优化代码逻辑

src/Editor/GetPointServices.ts

@@ -332,11 +332,6 @@ export class GetPointServices
     private GetNowPoint(): THREE.Vector3
     {
         let preView = app.m_Viewer.m_PreViewer;
-        //清理原先画的辅助线
-        this.DestroySnapLine();
-        //绘制捕捉光标列表
-        this.DrawSnapCross(preView);
-
         //如果存在捕捉
         if (preView.m_LastSnapPoint)
         {
@@ -344,6 +339,10 @@ export class GetPointServices
             app.m_Viewer.ScreenToWorld(retP);
             return retP;
         }
+        //清理原先画的辅助线
+        this.DestroySnapLine();
+        //绘制捕捉光标列表
+        this.DrawSnapCross(preView);
 
         //捕捉轴线列表
         let snapAxisList: { basePt: THREE.Vector3, snapPt: THREE.Vector3 }[] = [];