Gamepad event disptach

Gamepad events

// Accessing gamepads in the browser is a case of obtaining an array of gamepad "snapshots"
// in an event loop

function gamepads()
{
    var allGamepads = navigator.getGamepads();
    requestAnimationFrame(gamepads);
}

// Each time we get the gamepads collection we need to check each gamepad and each button to see if anything has changed
/// since the last time we checked (in the last tick).


// I want to add some custom events that I can trigger in my event loop (gamepads()) but I'm unsure what the EventTarget will be.
// Each time we call gamepads() we get a new collection of new gamepad snapshot objects for that tick.

// One option is to use something like `document` as the EventTarget for example:

var buttonZeroPress = new CustomEvent("buttonZeroPress", {
        detail : {
            time: new Date()
        },
        bubbles: true,
        cancelable: true
    });
    
document.addEventListener('buttonZeroPress', function (evt) {
        // Do stuff on screen
    });
    
// In the event loop we'll then dispatch the event with document
if(gamepad.buttons[i].pressed)
{
    document.dispatchEvent(buttonZeroPress);
}

// It seems a bit wrong to be dispatching the event on `document` when really it should be dispatched on
// the button press instance. Since the button instance is a different snapshot in each tick, i'm not sure
// that it would be possible to attach events to it.

// I'm open to ideas!

Hmm. I'm just impressed that you can get gamepad input at all in a browser that isn't embedded in a console.

I think rather than attaching events to the document you could attach them to a dedicated object accessible to all the parties that need it. The events could either be handled from there directly or the object could match the button hierarchy you get from a gamepad animation frame and then maybe it might be possible to copy the events onto each button press instance as and when they are retrieved.

Hopefully I've understood the problem OK!

Thanks, Mark. Here's a video of the gamepad working: http://youtu.be/Y_jsQOcXAyQ in Chrome Canary on my PC.

Your suggestion of dispatching the events on a central object is probably the way I'll have to go. I was using document as an example but I should be able to send the [button] instance along with the event in order to read values from it.

Cheers!