refs #865, hints get ground elevation from provider or from set value

* using CAltitude for elevation provider
* null() for CAltitude
* formatting of members
* fixme in fs9 client

src/blackmisc/aviation/altitude.cpp

@@ -106,5 +106,11 @@ namespace BlackMisc
             return BlackMisc::CIcon::iconByIndex(CIcons::GeoPosition);
         }
 
+        const CAltitude &CAltitude::null()
+        {
+            static const CAltitude null(0, CAltitude::MeanSeaLevel, CLengthUnit::nullUnit());
+            return null;
+        }
+
     } // namespace
 } // namespace

src/blackmisc/aviation/altitude.h

@@ -63,7 +63,7 @@ namespace BlackMisc
             /*!
              * Enum type to distinguish between MSL and AGL
              */
-            enum ReferenceDatum : uint
+            enum ReferenceDatum
             {
                 MeanSeaLevel = 0,   //!< MSL
                 AboveGround,        //!< AGL
@@ -115,6 +115,9 @@ namespace BlackMisc
             //! \copydoc BlackMisc::Mixin::Icon::toIcon
             BlackMisc::CIcon toIcon() const;
 
+            //! Null altitude (MSL)
+            static const CAltitude &null();
+
         private:
             ReferenceDatum m_datum; //!< MSL or AGL?
 

src/blackmisc/simulation/interpolationhints.cpp

@@ -10,6 +10,7 @@
 #include "interpolationhints.h"
 #include "blackmisc/aviation/aircraftsituation.h"
 
+using namespace BlackMisc::Aviation;
 using namespace BlackMisc::Geo;
 using namespace BlackMisc::PhysicalQuantities;
 
@@ -22,6 +23,13 @@ namespace BlackMisc
         CInterpolationHints::CInterpolationHints(bool isVtolAircraft) : m_isVtol(isVtolAircraft)
         { }
 
+        CAltitude CInterpolationHints::getGroundElevation(const Aviation::CAircraftSituation &situation) const
+        {
+            if (m_elevationProvider) { return m_elevationProvider(situation); }
+            if (m_elevation.isNull() || !m_elevation.isWithinRange(situation)) { return CAltitude::null(); }
+            return m_elevation.geodeticHeight();
+        }
+
         void CInterpolationHints::resetElevation()
         {
             m_elevation = CElevationPlane();
@@ -33,6 +41,12 @@ namespace BlackMisc
             return m_elevation.isWithinRange(coordinate);
         }
 
+        void CInterpolationHints::setAircraftParts(const CAircraftParts &parts, bool hasParts)
+        {
+            m_hasParts = hasParts;
+            m_aircraftParts = parts;
+        }
+
         CVariant CInterpolationHints::propertyByIndex(const CPropertyIndex &index) const
         {
             if (index.isMyself()) { return CVariant::from(*this); }

src/blackmisc/simulation/interpolationhints.h

@@ -20,7 +20,6 @@
 namespace BlackMisc
 {
     namespace Aviation { class CAircraftSituation; }
-
     namespace Simulation
     {
         //! Hints for interpolator such as ground elevation
@@ -45,6 +44,9 @@ namespace BlackMisc
             //! Get elevation
             const BlackMisc::Geo::CElevationPlane &getElevation() const { return m_elevation;}
 
+            //! Get elevation from CInterpolationHints::getElevationProvider or CInterpolationHints::getElevation
+            Aviation::CAltitude getGroundElevation(const BlackMisc::Aviation::CAircraftSituation &situation) const;
+
             //! Set elevation
             void setElevation(const BlackMisc::Geo::CElevationPlane &elevation) { m_elevation = elevation; }
 
@@ -69,16 +71,18 @@ namespace BlackMisc
             //! Has valid aircraft parts?
             bool hasAircraftParts() const { return m_hasParts; }
 
-            //! Aircraft parts
+            //! Aircraft parts required for interpolation
             BlackMisc::Aviation::CAircraftParts getAircraftParts() const { return m_aircraftParts; }
 
-            //! Set aircraft parts
+            //! Set aircraft parts required for interpolation if any
-            void setAircraftParts(const BlackMisc::Aviation::CAircraftParts &parts) { m_hasParts = true; m_aircraftParts = parts; }
+            //! \remark when used to reset value (default object) use hasParts false. Needed as there is no null parts object
+            void setAircraftParts(const BlackMisc::Aviation::CAircraftParts &parts, bool hasParts = true);
 
             //! Function object that can obtain ground elevation
-            using ElevationProvider = std::function<BlackMisc::PhysicalQuantities::CLength(const BlackMisc::Aviation::CAircraftSituation &)>;
+            using ElevationProvider = std::function<BlackMisc::Aviation::CAltitude(const BlackMisc::Aviation::CAircraftSituation &)>;
 
             //! Function object that can obtain ground elevation
+            //! \remark either a provider or a value set can be used
             const ElevationProvider &getElevationProvider() const { return m_elevationProvider; }
 
             //! Set function object that can obtain ground elevation
@@ -98,11 +102,11 @@ namespace BlackMisc
 
         private:
             bool m_isVtol = false;   //!< VTOL aircraft?
-            BlackMisc::Geo::CElevationPlane m_elevation; //!< aircraft's elevation if available
-            BlackMisc::PhysicalQuantities::CLength m_cgAboveGround { 0, nullptr }; //!< center of gravity above ground
             bool m_hasParts = false; //!< Has valid aircraft parts?
             BlackMisc::Aviation::CAircraftParts m_aircraftParts; //!< Aircraft parts
+            BlackMisc::Geo::CElevationPlane m_elevation; //!< aircraft's elevation if available
             ElevationProvider m_elevationProvider;       //!< Provider of ground elevation (lazy computation)
+            BlackMisc::PhysicalQuantities::CLength m_cgAboveGround { 0, nullptr }; //!< center of gravity above ground
 
             BLACK_METACLASS(
                 CInterpolationHints,

src/plugins/simulator/fs9/fs9client.cpp

@@ -170,7 +170,7 @@ namespace BlackSimPlugin
             if (m_clientStatus == Disconnected) { return; }
 
             IInterpolator::InterpolationStatus status;
-            const CInterpolationHints hints;
+            const CInterpolationHints hints; // \fixme 201701 #865 KB if there is an elevation provider for FS9 add it here or set elevation
             const CAircraftSituation situation = this->m_interpolator->getInterpolatedSituation(m_callsign, -1, hints, status);
 
             // Test only for successful interpolation. FS9 requires constant positions

src/xbus/traffic.cpp

@@ -50,12 +50,14 @@ namespace XBus
         hints.setElevationProvider([this](const auto &situation)
         {
             using namespace BlackMisc::PhysicalQuantities;
-            const auto meters = terrainProbe.getElevation(situation.latitude().value(CAngleUnit::deg()),
+            using namespace BlackMisc::Aviation;
+            const auto meters = terrainProbe.getElevation(
+                                    situation.latitude().value(CAngleUnit::deg()),
                                     situation.longitude().value(CAngleUnit::deg()),
                                     situation.getAltitude().value(CLengthUnit::m()));
-            if (std::isnan(meters)) { return CLength(0, nullptr); }
+            if (std::isnan(meters)) { return CAltitude::null(); }
             constexpr decltype(meters) fudgeFactor = 3.0; //! \fixme Value should be different for each plane, derived from the CSL model geometry
-            return CLength(meters + fudgeFactor, CLengthUnit::m());
+            return CAltitude(CLength(meters + fudgeFactor, CLengthUnit::m()), CAltitude::MeanSeaLevel);
         });
         return hints;
     }