tweak unloader combine harvester

getPipeRoot calculate the root component based on discharge node
calculate getPipeSide based on getPipeRoot to prevent wrong side detection if harvester is stopped in a turn position
calculate getPipeLength based on getPipeRoot to ensure correct distance and position if harvester is stopped in a turn position
disabled angleToSideChaseSide to angleToRearChaseSide comparison in getPipeChasePosition - should fix #391

scripts/Modes/CombineUnloaderMode.lua

@@ -492,7 +492,7 @@ function CombineUnloaderMode:getSideChaseOffsetX()
     local headerExtra = math.max((AutoDrive.getFrontToolWidth(self.combine) - self.combine.size.width) / 2, 0)
 
     local sideChaseTermPipeIn = self.combine.size.width / 2 + unloaderWidest / 2 + headerExtra
-    local sideChaseTermPipeOut = self.combine.size.width / 2 + (AutoDrive.getPipeLength(self.combine))
+    local sideChaseTermPipeOut = AutoDrive.getPipeLength(self.combine)
     -- Some combines fold up their pipe so tight that targeting it could cause a collision.
     -- So, choose the max between the two to avoid a collison
     local sideChaseTermX = math.max(sideChaseTermPipeIn, sideChaseTermPipeOut)
@@ -520,7 +520,6 @@ function CombineUnloaderMode:getSideChaseOffsetX_new()
     local headerExtra = math.max((AutoDrive.getFrontToolWidth(self.combine) - self.combine.size.width) / 2, 0)
 
     local sideChaseTermPipeIn = self.combine.size.width / 2 + unloaderWidest / 2 + headerExtra
-    local sideChaseTermPipeOut = self.combine.size.width / 2 + (AutoDrive.getPipeLength(self.combine))
     -- Some combines fold up their pipe so tight that targeting it could cause a collision.
     -- So, choose the max between the two to avoid a collison
     local sideChaseTermX = 0
@@ -737,7 +736,7 @@ function CombineUnloaderMode:getPipeChasePosition(planningPhase)
                 (
                     (
                         self:isUnloaderOnCorrectSide(self.pipeSide) 
-                        and math.abs(angleToSideChaseSide) < math.abs(angleToRearChaseSide)
+                        -- and math.abs(angleToSideChaseSide) < math.abs(angleToRearChaseSide)
                     )
                     or (planningPhase == true)
                 )

scripts/Utils/CombineUtil.lua

@@ -23,7 +23,7 @@ function AutoDrive.getDischargeNode(combine)
     end
 end
 
-function AutoDrive.getPipeRoot(combine)
+function AutoDrive.getPipeRoot_old(combine)
     if combine.ad ~= nil and combine.ad.pipeRoot ~= nil then
         return combine.ad.pipeRoot
     end
@@ -68,11 +68,55 @@ function AutoDrive.getPipeRoot(combine)
     return pipeRoot
 end
 
+
+function AutoDrive.getPipeRoot(combine)
+    if combine.ad ~= nil and combine.ad.pipeRoot ~= nil then
+        return combine.ad.pipeRoot
+    end
+    local dischargeNode = AutoDrive.getDischargeNode(combine)
+    local pipeRoot = nil
+
+    if dischargeNode then
+        for _, component in ipairs(combine.components) do
+
+            local node = dischargeNode
+            local count = 0
+            repeat
+                node = getParent(node)
+                count = count + 1
+            until ((node == component.node) or (node == 0) or (node == nil) or count >= 100)
+
+            if node and node ~= 0 then
+                -- found
+                pipeRoot = node
+                break
+            end
+        end
+    end
+    if pipeRoot == nil or pipeRoot == 0 then
+        -- fallback
+        pipeRoot = combine.components[1].node
+    end
+
+    if combine.ad ~= nil then
+        combine.ad.pipeRoot = pipeRoot
+    end
+    return pipeRoot
+end
+
+-- ret: -1 right, 1 left, 0 behind
+-- not for sugarcane harvesters, choppers!!!
 function AutoDrive.getPipeSide(combine)
-    local combineNode = combine.components[1].node
+    if combine.ad ~= nil and combine.ad.storedPipeSide ~= nil then
+        return combine.ad.storedPipeSide
+    end
+    local combineNode = AutoDrive.getPipeRoot(combine)
     local dischargeNode = AutoDrive.getDischargeNode(combine)
     local dischargeX, dichargeY, dischargeZ = getWorldTranslation(dischargeNode)
     local diffX, _, _ = worldToLocal(combineNode, dischargeX, dichargeY, dischargeZ)
+    if combine.ad ~= nil then
+        combine.ad.storedPipeSide = AutoDrive.sign(diffX)
+    end
     return AutoDrive.sign(diffX)
 end
 
@@ -88,10 +132,10 @@ function AutoDrive.getPipeLength(combine)
                                         pipeRootZ - dischargeZ)
     --AutoDrive.debugPrint(combine, AutoDrive.DC_COMBINEINFO, "AutoDrive.getPipeLength - " .. length)
     if AutoDrive.isPipeOut(combine) and not AutoDrive.getIsBufferCombine(combine) then
-        local combineNode = combine.components[1].node
+        local combineNode = AutoDrive.getPipeRoot(combine)
         local dischargeX, dichargeY, dischargeZ = getWorldTranslation(AutoDrive.getDischargeNode(combine))
         diffX, _, _ = worldToLocal(combineNode, dischargeX, dichargeY, dischargeZ)
-        length = math.abs(diffX) - combine.size.width /2
+        length = math.abs(diffX)
 
         -- Store pipe length for 'normal' harvesters
         if combine.ad ~= nil then