From 6d105b9665201bb8cb2e58fc5ebdc9e6b667f75d Mon Sep 17 00:00:00 2001
From: Klaus Basan <klaus.basan@klausbasan.de>
Date: Mon, 7 May 2018 11:43:11 +0200
Subject: [PATCH] Ref T261, make sure the unit is correct in spline altitude
 interpolation

See slack discussion here https://swift-project.slack.com/archives/G7GD2UP9C/p1525605407000025
---
 .../simulation/interpolatorspline.cpp         | 23 +++++--------------
 src/blackmisc/simulation/interpolatorspline.h |  3 ---
 2 files changed, 6 insertions(+), 20 deletions(-)

diff --git a/src/blackmisc/simulation/interpolatorspline.cpp b/src/blackmisc/simulation/interpolatorspline.cpp
index 27459f5c4..472124524 100644
--- a/src/blackmisc/simulation/interpolatorspline.cpp
+++ b/src/blackmisc/simulation/interpolatorspline.cpp
@@ -174,21 +174,21 @@ namespace BlackMisc
                 // - and the elevation remains (almost) constant for a wider area
                 // - during flying the ground elevation not really matters
                 this->updateElevations();
-                const CLength cg(this->getModelCG());
-                const double a0 = m_s[0].getCorrectedAltitude(cg).value(); // oldest
-                const double a1 = m_s[1].getCorrectedAltitude(cg).value();
-                const double a2 = m_s[2].getCorrectedAltitude(cg).value(); // latest
+                static const CLengthUnit altUnit = CAltitude::defaultUnit();
+                const CLength cg(this->getModelCG().switchedUnit(altUnit));
+                const double a0 = m_s[0].getCorrectedAltitude(cg).value(altUnit); // oldest
+                const double a1 = m_s[1].getCorrectedAltitude(cg).value(altUnit);
+                const double a2 = m_s[2].getCorrectedAltitude(cg).value(altUnit); // latest
                 pa.a = {{ a0, a1, a2 }};
                 pa.gnd = {{ m_s[0].getOnGroundFactor(), m_s[1].getOnGroundFactor(), m_s[2].getOnGroundFactor() }};
                 pa.da = getDerivatives(pa.t, pa.a);
                 pa.dgnd = getDerivatives(pa.t, pa.gnd);
-                Q_ASSERT_X(this->areAltitudeUnitsSame(), Q_FUNC_INFO, "Altitude unit mismatch");
 
                 m_prevSampleAdjustedTime = m_s[1].getAdjustedMSecsSinceEpoch();
                 m_nextSampleAdjustedTime = m_s[2].getAdjustedMSecsSinceEpoch(); // latest
                 m_prevSampleTime = m_s[1].getMSecsSinceEpoch();
                 m_nextSampleTime = m_s[2].getMSecsSinceEpoch(); // latest
-                m_interpolant = CInterpolant(pa, m_s[2].getAltitudeUnit(), CInterpolatorPbh(m_s[1], m_s[2]));
+                m_interpolant = CInterpolant(pa, altUnit, CInterpolatorPbh(m_s[1], m_s[2]));
                 Q_ASSERT_X(m_prevSampleAdjustedTime < m_nextSampleAdjustedTime, Q_FUNC_INFO, "Wrong time order");
             }
 
@@ -262,17 +262,6 @@ namespace BlackMisc
             return false;
         }
 
-        bool CInterpolatorSpline::areAltitudeUnitsSame(const CLengthUnit &compare) const
-        {
-            if (m_s.size() < 1) { return true; }
-            const CLengthUnit c = compare.isNull() ? m_s[0].getAltitudeUnit() : compare;
-            for (unsigned int i = 0; i < m_s.size(); i++)
-            {
-                if (m_s[i].getAltitudeUnit() != c) { return false; }
-            }
-            return true;
-        }
-
         CInterpolatorSpline::CInterpolant::CInterpolant(const CInterpolatorSpline::PosArray &pa, const CLengthUnit &altitudeUnit, const CInterpolatorPbh &pbh) :
             m_pa(pa), m_altitudeUnit(altitudeUnit)
         {
diff --git a/src/blackmisc/simulation/interpolatorspline.h b/src/blackmisc/simulation/interpolatorspline.h
index f6f58df6f..70f1dc8f6 100644
--- a/src/blackmisc/simulation/interpolatorspline.h
+++ b/src/blackmisc/simulation/interpolatorspline.h
@@ -92,9 +92,6 @@ namespace BlackMisc
             //! Ground relevant
             bool isAnySituationNearGroundRelevant() const;
 
-            //! Are the altitude units all the same
-            bool areAltitudeUnitsSame(const PhysicalQuantities::CLengthUnit &compare = PhysicalQuantities::CLengthUnit::nullUnit()) const;
-
             //! Fill the situations array
             bool fillSituationsArray();