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Re: [csswg-drafts] [css-values-4] Explicitly undefine CSS numeric precision in general (#4552)

From: Tab Atkins Jr. via GitHub <sysbot+gh@w3.org>
Date: Mon, 02 Dec 2019 19:50:23 +0000
To: public-css-archive@w3.org
Message-ID: <issue_comment.created-560553075-1575316222-sysbot+gh@w3.org>
Going much smaller than a px wouldn't help either. Impls won't want to switch to a substantially smaller LayoutUnit, because that would reduce the maximum length they can represent; right now an s32 LayoutUnit's upper range is between 1e7px and 1e8px (exact value depends on the LU->px conversion in use). Going up a few more bits will reduce that max by 1/4 or 1/8; maybe ok, but pushing it on reasonably supportable max page lengths.

Plus, the reasoning for the current LayoutUnits aren't compatible: FF chose 60 per px to give lots of good divisors (can easily represent 1/2, 1/3, 1/4, 1/5, 1/6, 1/10, 1/12, 1/15, 1/20, 1/30 of a px); Chrome chose 64 for easy binary conversion to/from px; old-Edge chose 100 for easy human readability and a reasonable amount of good divisors.

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Received on Monday, 2 December 2019 19:50:24 UTC

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