How can I pass argument with requestAnimationFrame?

Question

In the main program I randomly choose an object which I'd like to animate, so I call the function with the object as the argument. The first loop is okay, x is finely set, but in the next turn it becomes undefined.

Something like this:

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

        update: function(x) {

        },

        redraw: function(x) {

        }
};

var n=Math.floor(Math.random() * (ArrayOfAnimObject.length));
anim.mainFunc(ArrayOfAnimObject[n]);

Answer 1

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);
    });
}