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[csswg-drafts] [filter-effects] Specify rounding behaviour of feMorphology radius attribute (#3619)

From: Paul LeBeau via GitHub <sysbot+gh@w3.org>
Date: Wed, 06 Feb 2019 04:18:42 +0000
To: public-css-archive@w3.org
Message-ID: <issues.opened-407075053-1549426722-sysbot+gh@w3.org>
BigBadaboom has just created a new issue for https://github.com/w3c/csswg-drafts:

== [filter-effects] Specify rounding behaviour of feMorphology radius attribute ==
https://www.w3.org/TR/filter-effects/#element-attrdef-femorphology-radius

The `radius` attribute determines the size (row and column count) of a convolution kernel.  Obviously this eventually has to be rounded to an integer to create the matrix. However the spec does not say what the rounding method is.

Testing this, it appears that FF always rounds up, and Webkit always rounds down.  So, for example 0.4 becomes 0 on Chrome (disabling the filter) and 1 on Firefox (filter works).

I believe it would be a good idea to add a note to this section formalising the rounding method.  If you are familiar with convolutions, it is obvious that only integers should be used, but that is not obvious to the average person.



Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/3619 using your GitHub account
Received on Wednesday, 6 February 2019 04:18:44 UTC

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