daily update on 20230525 by nitload youmu, ses00001 not solved

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

@@ -2,6 +2,7 @@
 using StgSharp.Math;
 using System;
 using System.Collections.Generic;
+using System.Data.SqlTypes;
 using System.Drawing;
 using System.Runtime.InteropServices;
 using System.Text;
@@ -9,7 +10,7 @@ using System.Text;
 
 namespace StgSharp.Geometries
 {
-    public unsafe class Point : INode<Point>
+    public unsafe class Point :  INode<Point>, INullable
     {
         internal vec3d* positionPtr;
 
@@ -46,12 +47,14 @@ namespace StgSharp.Geometries
 
         public bool IsVertex => isVertex;
 
+        bool INullable.IsNull { get;  }
+
         /// <summary>
-        /// 刷新点的位置，即移动点。当该点是某个几何体的从动点时
-        /// （即点坐标由几何体其他点约束或点参数已经在创建几何体时定义）
-        /// 请不要再次进行定义，程序将自行忽略此处的代码。
+        /// Update the coordinate of the point. If this is a moving point,
+        /// (Points on sides or surface if other geometry items)
+        /// please do not define any motion here, codes will be ignored by program
         /// </summary>
-        /// <param name="tick">当前游戏刻</param>
+        /// <param name="tick">Time passes since the program begin, counted by frames</param>
         public virtual void Update(uint tick) {}
 
         public bool IsInGeometry(IPlainGeometry geo)