Ok, that makes sense. I think you should maybe add the word "floor" in the nitty-gritty documentation. You might also link from that discussion in the docs to the Cairo docs here: http://cairographics.org/operators/ . However, I can't find anything where they say they round down rather than to nearest. Grrr. Makes me glad for the Racket documentation (such as all the nitty-gritty sections you've written).
On Fri, Feb 22, 2013 at 4:49 PM, Robby Findler <ro...@eecs.northwestern.edu> wrote: > No, I don't think it does. The drawing operation is called "over" and it > takes two colors (rgb, say), and an alpha and produces a color (rgb). So you > always start with some solid color in the background and draw the shape on > top of it, resulting in another color that some other shape can be drawn on > top of. > > > On Fri, Feb 22, 2013 at 3:45 PM, Sam Tobin-Hochstadt <sa...@ccs.neu.edu> > wrote: >> >> On Fri, Feb 22, 2013 at 4:40 PM, <ro...@racket-lang.org> wrote: >> > >> > + The list of colors is obtained by drawing the image on a white >> > + background and then reading off the colors of the pixels that were >> > drawn. >> >> Is there a particular reason to choose white, as opposed to clear, for >> the background in this test? Does drawing on a "clear" background >> even make any sense in this case? >> >> Sam > > _________________________ Racket Developers list: http://lists.racket-lang.org/dev
