Expose correct morph target cast, fixes vpenades#239

Author: vpenades

src/Shared/_Extensions.cs

@@ -293,6 +293,7 @@ internal static ArraySegment<T> Slice<T>(this T[] array, int offset)
             return new ArraySegment<T>(array, offset, array.Length - offset);
         }
 
+        #if NETSTANDARD2_0
         internal static ArraySegment<T> Slice<T>(this ArraySegment<T> array, int offset)
         {
             return new ArraySegment<T>(array.Array, array.Offset + offset, array.Count - offset);
@@ -302,6 +303,7 @@ internal static ArraySegment<T> Slice<T>(this ArraySegment<T> array, int offset,
         {
             return new ArraySegment<T>(array.Array, array.Offset + offset, count);
         }
+        #endif
 
         internal static T[] CloneArray<T>(this T[] srcArray)
         {
@@ -438,6 +440,70 @@ public static void SanitizeTangents(this IList<Vector4> tangents)
             }
         }
 
+        public static IReadOnlyList<TResult> SelectList<TSource,TResult>(this IReadOnlyList<TSource> collection, Func<TSource,TResult> selector)
+        {
+            return new _ListSelect<TSource,TResult>(collection, selector);
+        }
+
+        public static IReadOnlyCollection<TResult> SelectCollection<TSource, TResult>(this IReadOnlyCollection<TSource> collection, Func<TSource, TResult> selector)
+        {
+            return new _CollectionSelect<TSource, TResult>(collection, selector);
+        }
+
+        private readonly struct _ListSelect<TSource,TResult> : IReadOnlyList<TResult>
+        {
+            public _ListSelect(IReadOnlyList<TSource> list, Func<TSource,TResult> selector)
+            {
+                _List = list;
+                _Selector = selector;
+            }
+
+            [System.Diagnostics.DebuggerBrowsable(System.Diagnostics.DebuggerBrowsableState.RootHidden)]
+            private readonly IReadOnlyList<TSource> _List;
+            [System.Diagnostics.DebuggerBrowsable(System.Diagnostics.DebuggerBrowsableState.Never)]
+            private readonly Func<TSource, TResult> _Selector;
+
+            public TResult this[int index] => _Selector(_List[index]);
+
+            public int Count => _List.Count;
+
+            public IEnumerator<TResult> GetEnumerator()
+            {
+                foreach (var item in _List) yield return _Selector(item);
+            }
+
+            System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+            {
+                foreach (var item in _List) yield return _Selector(item);
+            }
+        }
+
+        private readonly struct _CollectionSelect<TSource, TResult> : IReadOnlyCollection<TResult>
+        {
+            public _CollectionSelect(IReadOnlyCollection<TSource> list, Func<TSource, TResult> selector)
+            {
+                _List = list;
+                _Selector = selector;
+            }
+
+            [System.Diagnostics.DebuggerBrowsable(System.Diagnostics.DebuggerBrowsableState.RootHidden)]
+            private readonly IReadOnlyCollection<TSource> _List;
+            [System.Diagnostics.DebuggerBrowsable(System.Diagnostics.DebuggerBrowsableState.Never)]
+            private readonly Func<TSource, TResult> _Selector;            
+
+            public int Count => _List.Count;
+
+            public IEnumerator<TResult> GetEnumerator()
+            {
+                foreach (var item in _List) yield return _Selector(item);
+            }
+
+            System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+            {
+                foreach (var item in _List) yield return _Selector(item);
+            }
+        }
+
         #endregion
 
         #region vertex & index accessors
@@ -777,12 +843,12 @@ private static Byte[] _TryParseBase64Unchecked(string uri, string prefix)
         public static string _EscapeStringInternal(this string uri)
         {
             // https://stackoverflow.com/questions/4396598/whats-the-difference-between-escapeuristring-and-escapedatastring
-            #pragma warning disable SYSLIB0013 // Type or member is obsolete
+#pragma warning disable SYSLIB0013 // Type or member is obsolete
             return Uri.EscapeUriString(uri);
-            #pragma warning restore SYSLIB0013 // Type or member is obsolete
+#pragma warning restore SYSLIB0013 // Type or member is obsolete
         }
 
-        #if NET6_0
+#if NET6_0
 
         /// <summary>
         /// Creates a new instance of the <see cref="JsonNode"/>.
@@ -794,11 +860,11 @@ public static string _EscapeStringInternal(this string uri)
         /// </remarks>
         /// <param name="node">The node to clone.</param>
         /// <returns>A clone of <paramref name="node"/>.</returns>        
-        #if NET6_0_OR_GREATER
+#if NET6_0_OR_GREATER
         [System.Diagnostics.CodeAnalysis.DynamicDependency(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.All, typeof(System.Text.Json.Nodes.JsonValue))]
         [System.Diagnostics.CodeAnalysis.DynamicDependency(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.All, typeof(System.Text.Json.Nodes.JsonArray))]
         [System.Diagnostics.CodeAnalysis.DynamicDependency(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.All, typeof(System.Text.Json.Nodes.JsonObject))]
-        #endif
+#endif
         public static System.Text.Json.Nodes.JsonNode DeepClone(this System.Text.Json.Nodes.JsonNode node)
         {
             // issue tracking both DeepClone and DeepEquals: https://github.com/dotnet/runtime/issues/56592            
@@ -807,14 +873,14 @@ public static System.Text.Json.Nodes.JsonNode DeepClone(this System.Text.Json.No
 
             System.Text.Json.Nodes.JsonNode clone = null;            
 
-            #pragma warning disable IL2026 // Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code
+#pragma warning disable IL2026 // Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code
             switch(node)
             {
                 case System.Text.Json.Nodes.JsonValue asValue: clone = System.Text.Json.JsonSerializer.Deserialize<System.Text.Json.Nodes.JsonValue>(asValue); break;
                 case System.Text.Json.Nodes.JsonArray asArray: clone = System.Text.Json.JsonSerializer.Deserialize<System.Text.Json.Nodes.JsonArray>(asArray); break;
                 case System.Text.Json.Nodes.JsonObject asObject: clone = System.Text.Json.JsonSerializer.Deserialize<System.Text.Json.Nodes.JsonObject>(asObject); break;
             }            
-            #pragma warning restore IL2026 // Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code
+#pragma warning restore IL2026 // Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code
 
             if (clone == null) throw new NotImplementedException();
 
@@ -823,15 +889,15 @@ public static System.Text.Json.Nodes.JsonNode DeepClone(this System.Text.Json.No
             return clone;
         }
 
-        #endif        
+#endif
 
         public static bool DeepEquals(this System.Text.Json.Nodes.JsonNode x, System.Text.Json.Nodes.JsonNode y, double precission)
         {
-            #if !NET6_0
+#if !NET6_0
 
             return System.Text.Json.Nodes.JsonNode.DeepEquals(x, y);
 
-            #else
+#else
 
             if (x == y) return true;
             if (x == null) return false;
@@ -888,7 +954,7 @@ public static bool DeepEquals(this System.Text.Json.Nodes.JsonNode x, System.Tex
 
             return false;
 
-            #endif
+#endif
         }
 
         #endregion

src/SharpGLTF.Toolkit/Geometry/MorphTargetBuilder.cs

@@ -404,13 +404,13 @@ public void SetVertex(TvG meshVertex, TvG morphVertex)
         public IReadOnlyCollection<Vector3> Positions => _Positions.Keys;
 
         /// <inheritdoc/>
-        IReadOnlyCollection<IVertexGeometry> IMorphTargetBuilder.Vertices => (IReadOnlyList<IVertexGeometry>)(IReadOnlyCollection<TvG>)_Vertices.Keys;
+        IReadOnlyCollection<IVertexGeometry> IMorphTargetBuilder.Vertices => _Vertices.Keys.SelectCollection(item => (IVertexGeometry)item);
 
         /// <inheritdoc/>
         IReadOnlyList<IVertexGeometry> IMorphTargetBuilder.GetVertices(Vector3 position)
         {
             return _Positions.TryGetValue(position, out List<TvG> geos)
-                ? (IReadOnlyList<IVertexGeometry>)geos
+                ? geos.SelectList(item => (IVertexGeometry)item)
                 : Array.Empty<IVertexGeometry>();
         }