修复:带槽的板件切割错误

src/DatabaseServices/Entity/Entity.ts

@@ -222,6 +222,7 @@ export class Entity extends CADObject
         for (let [, obj] of this._CacheDrawObject)
             DisposeThreeObj(obj);
         this._CacheDrawObject.clear();
+        return this;
     }
     ClearDrawOfJig()
     {

src/DatabaseServices/Entity/Extrude.ts

@@ -814,7 +814,7 @@ export class ExtrudeSolid extends Entity
         let n2 = target.Normal;
         if (isParallelTo(n1, n2))
         {
-            target = target.Clone();
+            target = target.Clone().ClearDraw();
             if (!equalv3(n1, n2))
             {
                 let mtx = target._Matrix;
@@ -880,7 +880,7 @@ export class ExtrudeSolid extends Entity
             let projection2SideMatrix4 = new Matrix4().makeBasis(xv, yv, zv);
             for (let c of contours)
             {
-                let g = target.Clone();
+                let g = target.Clone().ClearDraw();
                 let gs = [g];
                 g.ContourCurve = c.Curve;
                 g.GrooveCheckAll(gs);
@@ -1005,7 +1005,7 @@ export class ExtrudeSolid extends Entity
             let grooves: ExtrudeSolid[] = [];
             for (let contour of inters)
             {
-                let ext = target.Clone();
+                let ext = target.Clone().ClearDraw();
                 ext.ContourCurve = contour.Outline.Curve;
                 ext.GrooveCheckAll(grooves);
                 grooves.push(ext);
@@ -1280,6 +1280,10 @@ export class ExtrudeSolid extends Entity
             return this._MeshGeometry;
 
         this.csg = undefined;
+
+        if (this.thickness <= 0)
+            return new BufferGeometry();
+
         let grooves = this.Grooves;
         if (grooves.every(g => equaln(g.thickness, this.thickness)))
         {

src/Geometry/ExtrudeEdgeGeometry2.ts

@@ -1082,6 +1082,8 @@ function UnionRange(a: number, b: number, c: number, d: number, end: number): [n
 
 function SubtractRange(a: number, b: number, c: number, d: number, end: number): Range[]
 {
+    if (a < 0 || b < 0) return [];
+
     if (a > b)
         return [...SubtractRange(a, end, c, d, end), ...SubtractRange(0, b, c, d, end)];
     if (c > d)