From 4b949176d3cce6b1de9f0737087dd09ea92e69af Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Mon, 16 Jan 2012 22:39:44 -0700
Subject: [PATCH] Move mercator transforms to Projection.js.

The SphericalMercator mixin is not required for coordinate transforms.  Default transforms included whenever Projection.js is included.
---
 examples/web-mercator.js                  |   8 --
 lib/OpenLayers/Layer/SphericalMercator.js | 103 ++++------------------
 lib/OpenLayers/Projection.js              |  60 +++++++++++--
 tests/Layer/Google/v3.html                |   6 +-
 tests/Layer/SphericalMercator.html        |  23 ++---
 5 files changed, 75 insertions(+), 125 deletions(-)

diff --git a/examples/web-mercator.js b/examples/web-mercator.js
index ed14d940b7..7a25d373c6 100644
--- a/examples/web-mercator.js
+++ b/examples/web-mercator.js
@@ -1,14 +1,6 @@
 // make map available for easy debugging
 var map;
 
-// if your application transforms coordinates to and from EPSG:102113 then
-// you must uncomment the lines below
-
-// OpenLayers.Projection.addTransform("EPSG:4326", "EPSG:102113",
-//     OpenLayers.Layer.SphericalMercator.projectForward);
-// OpenLayers.Projection.addTransform("EPSG:102113", "EPSG:4326",
-//     OpenLayers.Layer.SphericalMercator.projectInverse);
-
 function init() {
 
     var options = {
diff --git a/lib/OpenLayers/Layer/SphericalMercator.js b/lib/OpenLayers/Layer/SphericalMercator.js
index 2b5a764353..7f0e35321d 100644
--- a/lib/OpenLayers/Layer/SphericalMercator.js
+++ b/lib/OpenLayers/Layer/SphericalMercator.js
@@ -114,14 +114,14 @@ OpenLayers.Layer.SphericalMercator = {
      * Returns:
      * {<OpenLayers.LonLat>} The coordinates transformed to Mercator.
      */
-    forwardMercator: function(lon, lat) {
-        var x = lon * 20037508.34 / 180;
-        var y = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180);
-
-        y = y * 20037508.34 / 180;
-        
-        return new OpenLayers.LonLat(x, y);
-    },
+    forwardMercator: (function() {
+        var gg = new OpenLayers.Projection("EPSG:4326");
+        var sm = new OpenLayers.Projection("EPSG:900913");
+        return function(lon, lat) {
+            var point = OpenLayers.Projection.transform({x: lon, y: lat}, gg, sm);
+            return new OpenLayers.LonLat(point.x, point.y);
+        };
+    })(),
 
     /**
      * APIMethod: inverseMercator
@@ -134,84 +134,13 @@ OpenLayers.Layer.SphericalMercator = {
      * Returns:
      * {<OpenLayers.LonLat>} The coordinates transformed to EPSG:4326.
      */
-    inverseMercator: function(x, y) {
-
-        var lon = (x / 20037508.34) * 180;
-        var lat = (y / 20037508.34) * 180;
-
-        lat = 180/Math.PI * (2 * Math.atan(Math.exp(lat * Math.PI / 180)) - Math.PI / 2);
-        
-        return new OpenLayers.LonLat(lon, lat);
-    },
-
-    /**
-     * Method: projectForward 
-     * Given an object with x and y properties in EPSG:4326, modify the x,y
-     * properties on the object to be the Spherical Mercator projected
-     * coordinates.
-     *
-     * Parameters:
-     * point - {Object} An object with x and y properties. 
-     * 
-     * Returns:
-     * {Object} The point, with the x and y properties transformed to spherical
-     * mercator.
-     */
-    projectForward: function(point) {
-        var lonlat = OpenLayers.Layer.SphericalMercator.forwardMercator(point.x, point.y);
-        point.x = lonlat.lon;
-        point.y = lonlat.lat;
-        return point;
-    },
-    
-    /**
-     * Method: projectInverse
-     * Given an object with x and y properties in Spherical Mercator, modify
-     * the x,y properties on the object to be the unprojected coordinates.
-     *
-     * Parameters:
-     * point - {Object} An object with x and y properties. 
-     * 
-     * Returns:
-     * {Object} The point, with the x and y properties transformed from
-     * spherical mercator to unprojected coordinates..
-     */
-    projectInverse: function(point) {
-        var lonlat = OpenLayers.Layer.SphericalMercator.inverseMercator(point.x, point.y);
-        point.x = lonlat.lon;
-        point.y = lonlat.lat;
-        return point;
-    }
+    inverseMercator: (function() {
+        var gg = new OpenLayers.Projection("EPSG:4326");
+        var sm = new OpenLayers.Projection("EPSG:900913");
+        return function(x, y) {
+            var point = OpenLayers.Projection.transform({x: x, y: y}, sm, gg);
+            return new OpenLayers.LonLat(point.x, point.y);
+        };
+    })()
 
 };
-
-/**
- * Note: Transforms for web mercator <-> EPSG:4326
- * OpenLayers recognizes EPSG:3857, EPSG:900913, EPSG:102113 and EPSG:102100.
- * OpenLayers originally started referring to EPSG:900913 as web mercator.
- * The EPSG has declared EPSG:3857 to be web mercator.  
- * ArcGIS 10 recognizes the EPSG:3857, EPSG:102113, and EPSG:102100 as 
- * equivalent.  See http://blogs.esri.com/Dev/blogs/arcgisserver/archive/2009/11/20/ArcGIS-Online-moving-to-Google-_2F00_-Bing-tiling-scheme_3A00_-What-does-this-mean-for-you_3F00_.aspx#12084
- */
-(function() {
-    
-    // list of equivalent codes for web mercator
-    var codes = ["EPSG:900913", "EPSG:3857", "EPSG:102113", "EPSG:102100"];
-    
-    var add = OpenLayers.Projection.addTransform;
-    var merc = OpenLayers.Layer.SphericalMercator;
-    var same = OpenLayers.Projection.nullTransform;
-    
-    var i, len, code, other, j;
-    for (i=0, len=codes.length; i<len; ++i) {
-        code = codes[i];
-        add("EPSG:4326", code, merc.projectForward);
-        add(code, "EPSG:4326", merc.projectInverse);
-        for (j=i+1; j<len; ++j) {
-            other = codes[j];
-            add(code, other, same);
-            add(other, code, same);
-        }
-    }
-    
-})();
diff --git a/lib/OpenLayers/Projection.js b/lib/OpenLayers/Projection.js
index 711dce8abd..8c1f6a6a66 100644
--- a/lib/OpenLayers/Projection.js
+++ b/lib/OpenLayers/Projection.js
@@ -195,10 +195,14 @@ OpenLayers.Projection.transform = function(point, source, dest) {
         }
         if (source.proj && dest.proj) {
             point = Proj4js.transform(source.proj, dest.proj, point);
-        } else if (OpenLayers.Projection.transforms[source.getCode()] && 
-                   OpenLayers.Projection.transforms[source.getCode()][dest.getCode()]) {
-            OpenLayers.Projection.transforms[source.getCode()][dest.getCode()](point); 
-        }        
+        } else {
+            var sourceCode = source.getCode();
+            var destCode = dest.getCode();
+            var transforms = OpenLayers.Projection.transforms;
+            if (transforms[sourceCode] && transforms[sourceCode][destCode]) {
+                transforms[sourceCode][destCode](point);
+            }
+        }
     }
     return point;
 };
@@ -209,10 +213,6 @@ OpenLayers.Projection.transform = function(point, source, dest) {
  * proj4js is not available:
  *
  * (code)
- * OpenLayers.Projection.addTransform("EPSG:4326", "EPSG:3857",
- *     OpenLayers.Layer.SphericalMercator.projectForward);
- * OpenLayers.Projection.addTransform("EPSG:3857", "EPSG:3857",
- *     OpenLayers.Layer.SphericalMercator.projectInverse);
  * OpenLayers.Projection.addTransform("EPSG:3857", "EPSG:900913",
  *     OpenLayers.Projection.nullTransform);
  * OpenLayers.Projection.addTransform("EPSG:900913", "EPSG:3857",
@@ -222,3 +222,47 @@ OpenLayers.Projection.transform = function(point, source, dest) {
 OpenLayers.Projection.nullTransform = function(point) {
     return point;
 };
+
+/**
+ * Note: Transforms for web mercator <-> EPSG:4326
+ * OpenLayers recognizes EPSG:3857, EPSG:900913, EPSG:102113 and EPSG:102100.
+ * OpenLayers originally started referring to EPSG:900913 as web mercator.
+ * The EPSG has declared EPSG:3857 to be web mercator.
+ * ArcGIS 10 recognizes the EPSG:3857, EPSG:102113, and EPSG:102100 as
+ * equivalent.  See http://blogs.esri.com/Dev/blogs/arcgisserver/archive/2009/11/20/ArcGIS-Online-moving-to-Google-_2F00_-Bing-tiling-scheme_3A00_-What-does-this-mean-for-you_3F00_.aspx#12084
+ */
+(function() {
+
+    var pole = 20037508.34;
+
+    function inverseMercator(xy) {
+        xy.x = 180 * xy.x / pole;
+        xy.y = 180 / Math.PI * (2 * Math.atan(Math.exp((xy.y / pole) * Math.PI)) - Math.PI / 2);
+        return xy;
+    }
+
+    function forwardMercator(xy) {
+        xy.x = xy.x * pole / 180;
+        xy.y = Math.log(Math.tan((90 + xy.y) * Math.PI / 360)) / Math.PI * pole;
+        return xy;
+    }
+
+    // list of equivalent codes for web mercator
+    var codes = ["EPSG:900913", "EPSG:3857", "EPSG:102113", "EPSG:102100"];
+
+    var add = OpenLayers.Projection.addTransform;
+    var same = OpenLayers.Projection.nullTransform;
+
+    var i, len, code, other, j;
+    for (i=0, len=codes.length; i<len; ++i) {
+        code = codes[i];
+        add("EPSG:4326", code, forwardMercator);
+        add(code, "EPSG:4326", inverseMercator);
+        for (j=i+1; j<len; ++j) {
+            other = codes[j];
+            add(code, other, same);
+            add(other, code, same);
+        }
+    }
+
+})();
diff --git a/tests/Layer/Google/v3.html b/tests/Layer/Google/v3.html
index d7c8c7a077..27de3b04f5 100644
--- a/tests/Layer/Google/v3.html
+++ b/tests/Layer/Google/v3.html
@@ -65,11 +65,7 @@
     //  works correctly both ways.
        var gLatLng = new google.maps.LatLng(50,100);
        // v3 uses sphericalMercator by default
-       var correspondingOLLonLat = new OpenLayers.LonLat(100,50).transform(
-           new OpenLayers.Projection("EPSG:4326"),
-           map.getProjectionObject()
-       );
-    
+       var correspondingOLLonLat = layer.forwardMercator(100, 50);
     
        olLonLat = layer.getOLLonLatFromMapObjectLonLat(gLatLng);
        t.ok(olLonLat.equals(correspondingOLLonLat), "Translation from GLatLng to OpenLayers.LonLat works");
diff --git a/tests/Layer/SphericalMercator.html b/tests/Layer/SphericalMercator.html
index c2bbdfc632..463ffe1697 100644
--- a/tests/Layer/SphericalMercator.html
+++ b/tests/Layer/SphericalMercator.html
@@ -38,8 +38,8 @@
         t.eq(sw.lon, -180, "Southwest lon correct");
         t.eq(ne.lon, 180, "Northeast lon correct");
         
-        t.eq(sw.lat, -85.051128779807, "Southwest lat correct");
-        t.eq(ne.lat, 85.051128779807, "Northeast lat correct");
+        t.eq(sw.lat.toFixed(10), "-85.0511287798", "Southwest lat correct");
+        t.eq(ne.lat.toFixed(10), "85.0511287798", "Northeast lat correct");
     }
 
     function strToFixed(str, dig) { 
@@ -51,22 +51,11 @@
         }); 
     } 
  
-    function test_SphericalMercator_projectForward(t) { 
-        t.plan(1);
-        var point = new OpenLayers.Geometry.Point(10, 20); 
-        OpenLayers.Layer.SphericalMercator.projectForward(point); 
-
-        t.eq(strToFixed(point.toString()), 
-             strToFixed("POINT(1113194.9077777779 2273030.9266712805)"), 
-             "point transforms from EPSG:4326 to Spherical Mercator"); 
-    } 
-         
     function test_SphericalMercator_to4326(t) { 
         t.plan(1);
-        var point = new OpenLayers.Geometry.Point(1113195, 2273031); 
+        var point = new OpenLayers.Geometry.Point(1113195, 2273031);
+        point.transform("EPSG:900913", "EPSG:4326");
 
-        OpenLayers.Layer.SphericalMercator.projectInverse(point); 
-         
         t.eq(strToFixed(point.toString()), 
              strToFixed("POINT(10.000000828446318 20.000000618997227)"), 
              "point transforms from Spherical Mercator to EPSG:4326"); 
@@ -82,9 +71,9 @@
         var smerc = OpenLayers.Projection.transforms["EPSG:900913"];
         t.ok(smerc instanceof Object, "EPSG:900913 exists in table");
         
-        t.ok(wgs84["EPSG:900913"] === OpenLayers.Layer.SphericalMercator.projectForward,
+        t.ok(typeof(wgs84["EPSG:900913"]) === "function",
              "from EPSG:4326 to EPSG:900913 correctly defined");
-        t.ok(smerc["EPSG:4326"] === OpenLayers.Layer.SphericalMercator.projectInverse,
+        t.ok(typeof(smerc["EPSG:4326"]) === "function",
              "from EPSG:900913 to EPSG:4326 correctly defined");
     }