Re: [csswg-drafts] [css-fonts] Proposal to extend CSS font-optical-sizing (#4430)

> Should this take a <length> rather than a <number>?

The optical size perceived by a human observer is the result of two physical measurements - the size of text as rendered, and the viewing distance to a display the text is rendered on. A text rendered at 12 pt. viewed at _normal_ viewing distance will have the same optical size (e.g. if measured in arc angle) as one rendered at 36 pt. and viewed at 3X the normal viewing distance - developing an override mechanism to account for these conditions would be justified.

What is not clear (to me) though is whether (and how) an author would be able to know ahead of time about specific viewing conditions to make override decision. E.g., a webpage that can be viewed using a PC screen or a handheld device at a _normal_ distance can also be viewed in a browser running on e.g. a SmartTV device, with display size 5X larger than a typical PC screen but viewed at about 8-10X the normal viewing distance. I am not sure how author could account for this; however, it seems plausible that the browser itself could make override decisions based on the display properties (signage, TV, etc.)


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Received on Thursday, 4 February 2021 04:47:12 UTC