Re: Possible Pango 1.4 ideas

[Noah Levitt <nlevitt columbia edu>]

Hello,

I have another feature request, hopefully also just a
doddle— smarter rendering of so-called invalid combinations.

OpenType documentation[1] seems to say that invalid
combinations should be handled thusly:

 - If a combining character is preceded by a space and a
   zero width joiner, render it all by itself.

 - Otherwise, render it on top of U+25CC DOTTED CIRCLE.
   This way it will look the way it does in the unicode.org
   code charts.
   
Note also that the Unicode Standard 3.2, section 2.6, says:
"By convention, diacritical marks used by the Unicode
Standard may be exhibited in (apparent) isolation by
applying them to U+0020 SPACE or to U+00A0 NO BREAK SPACE."

Noah

[1] http://microsoft.com/typography/otfntdev/indicot/other.htm
    http://microsoft.com/typography/otfntdev/arabicot/other.htm


On Wed, Jan 15, 2003 at 18:02:08 +0000, Damon Chaplin wrote:
> 
> Hi,
> 
> I noticed the discussions on gtk-devel about GTK+ 2.4 plans, so I
> wondered if we should try to get some better layout features into Pango
> for the next release. Quite a few people seem interested in using Pango
> for DTP or printing now!
> 
> I'm going to work on these (practically full-time):
> 
>  o Hyphenation.
>  o Justification.
>  o Tab stops - left/center/right alignment, fill characters,
>    aligning on specific characters.
>  o Underlines - word-underline (only underlines characters,
>    not whitespace), and squiggly red underlines, for spelling errors.
>  o Displaying invisible chars, like spaces, tabs, paragraph terminators.
>  o Drop capitals.
>  o Small caps for first n lines of paragraph.
>  o Kerning - customizable kerning for particular character pairs.
>  o Tracking - customizable for particular paragraphs.
>  o Runarounds & shaped text boxes - would need to cooperate with
>    higher-level code to determine where text can be placed on each line.
>  o Leading - locking to a baseline grid.
> 
> I think that lot should make it possible to produce fairly decent
> word-processor/DTP apps (if we can get printing working as well!).
> 
> TeX-like hyphenation & justification is well underway (it works but
> there are lots of bits to sort out). And compared to those, the others
> are a doddle.
> 
> We don't have to make a decision now, though - if I can get a reasonable
> patch ready by May/June we can decide then. But it's something to bear
> in mind.
> 
> Damon