No subject

older cmap formats in the font? It seems like it won't come into its own in
that respect until you can dispense with including coverage for the same
characters in legacy cmap formats. Is that fair?

Of course, depending on the intended usage of the font, even one savvy
consumer might be enough. If you're making a font to be embedded in a
device, you just need that device to support the new functionality.

trivia: I assume "dieresiscob.cap" is a typo for "dieresiscomb.cap" ("comb"
being short for "combining")

Cheers,

T

On Tue, Apr 3, 2012 at 2:21 PM, John Hudson <john at tiro.ca> wrote:

> **
>
>
> The format 14 subtable, which implements support for Unicode variation
> selectors, maps from sequences of two Unicode values to a single variant
> glyph. It is fairly simple and elegant, and enables a character level
> solution for variant selector sequences, which seems appropriate.
>
> I would like to explore the possibility of adding a new cmap format that
> would perform the opposite operation, i.e. that would map from a single
> Unicode codepoint to a sequence of two or more glyphs. My thinking
> behind this is that it is currently necessary for fonts to include large
> numbers of glyphs for Unicode precomposed diacritic characters, even
> though the great majority of these can be represented using glyph
> sequences and dynamic mark positioning. Although the effect of all these
> glyphs of glyf or css table size is negligible if composites or
> subroutines are used, they have a significant impact on font development
> time -- not least in maintaining consistency between precomposed glyphs
> and dynamic mark positioning -- and on GSUB and GPOS table size.
>
> My idea is a cmap that would map from a single Unicode codepoint to a
> sequence of two or more GIDs that, in combination with GPOS, would be
> able to display that Unicode character. So instead of mapping
>
> U+00C4 to /Adieresis/
>
> the new format cmap would map
>
> U+00C4 to /A/ /dieresiscob.cap/
>
> Note how this kind if mapping can also bypass contextual GSUB
> substitutions to access appropriate variant mark glyphs etc., which
> should be more efficient.
>
> Thoughts?
>
> JH
>
> --
>
> Tiro Typeworks www.tiro.com
> Gulf Islands, BC tiro at tiro.com
>
> The criminologist's definition of 'public order
> crimes' comes perilously close to the historian's
> description of 'working-class leisure-time activity.'
> - Sidney Harring, _Policing a Class Society_
>=20=20
>



--=20
=93Why shouldn't truth be stranger than fiction? Fiction, after all, has to
make sense.=94
 =97Mark Twain

--00221532c3c8b2474204bccd6d5d
Content-Type: text/html; charset=windows-1252
Content-Transfer-Encoding: quoted-printable

<font face=3D"verdana,sans-serif">That's an interesting proposal, John.=
 I rather like it.</font><div><div><font face=3D"verdana,sans-serif"><br></=
font></div><div><font face=3D"verdana,sans-serif">From a font dev POV, how =
useful is it when you still have to also support older cmap formats in the =
font? It seems like it won't come into its own in that respect until yo=
u can dispense with including coverage for the same characters in legacy cm=
ap formats. Is that fair?</font></div>

<div><font face=3D"verdana,sans-serif"><br></font></div><div><font face=3D"=
verdana,sans-serif">Of course, depending on the intended usage of the font,=
 even one savvy consumer might be enough. If you're making a font to be=
 embedded in a device, you just need that device to support the new functio=
nality.</font></div>

<div><font face=3D"verdana,sans-serif"><br></font></div><div><font face=3D"=
verdana, sans-serif">trivia: I assume "</font>dieresiscob.cap" is=
 a typo for "dieresiscomb.cap" ("comb" being short for =
"combining")</div>

<div><br></div><div>Cheers,</div><div><br></div><div>T</div><div><br><div c=
lass=3D"gmail_quote">On Tue, Apr 3, 2012 at 2:21 PM, John Hudson <span dir=
=3D"ltr"><<a href=3D"mailto:john at tiro.ca">john at tiro.ca</a>></span> wr=
ote:<br>

<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">


<u></u>










<div style>
<span>=A0</span>


<div>
  <div>


    <div>
=20=20=20=20=20=20
=20=20=20=20=20=20
      <p>The format 14 subtable, which implements support for Unicode varia=
tion <br>
selectors, maps from sequences of two Unicode values to a single variant <b=
r>
glyph. It is fairly simple and elegant, and enables a character level <br>
solution for variant selector sequences, which seems appropriate.<br>
<br>
I would like to explore the possibility of adding a new cmap format that <b=
r>
would perform the opposite operation, i.e. that would map from a single <br=
>
Unicode codepoint to a sequence of two or more glyphs. My thinking <br>
behind this is that it is currently necessary for fonts to include large <b=
r>
numbers of glyphs for Unicode precomposed diacritic characters, even <br>
though the great majority of these can be represented using glyph <br>
sequences and dynamic mark positioning. Although the effect of all these <b=
r>
glyphs of glyf or css table size is negligible if composites or <br>
subroutines are used, they have a significant impact on font development <b=
r>
time -- not least in maintaining consistency between precomposed glyphs <br=
>
and dynamic mark positioning -- and on GSUB and GPOS table size.<br>
<br>
My idea is a cmap that would map from a single Unicode codepoint to a <br>
sequence of two or more GIDs that, in combination with GPOS, would be <br>
able to display that Unicode character. So instead of mapping<br>
<br>
	U+00C4 to /Adieresis/<br>
<br>
the new format cmap would map<br>
<br>
	U+00C4 to /A/ /dieresiscob.cap/<br>
<br>
Note how this kind if mapping can also bypass contextual GSUB <br>
substitutions to access appropriate variant mark glyphs etc., which <br>
should be more efficient.<br>
<br>
Thoughts?<br>
<br>
JH<br>
<br>
-- <br>
<br>
Tiro Typeworks        <a href=3D"http://www.tiro.com" target=3D"_blank">www=
.tiro.com</a><br>
Gulf Islands, BC      <a href=3D"mailto:tiro%40tiro.com" target=3D"_blank">=
tiro at tiro.com</a><br>
<br>
The criminologist's definition of 'public order<br>
crimes' comes perilously close to the historian's<br>
description of 'working-class leisure-time activity.'<br>
  - Sidney Harring, _Policing a Class Society_<br>
</p>

    </div>
=20=20=20=20=20

=20=20=20=20
    <div style=3D"color:#fff;min-height:0"></div>


</div>



=20=20






</blockquote></div><br><br clear=3D"all"><div><br></div>-- <br>=93Why shoul=
dn't truth be stranger than fiction? Fiction, after all, has to make se=
nse.=94<br>=A0=97Mark Twain<br>
</div></div>

--00221532c3c8b2474204bccd6d5d--