From 9445bd56a30811132e2e839c940ecdfc878b5a29 Mon Sep 17 00:00:00 2001
From: Klaus Basan <klaus.basan@klausbasan.de>
Date: Fri, 4 Aug 2017 01:27:23 +0200
Subject: [PATCH] Ref T111, normalize utility functions

---
 src/blackmisc/math/mathutils.cpp | 10 ++++++++--
 src/blackmisc/math/mathutils.h   |  5 ++++-
 src/blackmisc/pq/angle.cpp       | 13 +++++++++++++
 src/blackmisc/pq/angle.h         |  6 ++++++
 4 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/src/blackmisc/math/mathutils.cpp b/src/blackmisc/math/mathutils.cpp
index 23387c017..859222f24 100644
--- a/src/blackmisc/math/mathutils.cpp
+++ b/src/blackmisc/math/mathutils.cpp
@@ -79,9 +79,15 @@ namespace BlackMisc
             return radians * 180.0 / CMathUtils::PI();
         }
 
-        double CMathUtils::normalizeDegrees(double degrees)
+        double CMathUtils::normalizeDegrees180(double degrees)
         {
-            double result = std::fmod(degrees, 360.0);
+            const double result = CMathUtils::normalizeDegrees360(degrees + 180.0) - 180.0;
+            return (result <= -180.0) ? 180.0 : result; // -180->180
+        }
+
+        double CMathUtils::normalizeDegrees360(double degrees)
+        {
+            const double result = std::fmod(degrees, 360.0);
             return (result >= 0.0) ? result : result + 360.0;
         }
 
diff --git a/src/blackmisc/math/mathutils.h b/src/blackmisc/math/mathutils.h
index 16ae90b09..83ebb3d2d 100644
--- a/src/blackmisc/math/mathutils.h
+++ b/src/blackmisc/math/mathutils.h
@@ -96,8 +96,11 @@ namespace BlackMisc
             //! Radians to degrees
             static double rad2deg(double radians);
 
+            //! Normalize: -180< degrees ≤180
+            static double normalizeDegrees180(double degrees);
+
             //! Normalize: 0≤ degrees <360
-            static double normalizeDegrees(double degrees);
+            static double normalizeDegrees360(double degrees);
 
             //! Random number between low and high
             static int randomInteger(int low, int high);
diff --git a/src/blackmisc/pq/angle.cpp b/src/blackmisc/pq/angle.cpp
index 33a104189..6ca2c7fd6 100644
--- a/src/blackmisc/pq/angle.cpp
+++ b/src/blackmisc/pq/angle.cpp
@@ -126,5 +126,18 @@ namespace BlackMisc
         {
             return std::tan(this->value(CAngleUnit::rad()));
         }
+
+        double CAngle::normalizeDegrees180(double degrees, int roundDigits)
+        {
+            double d = CMathUtils::normalizeDegrees360(degrees + 180.0) - 180.0;
+            if (d <= -180.0) { d = 180.0; } // -180 -> 180
+            return roundDigits < 0 ? d : CMathUtils::round(d, roundDigits);
+        }
+
+        double CAngle::normalizeDegrees360(double degrees, int roundDigits)
+        {
+            const double d = CMathUtils::normalizeDegrees360(degrees);
+            return roundDigits < 0 ? d : CMathUtils::round(d, roundDigits);
+        }
     } // ns
 } // ns
diff --git a/src/blackmisc/pq/angle.h b/src/blackmisc/pq/angle.h
index afb7d1b0a..c04f126eb 100644
--- a/src/blackmisc/pq/angle.h
+++ b/src/blackmisc/pq/angle.h
@@ -96,6 +96,12 @@ namespace BlackMisc
 
             //! Tangent of angle
             double tan() const;
+
+            //! Normalize: -180< degrees ≤180
+            static double normalizeDegrees180(double degrees, int roundDigits = -1);
+
+            //! Normalize: 0≤ degrees <360
+            static double normalizeDegrees360(double degrees, int roundDigits = -1);
         };
     } // ns
 } // ns