修复捕捉基点被丢弃

src/Editor/SnapServices.ts

@@ -274,15 +274,21 @@ export class SnapServices
                     () =>
                     {
                         let fIndex = this.m_SupportSnapPoints.findIndex(p => equalv3(p.Point, snapData.Point));
-                        if (fIndex > 0)//基点不移除
+                        if (fIndex !== -1)
                         {
-                            this.m_SupportSnapPoints.splice(fIndex, 1);
+                            if (!(fIndex === 0 && this.m_HasBasePoint))//基点不移除
+                                this.m_SupportSnapPoints.splice(fIndex, 1);
                         }
                         else
                         {
                             this.m_SupportSnapPoints.push(snapData);
                             if (this.m_SupportSnapPoints.length > 7)
-                                this.m_SupportSnapPoints.shift();
+                            {
+                                if (this.m_HasBasePoint)
+                                    this.m_SupportSnapPoints.splice(1, 1);
+                                else
+                                    this.m_SupportSnapPoints.shift();
+                            }
                         }
                         this.UpdateCrossCursor();
                     },