RE: [css3-fonts] Synthesizing oblique, to which direction in RTL and vertical flow?

We say "an oblique face can by synthesized" but not defining it in an interoperable way doesn't make sense to me.

> Where "most word processor users" means "how Word does it"? ;)

Word and Windows copied behavior from all existing word processors. It's been #6 since late '70 in word processor market, zero exceptions, so it was rather easy to copy for a word processor. Today there are not many word processors in the market but the other one from a Japanese company, Ichitaro, does #6 too.

As I wrote before and as Ambrose confirmed, the most common case for paper-based typography is #3/#4 for Japanese, #2/#4/#6/#8 for Latin characters, and not well defined :( for mixed-case.

You can't say whether IE is wacky or WebKit is unless we define, and I guess it justifies the motivation to define the way we would like it to be synthesized.

I prefer to prioritize word processors as I believe it is the majority, but I can live with other options too if there were consensus.

But leaving this undefined doesn't look right to me.

/koji

-----Original Message-----
From: John Daggett [mailto:jdaggett@mozilla.com] 
Sent: Monday, February 04, 2013 8:36 PM
To: www-style@w3.org
Cc: 'WWW International' (www-international@w3.org); CJK discussion (public-i18n-cjk@w3.org); public-i18n-bidi@w3.org
Subject: Re: [css3-fonts] Synthesizing oblique, to which direction in RTL and vertical flow?

Koji Ishii wrote:

> In the font-style property[1], it says:
> 
>   A value of 'italic' selects a font that is labeled 'italic',
>   or, if that is not available, one labeled 'oblique'. If no
>   italic or oblique faces is available, an oblique face can
>   by synthesized by rendering the normal face with a
>   sloping transformation applied.
> 
> But it does not state to which direction the slope should be.
> 
> There is no question for slope direction in LTR scripts, but is 
> controversial for RTL and for vertical flow. Could this be clarified?
> 
> For RTL, there was a post to www-style in 1999[2], and there are some 
> discussions on the web[3]. It looks to me that back-slant is the right 
> way to go but I'm no experts here.

I'm not sure I see a reason for wading into these waters.  "Synthetic oblique" is done the same way by all user agents today, modulo the wackiness in vertical text in IE10.  Synthetic italics, along with synthetic bold, are holdovers from the days of word processors with "Italic" and "Bold" buttons that simply applied synthetic transforms if real faces didn't exist. The right answer here is really to use a font designed the way an author desires, be it left or right leaning for RTL scripts.

I really don't think we should try to resolve anything here for the
CSS3 Fonts spec.

> For vertical flow, there are several possibly right answers as in the 
> picture here[4], and my investigation concluded that it varies by who 
> you ask to:
> a. Most word processor users consider #6 is the right answer.
> b. Professional printers and font designers think differently by
>    context; #2 or #6 for primarily Latin context such as citations,
>    and #3 for primarily Japanese context. In addition, for primarily
>    Japanese context, authors would like to specify directions and
>    angles.
> c. WebKit renders #8 today, and IE10 renders #6.

Where "most word processor users" means "how Word does it"? ;)

Here again, the right answer is to use an italic face.  For upright ideographic characters I'm mystified why someone would consider #6 to be correct, the rendering of basic ideographic characters shouldn't vary whether it's included in horizontal or vertical runs.  The Webkit rendering (#8) seems like the better choice.

In this case also, I don't think we should try and resolve anything related to this issue for CSS3 Fonts.

Regards,

John Daggett

Received on Tuesday, 5 February 2013 20:08:57 UTC