def scale_rect_ip(rect, amount):
	"""
	Scale given rect by given multiplier where 1.0 is 100%

	:param rect: the rect you want to scale
	:param amount: < 1.0 will shrink the rect, above 1.0 will enlarge it
	:rvalue None:
	"""
	c = rect.center
	rect.width *= amount
	rect.height *= amount
	rect.center = c
	return rect