Re: [filters] computed value of the 'filter' property

On Tue, Jul 23, 2013 at 10:56 PM, Dirk Schulze <> wrote:
> On Jul 24, 2013, at 7:20 AM, Tab Atkins Jr. <> wrote:
>> On Tue, Jul 23, 2013 at 5:36 PM, Cameron McCormack <> wrote:
>>> I don't think it's useful to have the computed value for the 'filter'
>>> property to keep distinguishing whether a filter primitive function's
>>> argument was a number or a percentage.  So can the 'Computed value' say
>>> something like:
>>>  as specified, but with numbers that indicate percentage values
>>>  computed to percentages
>>> or whatever is the appropriate way to word it.  I'm not sure whether
>>> computing these values to the percentage or the number or more common, so
>>> whichever way makes more sense.
>>> I'm assuming that numbers can be used to mean the same thing as percentages
>>> (with 0..1 meaning the same as 0%..100%), but this needs to be said
>>> explicitly.
>> Assuming that percentages are computed against something known ahead
>> of time (which I think they all are), yes, the computed value
>> shouldn't preserve the type.
> I disagree on this. It would be inconsistent with other usage of unit values in other properties.

Which other properties?  Note that in CSS in general, computed values
are as absolute as possible without layout information.  When we can,
we compute away percentages - they only stick around if they can't be
resolved at computed-value time.

> We should preserve the unit. Furthermore, Cam is talking about some filter functions. There are others that take length values and degrees. We certainly want to keep units here.

I'm not sure what these sentences have to do with Cameron's
suggestions.  If I'm reading him correctly, he's suggesting computing
away the percentage.  His description was about primitives where the
percentage is relative to a number, but obviously if they were
relative to a length or an angle, the result would be a length (in px)
or an angle (in deg) (because those are the generally acknowledged
"absolute" units).

> If we do not have the percentage value on the filter functions mentioned by Cam, the computed property values would look inconsistent in itself.

I don't understand, unless this paragraph is calling back to your
previous paragraph, where you thought that percentages would only be
resolved for some of the primitives.


Received on Wednesday, 24 July 2013 07:48:19 UTC