bug#295: 23.0.60; wrong glyph widths of some Unicode codepoints

bug#295: 23.0.60; wrong glyph widths of some Unicode codepoints

[Torsten Bronger]

The sub/superscripts (e.g. ⁴ or ₃) are narrower than the ordinary
characters if using a monospace font (monospace-13 in my case), with
the exceptions of ¹²³.  The same is true at least for the prime
character ′.  The right arrow → and the cubic root ∛ used to have a
"correct" width, but with the recent Emacs, it is too wide (the
cubic root even too tall, too).

Is it sensible at all to report such observations, maybe on a more
systematic/complete basis?


In GNU Emacs 23.0.60.3 (x86_64-unknown-linux-gnu)
 of 2008-05-22 on wilson
Windowing system distributor `The X.Org Foundation', version 11.0.10400090
configured using `configure '--prefix=/usr/local/'
--mandir=/usr/local/share/man/' '--infodir=/usr/local/share/info/'
--with-x-toolkit=no' '--with-xpm' '--with-jpeg' '--with-tiff' '--with-gif'
--with-png' '--with-x''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: de_DE.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Summary

Minor modes in effect:
  global-auto-revert-mode: t
  savehist-mode: t
  display-time-mode: t
  desktop-save-mode: t
  mouse-wheel-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t

bug#295: 23.0.60; wrong glyph widths of some Unicode codepoints

[Chong Yidong]

>> The sub/superscripts are narrower than the ordinary characters if
>> using a monospace font (monospace-13 in my case)
>
> IIUC your problem is that not all thsoe characters use the same font.
> This may be due to your font not having those chars, or to Emacs doing
> something wrong.
>
> Can you check again with the latest code (where some font problems
> have been fixed)?  Use C-u C-x = to find the font used for the char at
> point.

Do you still see this problem?

bug#295: 23.0.60; wrong glyph widths of some Unicode codepoints

[Torsten Bronger]

Hallöchen!

Chong Yidong writes:

>>> The sub/superscripts are narrower than the ordinary characters if
>>> using a monospace font (monospace-13 in my case)
>>
>> IIUC your problem is that not all thsoe characters use the same font.
>> This may be due to your font not having those chars, or to Emacs doing
>> something wrong.
>>
>> Can you check again with the latest code (where some font problems
>> have been fixed)?  Use C-u C-x = to find the font used for the char at
>> point.
>
> Do you still see this problem?

Yes.  Take for example left and right German double quotes (which
are alternative interpretations of x201e and x201c):

            character: „ (8222, #o20036, #x201e)
    preferred charset: unicode (Unicode (ISO10646))
           code point: 0x201E
               syntax: . 	which means: punctuation
             to input: type "\glqq" or "\"`" with TeX
          buffer code: #xE2 #x80 #x9E
            file code: #xE2 #x80 #x9E (encoded by coding system utf-8-emacs-unix)
              display: by this font (glyph code)
        xft:-unknown-DejaVu Sans Mono-normal-normal-normal-*-17-*-*-*-m-0-iso10646-1 (#x68F)

    Character code properties: customize what to show
      name: DOUBLE LOW-9 QUOTATION MARK
      general-category: Ps (Punctuation, Open)
      old-name: LOW DOUBLE COMMA QUOTATION MARK


versus

            character: “ (8220, #o20034, #x201c)
    preferred charset: unicode (Unicode (ISO10646))
           code point: 0x201C
               syntax: . 	which means: punctuation
             category: c:Chinese h:Korean j:Japanese
             to input: type "\grqq" or "\ldq" or "\"'" with TeX
          buffer code: #xE2 #x80 #x9C
            file code: #xE2 #x80 #x9C (encoded by coding system utf-8-emacs-unix)
              display: by this font (glyph code)
        xft:-unknown-Kochi Gothic-normal-normal-normal-*-17-*-*-*-*-0-iso10646-1 (#x26C)

    Character code properties: customize what to show
      name: LEFT DOUBLE QUOTATION MARK
      general-category: Pi (Punctuation, Initial quote)
      old-name: DOUBLE TURNED COMMA QUOTATION MARK


While the first one is displayed correctly, the second one has no
anti-aliasing and is too wide.  I see the "category" item in the
second character.  Maybe this is the cause of this trouble?

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus
                   Jabber ID: torsten.bronger@jabber.rwth-aachen.de

bug#295: 23.0.60; wrong glyph widths of some Unicode codepoints

[Torsten Bronger]

Hallöchen!

Torsten Bronger writes:

> Chong Yidong writes:
>
>>>> The sub/superscripts are narrower than the ordinary characters
>>>> if using a monospace font (monospace-13 in my case)
>>>
>>> IIUC your problem is that not all thsoe characters use the same
>>> font.  This may be due to your font not having those chars, or
>>> to Emacs doing something wrong.
>>>
>>> Can you check again with the latest code (where some font
>>> problems have been fixed)?  Use C-u C-x = to find the font used
>>> for the char at point.
>>
>> Do you still see this problem?
>
> Yes.  Take for example left and right German double quotes (which
> are alternative interpretations of x201e and x201c):
>
> [...]

I mixed up the bugs, so my reply was only partly true.  For the sub-
superscript numbers, everything is alright now.  The other glyphs
indeed still look sub-optimal, though.

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus
                   Jabber ID: torsten.bronger@jabber.rwth-aachen.de