On Mon, 29 Apr 2013 20:46:47 -0400 Todd Showalter <todd@xxxxxxxxxxxxxxxx> wrote: > On Mon, Apr 29, 2013 at 5:04 PM, Dmitry Torokhov > <dmitry.torokhov@xxxxxxxxx> wrote: > > >> I'm a game developer, and I'm interested in discussing changes in > >> the way gamepad input is handled at the evdev and device level; is > >> this the correct place to do that? > > > > It might or it might not. It would be great if you could tell a bit about > > your issues. > > My primary concern is game controllers (specifically gamepads). > I'd like to see a standard game controller (something akin to the > input functionality of the xbox 360 controller) become a first-class > input citizen alongside the keyboard and mouse. My argument is > essentially that amongst the major gamepads (the ps3 6axis controller, > the xbox 360 controller, the xbox controller, the wii classic > controller, the ouya controller, and various OEM versions and > imitations of the same) there is a lot of common functionality that is > worth exposing as a standard gamepad the same way systems now expose a > standard mouse. > > My proposed standard gamepad is: > > - left stick (2d vector, each component [-1.0f .. 1.0f]) > - right stick (2d vector, each component [-1.0f .. 1.0f]) > - left trigger (1d vector, [-1.0f .. 1.0f]) > - right trigger (1d vector, [-1.0f .. 1.0f]) > - dpad > - start button > - system button (home on wii, ps on ps3, glowy x on xbox 360) The "Share" button on DualShock4? > - four face buttons (north, south, east, west) > - two shoulder buttons > - two stick click buttons > > What I'd like to request at the evdev level is that things which > are gamepads export these values in standard offsets, so that: > > EV_ABS 0 == left stick x > EV_ABS 1 == left stick y > EV_ABS 2 == right stick x > EV_ABS 3 == right stick y > EV_ABS 4 == dpad x > EV_ABS 5 == dpad y > EV_ABS 6 == left trigger > EV_ABS 7 == right trigger > > Or some similar defined order. I'd like buttons to be similarly mapped: > > BTN_START == start button > BTN_WEST == xbox x, ps square > BTN_NORTH == xbox y, ps triangle > BTN_EAST == xbox b, ps circle > BTN_SOUTH == xbox a, ps x > BTN_TL == xbox tl, ps l1 > BTN_TR == xbox tr, ps r1 > BTN_MODE == xbox glowy x, ps ps > BTN_THUMBL == stick click l > BTN_THUMBR == stick click r > > I'm aware that the xbox and xbox 360 controllers are already > largely mapped this way, but the ps3 controller is not, at least from > what I can tell, and I have no other gamepad hardware to test. My > goal here is to make it so that something reading an evdev gamepad > stream doesn't need to know what kind of hardware device is backing it > *if* all the reader cares about is the standard gamepad functionality. > WRT the PS3 controllers the problem is the HID descriptor, it should be rewritten to expose saner event codes, and/or a .input_mapping callback should be added. I can give some hints about how to proceed if anyone is up to it; it would something along the line of drivers/hid/hid-ps3remote.c > The analogy here is mice; while you can get mice with variable DPI > settings, macro engines and loads of buttons or scroll wheels, normal > applications don't have to query the mouse type to know how the core > functionality is mapped. If all I want in a game is the left stick > for movement, the bottom face button for jump and the right face > button for shoot, I shouldn't have to be querying the controller to > figure out how those are mapped. I should be able to take ABS_X and > ABS_Y for the left stick, BTN_SOUTH for jump and BTN_EAST for shoot, > and it should map to the proper buttons and stick regardless of > whether the player has an xbox controller, a logitech controller, a > ps3 controller or a wiimote with a classic controller plugged in. > BTW have you looked at the joystick driver/API? (Documentation/input/joystick.txt), it allows some form of remapping and calibration to have normalized axis values across different controllers but I don't know it that suits what you have in mind. > There are several advantages of doing this remapping at the driver > level, but the most important ones from my point of view are that it > is simplest to do near the source, and it makes supporting a standard > gamepad as part of (for instance) Wayland a much simpler and thinner > translation layer. I want to do this through a Wayland (or X11) event > protocol because I want my game (which may be running mods or scripts > downloaded from forums) to be as isolated as possible from the > elevated privileges that opening evdev streams requires. > > So, that's my issue, really; I'd like a standardized core gamepad > protocol in Linux, and I'm talking to people at every level of the > stack to see if I can make it happen. > > Todd. Conventions are good, having drivers following them would be even better ;) Ciao, Antonio -- Antonio Ospite http://ao2.it A: Because it messes up the order in which people normally read text. See http://en.wikipedia.org/wiki/Posting_style Q: Why is top-posting such a bad thing? -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
