source: other-projects/playing-in-the-street/summer-2013/trunk/Playing-in-the-Street-WPF/Content/Web/mrdoob-three.js-4862f5f/src/core/Clock.js@ 28897

/**
 * @author alteredq / http://alteredqualia.com/
 */

THREE.Clock = function ( autoStart ) {

    this.autoStart = ( autoStart !== undefined ) ? autoStart : true;

    this.startTime = 0;
    this.oldTime = 0;
    this.elapsedTime = 0;

    this.running = false;

};

THREE.Clock.prototype = {

    constructor: THREE.Clock,

    start: function () {

        this.startTime = self.performance !== undefined && self.performance.now !== undefined
                    ? self.performance.now()
                    : Date.now();

        this.oldTime = this.startTime;
        this.running = true;
    },

    stop: function () {

        this.getElapsedTime();
        this.running = false;

    },

    getElapsedTime: function () {

        this.getDelta();
        return this.elapsedTime;

    },

    getDelta: function () {

        var diff = 0;

        if ( this.autoStart && ! this.running ) {

            this.start();

        }

        if ( this.running ) {

            var newTime = self.performance !== undefined && self.performance.now !== undefined
                    ? self.performance.now()
                    : Date.now();

            diff = 0.001 * ( newTime - this.oldTime );
            this.oldTime = newTime;

            this.elapsedTime += diff;

        }

        return diff;

    }

};