From 95a286df153e001a823a3aad8213ccdd68d00a86 Mon Sep 17 00:00:00 2001
From: furti <daniel.furtlehner@gmx.net>
Date: Fri, 8 Mar 2019 20:30:23 +0100
Subject: [PATCH] Arch: Add property to switch to true north

When enabled, the whole coin scene graph is rotated by the declination
property of the site. So one can see the whole geometry oriented like in
real life.
---
 src/Mod/Arch/ArchSite.py | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/src/Mod/Arch/ArchSite.py b/src/Mod/Arch/ArchSite.py
index 9df2de2c70..b35ec80c97 100644
--- a/src/Mod/Arch/ArchSite.py
+++ b/src/Mod/Arch/ArchSite.py
@@ -686,6 +686,12 @@ class _ViewProviderSite(ArchFloor._ViewProviderFloor):
         if not "SolarDiagramColor" in pl:
             vobj.addProperty("App::PropertyColor","SolarDiagramColor","Site",QT_TRANSLATE_NOOP("App::Property","The color of the solar diagram"))
             vobj.SolarDiagramColor = (0.16,0.16,0.25)
+        if not "Orientation" in pl:
+            vobj.addProperty("App::PropertyEnumeration", "Orientation", "Site", QT_TRANSLATE_NOOP(
+                "App::Property", "When set to 'True North' the whole geometry will be rotated to match the true north of this site"))
+            
+            vobj.Orientation = ["Project North", "True North"]
+            vobj.Orientation = "Project North"
 
     def onDocumentRestored(self,vobj):
 
@@ -748,6 +754,7 @@ class _ViewProviderSite(ArchFloor._ViewProviderFloor):
             self.onChanged(obj.ViewObject,"SolarDiagram")
         elif prop == "Declination":
             self.onChanged(obj.ViewObject,"SolarDiagramPosition")
+            self.updateTrueNorthRotation()
         elif prop == "Terrain":
             self.updateCompassLocation(obj)
         elif prop == "Compass":
@@ -787,7 +794,40 @@ class _ViewProviderSite(ArchFloor._ViewProviderFloor):
                 self.updateCompassVisibility(self.Object)
             else:
                 self.compass.hide()
+        elif prop == 'Orientation':
+            if vobj.Orientation == 'True North':
+                self.addTrueNorthRotation()
+            else:
+                self.removeTrueNorthRotation()
     
+    def addTrueNorthRotation(self):
+        if hasattr(self, 'trueNorthRotation') and self.trueNorthRotation is not None:
+            return
+        
+        from pivy import coin
+        
+        self.trueNorthRotation = coin.SoTransform()
+
+        sg = FreeCADGui.ActiveDocument.ActiveView.getSceneGraph()
+        sg.insertChild(self.trueNorthRotation, 0)
+
+        self.updateTrueNorthRotation()
+    
+    def removeTrueNorthRotation(self):
+        if hasattr(self, 'trueNorthRotation') and self.trueNorthRotation is not None:
+            sg = FreeCADGui.ActiveDocument.ActiveView.getSceneGraph()
+
+            sg.removeChild(self.trueNorthRotation)
+            self.trueNorthRotation = None
+    
+    def updateTrueNorthRotation(self):
+        if hasattr(self, 'trueNorthRotation') and self.trueNorthRotation is not None:
+            from pivy import coin
+            
+            angle = self.Object.Declination.Value
+
+            self.trueNorthRotation.rotation.setValue(coin.SbVec3f(0, 0, 1), math.radians(-angle))
+
     def updateCompassVisibility(self, obj):
         if not hasattr(self, 'compass'):
             return