LOD fix

libs/graphic/graphic.cpp

@@ -2206,12 +2206,14 @@ void Graphic::calcLOD(int index) {
 	if (!m_LODOptimization) return;
 	GraphicType & t(graphics[index]);
 	t._lod.clear();
+	t._lod.reserve(32);
 	int pcnt = t.polyline.size();
 	// qDebug() << "calcLOD" << index;
 	while (pcnt >= 10) {
 		QPolygonF & pl(t._lod.isEmpty() ? t.polyline : t._lod.back());
 		t._lod.append(QPolygonF());
 		QPolygonF & cl(t._lod.back());
+		if (pl.size() > 4) {
 			cl << pl.front();
 			int qcnt    = (pl.size() + 1) / 4;
 			pcnt        = qcnt * 2 + 2;
@@ -2243,6 +2245,8 @@ void Graphic::calcLOD(int index) {
 					cl << QPointF(cx - dx, my[1]) << QPointF(cx + dx, my[0]);
 			}
 			cl << pl.back();
+		} else
+			cl = pl;
 		// qDebug() << "lod" << t._lod.size() << "->" << cl.size();
 	}
 }