PANEL* pan_radaroverlay = 
{
    bmap = "overlay.png";
    center_x = 32;        //The overlay = 64px²
    center_y = 32;
    flags = SHOW;
}
function radar_startup()
{
    while(1)
    {
        pan_radaroverlay.angle += 5 * time_step; //5 is rotation speed
        wait(1;
    }
}