diff --git a/platform/x11/os_x11.cpp b/platform/x11/os_x11.cpp index 34ec8709c41..f15dd35d65d 100644 --- a/platform/x11/os_x11.cpp +++ b/platform/x11/os_x11.cpp @@ -1885,12 +1885,23 @@ void OS_X11::process_xevents() { // Determine the axis used (called valuators in XInput for some forsaken reason) // Mask is a bitmask indicating which axes are involved. // We are interested in the values of axes 0 and 1. - if (raw_event->valuators.mask_len <= 0 || !XIMaskIsSet(raw_event->valuators.mask, 0) || !XIMaskIsSet(raw_event->valuators.mask, 1)) { + if (raw_event->valuators.mask_len <= 0) { break; } - double rel_x = raw_event->raw_values[0]; - double rel_y = raw_event->raw_values[1]; + const double *values = raw_event->raw_values; + + double rel_x = 0.0; + double rel_y = 0.0; + + if (XIMaskIsSet(raw_event->valuators.mask, 0)) { + rel_x = *values; + values++; + } + + if (XIMaskIsSet(raw_event->valuators.mask, 1)) { + rel_y = *values; + } // https://bugs.freedesktop.org/show_bug.cgi?id=71609 // http://lists.libsdl.org/pipermail/commits-libsdl.org/2015-June/000282.html