erasers performance: pragmas

src/domain/UBGraphicsScene.cpp

@@ -767,18 +767,24 @@ void UBGraphicsScene::eraseLineTo(const QPointF &pEndPoint, const qreal &pWidth)
         QPainterPath itemPainterPath;
         itemPainterPath.addPolygon(pi->sceneTransform().map(pi->polygon()));
         if (eraserPath.contains(itemPainterPath))
+        {
+            #pragma omp critical
             {
                 // Compele remove item
                 intersectedItems << pi;
                 intersectedPolygons << QPolygonF();
             }
+        }
         else if (eraserPath.intersects(itemPainterPath))
         {   
             QPainterPath newPath = itemPainterPath.subtracted(eraserPath);
+            #pragma omp critical
+            {
                intersectedItems << pi;
                intersectedPolygons << newPath.simplified().toFillPolygon(pi->sceneTransform().inverted());
             }
         }
+    }
 
     for(int i=0; i<intersectedItems.size(); i++)
     {