diff options
Diffstat (limited to 'mobile-widgets/qmlmapwidgethelper.cpp')
| -rw-r--r-- | mobile-widgets/qmlmapwidgethelper.cpp | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/mobile-widgets/qmlmapwidgethelper.cpp b/mobile-widgets/qmlmapwidgethelper.cpp index 83a78582e..27505d192 100644 --- a/mobile-widgets/qmlmapwidgethelper.cpp +++ b/mobile-widgets/qmlmapwidgethelper.cpp @@ -10,6 +10,7 @@ #include "qt-models/maplocationmodel.h"
#define MIN_DISTANCE_BETWEEN_DIVE_SITES_M 50.0
+#define SMALL_CIRCLE_RADIUS_PX 26.0
MapWidgetHelper::MapWidgetHelper(QObject *parent) : QObject(parent)
{
@@ -61,6 +62,30 @@ void MapWidgetHelper::selectedLocationChanged(MapLocation *location) qDebug() << location;
}
+/*
+ * Based on a 2D Map widget circle with center "coord" and radius SMALL_CIRCLE_RADIUS_PX,
+ * obtain a "small circle" with radius m_smallCircleRadius in meters:
+ * https://en.wikipedia.org/wiki/Circle_of_a_sphere
+ *
+ * The idea behind this circle is to be able to select multiple nearby dives, when clicking on
+ * the map. This code can be in QML, but it is in C++ instead for performance reasons.
+ *
+ * This can be made faster with an exponential regression [a * exp(b * x)], with a pretty
+ * decent R-squared, but it becomes bound to map provider zoom level mappings and the
+ * SMALL_CIRCLE_RADIUS_PX value, which makes the code hard to maintain.
+ */
+void MapWidgetHelper::calculateSmallCircleRadius(QGeoCoordinate coord)
+{
+ QPointF point;
+ QMetaObject::invokeMethod(m_map, "fromCoordinate", Q_RETURN_ARG(QPointF, point),
+ Q_ARG(QGeoCoordinate, coord), Q_ARG(bool, false));
+ QPointF point2(point.x() + SMALL_CIRCLE_RADIUS_PX, point.y());
+ QGeoCoordinate coord2;
+ QMetaObject::invokeMethod(m_map, "toCoordinate", Q_RETURN_ARG(QGeoCoordinate, coord2),
+ Q_ARG(QPointF, point2), Q_ARG(bool, false));
+ m_smallCircleRadius = coord2.distanceTo(coord);
+}
+
void MapWidgetHelper::copyToClipboardCoordinates(QGeoCoordinate coord, bool formatTraditional)
{
bool savep = prefs.coordinates_traditional;
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