Re: [csswg-drafts] [css-values] Ability to address actual physical size (#614)

this discussion seems to go around in circles at various points, but i think the most salient one is:

- IF operating systems could correctly identify, in all situations, the physical dimensions of their displays/the exact actual DPI (and this still assumes that users themselves haven't messed around in the monitor settings with things like setting their own stretching/geometry etc, which isn't a given)
- THEN browsers could access this information and use it to calculate/apply real-world physical measurements

I believe the biggest blocker is the first step, and not necessarily browsers being unwilling to do it. And the thing is: unless there's a guarantee that for the first step the OS will always report the absolutely exact measurement/real-world DPI it has (down to the highest possible level of accuracy, not just rounded/guesstimated), this will be utterly pointless to implement.

but even assuming that this does work out, the best way to implement this may well be that on those correct platforms that do provide rock-solid monitor/display metrics for the browser to use, the UA could decide to anchor to the physical size, rather than the CSS px size? this way, the various measures like `cm`, `mm` etc already in CSS can still be used exactly the same way. on browsers/platforms where the right physical measures are conveyed, browsers would render `1cm` as an exact centimetre as measured on screen. on other platforms, they would do the same as they currently do. it would then be up to users who have use cases where they want to use their screen as an accurate template/measure to make sure they're using a correctly calibrated and supported environment/display.

-- 
GitHub Notification of comment by patrickhlauke
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/614#issuecomment-610337742 using your GitHub account

Received on Tuesday, 7 April 2020 11:41:32 UTC