Re: [css-fonts] Specifying changes to parameters for fallback fonts

Le 2016-05-25 14:01, Florian Rivoal a écrit :
>> On May 26, 2016, at 00:58, ishida@w3.org wrote:
>> 
>> since we don't have an automatic notification system in place yet, and 
>> since the discussion is beginning to assume some momentum, i thought 
>> i'd send one manually to the list:
>> 
>> r12a has created an issue for https://github.com/w3c/csswg-drafts:
>> 
>> == [css-fonts] Specifying changes to parameters for fallback fonts ==
>> After another session of fruitless wrestling with fonts, i thought i
>> should make sure (a) i'm not missing something obvious, and (b) if
>> not, ask whether we can improve CSS.
>> 
>> This time i was trying to get a particular look across Mac- and
>> Windows-based browsers. On the Mac i like the look of Helvetica Neue
>> with font-weight set to 300 at a font size of 16px.  But i can't find
>> anything to match that in Windows standard fonts – well, i could get
>> reasonably close, but i'd need to be able to change the font weight
>> and the font size for a font-family name specified as a fallback.
>> 
>> I've never understood why, in CSS, i can't say something like
>> 
>> p { font: 'macfont' 300 16px, 'windowsfont' 500 18px, sans-serif  }
>> 
>> This is a much bigger problem in non-Latin scripts, where glyph
>> dimensions can vary widely from font to font at the same font-size.
>> For example, compare the same glyphs set to the exact same font-size
>> in Mongolian Baiti and Noto Sans Mongolian:
>> 
>> ![screen shot 2016-05-18 at 16 45
>> 32](https://cloud.githubusercontent.com/assets/4839211/15365391/03a38354-1d18-11e6-82cf-0db2412a3bb0.png)
>> 
>> It's not just mongolian, this is a constant problem in arabic, and
>> many other scripts.
>> 
>> And by the way, i thought about web fonts, but i can't help thinking
>> that you should be able to just use standard platform fonts if you
>> want to.  Note that that tweaking the size/weight of such fonts would
>> be easier than finding fonts that look good and can be used for free
>> to cover the up to 15 languages we have on the i18n site, but also
>> we're often dealing with multiple languages on a given page for
>> examples etc, which also ramps up the bandwidth when using webfonts.
>> 
>> What am i missing?
>> 
>> See https://github.com/w3c/csswg-drafts/issues/126
> 
> 
> I don't know what you're missing, but I am missing it too.
> 
> No need to reach for mongolian, the same happens just fine in English.
> Baskerville as found on OS X vs Libre Baskerville, at the same font
> size and same weight, are very differently sized.
> 
> I've found myself wanting to use the OS X one as a default (it's got
> more open type features), and the libre one as a fallback, but the
> size being very different makes it tricky, and font-size-adjust cannot
> be used to adjust only some of the fallback fonts.
> 
>  - Florian

Florian,

Can you explain why you believe that 'font-size-adjust' can not be used 
to adjust (compensate) fallback fonts. I am not sure I understand what 
you are saying.

3.6 Relative sizing: the font-size-adjust property
https://www.w3.org/TR/css-fonts-3/#font-size-adjust-prop

In my mind, 'font-size-adjust' has been created specifically so that a 
fallback font (not available on a system) used size will be adjusted to 
match the first font of a list or to constrain all possible match of a 
font list to a certain size.

The glyphs will likely/possibly/probably not look the same but their 
relative size (aspect value) will be the same, must be the same:

http://test.csswg.org/suites/css-fonts-3_dev/nightly-unstable/html/font-size-adjust-003.htm

Gérard

Received on Wednesday, 25 May 2016 19:42:59 UTC