(function :Void bringToFront <>[:FlxObject T] [:FlxTypedGroup<T> group :T obj]
    (when (contains group.members obj)
        (group.members.remove obj)
        (group.members.push obj)))

(function :Void sendToBack <>[:FlxObject T] [:FlxTypedGroup<T> group :T obj]
    (when (contains group.members obj)
        (group.remove obj)
        (group.insert 0 obj)))

(function :FlxRect calculateScreenBounds <>[:FlxSprite T] [:FlxTypedGroup<T> group &opt :FlxCamera camera :Float margin]
    (unless margin (set margin 0))
    (let [s (group.getFirstAlive)
            r (new FlxRect)
            bounds (s.getScreenBounds r camera)
            &mut minX bounds.left
            &mut maxX bounds.right
            &mut minY bounds.top
            &mut maxY bounds.bottom]
        
        (group.forEach ->sprite
            (let [bounds (sprite.getScreenBounds r camera)]
                (setMin minX bounds.left)
                (setMin minY bounds.top)
                (setMax maxX bounds.right)
                (setMax maxY bounds.bottom)))

        (r.fromTwoPoints
            (new FlxPoint (- minX margin) (- minY margin))
            (new FlxPoint (+ maxX margin) (+ maxY margin)))))