Insure that our compass points to true north, not the grid north

opengisch · Jun 24, 2023 · 3dfc6f5 · 3dfc6f5 · qfield-fairy · Jun 24, 2023
1 parent f56282e
commit 3dfc6f5
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Showing 4 changed files with 40 additions and 7 deletions.
diff --git a/src/core/utils/positioningutils.cpp b/src/core/utils/positioningutils.cpp
@@ -17,6 +17,10 @@
 #include "gnsspositioninformation.h"
 #include "positioningutils.h"
 
+#include <qgsbearingutils.h>
+#include <qgscoordinatetransformcontext.h>
+#include <qgsproject.h>
+
 PositioningUtils::PositioningUtils( QObject *parent )
   : QObject( parent )
 {
@@ -111,3 +115,21 @@ GnssPositionInformation PositioningUtils::averagedPositionInformation( const QLi
                                   fixMode, fixType, quality, satellitesUsed, status, satPrn, satInfoComplete,
                                   verticalSpeed / positionsInformationCount, magneticVariation / positionsInformationCount, positionsInformationCount, sourceName );
 }
+
+double PositioningUtils::bearingTrueNorth( const QgsPoint &position, const QgsCoordinateReferenceSystem &crs )
+{
+  const QgsCoordinateTransformContext transformContext = QgsProject::instance()->transformContext();
+
+  double bearing = 0.0;
+  try
+  {
+    bearing = QgsBearingUtils::bearingTrueNorth( crs, transformContext, position );
+  }
+  catch ( QgsException &e )
+  {
+    Q_UNUSED( e )
+    QgsDebugMsgLevel( QStringLiteral( "Caught exception %1" ).arg( e.what() ), 2 );
+  }
+
+  return bearing;
+}
diff --git a/src/core/utils/positioningutils.h b/src/core/utils/positioningutils.h
@@ -19,6 +19,8 @@
 #include "qfield_core_export.h"
 
 #include <QObject>
+#include <qgscoordinatereferencesystem.h>
+#include <qgspoint.h>
 
 class GnssPositionInformation;
 
@@ -44,6 +46,11 @@ class QFIELD_CORE_EXPORT PositioningUtils : public QObject
      * Returns an average GnssPositionInformation from a list of position information
      */
     static Q_INVOKABLE GnssPositionInformation averagedPositionInformation( const QList<QVariant> &positionsInformation );
+
+    /**
+     * Returns the true north bearing from a given position and CRS
+     */
+    static Q_INVOKABLE double bearingTrueNorth( const QgsPoint &position, const QgsCoordinateReferenceSystem &crs );
 };
 
 #endif // POSITIONINGUTILS_H
diff --git a/src/qml/PositioningPreciseView.qml b/src/qml/PositioningPreciseView.qml
@@ -54,7 +54,7 @@ Item {
       width: Math.min(positioningPreciseView.height - 10,
                       positioningPreciseView.width - preciseElevation.width - labelTarget.contentWidth - labelElevation.width - 20)
       height: width
-      rotation: magnetometer.hasValue ? -magnetometer.orientation : 0
+      rotation: magnetometer.hasValue ? -magnetometer.orientation + positionSource.bearingTrueNorth : 0
 
       ShapePath {
         strokeWidth: 1

diff --git a/src/qml/qgismobileapp.qml b/src/qml/qgismobileapp.qml
@@ -202,6 +202,7 @@ ApplicationWindow {
 
     property bool currentness: false;
     property alias destinationCrs: positionSource.coordinateTransformer.destinationCrs
+    property real bearingTrueNorth: 0.0
 
     coordinateTransformer: CoordinateTransformer {
       destinationCrs: mapCanvas.mapSettings.destinationCrs
@@ -215,8 +216,11 @@ ApplicationWindow {
     logging: positioningSettings.logging
 
     onProjectedPositionChanged: {
-      if (active && gnssButton.followActive) {
-        gnssButton.followLocation(false);
+      if (active) {
+        bearingTrueNorth = PositioningUtils.bearingTrueNorth(positionSource.projectedPosition, mapCanvas.mapSettings.destinationCrs)
+        if (gnssButton.followActive) {
+          gnssButton.followLocation(false);
+        }
       }
     }
 
@@ -248,8 +252,8 @@ ApplicationWindow {
     returnGeoValues: false
 
     property bool hasValue: false
-    property real orientation: 0
     property real lastAcceptedReading: 0
+    property real orientation: 0
 
     Screen.onOrientationChanged: {
         switch (Screen.orientation) {
@@ -691,9 +695,9 @@ ApplicationWindow {
              ? positionSource.positionInformation.speed
              : -1
       orientation: magnetometer.hasValue
-                   ? magnetometer.orientation < 0
-                     ? 360 + magnetometer.orientation
-                     : magnetometer.orientation
+                   ? magnetometer.orientation + positionSource.bearingTrueNorth < 0
+                     ? 360 + magnetometer.orientation + positionSource.bearingTrueNorth
+                     : magnetometer.orientation + positionSource.bearingTrueNorth
                    : -1
     }