device: put to fullscreen immediately

docs/changelog.rst

@@ -21,6 +21,7 @@ Changelog
 * Tools: fixed missing SKINNING define in materials when importing animated FBX meshes.
 * Tools: fixed shadows when rendering animated meshes.
 * Tools: fixed Level Tree showing previous objects when creating new levels.
+* Runtime: Linux: fixed ``Window.set_fullscreen()`` to put the window fullscreen without delays.
 * Compiler: the compiler will now return with an error if any source dir does not exist.
 
 0.57.0 --- 13 Jun 2025

src/device/main_linux.cpp

@@ -881,6 +881,7 @@ struct WindowX11 : public Window
 		xev.xclient.data.l[0] = full ? 1 : 0;
 		xev.xclient.data.l[1] = s_linux_device->_net_wm_state_fullscreen;
 		XSendEvent(s_linux_device->_x11_display, DefaultRootWindow(s_linux_device->_x11_display), False, SubstructureNotifyMask | SubstructureRedirectMask, &xev);
+		XFlush(s_linux_device->_x11_display);
 	}
 
 	void set_cursor(MouseCursor::Enum cursor) override