HTML5 Gamepad API on Chrome

Question

I'm using Chrome (Version 19.0.1084.46). I enabled the Gamepad API in chrome://flags. I plugged in some game pads, but navigator.webkitGamepads is always an array of length 4 containing only undefined.

navigator.webkitGamepads
GamepadList
  0: undefined
  1: undefined
  2: undefined
  3: undefined
  length: 4
  __proto__: GamepadList

What do I need to do to test out using gamepads? I'm on Ubuntu Linux if that matters.

Answer 1

I was having trouble with this as well (on Ubuntu 10.04 with Chrome 21.0.1163.0 dev). I ran across this from a thread on chromium-discussions:

Note that you need to press a face button on the gamepad before data will be available. This is due to fingerprinting concerns.

I wrote a quick test page that seems to work if you hold a controller button down while refreshing the page. I'm using a Gamestop-branded Xbox 360 wired controller with the xboxdrv driver.

Also, one other important thing to note - Chrome treats these Gamepad objects like snapshots of the controller state. So if you pass around the actual Gamepad object, you'll never get updated information. Chrome seems to only poll the controller when you call the navigator.webkitGamepads[x] getter (see line 23 in my test page).