From f67d51492a81a325ed1a63ff3dcf2e4df7d7349c Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@7thposition.com>
Date: Wed, 1 Apr 2015 11:04:20 -0400
Subject: [PATCH] add d3.geo.length

---
 Makefile        |   1 +
 js/lib/d3.v3.js | 179 +++++++++++++++++++++++++++++-------------------
 2 files changed, 110 insertions(+), 70 deletions(-)

diff --git a/Makefile b/Makefile
index 3a36953af..a43441053 100644
--- a/Makefile
+++ b/Makefile
@@ -115,6 +115,7 @@ D3_FILES = \
 	node_modules/d3/src/behavior/zoom.js \
 	node_modules/d3/src/core/index.js \
 	node_modules/d3/src/event/index.js \
+	node_modules/d3/src/geo/length.js \
 	node_modules/d3/src/geo/mercator.js \
 	node_modules/d3/src/geo/path.js \
 	node_modules/d3/src/geo/stream.js \
diff --git a/js/lib/d3.v3.js b/js/lib/d3.v3.js
index bfe981c2b..e05ce8547 100644
--- a/js/lib/d3.v3.js
+++ b/js/lib/d3.v3.js
@@ -2075,6 +2075,115 @@ function d3_timer_sweep() {
   return time;
 }
 d3.geo = {};
+
+d3.geo.stream = function(object, listener) {
+  if (object && d3_geo_streamObjectType.hasOwnProperty(object.type)) {
+    d3_geo_streamObjectType[object.type](object, listener);
+  } else {
+    d3_geo_streamGeometry(object, listener);
+  }
+};
+
+function d3_geo_streamGeometry(geometry, listener) {
+  if (geometry && d3_geo_streamGeometryType.hasOwnProperty(geometry.type)) {
+    d3_geo_streamGeometryType[geometry.type](geometry, listener);
+  }
+}
+
+var d3_geo_streamObjectType = {
+  Feature: function(feature, listener) {
+    d3_geo_streamGeometry(feature.geometry, listener);
+  },
+  FeatureCollection: function(object, listener) {
+    var features = object.features, i = -1, n = features.length;
+    while (++i < n) d3_geo_streamGeometry(features[i].geometry, listener);
+  }
+};
+
+var d3_geo_streamGeometryType = {
+  Sphere: function(object, listener) {
+    listener.sphere();
+  },
+  Point: function(object, listener) {
+    object = object.coordinates;
+    listener.point(object[0], object[1], object[2]);
+  },
+  MultiPoint: function(object, listener) {
+    var coordinates = object.coordinates, i = -1, n = coordinates.length;
+    while (++i < n) object = coordinates[i], listener.point(object[0], object[1], object[2]);
+  },
+  LineString: function(object, listener) {
+    d3_geo_streamLine(object.coordinates, listener, 0);
+  },
+  MultiLineString: function(object, listener) {
+    var coordinates = object.coordinates, i = -1, n = coordinates.length;
+    while (++i < n) d3_geo_streamLine(coordinates[i], listener, 0);
+  },
+  Polygon: function(object, listener) {
+    d3_geo_streamPolygon(object.coordinates, listener);
+  },
+  MultiPolygon: function(object, listener) {
+    var coordinates = object.coordinates, i = -1, n = coordinates.length;
+    while (++i < n) d3_geo_streamPolygon(coordinates[i], listener);
+  },
+  GeometryCollection: function(object, listener) {
+    var geometries = object.geometries, i = -1, n = geometries.length;
+    while (++i < n) d3_geo_streamGeometry(geometries[i], listener);
+  }
+};
+
+function d3_geo_streamLine(coordinates, listener, closed) {
+  var i = -1, n = coordinates.length - closed, coordinate;
+  listener.lineStart();
+  while (++i < n) coordinate = coordinates[i], listener.point(coordinate[0], coordinate[1], coordinate[2]);
+  listener.lineEnd();
+}
+
+function d3_geo_streamPolygon(coordinates, listener) {
+  var i = -1, n = coordinates.length;
+  listener.polygonStart();
+  while (++i < n) d3_geo_streamLine(coordinates[i], listener, 1);
+  listener.polygonEnd();
+}
+
+d3.geo.length = function(object) {
+  d3_geo_lengthSum = 0;
+  d3.geo.stream(object, d3_geo_length);
+  return d3_geo_lengthSum;
+};
+
+var d3_geo_lengthSum;
+
+var d3_geo_length = {
+  sphere: d3_noop,
+  point: d3_noop,
+  lineStart: d3_geo_lengthLineStart,
+  lineEnd: d3_noop,
+  polygonStart: d3_noop,
+  polygonEnd: d3_noop
+};
+
+function d3_geo_lengthLineStart() {
+  var λ0, sinφ0, cosφ0;
+
+  d3_geo_length.point = function(λ, φ) {
+    λ0 = λ * d3_radians, sinφ0 = Math.sin(φ *= d3_radians), cosφ0 = Math.cos(φ);
+    d3_geo_length.point = nextPoint;
+  };
+
+  d3_geo_length.lineEnd = function() {
+    d3_geo_length.point = d3_geo_length.lineEnd = d3_noop;
+  };
+
+  function nextPoint(λ, φ) {
+    var sinφ = Math.sin(φ *= d3_radians),
+        cosφ = Math.cos(φ),
+        t = abs((λ *= d3_radians) - λ0),
+        cosΔλ = Math.cos(t);
+    d3_geo_lengthSum += Math.atan2(Math.sqrt((t = cosφ * Math.sin(t)) * t + (t = cosφ0 * sinφ - sinφ0 * cosφ * cosΔλ) * t), sinφ0 * sinφ + cosφ0 * cosφ * cosΔλ);
+    λ0 = λ, sinφ0 = sinφ, cosφ0 = cosφ;
+  }
+}
 function d3_identity(d) {
   return d;
 }
@@ -2683,76 +2792,6 @@ function d3_adderSum(a, b, o) {
   o.t = (a - av) + (b - bv); // a_roundoff + b_roundoff
 }
 
-d3.geo.stream = function(object, listener) {
-  if (object && d3_geo_streamObjectType.hasOwnProperty(object.type)) {
-    d3_geo_streamObjectType[object.type](object, listener);
-  } else {
-    d3_geo_streamGeometry(object, listener);
-  }
-};
-
-function d3_geo_streamGeometry(geometry, listener) {
-  if (geometry && d3_geo_streamGeometryType.hasOwnProperty(geometry.type)) {
-    d3_geo_streamGeometryType[geometry.type](geometry, listener);
-  }
-}
-
-var d3_geo_streamObjectType = {
-  Feature: function(feature, listener) {
-    d3_geo_streamGeometry(feature.geometry, listener);
-  },
-  FeatureCollection: function(object, listener) {
-    var features = object.features, i = -1, n = features.length;
-    while (++i < n) d3_geo_streamGeometry(features[i].geometry, listener);
-  }
-};
-
-var d3_geo_streamGeometryType = {
-  Sphere: function(object, listener) {
-    listener.sphere();
-  },
-  Point: function(object, listener) {
-    object = object.coordinates;
-    listener.point(object[0], object[1], object[2]);
-  },
-  MultiPoint: function(object, listener) {
-    var coordinates = object.coordinates, i = -1, n = coordinates.length;
-    while (++i < n) object = coordinates[i], listener.point(object[0], object[1], object[2]);
-  },
-  LineString: function(object, listener) {
-    d3_geo_streamLine(object.coordinates, listener, 0);
-  },
-  MultiLineString: function(object, listener) {
-    var coordinates = object.coordinates, i = -1, n = coordinates.length;
-    while (++i < n) d3_geo_streamLine(coordinates[i], listener, 0);
-  },
-  Polygon: function(object, listener) {
-    d3_geo_streamPolygon(object.coordinates, listener);
-  },
-  MultiPolygon: function(object, listener) {
-    var coordinates = object.coordinates, i = -1, n = coordinates.length;
-    while (++i < n) d3_geo_streamPolygon(coordinates[i], listener);
-  },
-  GeometryCollection: function(object, listener) {
-    var geometries = object.geometries, i = -1, n = geometries.length;
-    while (++i < n) d3_geo_streamGeometry(geometries[i], listener);
-  }
-};
-
-function d3_geo_streamLine(coordinates, listener, closed) {
-  var i = -1, n = coordinates.length - closed, coordinate;
-  listener.lineStart();
-  while (++i < n) coordinate = coordinates[i], listener.point(coordinate[0], coordinate[1], coordinate[2]);
-  listener.lineEnd();
-}
-
-function d3_geo_streamPolygon(coordinates, listener) {
-  var i = -1, n = coordinates.length;
-  listener.polygonStart();
-  while (++i < n) d3_geo_streamLine(coordinates[i], listener, 1);
-  listener.polygonEnd();
-}
-
 d3.geo.area = function(object) {
   d3_geo_areaSum = 0;
   d3.geo.stream(object, d3_geo_area);