import “../core/noop”; import “../math/trigonometry”; import “geo”; import “stream”;
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 = Math.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; }
}