From f18b5656f6f859e4d4e096d290afd9fae884a5b8 Mon Sep 17 00:00:00 2001
From: Torge Matthies <[EMAIL REDACTED]>
Date: Thu, 16 Feb 2023 19:11:43 +0100
Subject: [PATCH] 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>
---
src/video/x11/SDL_x11mouse.h | 1 -
src/video/x11/SDL_x11window.c | 2 +-
src/video/x11/SDL_x11xinput2.c | 5 -----
3 files changed, 1 insertion(+), 7 deletions(-)
diff --git a/src/video/x11/SDL_x11mouse.h b/src/video/x11/SDL_x11mouse.h
index a9c84ee486b1..313cb487cee6 100644
--- a/src/video/x11/SDL_x11mouse.h
+++ b/src/video/x11/SDL_x11mouse.h
@@ -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;
diff --git a/src/video/x11/SDL_x11window.c b/src/video/x11/SDL_x11window.c
index 1f2d0d773d6a..5ed302dac836 100644
--- a/src/video/x11/SDL_x11window.c
+++ b/src/video/x11/SDL_x11window.c
@@ -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;
diff --git a/src/video/x11/SDL_x11xinput2.c b/src/video/x11/SDL_x11xinput2.c
index 6396be39ceec..618eb6fad1fb 100644
--- a/src/video/x11/SDL_x11xinput2.c
+++ b/src/video/x11/SDL_x11xinput2.c
@@ -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;