diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/src/geo/path.js --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolkit/javascript/d3/src/geo/path.js Thu Apr 10 14:20:23 2014 +0200 @@ -0,0 +1,271 @@ +/** + * Returns a function that, given a GeoJSON object (e.g., a feature), returns + * the corresponding SVG path. The function can be customized by overriding the + * projection. Point features are mapped to circles with a default radius of + * 4.5px; the radius can be specified either as a constant or a function that + * is evaluated per object. + */ +d3.geo.path = function() { + var pointRadius = 4.5, + pointCircle = d3_path_circle(pointRadius), + projection = d3.geo.albersUsa(); + + function path(d, i) { + if (typeof pointRadius === "function") { + pointCircle = d3_path_circle(pointRadius.apply(this, arguments)); + } + return pathType(d) || null; + } + + function project(coordinates) { + return projection(coordinates).join(","); + } + + var pathType = d3_geo_type({ + + FeatureCollection: function(o) { + var path = [], + features = o.features, + i = -1, // features.index + n = features.length; + while (++i < n) path.push(pathType(features[i].geometry)); + return path.join(""); + }, + + Feature: function(o) { + return pathType(o.geometry); + }, + + Point: function(o) { + return "M" + project(o.coordinates) + pointCircle; + }, + + MultiPoint: function(o) { + var path = [], + coordinates = o.coordinates, + i = -1, // coordinates.index + n = coordinates.length; + while (++i < n) path.push("M", project(coordinates[i]), pointCircle); + return path.join(""); + }, + + LineString: function(o) { + var path = ["M"], + coordinates = o.coordinates, + i = -1, // coordinates.index + n = coordinates.length; + while (++i < n) path.push(project(coordinates[i]), "L"); + path.pop(); + return path.join(""); + }, + + MultiLineString: function(o) { + var path = [], + coordinates = o.coordinates, + i = -1, // coordinates.index + n = coordinates.length, + subcoordinates, // coordinates[i] + j, // subcoordinates.index + m; // subcoordinates.length + while (++i < n) { + subcoordinates = coordinates[i]; + j = -1; + m = subcoordinates.length; + path.push("M"); + while (++j < m) path.push(project(subcoordinates[j]), "L"); + path.pop(); + } + return path.join(""); + }, + + Polygon: function(o) { + var path = [], + coordinates = o.coordinates, + i = -1, // coordinates.index + n = coordinates.length, + subcoordinates, // coordinates[i] + j, // subcoordinates.index + m; // subcoordinates.length + while (++i < n) { + subcoordinates = coordinates[i]; + j = -1; + if ((m = subcoordinates.length - 1) > 0) { + path.push("M"); + while (++j < m) path.push(project(subcoordinates[j]), "L"); + path[path.length - 1] = "Z"; + } + } + return path.join(""); + }, + + MultiPolygon: function(o) { + var path = [], + coordinates = o.coordinates, + i = -1, // coordinates index + n = coordinates.length, + subcoordinates, // coordinates[i] + j, // subcoordinates index + m, // subcoordinates.length + subsubcoordinates, // subcoordinates[j] + k, // subsubcoordinates index + p; // subsubcoordinates.length + while (++i < n) { + subcoordinates = coordinates[i]; + j = -1; + m = subcoordinates.length; + while (++j < m) { + subsubcoordinates = subcoordinates[j]; + k = -1; + if ((p = subsubcoordinates.length - 1) > 0) { + path.push("M"); + while (++k < p) path.push(project(subsubcoordinates[k]), "L"); + path[path.length - 1] = "Z"; + } + } + } + return path.join(""); + }, + + GeometryCollection: function(o) { + var path = [], + geometries = o.geometries, + i = -1, // geometries index + n = geometries.length; + while (++i < n) path.push(pathType(geometries[i])); + return path.join(""); + } + + }); + + var areaType = path.area = d3_geo_type({ + + FeatureCollection: function(o) { + var area = 0, + features = o.features, + i = -1, // features.index + n = features.length; + while (++i < n) area += areaType(features[i]); + return area; + }, + + Feature: function(o) { + return areaType(o.geometry); + }, + + Polygon: function(o) { + return polygonArea(o.coordinates); + }, + + MultiPolygon: function(o) { + var sum = 0, + coordinates = o.coordinates, + i = -1, // coordinates index + n = coordinates.length; + while (++i < n) sum += polygonArea(coordinates[i]); + return sum; + }, + + GeometryCollection: function(o) { + var sum = 0, + geometries = o.geometries, + i = -1, // geometries index + n = geometries.length; + while (++i < n) sum += areaType(geometries[i]); + return sum; + } + + }, 0); + + function polygonArea(coordinates) { + var sum = area(coordinates[0]), // exterior ring + i = 0, // coordinates.index + n = coordinates.length; + while (++i < n) sum -= area(coordinates[i]); // holes + return sum; + } + + function polygonCentroid(coordinates) { + var polygon = d3.geom.polygon(coordinates[0].map(projection)), // exterior ring + area = polygon.area(), + centroid = polygon.centroid(area < 0 ? (area *= -1, 1) : -1), + x = centroid[0], + y = centroid[1], + z = area, + i = 0, // coordinates index + n = coordinates.length; + while (++i < n) { + polygon = d3.geom.polygon(coordinates[i].map(projection)); // holes + area = polygon.area(); + centroid = polygon.centroid(area < 0 ? (area *= -1, 1) : -1); + x -= centroid[0]; + y -= centroid[1]; + z -= area; + } + return [x, y, 6 * z]; // weighted centroid + } + + var centroidType = path.centroid = d3_geo_type({ + + // TODO FeatureCollection + // TODO Point + // TODO MultiPoint + // TODO LineString + // TODO MultiLineString + // TODO GeometryCollection + + Feature: function(o) { + return centroidType(o.geometry); + }, + + Polygon: function(o) { + var centroid = polygonCentroid(o.coordinates); + return [centroid[0] / centroid[2], centroid[1] / centroid[2]]; + }, + + MultiPolygon: function(o) { + var area = 0, + coordinates = o.coordinates, + centroid, + x = 0, + y = 0, + z = 0, + i = -1, // coordinates index + n = coordinates.length; + while (++i < n) { + centroid = polygonCentroid(coordinates[i]); + x += centroid[0]; + y += centroid[1]; + z += centroid[2]; + } + return [x / z, y / z]; + } + + }); + + function area(coordinates) { + return Math.abs(d3.geom.polygon(coordinates.map(projection)).area()); + } + + path.projection = function(x) { + projection = x; + return path; + }; + + path.pointRadius = function(x) { + if (typeof x === "function") pointRadius = x; + else { + pointRadius = +x; + pointCircle = d3_path_circle(pointRadius); + } + return path; + }; + + return path; +}; + +function d3_path_circle(radius) { + return "m0," + radius + + "a" + radius + "," + radius + " 0 1,1 0," + (-2 * radius) + + "a" + radius + "," + radius + " 0 1,1 0," + (+2 * radius) + + "z"; +}