- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Mon, 14 Mar 2016 17:52:30 -0700
- To: Amelia Bellamy-Royds <amelia.bellamy.royds@gmail.com>
- Cc: Chris Lilley <chris@w3.org>, "public-fx@w3.org" <public-fx@w3.org>
On Mon, Feb 1, 2016 at 2:25 PM, Amelia Bellamy-Royds <amelia.bellamy.royds@gmail.com> wrote: > On 1 February 2016 at 15:02, Chris Lilley <chris@w3.org> wrote: >> The ED of filters says that the lacuna value for the grayscale filter is >> zero. >> https://drafts.fxtf.org/filters/#FilterProperty >> >> However: >> >> - the syntax does not seem to allow the argument to be omitted so how >> can the lacuna value be used >> - if it did, then 0 is an odd value >> >> 0 means no change. Thus seems unintuitive. I would expect grayscale() >> to be equivalent to grayscale(100%) which is likely what authors would >> expect and would be convenient for the most common use case "make this >> grayscale". >> >> Suggested fix: >> >> - change the grayscale filter syntax to make the argument optional >> - change the lacuna value to 1 >> >> Btw I added some tests for grayscale since there was only one (100%) >> so I added 1, 0, 0% and 300% as well. > > For what it's worth, this seems to be how -webkit-filter is implemented. In > other words, -webkit-filter: grayscale() applies 100% grayscale filter (in > Chrome anyway, haven't tested Safari). > > For implementers of the standard property, neither Edge nor Firefox > currently support the function without a parameter, so changing the lacuna > value would not break anything that isn't already broken. > > I also agree that it is more useful/logical to have the default function be > complete grayscale. Yes, it should be omittable. All of the functions need similar edits. I'm not even sure what "the lacuna value for interpolation" *is*. First, "Lacuna value" is an SVG-ism defined in that spec; CSS specs instead use normal English and talk about what to do when something is omitted. ^_^ Second, this is the default value *in general*; I don't know what this has to do with interpolation. ~TJ
Received on Tuesday, 15 March 2016 00:53:17 UTC