Re: Rendering Raised FULL STOP between Digits

From: Richard Wordingham <richard.wordingham_at_ntlworld.com>
Date: Mon, 11 Mar 2013 09:00:11 +0000

On Mon, 11 Mar 2013 05:27:35 +0100
Philippe Verdy <verdy_p_at_wanadoo.fr> wrote:

> 2013/3/10 Richard Wordingham <richard.wordingham_at_ntlworld.com>:

> > If we unify U+00B7's three possible roles of (a) digraph breaker,
> > (b) ano teleia and (c) decimal point, we could have the following
> > scheme:

> > (1) Before digit, use decimal point glyph;
> > (2) Else before letter, use digraph breaker glyph;
 
> Note that this case 2 includes Catalan where it is more than just a
> digraph breaker (between two l/L), and where it plays a role similar
> to a diacritic for the letter (l/L) before it. This complicates things
> a bit when the letter before it is a capital L, because it will be
> typically be kerned into it (ecept possibly in cursive decorated
> fonts).

Are you sure that's <U+004C, U+00B7> and not U+013F? They're not
canonically equivalent. I didn't see any kerning with Libreoffice's
default font.

> Your algorithm may be in fact part of substitution rules
> implemented in fonts.

That's where I would expect it to be implemented.

> But as a digraph breaker in Catalan, it also plays a role in line
> breakers (where the dot remains at end of line and will not be
> followed by a visible hyphen. In which case there's an extra
> complication : line breaks may already be part of the encoded text and
> you need another case:
 
> > (2b) Else before end of line, use digraph breaker glyphs.
 
> Can this extra case work with Greek's use as ano teleia ?

Underlying text <U+004C, U+00B7, U+2028 LINE SEPARATOR> seems to be
totally ambiguous between the 'digraph breaker' and ano teleia. If
they shall be rendered differently, the renderer will fail. It seems
it can only be handled in a way that no compliant process can
require, namely to distinguish U+0387 GREEK ANO TELEIA and U+00B7 MIDDLE
DOT. It reminds me of the apparently unusable Unicode property
Diacritic - U+00B7 has the property and canonically equivalent U+0387
does not.

Richard.
Received on Mon Mar 11 2013 - 04:03:40 CDT

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