- From: fantasai <fantasai.lists@inkedblade.net>
- Date: Sat, 03 Oct 2009 00:35:58 -0700
- To: Brad Kemper <brad.kemper@gmail.com>
- CC: www-style list <www-style@w3.org>
Brad Kemper wrote: > I'm looking at the editor's Draft of the "CSS Backgrounds and Borders > Module Level 3". I noticed that in 5.3 'border-image-width' that it says > the following: > > If two opposite ‘|border-image-width > <http://dev.w3.org/csswg/css3-background/#border-image-width>|’ offsets > are large enough that they overlap, then their used values are > proportionally reduced until they no longer overlap. > > That is a good idea, because it sounds like I can use 'border-image' > analogously to 'border-radius' when the box is too small for the > specified values, as I think it should. But I wonder if we should be a > bit more explicit, with language and formula matching that of > 'border-radius', which says this: > ... > That does make it clear (-ish) that all offsets are reduced > proportionally, not just the two opposite offsets (if I understand this > formula correctly). If it was just the two opposite offsets, there would > be unwanted distortion, and an unwanted difference between rounded > corners created via 'border-radius' and rounded corner images used in > 'border-image'. On the other had, maybe this formula could be stated > more simply for both border-radius and border-image? Ok, here's the checkin: http://dev.w3.org/cvsweb/csswg/css3-background/Overview.src.html.diff?r1=1.174&r2=1.175&f=h Probably easier to read the formatted version, though: http://dev.w3.org/csswg/css3-background/#the-border-image-width I changed border-image-width to reduce all widths proportionally and added some mathematical notation for it. (I also updated the prose for border-radius so it matches the math a little better; seems like there were a few sentences left over from before we had a concrete algorithm.) I didn't simplify the border-radius formula because I couldn't figure out a better way to explain it. > We could also go further, in item 2 (Scale to length) of 5.6 > (Border-image drawing process), add another bullet: > > 1. Scale to length. > * > *If the the middle part of the border-image area has zero > width, then the top, middle and bottom images are not drawn.* I think this is unambiguously implied by the relevant maths. :) > By the way, I was thoroughly confused by the following sentence/formula: > > * If X ≠ 0 is the width of the image and W is the width of the > padding area, then the rounded width X' = W / ceil(W / X) > > I start reading it as "If X is not equal to zero is the width..." That > seems to have two verbs. It's a subclause. "If X, that is not equal to zero, is the width...". > Also, I don't think the padding area is > relevant to this calculation any more, since the introduction of the > whole 'background-image-offset' idea. That particular paragraph was removed in one of my earlier edits; the remaining wording doesn't have this problem afaict. http://dev.w3.org/csswg/css3-background/#border-image-process http://dev.w3.org/csswg/css3-background/#background-size ~fantasai
Received on Saturday, 3 October 2009 07:36:36 UTC