The Dot is Black had a neat image the other day that got me thinking about this. [2014.10.12_14.45.55_frame_0001, http://thedotisblack.tumblr.com/post/165615923452/20141012144555frame0001-made-with] And I love crazy function visualizations.
The endpoints are all controlled by functions with domain & range within [0,1]. The left border and right border are most simply x or 1-x, and there are two functions that separately control the x- and y-cordinates of the middle endpoints.
Hope you have fun exploring!