From 56813a800c54c72d72f5d23db28137774938ebd7 Mon Sep 17 00:00:00 2001
From: FlightControl_Master <sven.van.de.velde@telenet.be>
Date: Fri, 15 Sep 2017 19:38:19 +0200
Subject: [PATCH] Fixed the impossible bearing calculation problem

* Bearing is only known of a SET_UNIT, if all units of the set are
heading +/- 5 degrees in the same direction.
---
 Moose Development/Moose/Core/Point.lua |  4 ++--
 Moose Development/Moose/Core/Set.lua   | 19 ++++++++++++-------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/Moose Development/Moose/Core/Point.lua b/Moose Development/Moose/Core/Point.lua
index d49a2d0c4..58fdefccd 100644
--- a/Moose Development/Moose/Core/Point.lua	
+++ b/Moose Development/Moose/Core/Point.lua	
@@ -488,9 +488,9 @@ do -- COORDINATE
   function COORDINATE:GetHeadingText( Settings )
     local Heading = self:GetHeading()
     if Heading then
-      return string.format( " heading %3.2f °", Heading )
+      return string.format( " bearing %3d°", Heading )
     else
-      return " heading cannot be determined"
+      return " bearing unknown"
     end
   end
 
diff --git a/Moose Development/Moose/Core/Set.lua b/Moose Development/Moose/Core/Set.lua
index 84d0763dd..c7dda4192 100644
--- a/Moose Development/Moose/Core/Set.lua	
+++ b/Moose Development/Moose/Core/Set.lua	
@@ -1883,7 +1883,7 @@ end
 -- @return #number Heading Heading in degrees and speed in mps in case of moving units.
 function SET_UNIT:GetHeading()
 
-  local AvgHeading = nil
+  local HeadingSet = nil
   local MovingCount = 0
 
   for UnitName, UnitData in pairs( self:GetSet() ) do
@@ -1894,15 +1894,20 @@ function SET_UNIT:GetHeading()
     local Velocity = Coordinate:GetVelocity()
     if Velocity ~= 0  then
       local Heading = Coordinate:GetHeading()
-      AvgHeading = AvgHeading and ( AvgHeading + Heading ) or Heading
-      MovingCount = MovingCount + 1
+      if HeadingSet == nil then
+        HeadingSet = Heading
+      else
+        local HeadingDiff = ( HeadingSet - Heading + 180 + 360 ) % 360 - 180
+        HeadingDiff = math.abs( HeadingDiff )
+        if HeadingDiff > 5 then
+          HeadingSet = nil
+          break
+        end
+      end        
     end
   end
 
-  AvgHeading = AvgHeading and ( AvgHeading / MovingCount )
-  
-  self:F( { AvgHeading = AvgHeading } )
-  return AvgHeading
+  return HeadingSet
 
 end