Used the GeographicLib to translate from longitude/latitude to UTM.

Added functions to set/get the UTM zone to use (default 31).
Used the file header bounds to compute the center of the map (instad of the node locations).

include/osm/osm_map.h

@@ -9,6 +9,7 @@
 #include "road_map.h"
 
 #include <osmium/handler.hpp>
+#include <osmium/io/header.hpp>
 #include <osmium/tags/tags_filter.hpp>
 
 class COSMMap : public osmium::handler::Handler
@@ -24,9 +25,8 @@ class COSMMap : public osmium::handler::Handler
     std::vector<COSMRestriction *> restrictions;
     osmium::TagsFilter way_filter;
     osmium::TagsFilter relation_filter;
-    double max_x,min_x,width;
-    double max_y,min_y,height;
     long int max_id;
+    int utm_zone;
   protected:
     void free(void);
     void process_map(void);
@@ -39,9 +39,11 @@ class COSMMap : public osmium::handler::Handler
     void add_node(COSMNode *node);
     COSMNode *get_node_by_id(long int id);
     void add_restriction(COSMRestriction *restriction);
-    void normalize_locations(void);
+    void normalize_locations(std::vector<osmium::Box> &boxes);
   public:
     COSMMap();
+    void set_utm_zone(int zone);
+    int get_utm_zone(void);
     void load(const std::string &filename);
     void node(const osmium::Node& node);
     void way(const osmium::Way& way);

src/CMakeLists.txt

@@ -10,10 +10,13 @@ SET(osm_headers ../include/osm/osm_map.h ../include/osm/osm_node.h ../include/os
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/libosmium")
 
+set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH};/usr/share/cmake/geographiclib")
+
 # locate the necessary dependencies
 find_package(Eigen3 REQUIRED)
 find_package(iriutils REQUIRED)
 find_package(Osmium REQUIRED COMPONENTS xml io gdal) 
+find_package(GeographicLib REQUIRED)
 
 ADD_SUBDIRECTORY(xml)
 
@@ -23,6 +26,7 @@ INCLUDE_DIRECTORIES(./)
 INCLUDE_DIRECTORIES(${EIGEN3_INCLUDE_DIR})
 INCLUDE_DIRECTORIES(${iriutils_INCLUDE_DIR})
 INCLUDE_DIRECTORIES(${OSMIUM_INCLUDE_DIRS})
+INCLUDE_DIRECTORIES(${GeographicLib_INCLUDE_DIRS})
 
 # create the shared library
 ADD_LIBRARY(${PROJECT_NAME} SHARED ${sources} ${opendrive_sources} ${osm_sources} ${XSD_SOURCES})
@@ -30,6 +34,7 @@ ADD_LIBRARY(${PROJECT_NAME} SHARED ${sources} ${opendrive_sources} ${osm_sources
 TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${XSD_LIBRARY})
 TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${iriutils_LIBRARY})
 TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${OSMIUM_LIBRARIES})
+TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${GeographicLib_LIBRARIES})
 
 ADD_DEPENDENCIES(${PROJECT_NAME} xsd_files_gen)
 

src/osm/osm_map.cpp

@@ -6,6 +6,7 @@
 #include <osmium/io/xml_input.hpp>
 #include <osmium/visitor.hpp>
 #include <osmium/tags/taglist.hpp>
+#include <GeographicLib/UTMUPS.hpp>
 
 #include "road.h"
 
@@ -20,13 +21,8 @@ COSMMap::COSMMap() :
     this->way_filter.add_rule(true, "highway", highway_tags[i]);
   for(unsigned int i=0;i<relation_type_tags.size();i++)
     this->relation_filter.add_rule(true, "type", relation_type_tags[i]);
-  this->max_x=-std::numeric_limits<double>::max();
-  this->min_x=std::numeric_limits<double>::max();
-  this->width=0.0;
-  this->max_y=-std::numeric_limits<double>::max();
-  this->min_y=std::numeric_limits<double>::max();
-  this->height=0.0;
   this->max_id=-std::numeric_limits<long int>::max();
+  this->utm_zone=31;
 }
 
 void COSMMap::free(void)
@@ -61,19 +57,12 @@ void COSMMap::free(void)
     this->restrictions[i]=NULL;
   }
   this->ways.clear();
-  this->max_x=-std::numeric_limits<double>::max();
-  this->min_x=std::numeric_limits<double>::max();
-  this->width=0.0;
-  this->max_y=-std::numeric_limits<double>::max();
-  this->min_y=std::numeric_limits<double>::max();
-  this->height=0.0; 
 }
 
 void COSMMap::process_map(void)
 {
   std::vector<COSMNode *>::iterator node_it;
   std::vector<COSMWay *>::iterator way_it;
-  double x,y;
 
   // remove all nodes that do not belong to any road
   for(node_it=this->nodes.begin();node_it!=this->nodes.end();)
@@ -103,20 +92,6 @@ void COSMMap::process_map(void)
   // remove nodes inside other ways width
   for(unsigned int i=0;i<this->nodes.size();i++)
     this->nodes[i]->remove_in_junction_nodes();
-  for(unsigned int i=0;i<this->nodes.size();i++)
-  {
-    this->nodes[i]->get_location(x,y);
-    // get the coordinates
-    if(x>this->max_x)
-      this->max_x=x;
-    if(x<this->min_x)
-      this->min_x=x;
-    if(y>this->max_y)
-      this->max_y=y;
-    if(y<this->min_y)
-      this->min_y=y;
-  }
-  this->normalize_locations();
 }
 
 void COSMMap::create_junctions(void)
@@ -242,21 +217,36 @@ void COSMMap::add_restriction(COSMRestriction *restriction)
   this->restrictions.push_back(restriction);
 }
 
-void COSMMap::normalize_locations(void)
+void COSMMap::normalize_locations(std::vector<osmium::Box> &boxes)
 {
-  double center_x,center_y;
+  double max_x,min_x,max_y,min_y,center_x,center_y,gamma,k;
+  int zone;
+  bool northp;
 
-  center_x=(this->max_x+this->min_x)/2.0;
-  center_y=(this->max_y+this->min_y)/2.0;
+  if(boxes.size()!=1)
+  {
+    this->free();
+    throw CException(_HERE_,"Invalid number of bounding boxes. Only one supported");
+  }
+  osmium::Location top_right=boxes[0].top_right();
+  osmium::Location bottom_left=boxes[0].bottom_left();
+  GeographicLib::UTMUPS::Forward(top_right.lat(),top_right.lon(),zone,northp,max_x,max_y,gamma,k,this->utm_zone);
+  GeographicLib::UTMUPS::Forward(bottom_left.lat(),bottom_left.lon(),zone,northp,min_x,min_y,gamma,k,this->utm_zone);
+  center_x=(max_x+min_x)/2.0;
+  center_y=(max_y+min_y)/2.0;
+  std::cout << max_x << "," << min_x << "," << max_y << "," << min_y << "," << center_x << "," << center_y << std::endl;
   for(unsigned int i=0;i<this->nodes.size();i++)
     this->nodes[i]->normalize_location(center_x,center_y);
-  this->max_x-=center_x;
-  this->min_x-=center_x;
-  this->max_y-=center_y;
-  this->min_y-=center_y;
-  // compute the width and heigth
-  this->width=this->max_x-this->min_x;
-  this->height=this->max_y-this->min_y;
+}
+
+void COSMMap::set_utm_zone(int zone)
+{
+  this->utm_zone=zone;
+}
+
+int COSMMap::get_utm_zone(void)
+{
+  return this->utm_zone;
 }
 
 void COSMMap::load(const std::string &filename)
@@ -282,6 +272,10 @@ void COSMMap::load(const std::string &filename)
   osmium::apply(relation_reader,*this);
   relation_reader.close();
 
+  // read the bounds of the map
+  std::vector<osmium::Box> boxes=node_reader.header().boxes();
+  this->normalize_locations(boxes);
+
   this->process_map();
   this->create_road_segments();
   this->create_junctions();

src/osm/osm_node.cpp

@@ -8,14 +8,16 @@
 
 #include <osmium/geom/coordinates.hpp>
 #include <osmium/geom/mercator_projection.hpp>
+#include <GeographicLib/UTMUPS.hpp>
 
 COSMNode::COSMNode(const osmium::Node &node,COSMMap *parent)
 {
+  int zone;
+  bool northp;
+  double gamma,k;
+
   this->id=node.id();
-  osmium::geom::Coordinates loc(node.location());
-  osmium::geom::Coordinates utm_loc=osmium::geom::lonlat_to_mercator(loc);
-  this->location.x=utm_loc.x;
-  this->location.y=utm_loc.y;
+  GeographicLib::UTMUPS::Forward(node.location().lat(),node.location().lon(),zone,northp,this->location.x,this->location.y,gamma,k,parent->get_utm_zone());
   this->ways.clear();
   this->junction=NULL;
   this->restrictions.clear();