x11: Fix duplicate Xinput2 event reception

Passing True for owner_events in the XGrabPointer call makes all
XI_RawMotion events appear in the queue twice, with the only difference
between them being the value of XGenericEventCookie::cookie. These have
always been filtered out by a check in the XI_RawMotion handler,
however with a mouse that polls at more than 1 kHz frequency, there
also exist legitimate events that appear indistinguishable from these
duplicated events. These must not be filtered out, otherwise the
pointer may move at an inconsistent speed, appearing like a bad pointer
acceleration implementation.

Change owner_events to False in the XGrabPointer and remove the
duplicate event detection code to fix this.

Signed-off-by: Torge Matthies <openglfreak@googlemail.com>
This commit is contained in:
Torge Matthies 2023-02-16 19:11:43 +01:00 committed by Sam Lantinga
parent d73f2d76a0
commit f18b5656f6
3 changed files with 1 additions and 7 deletions

View File

@ -30,7 +30,6 @@ typedef struct SDL_XInput2DeviceInfo
double minval[2];
double maxval[2];
double prev_coords[2];
Time prev_time;
struct SDL_XInput2DeviceInfo *next;
} SDL_XInput2DeviceInfo;

View File

@ -1584,7 +1584,7 @@ void X11_SetWindowMouseGrab(_THIS, SDL_Window *window, SDL_bool grabbed)
/* Try for up to 5000ms (5s) to grab. If it still fails, stop trying. */
for (attempts = 0; attempts < 100; attempts++) {
result = X11_XGrabPointer(display, data->xwindow, True, mask, GrabModeAsync,
result = X11_XGrabPointer(display, data->xwindow, False, mask, GrabModeAsync,
GrabModeAsync, data->xwindow, None, CurrentTime);
if (result == GrabSuccess) {
data->mouse_grabbed = SDL_TRUE;

View File

@ -294,10 +294,6 @@ int X11_HandleXinput2Event(SDL_VideoData *videodata, XGenericEventCookie *cookie
parse_valuators(rawev->raw_values, rawev->valuators.mask,
rawev->valuators.mask_len, coords, 2);
if ((rawev->time == devinfo->prev_time) && (coords[0] == devinfo->prev_coords[0]) && (coords[1] == devinfo->prev_coords[1])) {
return 0; /* duplicate event, drop it. */
}
for (i = 0; i < 2; i++) {
if (devinfo->relative[i]) {
processed_coords[i] = coords[i];
@ -309,7 +305,6 @@ int X11_HandleXinput2Event(SDL_VideoData *videodata, XGenericEventCookie *cookie
SDL_SendMouseMotion(0, mouse->focus, mouse->mouseID, 1, (float)processed_coords[0], (float)processed_coords[1]);
devinfo->prev_coords[0] = coords[0];
devinfo->prev_coords[1] = coords[1];
devinfo->prev_time = rawev->time;
return 1;
} break;