bug#7913: 23.2; Mac OS X Dual Spacing Fonts Fix (Patch supplied)

bug#7913: 23.2; Mac OS X Dual Spacing Fonts Fix (Patch supplied)

[Dragan Ivanovic]

This bug report will be sent to the Free Software Foundation,
not to your local site managers!
Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the bug-gnu-emacs@gnu.org mailing list,
and to the gnu.emacs.bug news group.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug.  If you can, give
a recipe starting from `emacs -Q':

% ------------------------------------------------------------------

Emacs (v23.2 distro in my case) has a known problem with determining
pixel width of frames when using dual-space (Japanese) fonts.  It
arises because the maximum pixel width of characters in those fonts is
way bigger than (usually double the size of) the printable ASCII
characters.  Therefore, windows open twice as wide, and the
intelligent line wrapping (as in man or Mew, my favorite email reader)
gets the metrics wrong and forces the text to be wrapped to about one
third of the frame width.

Patches for X-Windows versions are known, and can be found on Ubuntu
mailing lists.  The same problem appears on NextSTEP, i.e., Mac OS
X/Cocoa version.  Below is the patch that solves the problem:

% ..................................................................

--- nsfont-old.m	2011-01-18 13:36:39.000000000 +0100
+++ nsfont.m	2011-01-18 13:36:17.000000000 +0100
@@ -885,9 +885,29 @@ nsfont_open (FRAME_PTR f, Lisp_Object fo
     font->ascent = lrint([sfont ascender]);
     font->descent = -lrint(floor([sfont descender]));
     font->min_width = ns_char_width(sfont, '|');
-    font->space_width = lrint (ns_char_width (sfont, ' '));
-    font->average_width = lrint (font_info->width);
-    font->max_width = lrint (font_info->max_bounds.width);
+    if([nsfont isFixedPitch]) {
+      /* This is a "dirty" fix to avoid problem with some (mostly
+	 Japanese) fonts that use dual spacing. Unlike in the patches
+	 to "ftfont.c" and "xftfont.c", in Cocoa we cannot rely on a
+	 flag (FC_DUAL) to tell us if a fixed width font uses dual
+	 spacing or not.
+
+	 To avoid some problems with spaces (e.g. inside the vebatim
+	 LaTeX environment when using AUCTeX), we measure the width of
+	 a "regular" character, e.g. M (the size of em-space). */
+      font->space_width = lrint (ns_char_width (sfont, 'M'));
+      /* We assume it is the average width. */
+      font->average_width = font->space_width;
+      /* We also assume it is the maximal width.  This may possibly
+	 cause some side effects, but I am not aware of any right
+	 now. */
+      font->max_width = font->space_width;
+    } else {
+      /* This is the normal v23.2 code */
+      font->space_width = lrint (ns_char_width (sfont, ' '));
+      font->average_width = lrint (font_info->width);
+      font->max_width = lrint (font_info->max_bounds.width);
+    }
     font->height = lrint (font_info->height);
     font->underline_position = lrint (font_info->underpos);
     font->underline_thickness = lrint (font_info->underwidth);

% ..................................................................

Best regards,

Dragan Ivanovic

% ------------------------------------------------------------------

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
For information about debugging Emacs, please read the file
/Applications/Emacs.app/Contents/Resources/etc/DEBUG.


In GNU Emacs 23.2.1 (i386-apple-darwin10.6.0, NS apple-appkit-1038.35)
 of 2011-01-18 on dhcp-191.imdea
Windowing system distributor `Apple', version 10.3.1038
configured using `configure  '--with-ns''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: C
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: nil
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Shell

Minor modes in effect:
  shell-dirtrack-mode: t
  diff-auto-refine-mode: t
  show-paren-mode: t
  global-hl-line-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
o <up> C-a C-y <up> <M-right> <up> C-a <M-right> C-e 
C-a <tab> <down> <down> <tab> <down> <tab> <up> <tab> 
<right> <tab> <tab> <tab> <tab> <down> <down> <down> 
<up> C-SPC <down> <down> C-w <up> <up> <return> C-x 
C-s <up> <up> <up> <up> <up> C-c C-t p <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <down> <C-right> <C-left> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<C-right> <C-right> <C-right> <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> R - 
2 0 1 1 <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<down> <C-left> <left> <left> <right> <right> <backspace> 
- <left> <left> <left> <left> <left> <S-left> C-_ <left> 
S C C . <backspace> 2 <backspace> - 2 0 1 0 <backspace> 
1 SPC C-a <right> <right> <right> C-c C-t p C-x C-s 
C-c a t <up> <up> <up> <up> <up> <up> <help-echo> <down-mouse-1> 
<mouse-1> t c N r N <up> <up> <up> <up> <up> <up> <down> 
<down> <down> <down> <down> <down> 4 r 4 0 0 r <help-echo> 
C-x 5 2 <help-echo> C-x C-f C-f ~ / i n s t / a c t 
i <tab> <return> <down> <down> <down> <down> <return> 
<down> <down> <down> <down> <down> <return> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> C-x 
k <return> <up> <up> <up> <up> <return> C-x k <return> 
<down> <down> <down> <down> <down> M-x e s h e l l 
<return> C-x k <return> M-x s h e l l <return> p w 
d <return> a n SPC <backspace> t SPC d e m o - s <backspace> 
<backspace> s <backspace> . s t a r t <return> <help-echo> 
M-x r e p o r <tab> b <tab> <return>

Recent messages:
Loading em-basic...done
Loading em-cmpl...done
Loading em-dirs...done
Loading em-glob...done
Loading em-hist...done
Loading em-ls...done
Loading em-prompt...done
Loading em-script...done
Loading em-term...done
Loading em-unix...done

Load-path shadows:
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~/elisp/org-mode/lisp/org-rmail hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-rmail
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~/elisp/org-mode/lisp/org-mac-message hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-mac-message
~/elisp/org-mode/lisp/org-list hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-list
~/elisp/org-mode/lisp/org-latex hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-latex
~/elisp/org-mode/lisp/org-jsinfo hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-jsinfo
~/elisp/org-mode/lisp/org-irc hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-irc
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~/elisp/org-mode/lisp/org-inlinetask hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-inlinetask
~/elisp/org-mode/lisp/org-info hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-info
~/elisp/org-mode/lisp/org-indent hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-indent
~/elisp/org-mode/lisp/org-id hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-id
~/elisp/org-mode/lisp/org-icalendar hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-icalendar
~/elisp/org-mode/lisp/org-html hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-html
~/elisp/org-mode/lisp/org-habit hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-habit
~/elisp/org-mode/lisp/org-gnus hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-gnus
~/elisp/org-mode/lisp/org-freemind hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-freemind
~/elisp/org-mode/lisp/org-footnote hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-footnote
~/elisp/org-mode/lisp/org-feed hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-feed
~/elisp/org-mode/lisp/org-faces hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-faces
~/elisp/org-mode/lisp/org-exp hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-exp
~/elisp/org-mode/lisp/org-exp-blocks hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-exp-blocks
~/elisp/org-mode/lisp/org-docbook hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-docbook
~/elisp/org-mode/lisp/org-datetree hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-datetree
~/elisp/org-mode/lisp/org-crypt hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-crypt
~/elisp/org-mode/lisp/org-compat hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-compat
~/elisp/org-mode/lisp/org-colview hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-colview
~/elisp/org-mode/lisp/org-clock hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-clock
~/elisp/org-mode/lisp/org-bibtex hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-bibtex
~/elisp/org-mode/lisp/org-bbdb hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-bbdb
~/elisp/org-mode/lisp/org-attach hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-attach
~/elisp/org-mode/lisp/org-ascii hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-ascii
~/elisp/org-mode/lisp/org-archive hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-archive
~/elisp/org-mode/lisp/org-agenda hides /Applications/Emacs.app/Contents/Resources/lisp/org/org-agenda
~/elisp/xsd-regexp hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/xsd-regexp
~/elisp/xmltok hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/xmltok
~/elisp/rng-xsd hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-xsd
~/elisp/rng-valid hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-valid
~/elisp/rng-util hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-util
~/elisp/rng-uri hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-uri
~/elisp/rng-pttrn hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-pttrn
~/elisp/rng-parse hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-parse
~/elisp/rng-nxml hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-nxml
~/elisp/rng-match hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-match
~/elisp/rng-maint hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-maint
~/elisp/rng-loc hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-loc
~/elisp/rng-dt hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-dt
~/elisp/rng-cmpct hides /Applications/Emacs.app/Contents/Resources/lisp/nxml/rng-cmpct

Features:
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bug#7913: 23.2; Mac OS X Dual Spacing Fonts Fix (Patch supplied)

[Jan Djärv]

>
> Emacs (v23.2 distro in my case) has a known problem with determining
> pixel width of frames when using dual-space (Japanese) fonts.  It
> arises because the maximum pixel width of characters in those fonts is
> way bigger than (usually double the size of) the printable ASCII
> characters.  Therefore, windows open twice as wide, and the
> intelligent line wrapping (as in man or Mew, my favorite email reader)
> gets the metrics wrong and forces the text to be wrapped to about one
> third of the frame width.
>
> Patches for X-Windows versions are known, and can be found on Ubuntu
> mailing lists.  The same problem appears on NextSTEP, i.e., Mac OS
> X/Cocoa version.  Below is the patch that solves the problem:
>
> % ..................................................................
>
> --- nsfont-old.m	2011-01-18 13:36:39.000000000 +0100
> +++ nsfont.m	2011-01-18 13:36:17.000000000 +0100
> @@ -885,9 +885,29 @@ nsfont_open (FRAME_PTR f, Lisp_Object fo
>       font->ascent = lrint([sfont ascender]);
>       font->descent = -lrint(floor([sfont descender]));
>       font->min_width = ns_char_width(sfont, '|');
> -    font->space_width = lrint (ns_char_width (sfont, ' '));
> -    font->average_width = lrint (font_info->width);
> -    font->max_width = lrint (font_info->max_bounds.width);
> +    if([nsfont isFixedPitch]) {
> +      /* This is a "dirty" fix to avoid problem with some (mostly
> +	 Japanese) fonts that use dual spacing. Unlike in the patches
> +	 to "ftfont.c" and "xftfont.c", in Cocoa we cannot rely on a
> +	 flag (FC_DUAL) to tell us if a fixed width font uses dual
> +	 spacing or not.
> +
> +	 To avoid some problems with spaces (e.g. inside the vebatim
> +	 LaTeX environment when using AUCTeX), we measure the width of
> +	 a "regular" character, e.g. M (the size of em-space). */
> +      font->space_width = lrint (ns_char_width (sfont, 'M'));
> +      /* We assume it is the average width. */
> +      font->average_width = font->space_width;
> +      /* We also assume it is the maximal width.  This may possibly
> +	 cause some side effects, but I am not aware of any right
> +	 now. */
> +      font->max_width = font->space_width;
> +    } else {
> +      /* This is the normal v23.2 code */
> +      font->space_width = lrint (ns_char_width (sfont, ' '));
> +      font->average_width = lrint (font_info->width);
> +      font->max_width = lrint (font_info->max_bounds.width);
> +    }
>       font->height = lrint (font_info->height);
>       font->underline_position = lrint (font_info->underpos);
>       font->underline_thickness = lrint (font_info->underwidth);

Basically what you do is replace average width with the width of 'M'?  If it 
is a fixed pitch font, max_width, average_width and space_width should all be 
the same so I don't understand why you substituted space for 'M'.  I'm 
guessing it is the setting of max_width that fixes the problem?
Does this make your frames half as big as they where before?

Do you have a font I can use to see the problem?

	Jan D.


	Jan D.

bug#7913: 23.2; Mac OS X Dual Spacing Fonts Fix (Patch supplied)

[Dragan Ivanovic]

Hi,

From: Jan Djärv <jan.h.d@swipnet.se>
Subject: Re: bug#7913: 23.2; Mac OS X Dual Spacing Fonts Fix (Patch supplied)
Date: Tue, 01 Feb 2011 08:49:55 +0100

> Basically what you do is replace average width with the width of 'M'?
> If it is a fixed pitch font, max_width, average_width and space_width
> should all be the same so I don't understand why you substituted space
> for 'M'.  I'm guessing it is the setting of max_width that fixes the
> problem?
> Does this make your frames half as big as they where before?

It turns out that some very good monospace fonts (mostly
Japanese-made), such as those in the M+ family:

http://mplus-fonts.sourceforge.jp/

contain glyphs of two sizes: the "normal" size for ASCII characters,
and double width for ideograms (Japanese characters).  So the fonts
are declared as monospaced, and they are, but within these two
separate realms. While font attributes on X systems include FC_DUAL to
indicate that situation, on Macs the FixedPitch property does not
differentiate.  Therefore, max_width is not the same as average_width
and space_width.  Now, there are two problems I have experienced there
on Max/Cocoa, and tried to address in the patch I sent:

1) Frames open twice as wide when using e.g. "M+ 1m" font.  This is
   addressed by using the width of a printable character instead of
   the maximum width from the font metrics. (Btw., I don't know how
   this affects Japanese users.)  It is not just the annoyance of
   having to resize fonts, of course, but also that all automatic text
   wrapping works wrongly.  Font metrics is obviously not reliable in
   this case.  Admittedly, choice of a character in the range 32-126
   should not be significant here, but:

2) In my experience, some otherwise monospaced fonts, such as Courier,
   tend to have wrong width for space in Emacs (it is much thinner
   than other characters).  I used to run into this all the time while
   using LaTeX (AUCTeX) in Emacs, which, by default, uses Courier for
   the verbatim environment, where I usually put listings.  It is
   extremely annoying to have the space of the "|" width there and see
   your listings garbled for no obvious reason.  I don't know what's
   causing this.  Once I replaced ' ' with 'M' in calculation of the
   space size, this problem has vanished.  It could be another letter,
   but 'm' (em-space, the widest letter), 'x' (ex-space, medium width
   letter) and 'n' (en-space, a thin letter) are normally used as the
   characteristic character widths in typography, so I chose 'M'.

By the way, Emacs patches for 1) can be found on Ubuntu forums, of
course for the X-based systems.

Cheers,

-- Dragan

bug#7913: 23.2; Mac OS X Dual Spacing Fonts Fix (Patch supplied)

[Jan Djärv]

Dragan Ivanovic skrev 2011-02-01 11.12:

>
> 1) Frames open twice as wide when using e.g. "M+ 1m" font.  This is
>     addressed by using the width of a printable character instead of
>     the maximum width from the font metrics. (Btw., I don't know how
>     this affects Japanese users.)

It is this part that must be solved.  I guess these fonts are intended for 
Japanese users.

	Jan D.

bug#7913: 23.2; Mac OS X Dual Spacing Fonts Fix (Patch supplied)

[Chong Yidong]

Dragan Ivanovic <idragan@clip.dia.fi.upm.es> writes:

> 1) Frames open twice as wide when using e.g. "M+ 1m" font.  This is
>    addressed by using the width of a printable character instead of
>    the maximum width from the font metrics. (Btw., I don't know how
>    this affects Japanese users.)  It is not just the annoyance of
>    having to resize fonts, of course, but also that all automatic text
>    wrapping works wrongly.  Font metrics is obviously not reliable in
>    this case.  Admittedly, choice of a character in the range 32-126
>    should not be significant here, but:

I committed a change to trunk so that the average character width for a
font is now calculated by an average over printable ASCII characters
(similar to how we do it for Xft).  Could you try that and see if it
makes any difference?