1 files changed, 44 insertions, 0 deletions
diff --git a/Plugins/MonoGame.Extended/source/MonoGame.Extended.Tweening/TweenFieldMember.cs b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Tweening/TweenFieldMember.cs
new file mode 100644
index 0000000..da2f75d
--- /dev/null
+++ b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Tweening/TweenFieldMember.cs
@@ -0,0 +1,44 @@
+using System;
+using System.Diagnostics;
+using System.Linq.Expressions;
+using System.Reflection;
+
+namespace MonoGame.Extended.Tweening
+{
+    public sealed class TweenFieldMember<T> : TweenMember<T>
+        where T : struct 
+    {
+        private readonly FieldInfo _fieldInfo;
+
+        public TweenFieldMember(object target, FieldInfo fieldInfo) 
+            : base(target, CompileGetMethod(fieldInfo), CompileSetMethod(fieldInfo))
+        {
+            _fieldInfo = fieldInfo;
+        }
+
+        private static Func<object, object> CompileGetMethod(FieldInfo fieldInfo)
+        {
+            var self = Expression.Parameter(typeof(object));
+            var instance = Expression.Convert(self, fieldInfo.DeclaringType);
+            var field = Expression.Field(instance, fieldInfo);
+            var convert = Expression.TypeAs(field, typeof(object));
+
+            return Expression.Lambda<Func<object, object>>(convert, self).Compile();
+        }
+
+        private static Action<object, object> CompileSetMethod(FieldInfo fieldInfo)
+        {
+            Debug.Assert(fieldInfo.DeclaringType != null);
+
+            var self = Expression.Parameter(typeof(object));
+            var value = Expression.Parameter(typeof(object));
+            var fieldExp = Expression.Field(Expression.Convert(self, fieldInfo.DeclaringType), fieldInfo);
+            var assignExp = Expression.Assign(fieldExp, Expression.Convert(value, fieldInfo.FieldType));
+
+            return Expression.Lambda<Action<object, object>>(assignExp, self, value).Compile();
+        }
+
+        public override Type Type => _fieldInfo.FieldType;
+        public override string Name => _fieldInfo.Name;
+    }
+}
+\ No newline at end of file