From 90bc8dd70abdc01b55d584043456067f1422bf62 Mon Sep 17 00:00:00 2001
From: John Firebaugh <john.firebaugh@gmail.com>
Date: Wed, 14 May 2014 17:53:47 -0700
Subject: [PATCH] Extract iD.geo.RawMercator

---
 index.html                |  1 +
 js/id/geo/raw_mercator.js | 50 +++++++++++++++++++++++++++++++++++++++
 js/id/id.js               | 47 +-----------------------------------
 test/index.html           |  1 +
 4 files changed, 53 insertions(+), 46 deletions(-)
 create mode 100644 js/id/geo/raw_mercator.js

diff --git a/index.html b/index.html
index fec78cf5c..9f0c7a6f5 100644
--- a/index.html
+++ b/index.html
@@ -48,6 +48,7 @@
         <script src="js/id/geo.js"></script>
         <script src="js/id/geo/extent.js"></script>
         <script src="js/id/geo/multipolygon.js"></script>
+        <script src="js/id/geo/raw_mercator.js"></script>
         <script src="js/id/geo/turn.js"></script>
 
         <script src='js/id/renderer/background.js'></script>
diff --git a/js/id/geo/raw_mercator.js b/js/id/geo/raw_mercator.js
new file mode 100644
index 000000000..f34cb5d96
--- /dev/null
+++ b/js/id/geo/raw_mercator.js
@@ -0,0 +1,50 @@
+/*
+    Bypasses features of D3's default projection stream pipeline that are unnecessary:
+    * Antimeridian clipping
+    * Spherical rotation
+    * Resampling
+*/
+iD.geo.RawMercator = function () {
+    var project = d3.geo.mercator.raw,
+        k = 512 / Math.PI, // scale
+        x = 0, y = 0, // translate
+        clipExtent = [[0, 0], [0, 0]];
+
+    function projection(point) {
+        point = project(point[0] * Math.PI / 180, point[1] * Math.PI / 180);
+        return [point[0] * k + x, y - point[1] * k];
+    }
+
+    projection.invert = function(point) {
+        point = project.invert((point[0] - x) / k, (y - point[1]) / k);
+        return point && [point[0] * 180 / Math.PI, point[1] * 180 / Math.PI];
+    };
+
+    projection.scale = function(_) {
+        if (!arguments.length) return k;
+        k = +_;
+        return projection;
+    };
+
+    projection.translate = function(_) {
+        if (!arguments.length) return [x, y];
+        x = +_[0];
+        y = +_[1];
+        return projection;
+    };
+
+    projection.clipExtent = function(_) {
+        if (!arguments.length) return clipExtent;
+        clipExtent = _;
+        return projection;
+    };
+
+    projection.stream = d3.geo.transform({
+        point: function(x, y) {
+            x = projection([x, y]);
+            this.stream.point(x[0], x[1]);
+        }
+    }).stream;
+
+    return projection;
+};
diff --git a/js/id/id.js b/js/id/id.js
index 2dfc664d1..af51ef051 100644
--- a/js/id/id.js
+++ b/js/id/id.js
@@ -197,52 +197,7 @@ window.iD = function () {
     };
 
     /* Projection */
-    function rawMercator() {
-        var project = d3.geo.mercator.raw,
-            k = 512 / Math.PI, // scale
-            x = 0, y = 0, // translate
-            clipExtent = [[0, 0], [0, 0]];
-
-        function projection(point) {
-            point = project(point[0] * Math.PI / 180, point[1] * Math.PI / 180);
-            return [point[0] * k + x, y - point[1] * k];
-        }
-
-        projection.invert = function(point) {
-            point = project.invert((point[0] - x) / k, (y - point[1]) / k);
-            return point && [point[0] * 180 / Math.PI, point[1] * 180 / Math.PI];
-        };
-
-        projection.scale = function(_) {
-            if (!arguments.length) return k;
-            k = +_;
-            return projection;
-        };
-
-        projection.translate = function(_) {
-            if (!arguments.length) return [x, y];
-            x = +_[0];
-            y = +_[1];
-            return projection;
-        };
-
-        projection.clipExtent = function(_) {
-            if (!arguments.length) return clipExtent;
-            clipExtent = _;
-            return projection;
-        };
-
-        projection.stream = d3.geo.transform({
-            point: function(x, y) {
-                x = projection([x, y]);
-                this.stream.point(x[0], x[1]);
-            }
-        }).stream;
-
-        return projection;
-    }
-
-    context.projection = rawMercator();
+    context.projection = iD.geo.RawMercator();
 
     /* Background */
     var background = iD.Background(context);
diff --git a/test/index.html b/test/index.html
index 8fe2bc698..85dfeba68 100644
--- a/test/index.html
+++ b/test/index.html
@@ -46,6 +46,7 @@
     <script src="../js/id/geo.js"></script>
     <script src="../js/id/geo/extent.js"></script>
     <script src="../js/id/geo/multipolygon.js"></script>
+    <script src="../js/id/geo/raw_mercator.js"></script>
     <script src="../js/id/geo/turn.js"></script>
 
     <script src='../js/id/renderer/background.js'></script>