From 1690b4037b86bc2118b0876f8fb27002352c80eb Mon Sep 17 00:00:00 2001
From: Emil Tin <emil@tin.dk>
Date: Sat, 23 Feb 2013 13:17:57 +0100
Subject: [PATCH] simplified angle formula

---
 Contractor/EdgeBasedGraphFactory.cpp | 33 +++++++++-------------------
 features/testbot/turns.feature       |  7 +++---
 profiles/bicycle.lua                 |  6 ++++-
 3 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/Contractor/EdgeBasedGraphFactory.cpp b/Contractor/EdgeBasedGraphFactory.cpp
index 04957e7f2..476b4c353 100644
--- a/Contractor/EdgeBasedGraphFactory.cpp
+++ b/Contractor/EdgeBasedGraphFactory.cpp
@@ -379,32 +379,19 @@ unsigned EdgeBasedGraphFactory::GetNumberOfNodes() const {
     return _nodeBasedGraph->GetNumberOfEdges();
 }
 
-/* Get angle of line segment (A,C)->(C,B), atan2 magic, formerly cosine theorem*/
+// get angle of line segment AC -> CB
 template<class CoordinateT>
 double EdgeBasedGraphFactory::GetAngleBetweenTwoEdges(const CoordinateT& A, const CoordinateT& C, const CoordinateT& B) const {
-    double deltaLonCA,deltaLonBC,latA,latB,latC,x,y,a1,a2;
-    
-    latA = (A.lat/100000.)*M_PI/180;
-    latB = (B.lat/100000.)*M_PI/180;
-    latC = (C.lat/100000.)*M_PI/180;
-    deltaLonCA = (C.lon/100000. - A.lon/100000.)*M_PI/180;
-    deltaLonBC = (B.lon/100000. - C.lon/100000.)*M_PI/180;
-    
-    y = sin(deltaLonCA) * cos(latC);
-    x = cos(latA)*sin(latC) - sin(latA)*cos(latC)*cos(deltaLonCA);
-    a1 = atan2(y,x)*180/M_PI;
-    
-    y = sin(deltaLonBC) * cos(latB);
-    x = cos(latC)*sin(latB) - sin(latC)*cos(latB)*cos(deltaLonBC);
-    a2 = atan2(y,x)*180/M_PI;
+    const double v1x = A.lon - C.lon;
+    const double v1y = A.lat - C.lat;
+    const double v2x = B.lon - C.lon;
+    const double v2y = B.lat - C.lat;
+    const double latC = (C.lat/100000.)*M_PI/180.;
+    const double scale = cos(latC);                           //scale by length of longitude at latitude latC
+    const double a2 = atan2(v2y,v2x*scale)*180/M_PI;
+    const double a1 = atan2(v1y,v1x*scale)*180/M_PI;   
     const double angle = a2-a1;
-    
-    //const double v1x = A.lon - C.lon;
-    //const double v1y = A.lat - C.lat;
-    //const double v2x = B.lon - C.lon;
-    //const double v2y = B.lat - C.lat;
-    //const double angle = (atan2(v2y,v2x) - atan2(v1y,v1x) )*180/M_PI;
-    
+
     if(angle < 0) {
         return angle + 360;
     } else {
diff --git a/features/testbot/turns.feature b/features/testbot/turns.feature
index 5b8883019..77954c2d7 100644
--- a/features/testbot/turns.feature
+++ b/features/testbot/turns.feature
@@ -96,8 +96,8 @@ Feature: Turn directions/codes
 		 | g | a | xg,xa | head,slight_right,destination |
 		 | g | c | xg,xc | head,right,destination        |
 		 | g | e | xg,xe | head,sharp_right,destination  |
-	@xx
-	Scenario: Skadestuevej, København
+	
+	Scenario: Turn instructions at high latitude 
 	https://github.com/DennisOSRM/Project-OSRM/issues/532
 		Given the node locations
 		 | node | lat      | lon      |
@@ -112,4 +112,5 @@ Feature: Turn directions/codes
 
 		When I route I should get
 		 | from | to | route | turns                  |
-		 | a    | c  | ab,bc | head,left,destination |
+		 | a    | c  | ab,bc | head,left,destination  |
+		 | c    | a  | bc,ab | head,right,destination |
diff --git a/profiles/bicycle.lua b/profiles/bicycle.lua
index f6609d097..025a9bbf6 100644
--- a/profiles/bicycle.lua
+++ b/profiles/bicycle.lua
@@ -161,7 +161,11 @@ function way_function (way, numberOfNodesInWay)
 	local service	= way.tags:Find("service")
 	local area = way.tags:Find("area")
 	local foot = way.tags:Find("foot")
-
+    
+	if name ~= "Vej 6" and name ~= "Skadestuevejen" then
+        return 0
+    end
+    
 	-- name	
 	if "" ~= ref then
 		way.name = ref