icosahedron-draw/lib/Triangle/fix.js

renders points of an icosahedron

var _ = require('underscore');
var util = require('util');
var path = require('path');
var fs = require('fs');
var _DEBUG = false;

/* ************************************
 * 
 * ************************************ */

/* ******* CLOSURE ********* */

function _d2(a, b) {
    var x = a.x - b.x;
    var y = a.y - b.y;
    return Math.sqrt(x * x + y * y);
}

/* ********* EXPORTS ******** */

module.exports = function (t) {


    var ab = _d2(t.a, t.b);
    var bc = _d2(t.b, t.c);
    var ca = _d2(t.c, t.a);

    var distances = [
        {p: 'a', pt: t.a, others: [t.b, t.c], v: ab + ca},
        {p: 'b', pt: t.b, others: [t.a, t.c], v: ab + bc},
        {p: 'c', pt: t.c, others: [t.a, t.b], v: bc + ca}
    ];

    var best_dist = _.sortBy(distances, 'v').pop();

    var mutants = [
        [0, 0],
        [0, 1],
        [0, -1],
        [1, 0],
        [-1, 0]
    ];

    var mutant_distances = _.map(mutants, function (m) {
        var mutant = _.clone(best_dist);

        mutant.new_point = {
            ro: best_dist.pt.ro,
            x: best_dist.pt.x + m[0],
            y: best_dist.pt.y + m[1]
        };
        mutant.v = _.reduce(best_dist.others, function (out, p) {
            return out + _d2(p, mutant.new_point);
        }, 0);

        if (isNaN(mutant.v)) {
           throw new Error('bad distance');
        };

        return mutant;
    });

    var best_mutant = _.sortBy(mutant_distances, 'v').shift();
    t[best_dist.p] = best_mutant.new_point;

};