From c5f2a1ce4ebf1d3c73e0a4689b4e4375294178ed Mon Sep 17 00:00:00 2001 From: "Ryan C. Gordon" Date: Mon, 20 Apr 2020 16:01:36 -0400 Subject: [PATCH] joystick: On disconnect, recenter all game controller inputs. The joystick layer can't necessarily give us perfect centering, but we know that the game controller level has logical absolute idle positions that have nothing to do with the physical device. So send game controller events to make it look like the device is completely untouched before sending the final removal event. --- src/joystick/SDL_gamecontroller.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/src/joystick/SDL_gamecontroller.c b/src/joystick/SDL_gamecontroller.c index 4dcbd5dac..32eb9e2cb 100644 --- a/src/joystick/SDL_gamecontroller.c +++ b/src/joystick/SDL_gamecontroller.c @@ -344,6 +344,28 @@ static void HandleJoystickHat(SDL_GameController *gamecontroller, int hat, Uint8 gamecontroller->last_hat_mask[hat] = value; } + +/* The joystick layer will _also_ send events to recenter before disconnect, + but it has to make (sometimes incorrect) guesses at what being "centered" + is. The game controller layer, however, can set a definite logical idle + position, so set them all here. If we happened to already be at the + center thanks to the joystick layer or idle hands, this won't generate + duplicate events. */ +static void RecenterGameController(SDL_GameController *gamecontroller) +{ + SDL_GameControllerButton button; + SDL_GameControllerAxis axis; + + for (button = (SDL_GameControllerButton) 0; button < SDL_CONTROLLER_BUTTON_MAX; button++) { + SDL_PrivateGameControllerButton(gamecontroller, button, SDL_RELEASED); + } + + for (axis = (SDL_GameControllerAxis) 0; axis < SDL_CONTROLLER_AXIS_MAX; axis++) { + SDL_PrivateGameControllerAxis(gamecontroller, axis, 0); + } +} + + /* * Event filter to fire controller events from joystick ones */ @@ -404,6 +426,8 @@ static int SDLCALL SDL_GameControllerEventWatcher(void *userdata, SDL_Event * ev if (controllerlist->joystick->instance_id == event->jdevice.which) { SDL_Event deviceevent; + RecenterGameController(controllerlist); + deviceevent.type = SDL_CONTROLLERDEVICEREMOVED; deviceevent.cdevice.which = event->jdevice.which; SDL_PushEvent(&deviceevent);