W3C home > Mailing lists > Public > public-css-archive@w3.org > July 2020

Re: [csswg-drafts] [css-values-4] Flawed definition of the pixel unit (#5221)

From: Tab Atkins Jr. via GitHub <sysbot+gh@w3.org>
Date: Fri, 31 Jul 2020 00:22:55 +0000
To: public-css-archive@w3.org
Message-ID: <issue_comment.created-666813821-1596154974-sysbot+gh@w3.org>
Yes, the reference pixel is a viewing angle. When compared to lengths on a perpendicular surface, then, it represents the length that angle subtends on the surface, given the surface's viewing distance. This is playing *slightly* loose with terminology, but not in a way that causes any confusion; this sort of viewing angle/surface length comparison is rather common.

The 28" viewing distance is not in any way a requirement. It's used in the definition of the viewing angle, to give an explanation of why the angle is set to the value that it is. The very next paragraph after the reference pixel's definition shows the effect of different viewing distances on the size of the reference pixel (interpreted as a length on a perpendicular surface).

GitHub Notification of comment by tabatkins
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/5221#issuecomment-666813821 using your GitHub account

Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Friday, 31 July 2020 00:22:58 UTC

This archive was generated by hypermail 2.4.0 : Tuesday, 5 July 2022 06:42:12 UTC