Ref T602, read conversion table (ft/m) and functions from/to ft/m

src/blackmisc/aviation/altitude.cpp

@@ -11,6 +11,9 @@
 #include "blackmisc/pq/constants.h"
 #include "blackmisc/pq/pqstring.h"
 #include "blackmisc/math/mathutils.h"
+#include "blackmisc/fileutils.h"
+#include "blackmisc/directoryutils.h"
+#include "blackmisc/stringutils.h"
 #include "blackmisc/comparefunctions.h"
 #include "blackmisc/iconlist.h"
 #include "blackmisc/icons.h"
@@ -27,6 +30,28 @@ namespace BlackMisc
 {
     namespace Aviation
     {
+        namespace Private
+        {
+            QVector<CAltitude::MetricTuple> initMetricValues()
+            {
+                QVector<CAltitude::MetricTuple> v;
+                const QString f = CFileUtils::appendFilePaths(CDirectoryUtils::shareMiscDirectory(), "Metric Altitudes.csv");
+                const QString ma = CFileUtils::readFileToString(f);
+                const QStringList values = splitLines(ma);
+                for (const QString &value : values)
+                {
+                    const QStringList alts = value.split(";");
+                    int v1 = -1, v2 = -1, v3 = -1;
+                    if (alts.size() >= 1) { v1 = alts[0].toInt(); }
+                    if (alts.size() >= 2) { v2 = alts[1].toInt(); }
+                    if (alts.size() >= 3) { v3 = alts[2].toInt(); }
+                    const CAltitude::MetricTuple m(v1, v2, v3);
+                    v.push_back(m);
+                }
+                return v;
+            }
+        }
+
         void CAltitude::registerMetadata()
         {
             Mixin::MetaType<CAltitude>::registerMetadata();
@@ -34,6 +59,12 @@ namespace BlackMisc
             qRegisterMetaType<CAltitude::AltitudeType>();
         }
 
+        const QVector<CAltitude::MetricTuple> &CAltitude::metricTuples()
+        {
+            static const QVector<MetricTuple> v = Private::initMetricValues();
+            return v;
+        }
+
         CAltitude::CAltitude(const QString &altitudeAsString, CPqString::SeparatorMode mode) : CLength(0, CLengthUnit::m()), m_datum(MeanSeaLevel)
         {
             this->parseFromString(altitudeAsString, mode);
@@ -388,6 +419,26 @@ namespace BlackMisc
             return a;
         }
 
+        int CAltitude::findMetricAltitude(int feet)
+        {
+            // m/ft/FL
+            for (const MetricTuple &m : metricTuples())
+            {
+                if (std::get<1>(m) == feet) return std::get<0>(m);
+            }
+            return -1;
+        }
+
+        int CAltitude::findAltitudeForMetricAltitude(int metric)
+        {
+            // m/ft/FL
+            for (const MetricTuple &m : metricTuples())
+            {
+                if (std::get<0>(m) == metric) return std::get<1>(m);
+            }
+            return -1;
+        }
+
         const CAltitude &CAltitude::null()
         {
             static const CAltitude null(0, CAltitude::MeanSeaLevel, CLengthUnit::nullUnit());

src/blackmisc/aviation/altitude.h

@@ -30,6 +30,8 @@
 #include <QMetaType>
 #include <QString>
 #include <QRegularExpression>
+#include <QVector>
+#include <tuple>
 
 namespace BlackMisc
 {
@@ -57,6 +59,9 @@ namespace BlackMisc
             //! Base type
             using base_type = PhysicalQuantities::CLength;
 
+            //! Metric tuple
+            using MetricTuple = std::tuple<int, int, int>;
+
             BLACKMISC_DECLARE_USING_MIXIN_METATYPE(CAltitude)
             BLACKMISC_DECLARE_USING_MIXIN_STRING(CAltitude)
             BLACKMISC_DECLARE_USING_MIXIN_DBUS(CAltitude)
@@ -196,6 +201,11 @@ namespace BlackMisc
             //! \remark https://en.wikipedia.org/wiki/Flight_level
             CAltitude roundedToNearest100ft(bool roundDown) const;
 
+            //! Search the corresponding feet <-> metric / metric <-> feet @{
+            static int findMetricAltitude(int feet);
+            static int findAltitudeForMetricAltitude(int metric);
+            //! @}
+
             //! Null altitude (MSL)
             static const CAltitude &null();
 
@@ -213,6 +223,9 @@ namespace BlackMisc
             ReferenceDatum m_datum; //!< MSL or AGL?
             AltitudeType m_altitudeType = TrueAltitude; //!< type
 
+            //! The metric tuples m/ft/FL
+            static const QVector<MetricTuple> &metricTuples();
+
             BLACK_METACLASS(
                 CAltitude,
                 BLACK_METAMEMBER(datum),