From 88b57be5073446ff443f583ddb1dc097bedde9e3 Mon Sep 17 00:00:00 2001
From: ChenX <maple6@vip.qq.com>
Date: Tue, 17 Mar 2020 20:22:54 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8D:=E5=B8=A6=E6=A7=BD=E7=9A=84?=
 =?UTF-8?q?=E6=9D=BF=E4=BB=B6=E5=88=87=E5=89=B2=E9=94=99=E8=AF=AF?=
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---
 src/DatabaseServices/Entity/Entity.ts  |  1 +
 src/DatabaseServices/Entity/Extrude.ts | 10 +++++++---
 src/Geometry/ExtrudeEdgeGeometry2.ts   |  2 ++
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/DatabaseServices/Entity/Entity.ts b/src/DatabaseServices/Entity/Entity.ts
index 4051adda1..4c038bb5f 100644
--- a/src/DatabaseServices/Entity/Entity.ts
+++ b/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()
     {
diff --git a/src/DatabaseServices/Entity/Extrude.ts b/src/DatabaseServices/Entity/Extrude.ts
index 761a074ea..e33b1c36c 100644
--- a/src/DatabaseServices/Entity/Extrude.ts
+++ b/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)))
         {
diff --git a/src/Geometry/ExtrudeEdgeGeometry2.ts b/src/Geometry/ExtrudeEdgeGeometry2.ts
index b39f0c796..0b24fded4 100644
--- a/src/Geometry/ExtrudeEdgeGeometry2.ts
+++ b/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)