- From: Will Cassella via GitHub <sysbot+gh@w3.org>
- Date: Wed, 03 Nov 2021 23:29:40 +0000
- To: public-css-archive@w3.org
willcassella has just created a new issue for https://github.com/w3c/csswg-drafts: == [css-mediaqueries-5] Clarifications on [video-]dynamic-range MQs == [CSS Media Queries Level 5 introduced two new queries](https://www.w3.org/TR/mediaqueries-5/#dynamic-range): `dynamic-range` and `video-dynamic-range`. Both have similar wording, and currently the wording for `dynamic-range` is like so: > `dynamic-range` represents the combination of max brightness, color depth, and contrast ratio that are supported by the UA and output device. > > **high** > The combination of the User Agent and the output device fulfill all of the following criteria: > - it has a high peak brightness > - it has a high contrast ratio > - its color depth is greater than 24 bit or 8 bit per color component of RGB > > **standard** > - One or more of the criteria for a `high` `dynamic-range` is not fulfilled. The way [Safari has implemented this media query](https://github.com/WebKit/WebKit/blob/e1adc392ff841dee89aab69af21e3c429e4d5c88/Source/WebCore/css/MediaQueryEvaluator.cpp#L453) is to make `@media (dynamic-range: standard)` checks *always* pass, and `@media (dynamic-range: high)` check against the capabilities of the current display device. This makes sense from a future-proofing perspective, as `standard` can be seen as a subset of `high`, and if `ultra-high` dynamic-range displays are ever introduced, `high` should be a subset of that. However, the wording of the `standard` enum makes it sound as if `standard` and `high` should be mutually-exclusive. I think we should change this wording to reflect `standard` as a subset of `high`. Additionally, the wording of "The combination of the User Agent and the output device..." has caused some confusion about what the capabilities of the user agent must be in order for the `high` query to pass. In [the discussion surrounding the proposal for these queries](https://github.com/w3c/csswg-drafts/issues/4471), the idea was that this query would be a coarse representation of the display device's capabilities, and more detailed APIs such as MediaCapabilities could be used to gather specific information about the User Agent's capabilities for specific purposes. I think we should remove mention of the UA in the description of this media query to clarify this confusion. Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6793 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Wednesday, 3 November 2021 23:29:45 UTC