Merge branch 'projection' of https://github.com/jasondavies/d3 into projection

d3.v2.js

@@ -2030,22 +2030,46 @@
       coordinates = projectRotate.invert((coordinates[0] - δx) / k, (δy - coordinates[1]) / k);
       return [ coordinates[0] * d3_degrees, coordinates[1] * d3_degrees ];
     }
+    function intersect(λ0, φ0, λ1, φ1) {
+      var cosφ0, cosφ1, sinλ0_λ1 = Math.sin(λ0 - λ1);
+      return Math.abs(sinλ0_λ1) > ε ? Math.atan((Math.sin(φ0) * (cosφ1 = Math.cos(φ1)) * Math.sin(λ1) - Math.sin(φ1) * (cosφ0 = Math.cos(φ0)) * Math.sin(λ0)) / (cosφ0 * cosφ1 * sinλ0_λ1)) : (φ0 + φ1) / 2;
+    }
+    function rotateLocation(coordinates) {
+      return rotate(coordinates[0] * d3_radians, coordinates[1] * d3_radians);
+    }
+    function transformPoint(λ, φ) {
+      var point = project(λ, φ);
+      return [ point[0] * k + δx, δy - point[1] * k ];
+    }
     function reset() {
-      projectRotate = d3_geo_compose(d3_geo_rotation(δλ, δφ, δγ), project);
+      projectRotate = d3_geo_compose(rotate = d3_geo_rotation(δλ, δφ, δγ), project);
       var center = project(λ, φ);
       δx = x - center[0] * k;
       δy = y + center[1] * k;
       return p;
     }
-    var project, projectRotate, k = 150, x = 480, y = 250, λ = 0, φ = 0, δλ = 0, δφ = 0, δγ = 0, δx = x, δy = y;
+    var project, rotate, projectRotate, k = 150, x = 480, y = 250, λ = 0, φ = 0, δλ = 0, δφ = 0, δγ = 0, δx = x, δy = y;
     p.point = function(coordinates, context) {
       var point = p(coordinates);
       context.point(point[0], point[1]);
     };
     p.line = function(coordinates, context) {
-      var point = p(coordinates[0]), i = 0, n = coordinates.length;
+      if (!(n = coordinates.length)) return;
+      var location = rotateLocation(coordinates[0]), λ0 = location[0], φ0 = location[1], point = transformPoint(λ0, φ0), λ1, φ1, δλ, sλ0, n;
       context.moveTo(point[0], point[1]);
-      while (++i < n) context.lineTo((point = p(coordinates[i]))[0], point[1]);
+      for (var i = 0; i < n; i++) {
+        location = rotateLocation(coordinates[i]);
+        λ1 = location[0];
+        φ1 = location[1];
+        δλ = (Math.abs(λ1 - λ0) + 2 * π) % (2 * π);
+        sλ0 = λ0 > 0;
+        if (i && sλ0 ^ λ1 > 0 && (δλ >= π || δλ < ε && Math.abs(Math.abs(λ0) - π) < ε)) {
+          φ0 = intersect(λ0, φ0, λ1, φ1);
+          context.lineTo((point = transformPoint(sλ0 ? π : -π, φ0))[0], point[1]);
+          context.moveTo((point = transformPoint(sλ0 ? -π : π, φ0))[0], point[1]);
+        }
+        context.lineTo((point = transformPoint(λ0 = λ1, φ0 = φ1))[0], point[1]);
+      }
     };
     p.ring = function(coordinates, context) {
       p.line(coordinates, context);
@@ -2707,7 +2731,7 @@
   d3 = {
     version: "2.10.2"
   };
-  var π = Math.PI, d3_radians = π / 180, d3_degrees = 180 / π;
+  var π = Math.PI, ε = 1e-6, d3_radians = π / 180, d3_degrees = 180 / π;
   var d3_array = d3_arraySlice;
   try {
     d3_array(document.documentElement.childNodes)[0].nodeType;
@@ -6218,12 +6242,12 @@
     }
     var x1 = 180, x0 = -x1, y1 = 90, y0 = -y1, dx = 22.5, dy = dx;
     graticule.lines = function() {
-      var xLines = d3.range(Math.ceil(x0 / dx) * dx, y0, dx).map(function(x) {
+      var xSteps = d3.range(Math.ceil(x0 / dx) * dx, x1, dx).concat(x1), ySteps = d3.range(Math.ceil(y0 / dy) * dy, y1, dy).concat(y1), xLines = xSteps.map(function(x) {
-        return [ y0, y1 ].map(function(y) {
+        return ySteps.map(function(y) {
           return [ x, y ];
         });
-      }), yLines = d3.range(Math.ceil(x1 / dy) * dy, y1, dy).map(function(y) {
+      }), yLines = ySteps.map(function(y) {
-        return [ x0, x1 ].map(function(x) {
+        return xSteps.map(function(x) {
           return [ x, y ];
         });
       });
@@ -6323,6 +6347,10 @@
       });
       return buffer.length ? buffer.join("") : null;
     }
+    function pathObject(object, context) {
+      var pathType = pathObjectByType.get(object.type);
+      if (pathType) pathType(object, context);
+    }
     function pathGeometry(geometry, context) {
       var pathType = pathGeometryByType.get(geometry.type);
       if (pathType) pathType(geometry, context);
@@ -6363,11 +6391,7 @@
       var coordinates = polygon.coordinates, i = -1, n = coordinates.length;
       while (++i < n) projection.ring(coordinates[i], context);
     }
-    function pathObject(object, context) {
+    var pointRadius = 4.5, pointCircle = d3_geo_path_circle(pointRadius), projection = d3.geo.albersUsa(), context;
-      var pathType = pathObjectByType.get(object.type);
-      if (pathType) pathType(object, context);
-    }
-    var pointRadius = 4.5, pointCircle = d3_geo_path_circle(pointRadius), projection, context;
     var pathObjectByType = d3.map({
       Feature: pathFeature,
       FeatureCollection: pathFeatureCollection,
@@ -6403,7 +6427,7 @@
       if (typeof x === "function") pointRadius = x; else pointCircle = d3_geo_path_circle(pointRadius = +x);
       return path;
     };
-    return path.projection(d3.geo.albersUsa());
+    return path;
   };
   d3.geo.projection = d3_geo_projection;
   var d3_geo_stereographic = d3_geo_azimuthal(function(cosλcosφ) {

src/core/core.js

@@ -1,5 +1,6 @@
 d3 = {version: "2.10.2"}; // semver
 
 var π = Math.PI,
+    ε = 1e-6,
     d3_radians = π / 180,
     d3_degrees = 180 / π;

src/geo/graticule.js

@@ -12,8 +12,10 @@ d3.geo.graticule = function() {
   }
 
   graticule.lines = function() {
-    var xLines = d3.range(Math.ceil(x0 / dx) * dx, y0, dx).map(function(x) { return [y0, y1].map(function(y) { return [x, y]; }); }),
+    var xSteps = d3.range(Math.ceil(x0 / dx) * dx, x1, dx).concat(x1),
-        yLines = d3.range(Math.ceil(x1 / dy) * dy, y1, dy).map(function(y) { return [x0, x1].map(function(x) { return [x, y]; }); });
+        ySteps = d3.range(Math.ceil(y0 / dy) * dy, y1, dy).concat(y1),
+        xLines = xSteps.map(function(x) { return ySteps.map(function(y) { return [x, y]; }); }),
+        yLines = ySteps.map(function(y) { return xSteps.map(function(x) { return [x, y]; }); });
     return xLines.concat(yLines).map(function(coordinates) {
       return {
         type: "LineString",

src/geo/projection.js

@@ -7,6 +7,7 @@ function d3_geo_projection(project) {
 // TODO Expose this API? Not that happy with it.
 function d3_geo_projectionMutator(projectAt) {
   var project,
+      rotate,
       projectRotate,
       k = 150,
       x = 480,
@@ -35,9 +36,30 @@ function d3_geo_projectionMutator(projectAt) {
   };
 
   p.line = function(coordinates, context) {
-    var point = p(coordinates[0]), i = 0, n = coordinates.length;
+    if (!(n = coordinates.length)) return;
+    var location = rotateLocation(coordinates[0]),
+        λ0 = location[0],
+        φ0 = location[1],
+        point = transformPoint(λ0, φ0),
+        λ1,
+        φ1,
+        δλ,
+        sλ0,
+        n;
     context.moveTo(point[0], point[1]);
-    while (++i < n) context.lineTo((point = p(coordinates[i]))[0], point[1]);
+    for (var i = 0; i < n; i++) {
+      location = rotateLocation(coordinates[i]);
+      λ1 = location[0];
+      φ1 = location[1];
+      δλ = (Math.abs(λ1 - λ0) + 2 * π) % (2 * π);
+      sλ0 = λ0 > 0;
+      if (i && sλ0 ^ (λ1 > 0) && (δλ >= π || δλ < ε && Math.abs(Math.abs(λ0) - π) < ε)) {
+        φ0 = intersect(λ0, φ0, λ1, φ1);
+        context.lineTo((point = transformPoint(sλ0 ? π : -π, φ0))[0], point[1]);
+        context.moveTo((point = transformPoint(sλ0 ? -π : π, φ0))[0], point[1]);
+      }
+      context.lineTo((point = transformPoint(λ0 = λ1, φ0 = φ1))[0], point[1]);
+    }
   };
 
   p.ring = function(coordinates, context) {
@@ -45,6 +67,26 @@ function d3_geo_projectionMutator(projectAt) {
     context.closePath();
   };
 
+  function intersect(λ0, φ0, λ1, φ1) {
+    var cosφ0,
+        cosφ1,
+        sinλ0_λ1 = Math.sin(λ0 - λ1);
+    return Math.abs(sinλ0_λ1) > ε
+        ? Math.atan((Math.sin(φ0) * (cosφ1 = Math.cos(φ1)) * Math.sin(λ1)
+                   - Math.sin(φ1) * (cosφ0 = Math.cos(φ0)) * Math.sin(λ0))
+                   / (cosφ0 * cosφ1 * sinλ0_λ1))
+        : (φ0 + φ1) / 2;
+  }
+
+  function rotateLocation(coordinates) {
+    return rotate(coordinates[0] * d3_radians, coordinates[1] * d3_radians);
+  }
+
+  function transformPoint(λ, φ) {
+    var point = project(λ, φ);
+    return [point[0] * k + δx, δy - point[1] * k];
+  }
+
   p.scale = function(_) {
     if (!arguments.length) return k;
     k = +_;
@@ -74,7 +116,7 @@ function d3_geo_projectionMutator(projectAt) {
   };
 
   function reset() {
-    projectRotate = d3_geo_compose(d3_geo_rotation(δλ, δφ, δγ), project);
+    projectRotate = d3_geo_compose(rotate = d3_geo_rotation(δλ, δφ, δγ), project);
     var center = project(λ, φ);
     δx = x - center[0] * k;
     δy = y + center[1] * k;