Bug report #20871
Style "Meters at scale" hogs CPU
| Status: | Open | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: | - | ||
| Category: | Symbology | ||
| Affected QGIS version: | 3.4.2 | Regression?: | No |
| Operating System: | Linux/Xubuntu 18.04.1 | Easy fix?: | No |
| Pull Request or Patch supplied: | No | Resolution: | |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 28690 |
Description
After selecting "Meters at scale" option in a style QGIS becomes unresponsive for couple of seconds to several minutes. This involves at least the following situations:
- Opening the project takes several minutes
- Opening the layer settings which contains the "Meters at scale" option
- Clicking on an item in the symbol tree
- Changing an option of an item in the symbol tree
I attached gdb to a running QGIS process and pressed CTRL-C when clicking on symbol tab sheet in layer settings and the dialog got unresponsive for a minute or so. Maybe this helps a little bit.
Thread 1 "qgis.bin" received signal SIGINT, Interrupt. 0x00007fc790791fac in __sin_local (x=2.3596955266584345e-07) at ../sysdeps/ieee754/dbl-64/s_sin.c:473 473 ../sysdeps/ieee754/dbl-64/s_sin.c: Datei oder Verzeichnis nicht gefunden. (gdb) bac #0 0x00007fc790791fac in __sin_local (x=2.3596955266584345e-07) at ../sysdeps/ieee754/dbl-64/s_sin.c:473 #1 0x00007fc790791fac in __sincos (x=2.3596955266584345e-07, sinx=0x7ffc5e7817b8, cosx=0x7ffc5e7817b0) at ../sysdeps/ieee754/dbl-64/s_sincos.c:75 #2 0x00007fc79ba94d61 in QgsDistanceArea::computeSpheroidProject(QgsPointXY const&, double, double) const () at /usr/lib/libqgis_core.so.3.4.2 #3 0x00007fc79ba9527a in QgsDistanceArea::measureLineProjected(QgsPointXY const&, double, double, QgsPointXY*) const () at /usr/lib/libqgis_core.so.3.4.2 #4 0x00007fc79bc4459c in QgsRenderContext::convertMetersToMapUnits(double) const () at /usr/lib/libqgis_core.so.3.4.2 #5 0x00007fc79bc44715 in QgsRenderContext::convertToPainterUnits(double, QgsUnitTypes::RenderUnit, QgsMapUnitScale const&) const () at /usr/lib/libqgis_core.so.3.4.2 #6 0x00007fc79b8395fd in QgsMarkerSymbolLayer::markerOffset(QgsSymbolRenderContext&, double, double, QgsUnitTypes::RenderUnit, QgsUnitTypes::RenderUnit, double&, double&, QgsMapUnitScale const&, QgsMapUnitScale const&) const () at /usr/lib/libqgis_core.so.3.4.2 #7 0x00007fc79b8397af in QgsMarkerSymbolLayer::markerOffset(QgsSymbolRenderContext&, double, double, double&, double&) const () at /usr/lib/libqgis_core.so.3.4.2 #8 0x00007fc79b7f5c16 in QgsSimpleMarkerSymbolLayerBase::calculateOffsetAndRotation(QgsSymbolRenderContext&, double, bool&, QPointF&, double&) const () at /usr/lib/libqgis_core.so.3.4.2 #9 0x00007fc79b7f9646 in QgsSimpleMarkerSymbolLayerBase::renderPoint(QPointF, QgsSymbolRenderContext&) () at /usr/lib/libqgis_core.so.3.4.2 #10 0x00007fc79b7f9bfd in QgsSimpleMarkerSymbolLayer::renderPoint(QPointF, QgsSymbolRenderContext&) () at /usr/lib/libqgis_core.so.3.4.2 #11 0x00007fc79b864b31 in QgsMarkerSymbol::renderPointUsingLayer(QgsMarkerSymbolLayer*, QPointF, QgsSymbolRenderContext&) () at /usr/lib/libqgis_core.so.3.4.2 #12 0x00007fc79b86bb1d in QgsMarkerSymbol::renderPoint(QPointF, QgsFeature const*, QgsRenderContext&, int, bool) () at /usr/lib/libqgis_core.so.3.4.2 #13 0x00007fc79b7e9a5d in QgsMarkerLineSymbolLayer::renderPolylineInterval(QPolygonF const&, QgsSymbolRenderContext&) () at /usr/lib/libqgis_core.so.3.4.2 #14 0x00007fc79b7ead88 in QgsMarkerLineSymbolLayer::renderPolyline(QPolygonF const&, QgsSymbolRenderContext&) () at /usr/lib/libqgis_core.so.3.4.2 #15 0x00007fc79b839c0e in QgsLineSymbolLayer::drawPreviewIcon(QgsSymbolRenderContext&, QSize) () at /usr/lib/libqgis_core.so.3.4.2 #16 0x00007fc79b85ff0c in QgsSymbolLayerUtils::symbolLayerPreviewPicture(QgsSymbolLayer*, QgsUnitTypes::RenderUnit, QSize, QgsMapUnitScale const&) () at /usr/lib/libqgis_core.so.3.4.2 #17 0x00007fc7973e9788 in QgsLayerPropertiesWidget::emitSignalChanged() () at /usr/lib/libqgis_gui.so.3.4.2 #18 0x00007fc799f1e6cf in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #19 0x00007fc79ad5ebe2 in QAbstractButton::toggled(bool) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #20 0x00007fc79ad5f001 in () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #21 0x00007fc79ad60606 in QAbstractButton::setChecked(bool) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #22 0x00007fc7973e7400 in QgsLayerPropertiesWidget::QgsLayerPropertiesWidget(QgsSymbolLayer*, QgsSymbol const*, QgsVectorLayer*, QWidget*) () at /usr/lib/libqgis_gui.so.3.4.2 #23 0x00007fc797474255 in QgsSymbolSelectorWidget::layerChanged() () at /usr/lib/libqgis_gui.so.3.4.2 #24 0x00007fc799f1e6cf in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #25 0x00007fc799e9b67a in QItemSelectionModel::currentChanged(QModelIndex const&, QModelIndex const&) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #26 0x00007fc799e9b96e in QItemSelectionModel::setCurrentIndex(QModelIndex const&, QFlags<QItemSelectionModel::SelectionFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #27 0x00007fc79aebba4c in QAbstractItemView::mousePressEvent(QMouseEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #28 0x00007fc79af29a7b in QTreeView::mousePressEvent(QMouseEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #29 0x00007fc79acac98f in QWidget::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #30 0x00007fc79ad4d4be in QFrame::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #31 0x00007fc79aec0b3b in QAbstractItemView::viewportEvent(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
Bug report #18399 seems to be the same. However I cannot reopen it.
History
#1
Updated by Daniel Krüger over 5 years ago
I made some further debugging with Callgrind and added some qDebug() output to QgsMarkerLineSymbolLayer::renderPolylineInterval().
It seems that QgsSymbolLayerUtils::symbolLayerPreviewPicture() needs a large processing time for generating the icon. That's because it uses some default QgsRenderContext with default ellipsoid. So it draws millions of markers (repeated every 3 meters at scale) on the icon.
Where is the right place to fix this scaling issue?
If someone is interested I can provide a small test project. It takes a couple of minutes for opening the project.
#2
Updated by Johannes Kroeger about 5 years ago
- File uncertain borders.qgz added
I just ran into this option behaving weirdly and hogging CPU as well. In my case it is NOT hogging CPU when the canvas is EPSG:4326 but it is if the canvas is for example EPSG:3857 or EPSG:25832 (UTM32N).
Here is an example project, set the OTF projection to trigger the CPU hogging. You might need to pan around a bit to make it happen. Data is https://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/cultural/ne_10m_admin_0_countries.zip