QML MapView performance issue

Using a MapView with a large number of MapItem (MapQuickItem,MapPolyLine) takes a long time for initial rendering on a Labtop (2 cores, 2.5 Ghz, 8 MB RAM).

     5000*(node + edge + node) takes 12171ms

     10000 (node + edge + node) takes *24979ms

The documentation says : Maps are rendered using OpenGL (ES) and the Qt Scene Graph stack, and as a result perform quite well where GL accelerated hardware is available

In our case , the GPU activity seems low, but the CPU seems to be used intensively.

The tool OpenGL extension viewer indicate that OPENGL is available (any advice is welcome).

Some users report that starting with window minimized improve the performances.

Our application uses QAbstractItemModel, but to submit a test with a simple example, we use Qt.createQmlObject to instanciate all items.

Regards

import QtQuick 2.12
import QtQuick.Window 2.12
import QtLocation 5.12
import QtPositioning 5.12

Window {
id : app
width: Screen.width
height: Screen.height
visible: true
property int nbEdges : 10000
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Plugin

{ id : osmPlugin name: "osm" PluginParameter \{ name: "osm.mapping.host"; value: "http://tile.openstreetmap.org/" }

PluginParameter { name: "osm.mapping.providersrepository.disabled"; value: "true" }
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Plugin

{ id : offlinePlugin name: "osm" PluginParameter \{ name: "osm.mapping.offline.directory"; value: "."}

}
property string mqi:'import QtQuick 2.0;import QtLocation 5.3;
MapQuickItem {zoomLevel : map.zoomLevel < 16 ? 16:0;
anchorPoint.x: shape.x+shape.width/2;anchorPoint.y: shape.y+shape.height/2;
sourceItem:Rectangle {id:shape;width: 10;height: width;color: "yellow";radius: width; border.width : 1
MouseArea{anchors.fill:parent;onClicked:{console.log("clicked")}}}}'

property string mpl:'import QtQuick 2.0;import QtLocation 5.3;MapPolyline {}'

Map {
id: map
anchors.fill: parent
plugin: offlinePlugin
center: QtPositioning.coordinate(45.200744,5.703549) // Grenoble
zoomLevel: 14
property MapQuickItem node1
property MapQuickItem node2
property MapPolyline edge

function getRandom(max)

{ return Math.random() * max; }

Component.onCompleted: {
console.time("MapBench")
for(var i=0;i<nbEdges;i++)

{ // edge edge = Qt.createQmlObject(mpl, app) // first node node1 = Qt.createQmlObject(mqi, app) node1.coordinate = QtPositioning.coordinate(45.120744+getRandom(0.1),5.673549+getRandom(0.1)) map.addMapItem(node1) edge.addCoordinate(node1.coordinate) // second node node2 = Qt.createQmlObject(mqi, app) node2.coordinate = QtPositioning.coordinate(node1.coordinate.latitude+getRandom(0.001), node1.coordinate.longitude+getRandom(0.001)) edge.addCoordinate(node2.coordinate) map.addMapItem(node2) map.addMapItem(edge) }

console.timeEnd("MapBench")
}
}
}