def squareAspect(rect):
	"""
	Crops either the width or height, as necessary, to make a rectangle into a square.
	
	The input rectangle and return value are both a tuple of (x,y,w,h).
	"""
	
	# Determine which dimension needs to be cropped
	x,y,w,h = rect
	if w > h:
		cropX = (w - h) // 2
		return cropRect(rect, 0, 0, cropX, cropX)
	elif w < h:
		cropY = (h - w) // 2
		return cropRect(rect, cropY, cropY, 0, 0)
	
	# Already a square
	return rect