Sets the size of a window in GameMaker and centres to the first display in a single frame.

window_set_size_centre.gml

gml_pragma("forceinline");
/// @desc Sets the window to the desired size and centres it.
/// @param w {Integer} The width to set the window to.
/// @param h {Integer} The height to set the window to.
window_set_rectangle(
        (display_get_width() - argument0) div 2,
        (display_get_height() - argument1) div 2,
        argument0, argument1);