room transition

#event create
target_room = room_next(room);
active = -1;
#event draw_gui
if active = -1 { //idle
    if place_meeting(x,y,oplayer) {
        active = 0;
        persistent = true;
    }
} else { //activated
    if room != target_room {
        if active++ >= 10 {
            room_goto(target_room);
        }
    } else if !active-- {IDD();}
    //draw
    DSA(active/10);DSC(c_black);
    draw_rectangle(0,0,g.gui_width,g.gui_height, false );
    DSA(1);DSC(c_white);
}