ShaderLoader.js

var ShaderLoader = function()
{
    // Shaders

    ShaderLoader.get = function( id )
    {
        return ShaderLoader.shaders[ id ];
    };

};

ShaderLoader.prototype =
{

    loadShaders : function( shaders, baseUrl, callback )
    {
        ShaderLoader.shaders = shaders;

        this.baseUrl = baseUrl || "./";
        this.callback = callback;
        this.batchLoad( this, 'onShadersReady' );

    },

    batchLoad : function( scope, callback )
    {
        var queue = 0;
        for ( var name in ShaderLoader.shaders ) {

            queue++;
            var req = new XMLHttpRequest();
            req.onload = loadHandler( name, req );
            req.open( 'get', scope.baseUrl + name + '.glsl', true );
            req.send();
        }

        function loadHandler( name, req ) {
            return function()
            {
                ShaderLoader.shaders[ name ] = req.responseText;
                if ( --queue <= 0 ) scope[ callback ]();
            };
        }
    },

    onShadersReady : function()
    {
        if( this.callback ) this.callback();
    }
};