/**

* A plugin which enables rendering of math equations inside
* of reveal.js slides. Essentially a thin wrapper for MathJax.
*
* @author Hakim El Hattab
*/

var RevealMath = window.RevealMath || (function(){

var options = Reveal.getConfig().math || {};
options.mathjax = options.mathjax || 'http://cdn.mathjax.org/mathjax/latest/MathJax.js';
options.config = options.config || 'TeX-AMS_HTML-full';

loadScript( options.mathjax + '?config=' + options.config, function() {

        MathJax.Hub.Config({
                messageStyle: 'none',
                tex2jax: { inlineMath: [['$','$'],['\\(','\\)']] },
                skipStartupTypeset: true
        });

        // Typeset followed by an immediate reveal.js layout since
        // the typesetting process could affect slide height
        MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub ] );
        MathJax.Hub.Queue( Reveal.layout );

        // Reprocess equations in slides when they turn visible
        Reveal.addEventListener( 'slidechanged', function( event ) {

                MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub, event.currentSlide ] );

        } );

} );

function loadScript( url, callback ) {

        var head = document.querySelector( 'head' );
        var script = document.createElement( 'script' );
        script.type = 'text/javascript';
        script.src = url;

        // Wrapper for callback to make sure it only fires once
        var finish = function() {
                if( typeof callback === 'function' ) {
                        callback.call();
                        callback = null;
                }
        }

        script.onload = finish;

        // IE
        script.onreadystatechange = function() {
                if ( this.readyState === 'loaded' ) {
                        finish();
                }
        }

        // Normal browsers
        head.appendChild( script );

}

})();