Automatic clipExtent determination for mercator.

Since 3.1, the Mercator projection does not clamp y-values. For rendering
latitudes near the pole, the y-values can approach infinity. Rather than
clamping each point in the projection, d3.geo.mercator now sets the clipExtent
automatically (if not overridden) using the projection's scale and translate.

component.json

@@ -1,5 +1,5 @@
 {
   "name": "d3",
-  "version": "3.1.2",
+  "version": "3.1.3",
   "main": "./d3.js"
 }

d3.js

@@ -1,6 +1,6 @@
 d3 = function() {
   var d3 = {
-    version: "3.1.2"
+    version: "3.1.3"
   };
   if (!Date.now) Date.now = function() {
     return +new Date();
@@ -3625,8 +3625,32 @@ d3 = function() {
   d3_geo_mercator.invert = function(x, y) {
     return [ x, 2 * Math.atan(Math.exp(y)) - π / 2 ];
   };
+  function d3_geo_mercatorProjection(project) {
+    var m = d3_geo_projection(project), scale = m.scale, translate = m.translate, clipExtent = m.clipExtent, clipAuto;
+    m.scale = function() {
+      var v = scale.apply(m, arguments);
+      return v === m ? clipAuto ? m.clipExtent(null) : m : v;
+    };
+    m.translate = function() {
+      var v = translate.apply(m, arguments);
+      return v === m ? clipAuto ? m.clipExtent(null) : m : v;
+    };
+    m.clipExtent = function(_) {
+      var v = clipExtent.apply(m, arguments);
+      if (v === m) {
+        if (clipAuto = _ == null) {
+          var k = π * scale(), t = translate();
+          clipExtent([ [ t[0] - k, t[1] - k ], [ t[0] + k, t[1] + k ] ]);
+        }
+      } else if (clipAuto) {
+        v = null;
+      }
+      return v;
+    };
+    return m.clipExtent(null);
+  }
   (d3.geo.mercator = function() {
-    return d3_geo_projection(d3_geo_mercator);
+    return d3_geo_mercatorProjection(d3_geo_mercator);
   }).raw = d3_geo_mercator;
   var d3_geo_orthographic = d3_geo_azimuthal(function() {
     return 1;
@@ -3650,7 +3674,7 @@ d3 = function() {
     return [ Math.atan2(d3_sinh(x), Math.cos(y)), d3_asin(Math.sin(y) / d3_cosh(x)) ];
   };
   (d3.geo.transverseMercator = function() {
-    return d3_geo_projection(d3_geo_transverseMercator);
+    return d3_geo_mercatorProjection(d3_geo_transverseMercator);
   }).raw = d3_geo_transverseMercator;
   d3.geom = {};
   d3.svg = {};

package.json

@@ -1,6 +1,6 @@
 {
   "name": "d3",
-  "version": "3.1.2",
+  "version": "3.1.3",
   "description": "A small, free JavaScript library for manipulating documents based on data.",
   "keywords": [
     "dom",

src/geo/mercator.js

@@ -10,6 +10,39 @@ d3_geo_mercator.invert = function(x, y) {
   return [x, 2 * Math.atan(Math.exp(y)) - π / 2];
 };
 
+function d3_geo_mercatorProjection(project) {
+  var m = d3_geo_projection(project),
+      scale = m.scale,
+      translate = m.translate,
+      clipExtent = m.clipExtent,
+      clipAuto;
+
+  m.scale = function() {
+    var v = scale.apply(m, arguments);
+    return v === m ? (clipAuto ? m.clipExtent(null) : m) : v;
+  };
+
+  m.translate = function() {
+    var v = translate.apply(m, arguments);
+    return v === m ? (clipAuto ? m.clipExtent(null) : m) : v;
+  };
+
+  m.clipExtent = function(_) {
+    var v = clipExtent.apply(m, arguments);
+    if (v === m) {
+      if (clipAuto = _ == null) {
+        var k = π * scale(), t = translate();
+        clipExtent([[t[0] - k, t[1] - k], [t[0] + k, t[1] + k]]);
+      }
+    } else if (clipAuto) {
+      v = null;
+    }
+    return v;
+  };
+
+  return m.clipExtent(null);
+}
+
 (d3.geo.mercator = function() {
-  return d3_geo_projection(d3_geo_mercator);
+  return d3_geo_mercatorProjection(d3_geo_mercator);
 }).raw = d3_geo_mercator;

src/geo/transverse-mercator.js

@@ -1,5 +1,6 @@
 import "../math/trigonometry";
 import "geo";
+import "mercator";
 import "projection";
 
 function d3_geo_transverseMercator(λ, φ) {
@@ -18,5 +19,5 @@ d3_geo_transverseMercator.invert = function(x, y) {
 };
 
 (d3.geo.transverseMercator = function() {
-  return d3_geo_projection(d3_geo_transverseMercator);
+  return d3_geo_mercatorProjection(d3_geo_transverseMercator);
 }).raw = d3_geo_transverseMercator;

src/start.js

@@ -1,2 +1,2 @@
 d3 = (function(){
-  var d3 = {version: "3.1.2"}; // semver
+  var d3 = {version: "3.1.3"}; // semver