if asset is not referenceable
+            var referenceable = item.Asset.GetType().GetCustomAttribute<AssetDescriptionAttribute>()?.Referenceable ?? true;
+
             var location = item.Location;
-            if (mapPathToId.ContainsKey(location))
+            if (referenceable && mapPathToId.ContainsKey(location))
             {
                 throw new ArgumentException("An asset [{0}] with the same location [{1}] is already registered ".ToFormat(mapPathToId[location], location.GetDirectoryAndFileName()), "item");
             }

sources/editor/Xenko.Core.Assets.Editor/ViewModel/PackageViewModel.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Linq;
+using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
 using Xenko.Core.Assets.Analysis;
@@ -399,7 +400,7 @@ public void Delete()
 
         public void CheckConsistency()
         {
-            var assetList = Package.Assets.ToDictionary(x => x.Location.FullPath);
+            var assetList = Package.Assets.Where(item => item.Asset.GetType().GetCustomAttribute<AssetDescriptionAttribute>()?.Referenceable ?? true).ToDictionary(x => x.Location.FullPath);
             var assetViewModels = Assets.ToList();
             var logger = Session.AssetLog.GetLogger(LogKey.Get("Consistency"));
 

sources/engine/Xenko.Assets/Scripts/ScriptSourceFileAsset.cs

@@ -7,7 +7,7 @@
 namespace Xenko.Assets.Scripts
 {
     [DataContract("ScriptSourceFileAsset")]
-    [AssetDescription(Extension, AlwaysMarkAsRoot = true, AllowArchetype = false)]
+    [AssetDescription(Extension, AlwaysMarkAsRoot = true, AllowArchetype = false, Referenceable = false)]
     public sealed partial class ScriptSourceFileAsset : ProjectSourceCodeAsset
     {
         public const string Extension = ".cs";