# A 2d bounded object and an implementation of `Boxed`
#
# This class offers many constructors specialized for different usage. They are
# named according to the order of their arguments.
class Box[N: Numeric]
	super Boxed[N]

	redef var left: N
	redef var right: N
	redef var top: N
	redef var bottom: N

	# Create a `Box` covering all of the `boxed`
	#
	#     var box = new Box[Int].around(new Point[Int](-4,-4), new Point[Int](4,4))
	#     assert box.left == -4 and box.bottom == -4
	#     assert box.right == 4 and box.top == 4
	init around(boxed: Boxed[N]...)
	do
		assert not boxed.is_empty

		var left: nullable N = null
		var right: nullable N = null
		var top: nullable N = null
		var bottom: nullable N = null

		for box in boxed do
			if left == null or box.left < left then left = box.left
			if right == null or box.right > right then right = box.right
			if top == null or box.top > top then top = box.top
			if bottom == null or box.bottom < bottom then bottom = box.bottom
		end

		assert left != null and right != null and top != null and bottom != null

		init(left, right, top, bottom)
	end

	# Create a `Box` using left, right, bottom and top
	init lrbt(left, right, bottom, top: N)
	do
		init(left, right, top, bottom)
	end

	# Create a `Box` using left, right, top and bottom
	init lrtb(left, right, top, bottom: N)
	do
		init(left, right, top, bottom)
	end

	# Create a `Box` using left, bottom, width and height
	init lbwh(left, bottom, width, height: N)
	do
		init(left, left + width, bottom + height, bottom)
	end

	# Create a `Box` using left, top, width and height
	init ltwh(left, top, width, height: N)
	do
		init(left, left+width, top, top - height)
	end
end