From 2e03861300bca1a44d50a9e9c684ffc0e2d6ad65 Mon Sep 17 00:00:00 2001
From: Nick Whitelegg <nick_whitelegg@yahoo.co.uk>
Date: Mon, 7 Jan 2008 20:25:12 +0000
Subject: [PATCH] Began code for feature lookup: implemented code to respond to
 mouse click and latlon to non spherical Mercator (for the postgis database)

---
 app/views/site/index.rhtml |  9 +++++++
 config/database.yml        |  4 +--
 config/environment.rb      |  2 +-
 public/javascripts/map.js  | 50 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/app/views/site/index.rhtml b/app/views/site/index.rhtml
index 604ecdb32..878720efc 100644
--- a/app/views/site/index.rhtml
+++ b/app/views/site/index.rhtml
@@ -115,11 +115,20 @@ by the OpenStreetMap project and it's contributors.
 
     map.events.register("moveend", map, updateLocation);
     map.events.register("changelayer", map, updateLocation);
+    map.events.register("click", map, mapClick);
     updateLocation();
 
     handleResize();
   }
 
+  // Map click results in feature lookup
+  function mapClick(e) {
+      var pos = lonLatToNonSphericalMercator
+                (mercatorToLonLat
+                    (map.getLonLatFromViewPortPx 
+                        ( map.events.getMousePosition(e))));
+  }
+
   function getPosition() {
     return mercatorToLonLat(map.getCenter());
   }
diff --git a/config/database.yml b/config/database.yml
index 436e3d306..fccd05934 100644
--- a/config/database.yml
+++ b/config/database.yml
@@ -13,8 +13,8 @@
 development:
   adapter: mysql
   database: openstreetmap
-  username: TheUsername
-  password: ThePassword
+  username: openstreetmap 
+  password: openstreetmap 
   host: localhost
 
 # Warning: The database defined as 'test' will be erased and
diff --git a/config/environment.rb b/config/environment.rb
index ed7bb6774..493e1664e 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -5,7 +5,7 @@
 ENV['RAILS_ENV'] ||= 'production'
 
 # Specifies gem version of Rails to use when vendor/rails is not present
-RAILS_GEM_VERSION = '2.0.1' unless defined? RAILS_GEM_VERSION
+#RAILS_GEM_VERSION = '2.0.1' unless defined? RAILS_GEM_VERSION
 
 # Set the server URL
 SERVER_URL = ENV['OSM_SERVER_URL'] || 'www.openstreetmap.org'
diff --git a/public/javascripts/map.js b/public/javascripts/map.js
index abbc7f8ea..0c13b016e 100644
--- a/public/javascripts/map.js
+++ b/public/javascripts/map.js
@@ -146,6 +146,56 @@ function lonLatToMercator(ll) {
    return new OpenLayers.LonLat(lon, lat);
 }
 
+// for interacting with the PostGIS database which uses non spherical
+// Mercator. Taken from Freemap which in turn was taken from a standard
+// algorithm off the net.
+
+function lonLatToNonSphericalMercator(ll) {
+    var custLat  = ll.lat * (Math.PI/180);
+    var a = 6378137;
+    var b = 6356752.3142;
+    var f = (a-b)/a;
+    var e = Math.sqrt(2*f-Math.pow(f,2));
+    custLat=a*Math.log(Math.tan(Math.PI/4+custLat/2)*
+        Math.pow(( (1-e*Math.sin(custLat)) / (1+e*Math.sin(custLat))),e/2));
+    custLon = ll.lon * (Math.PI/180) * 6378137;
+    return new OpenLayers.LonLat (custLon,custLat);
+}
+
+function nonSphericalMercatorToLonLat(merc) {
+    var lon_deg, lat_deg;
+    var a = 6378137.0;
+    var b = 6356752.3142;
+    var k0 = 1.0;
+    var t = 1.0 - b/a;
+    var es = 2*t - t*t;
+    var e = Math.sqrt(es);
+    lon_deg = merc.lon;
+    lat_deg = merc.lat;
+    lon_deg /= a;
+    lat_deg /= a;
+    lon_deg /= k0;
+    lat_deg = phi2(Math.exp(-lat_deg/k0), e);
+    lon_deg *= (180/M_PI);
+    lat_deg *= (180/M_PI);
+    return new OpenLayers.LonLat(lon_deg,lat_deg);
+}
+
+function phi2 (ts,e) {
+    var eccnth = 0.5*e;
+    var Phi = (PI/2) - 2.0*Math.atan(ts);
+    var dphi;
+    var i=15;
+    do {
+        var con = e*Math.sin(Phi);
+        dphi = (PI/2) - 2.0*Math.atan(ts*Math.pow((1.0-con)/(1.0+con),eccnth))
+            - Phi;
+        Phi += dphi;
+    }
+    while(Math.abs(dphi) > 0.0000000001 && --i);
+    return Phi;
+}
+
 function scaleToZoom(scale) {
    return Math.log(360.0/(scale * 512.0)) / Math.log(2.0);
 }
-- 
2.39.5