elm-gamepad: experimental API for discussion

[Conrad Parker]

Hi,

I've recently updated elm-gamepad for Elm 0.18. I forked this from @zimbatm back in Elm 0.15 and have been updating it for the past few years as part of dreambuggy. I've now split it back out into its own repo:

https://github.com/kfish/elm-gamepad/

The API is still a fairly raw wrapper around the W3C Gamepad spec, which is not exactly a delightful interface. For example, button and axis(joystick) values are represented as long lists of floats.

Nevertheless you should be able to plug in a game controller and try this out in your app. There's many possible ways to improve the API and I'd love some suggestions or pull requests / forks.

I'm willing to continue maintaining this (I'm actively using it) and shepherding it towards eventual inclusion in elm.

Conrad.

[Martin Janiczek]

Kudos for your work on this :)

Have you thought about `Sub` interface similar to http://package.elm-lang.org/packages/elm-lang/keyboard/1.0.1/Keyboard ? It seems more declarative than asking for Cmds repeatedly, although that's maybe more suited for games?

[Conrad Parker]

Hi,

thanks, yes it'd be more natural to have a subscription, I'm just not quite sure how to go about it using the underlying polling API.

Conrad.

[Conrad Parker]

Just an update on kfish/elm-gamepad, I've added named fields for the StandardGamepad mapping, which browsers convert most gamepads into.

type alias Button =
  { pressed : Bool
  , value : Float
  }


type alias Stick =
    { x : Float
    , y : Float
    , button : Button
    }

type alias StandardGamepad_ =
    { id : String

   , buttonBack   : Button
   , buttonStart  : Button
   , buttonLogo   : Button

   , buttonA : Button
   , buttonB : Button
   , buttonX : Button
   , buttonY : Button

   , leftTrigger    : Button
   , leftBumper     : Button
   , leftStick      : Stick

   , rightTrigger    : Button
   , rightBumper     : Button
   , rightStick      : Stick

   , dPadUp    : Button
   , dPadDown  : Button
   , dPadLeft  : Button
   , dPadRight : Button
   }

Visually:

Conrad.

[john....@gmail.com]

You could record the state of the pad, poll it n times per second, and send a subscription message anytime a change is detected. Doesn't JavaScript do the same thing deep down for key(board) up/down events?