Is p contained in self ?

Property definitions

geometry $ APolygon :: contain
	# Is `p` contained in `self` ?
	fun contain(p: Point[Float]): Bool is abstract
lib/geometry/polygon.nit:146,2--147,47

geometry $ ConvexPolygon :: contain
	# ~~~
	# var p1 = new Point[Float](0.0, 0.0)
	# var p2 = new Point[Float](5.0, 0.0)
	# var p3 = new Point[Float](0.0, 5.0)
	# var p4 = new Point[Float](5.0, 5.0)
	# var p5 = new Point[Float](2.5, 2.5)
	# var arr = new Array[Point[Float]].with_items(p1, p2, p3, p4)
	# var poly = new ConvexPolygon(arr)
	# poly.sort_ccw
	# assert poly.contain(p5)
	# ~~~
	redef fun contain(p) do
		var prev = points[points.length - 1]
		var curr = p
		var next = points[0]
		var is_ccw = turn_left(prev, curr, next)
		for i in [1..points.length[ do
			prev = next
			next = points[i]
			if turn_left(prev, curr, next) != is_ccw then return false
		end
		return true
	end
lib/geometry/polygon.nit:203,2--225,4