[OpenType] Re: [mpeg-OTspec] Vertical ligatures

[Levantovsky, Vladimir]

FYI - forwarding all missing emails to MPEG list

> -----Original Message-----
> From: listmaster at indx.co.uk [mailto:listmaster at indx.co.uk] On Behalf Of
> David Lemon
> Sent: Friday, April 27, 2012 9:49 PM
> To: multiple recipients of OpenType
> Subject: [OpenType] Re: [mpeg-OTspec] Vertical ligatures
> 
> Message from OpenType list:
> 
> 
> At 11:20 PM -0700 4/26/12, John Daggett wrote:
> >...But to make it so
> >that the vertical ligatures don't end up in horizontal text runs, the
> >font supplies a set of "dummy" vertical alternate glyphs for
> characters
> >included in vertical ligatures.  The vertical ligature is then defined
> >in terms of these dummy vertical alternate glyphs, such that when the
> >'vert' feature is applied a vertical ligature results but not in the
> >horizontal case where 'vert' is not used.
> 
> Kazuraki has a different set of glyphs for horizontal and vertical
> setting because the layout model didn't allow us to define the
> different horizontal and vertical placement and advance widths.
> (Remember it's proportional in both directions.) The fact that the
> different GIDs enable it to apply layout features for different
> directions was simply a convenient side effect.
> 
> At 11:20 PM -0700 4/26/12, John Daggett wrote:
> >Note the title of the Ryu Murakami novel "69" or the use of "Wi-Fi" in
> >the iPad article, if the book was named "59" instead and the term
> >"Wifi" used, both these examples with a standard OpenType Japanese
> font
> >(e.g. Hiragino or Kozuka families) would exhibit the problem, the 'fi'
> >ligature would appear since the 'liga' feature is on by default.
> >So this *isn't* pure theoretics.
> 
> As Suzuki-san noted, these examples show stacked monospaced Latin.
> Note that these glyphs (which are different GIDS from proportional
> Latin) would not have 'liga' lookups in the first place, because
> ligation and monospace are stylistically incompatible.
> 
> At 11:20 PM -0700 4/26/12, John Daggett wrote:
> >Just imagine what would happen when a Japanese designer starts playing
> >with a contextual feature heavy font like Bello from Underware in
> >stacked runs.
> 
> Anyone who would stack a proportional Latin (whether Bello or any
> other) has strayed beyond the bounds of convention, and needs to take
> responsibility for handling unexpected results. There is no end to the
> list of designs that wouldn't work in this context. (Think of any
> connecting script!) Any proportional Latin is supposed to be rotated
> for vertical setting, in which case Bello would do just fine.
> 
> At 3:26 PM -0700 4/27/12, Eric Muller wrote:
> >[David Lemon wrote:]
> >
> >>  Indeed; we concluded that there was no real need to duplicate a set
> >> of horizontal layout features for vertical use.
> >
> >Can you explain vkrn?
> 
> Certainly. Kerning is a behavior that is generally needed in both
> horizontal and vertical text. Since most CJK fonts use the same glyphs
> for both directions, the only option we saw was to handle the different
> kerning values for different directions as separate layout features.
> 
> That's a fine thing to do if/when necessary. But we didn't consider it
> necessary to define separate vertical layout features for everything in
> the registry. There's also a practical aspect; many applications pick &
> choose which layout features to support. If we overwhelmed them with
> dozens of vertical-only features it seemed likely that only a few would
> ever get widespread implementation.
> 
> - thanks,
> --
> David Lemon
> Sr Manager, Type Development
> Adobe Systems, Inc.
> 
> 408 536 4152
> lemon at adobe.com
> http://blogs.adobe.com/typblography
> 
> 
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