Re: character composition seems much worse than before

[Miles Bader <miles@gnu.org>]

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Kenichi Handa <handa@m17n.org> writes:
>> This is pretty irritating, as Bitstream Vera Sans Mono seems to be
>> what Emacs uses by default on Debian...!
>
> How about the other programs?  For instance, can gedit display the
> same text correctly with that font?

Yes, it seems to.

I tried 3 different fonts, and two different character combinations
("e" + COMBINING ACUTE ACCENT [0x301], and "e" + COMBINING CIRCUMFLEX
ACCENT [0x302] + COMBINING ACUTE ACCENT), in Emacs and gedit:

                                 -Emacs-     -gedit-
  "Dejavu Sans Mono"            PERFECT     PERFECT
  "Bitstream Vera Sans Mono"    NONE        OK
  "Lucida Typewriter"           NONE        PASSABLE

According to "otfview", only Dejavu Sans Mono has those combining
accents (0x301 and 0x302), so gedit must have been doing some
substitution -- it looked pretty good though, especially with
Bitstream Vera Sans Mono.  [I tried Lucida Sans too because while the
letter shapes in Dejavu and Vera are basically identical, Lucida Sans
looks different, so it's easier to tell if substitutions are being
made.]

   "PERFECT" means:  correct letter-shape used (no wacky font
   substitution), perfect spacing/alignment/accent-positioning.

   "OK" means:  correct letter-shape used, correct spacing,
   accent-positioning slightly (~1 pixel) off but basically OK.

   "PASSABLE" means:  correct letter-shape used, correct spacing,
   accent-positioning slightly (~1 pixel) off but basically OK for a
   single accent, *but* smashed-together/overstruck for two
   simultaneous accents.

   "NONE" means: no combining done, letter and accents displayed as
   separate characters.

So gedit seems to be doing some substitution or something, but it does
a fairly good job of it except in the case of two accents being used
simultaneously.

-Miles

p.s. I've attached the text file I used for testing...



[-- Attachment #2: test file for combining accents --]
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this is a test é 1lI|0Oabcdef
ếếếếếế|
éééééé|
eeeeee|

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