Ref T111, normalize utility functions

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;
         }
 

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);

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

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