How can I pass argument with requestAnimationFrame?

You either need to create a reference or wrap the function call in another function like so:

mainFunc: function(x) {
    anim.update(x);
    anim.redraw(x);
    window.requestAnimationFrame(function() {
        anim.mainFunc(x);
    });
}

You can also use .bind.

mainFunc: function(x) {
    anim.update(x);
    anim.redraw(x);
    window.requestAnimationFrame(anim.mainFunc.bind(anim,x));
}