Graph of the int function, as in the C programming language. Note, that this image not mandatorily applies to other programming languages, e.g. PowerBasic, where the INT command works the same way as the floor function.
Then I opened the resulting SVG file in Inkscape, changed the fill style for the circles (either blue or white fill), brought the plot lines to the top, and then brought the circles to the top (over the lines).
(In short, this means that you can copy and modify the image freely as long as you provide attribution; preferably in the form of a link back to this page.)