Layer::makeTriangle = (direction)->
	this.borderColor = "transparent"
	this.borderWidth = this.width / 2
	this.style["border-#{direction}-color"] = this.backgroundColor.toHexString()
	this.backgroundColor = "transparent"

# ----------

rect = new Layer
	size: 20
	backgroundColor: "black"
	point: Align.center

rect.makeTriangle "bottom"

# Directions: "top", "right", "bottom", "left"