cannon/src/utils/TupleDictionary.js

A lightweight 3D physics engine written in JavaScript.

module.exports = TupleDictionary;

/**
 * @class TupleDictionary
 * @constructor
 */
function TupleDictionary() {

    /**
     * The data storage
     * @property data
     * @type {Object}
     */
    this.data = { keys:[] };
}

/**
 * @method get
 * @param  {Number} i
 * @param  {Number} j
 * @return {Number}
 */
TupleDictionary.prototype.get = function(i, j) {
    if (i > j) {
        // swap
        var temp = j;
        j = i;
        i = temp;
    }
    return this.data[i+'-'+j];
};

/**
 * @method set
 * @param  {Number} i
 * @param  {Number} j
 * @param {Number} value
 */
TupleDictionary.prototype.set = function(i, j, value) {
    if (i > j) {
        var temp = j;
        j = i;
        i = temp;
    }
    var key = i+'-'+j;

    // Check if key already exists
    if(!this.get(i,j)){
        this.data.keys.push(key);
    }

    this.data[key] = value;
};

/**
 * @method reset
 */
TupleDictionary.prototype.reset = function() {
    var data = this.data,
        keys = data.keys;
    while(keys.length > 0){
        var key = keys.pop();
        delete data[key];
    }
};