New IO structure, unexpexted error in C code

源代码/StgSharp/Geometries/PlainGeometry/Point.cs

@@ -1,16 +1,11 @@
-using StgSharp;
-using StgSharp.Math;
+using StgSharp.Math;
 using System;
-using System.Collections.Generic;
-using System.Data.SqlTypes;
-using System.Drawing;
 using System.Runtime.InteropServices;
-using System.Text;
 
 
 namespace StgSharp.Geometries
 {
-    public unsafe class Point :  INode<Point>, INullable
+    public unsafe class Point
     {
         internal vec3d* positionPtr;
         internal readonly bool isVertex;
@@ -59,7 +54,6 @@ namespace StgSharp.Geometries
 
         public bool IsVertex => isVertex;
 
-        bool INullable.IsNull { get;  }
 
         /// <summary>
         /// Update the coordinate of the point. If this is a moving point,
@@ -67,7 +61,7 @@ namespace StgSharp.Geometries
         /// please do not define any motion here, codes will be ignored by program
         /// </summary>
         /// <param name="tick">Time passes since the program begin, counted by frames</param>
-        public virtual void Update(uint tick) {}
+        public virtual void Update(uint tick) { }
 
         public bool IsInGeometry(IPlainGeometry geo)
         {