Re: [csswg-drafts] [css-fonts] Update font technology "incremental" into "incremental-patch", "incremental-range", "incremental-auto" (#7665)

We've had support for range `incremental` for some time, as by-product of the use of the same loading approach for PDF. So we're using it server-side, and I appreciate that the main purpose of incremental loading is for mobile or constrained-bandwidth use. 

Based on that I am very, very weakly against this, but mostly I just wanted to add some comments.

Firstly, `range` incremental as I understand it needs no particular support from the font - although the spec recommends that the font is reordered to make Range more efficient, all that's required is for the server to support the `Range` header and the client to support the incremental loading method. The font needs no particular structure internally, other than being OTF or TTF - WOFF, and in particular WOFF2 aren't so useful, as you need the whole table (WOFF) or file (WOFF2) to decompress it.

I'm not familiar with the patch method and we don't support it, but I see it's also done with HTTP headers and looks to be less dependent on the internal font layout.

After a bit of experimenting with `Range` incremental loading, we've started using it for very large fonts where we know in advance that only a few glyphs are going to be used - a page with only a few Chinese glyphs that references `Noto Sans CJK` as the font to display them is pretty much our canonical use case.

In other words we're using `incremental` as a hint to the client to tell it "you'll need this font on the page, but not much of it and it's big".

Given that, from our admittedly aypical perspective I don't see why the method of incremental loading would ever need to be controlled by the author as it's purpose is essentially as a hint as to how the font will be used rather than any specific technical aspect of the font. My question is - under what circumstances would `incremental-patch` be specified and `incremental-range` not wanted?

At the very least if this is approved, could I'd suggest `incremental` instead of `incremental-auto`.

-- 
GitHub Notification of comment by faceless2
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/7665#issuecomment-1232593434 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Wednesday, 31 August 2022 07:56:52 UTC