That means you probably need to change some graphics primitives. If you want to go this way (have mathematical geometric objects), then I think you're on the step off Juan Morphic 3... Nicolas 2013/2/14 Igor Stasenko <siguctua@gmail.com>:
Yet another perspective.. is that if we state:
Any two points form a rectangle..
Then, by construction it means that
Rectangle origin: pt1 corner: pt2
should be equal to:
Rectangle origin: pt2 corner: pt1
and here the evil part: if you use [) intervals you not get what you want, because in one case it will be rectangle which includes all points from pt1 to pt2 but not including pt2 while in another case, it will be rectangle which includes all points from pt1 to pt2 but not including pt1..
and this is why i inclined to use [] intervals for defining the rectangles.
-- Best regards, Igor Stasenko.