Ref T275, elevation plane improvements

* setRadiusOrMinimum
* ASSERT if there is no radius

src/blackcore/airspacemonitor.cpp

@@ -937,6 +937,7 @@ namespace BlackCore
         {
             const CLength distance(correctedSituation.getDistancePerTime(250));
             const CElevationPlane ep = this->findClosestElevationWithinRangeOrRequest(correctedSituation, distance, callsign);
+            Q_ASSERT_X(ep.isNull() || !ep.getRadius().isNull(), Q_FUNC_INFO, "null radius");
             correctedSituation.setGroundElevation(ep, CAircraftSituation::FromCache);
         }
 

src/blackmisc/aviation/aircraftsituation.cpp

@@ -560,6 +560,7 @@ namespace BlackMisc
         {
             if (!this->canTransferGroundElevation(otherSituation, radius)) { return false; }
             otherSituation.setGroundElevation(this->getGroundElevationPlane(), TransferredElevation);
+            Q_ASSERT_X(!otherSituation.getGroundElevationRadius().isNull(), Q_FUNC_INFO, "null radius");
             return true;
         }
 
@@ -620,6 +621,7 @@ namespace BlackMisc
             else
             {
                 this->setGroundElevationInfo(info);
+                Q_ASSERT_X(!m_groundElevationPlane.getRadius().isNull(), Q_FUNC_INFO, "Null radius");
                 m_groundElevationPlane.switchUnit(this->getAltitudeOrDefaultUnit()); // we use ft as internal unit, no "must" but simplification
             }
         }
@@ -633,7 +635,7 @@ namespace BlackMisc
             {
                 // better values
                 this->setGroundElevation(elevationPlane, info);
-                m_groundElevationPlane.setRadius(distance);
+                m_groundElevationPlane.setRadiusOrMinimum(distance);
                 return true;
             }
             return false;

src/blackmisc/geo/elevationplane.cpp

@@ -31,13 +31,18 @@ namespace BlackMisc
         CElevationPlane::CElevationPlane(const ICoordinateGeodetic &coordinate, const ICoordinateGeodetic &rangeCoordinate) :
             CCoordinateGeodetic(coordinate)
         {
-            m_radius = this->calculateGreatCircleDistance(rangeCoordinate);
+            this->setRadiusOrMinimum(this->calculateGreatCircleDistance(rangeCoordinate));
         }
 
         CElevationPlane::CElevationPlane(const ICoordinateGeodetic &coordinate, const CLength &radius) :
             CCoordinateGeodetic(coordinate), m_radius(radius)
         { }
 
+        void CElevationPlane::setRadiusOrMinimum(const CLength &radius)
+        {
+            m_radius = ((radius.isNull() || radius < CElevationPlane::singlePointRadius())) ? CElevationPlane::singlePointRadius() : radius;
+        }
+
         void CElevationPlane::addAltitudeOffset(const CLength &offset)
         {
             if (offset.isNull() || offset.isZeroEpsilonConsidered()) { return; }

src/blackmisc/geo/elevationplane.h

@@ -48,6 +48,9 @@ namespace BlackMisc
             //! Radius
             void setRadius(const PhysicalQuantities::CLength &radius) { m_radius = radius; }
 
+            //! Radius or minimum CElevationPlane::singlePointRadius
+            void setRadiusOrMinimum(const PhysicalQuantities::CLength &radius);
+
             //! Add offset to altitude
             void addAltitudeOffset(const PhysicalQuantities::CLength &offset);