Fix horizontal wheel scroll direction of X11.
diff --git a/src/video/x11/SDL_x11events.c b/src/video/x11/SDL_x11events.c
index f911313..e14f8d8 100644
--- a/src/video/x11/SDL_x11events.c
+++ b/src/video/x11/SDL_x11events.c
@@ -1228,7 +1228,7 @@ X11_DispatchEvent(_THIS, XEvent *xevent)
printf("window %p: ButtonPress (X11 button = %d)\n", data, xevent->xbutton.button);
#endif
if (X11_IsWheelEvent(display,xevent,&xticks, &yticks)) {
- SDL_SendMouseWheel(data->window, 0, (float) xticks, (float) yticks, SDL_MOUSEWHEEL_NORMAL);
+ SDL_SendMouseWheel(data->window, 0, (float) -xticks, (float) yticks, SDL_MOUSEWHEEL_NORMAL);
} else {
SDL_bool ignore_click = SDL_FALSE;
int button = xevent->xbutton.button;