Daily update 2 on 20240228 by nitload youmu

StgSharp.Model/STEP/FileStructure/IStepObject.cs

@@ -0,0 +1,21 @@
+using StgSharp.Blueprint;
+using StgSharp.Geometries;
+using StgSharp.Math;
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace StgSharp.Modeling.STEP
+{
+    public abstract class IStepObject: StepExpressionBase , IGeometry
+    {
+        public abstract Point this[int index] { get; set; }
+
+        public abstract Vec4[] VertexStream { get; }
+        public abstract CoordinationBase Coordination { get; }
+        public abstract int VertexCount { get; }
+        public abstract ReadOnlySpan<int> VertexIndices { get; }
+
+    }
+}