d3.geo.hexakisIcosahedron = (function () {
    'use strict';

    var Y = Math.atan2(1, 2) * 180 / Math.PI;
    var I = d3.geo.interpolate([0, Y], [72, Y])(0.5);

    var Y4 = (90 + Y) / 2;
    var Y3 = d3.geo.interpolate(I, [36, 90])(0.36)[1];
    var Y2 = I[1];
    var Y0 = d3.geo.interpolate(I, [36, -Y])(0.36)[1];

    function icosahedronPoints() {
        var points = [];

        points.push([0, -90]);

        for (var x = 0; x < 360; x += 72) {
            points.push([x, -Y], [x + 36, Y]);
        }

        points.push([0, 90]);

        return {type: 'MultiPoint', coordinates: points};
    }

    function hexakisCenterPoints() {
        var points = [];

        for (var x = 0; x < 360; x += 72) {
            points.push(
                [x + 36, -Y3],
                [x, Y0],
                [x + 72, Y3],
                [x + 72 + 36, -Y0]
            );
        }

        return {type: 'MultiPoint', coordinates: points};
    }

    function hexakisCrossPoints() {
        var points = [];

        for (var x = 0; x < 360; x += 72) {
            points.push(
                [x, -Y4],
                [x, Y2],
                [x + 18, 0],
                [x + 36, Y4],
                [x + 36, -Y2],
                [x + 36 + 18, 0]
            );
        }

        return {type: 'MultiPoint', coordinates: points};
    }

    function icosahedronEdges() {
        var edges = [];

        for (var x = 0; x < 360; x += 72) {
            edges.push([[x, -90], [x, -Y]]);
            edges.push([[x, -Y], [x + 72, -Y]]);
            edges.push([[x + 36, Y], [x - 36, Y]]);
            edges.push([[x + 36, Y], [x, -Y]]);
            edges.push([[x - 36, Y], [x, -Y]]);
            edges.push([[x + 36, 90], [x + 36, Y]]);
        }

        return {type: 'MultiLineString', coordinates: edges};
    }

    function hexakisCenterEdges() {
        var edges = [];

        for (var x = 0; x < 360; x += 72) {
            edges.push([[x, -90], [x + 36, -Y3]]);
            edges.push([[x, -Y], [x + 36, -Y3]]);
            edges.push([[x + 72, -Y], [x + 36, -Y3]]);
            edges.push([[x + 36, Y], [x + 36, -Y0]]);
            edges.push([[x, -Y], [x + 36, -Y0]]);
            edges.push([[x + 72, -Y], [x + 36, -Y0]]);
            edges.push([[x + 36, Y], [x, Y0]]);
            edges.push([[x - 36, Y], [x, Y0]]);
            edges.push([[x, -Y], [x, Y0]]);
            edges.push([[x, 90], [x, Y3]]);
            edges.push([[x + 36, Y], [x, Y3]]);
            edges.push([[x - 36, Y], [x, Y3]]);
        }

        return {type: 'MultiLineString', coordinates: edges};
    }


    function hexakisSideEdges() {
        var edges = [];

        for (var x = 0; x < 360; x += 72) {
            edges.push([[x, Y3], [x, Y0]]);
            edges.push([[x - 36, -Y0], [x, Y0]]);
            edges.push([[x + 36, -Y0], [x, Y0]]);
            edges.push([[x + 36, -Y0], [x + 36, -Y3]]);
            edges.push([[x - 36, -Y3], [x + 36, -Y3]]);
            edges.push([[x, Y3], [x + 72, Y3]]);
        }

        return {type: 'MultiLineString', coordinates: edges};
    }

    return {
        icosahedronPoints: icosahedronPoints,
        icosahedronEdges: icosahedronEdges,
        hexakisCenterPoints: hexakisCenterPoints,
        hexakisCenterEdges: hexakisCenterEdges,
        hexakisCrossPoints: hexakisCrossPoints,
        hexakisSideEdges: hexakisSideEdges
    };
})();