input/pointer: try harder to not send duplicate motion events
wl_fixed_t is a 32-bit data type, but our doubles are 64-bit. This meant
that two doubles that would map to the same wl_fixed_t could compare
unequal, and send a duplicate motion event.
Refs swaywm/sway#4632.
@@ -230,18 +230,21 @@ void wlr_seat_pointer_send_motion(struct wlr_seat *wlr_seat, uint32_t time,
return;
}
- if (wlr_seat->pointer_state.sx == sx && wlr_seat->pointer_state.sy == sy) {
- return;
- }
-
+ // Ensure we don't send duplicate motion events. Instead of comparing with an
+ // epsilon, chop off some precision by converting to a `wl_fixed_t` first,
+ // since that is what a client receives.
+ wl_fixed_t sx_fixed = wl_fixed_from_double(sx);
+ wl_fixed_t sy_fixed = wl_fixed_from_double(sy);
+ if (wl_fixed_from_double(wlr_seat->pointer_state.sx) != sx_fixed ||
+ wl_fixed_from_double(wlr_seat->pointer_state.sy) != sy_fixed) {
struct wl_resource *resource;
wl_resource_for_each(resource, &client->pointers) {
if (wlr_seat_client_from_pointer_resource(resource) == NULL) {
continue;
}
- wl_pointer_send_motion(resource, time, wl_fixed_from_double(sx),
- wl_fixed_from_double(sy));
+ wl_pointer_send_motion(resource, time, sx_fixed, sy_fixed);
+ }
}
wlr_seat_pointer_warp(wlr_seat, sx, sy);
