# [NTG-pdftex] [ pdftex-Bugs-199 ] font expansion: characters may vanish

Mon Jan 31 02:59:55 CET 2005

Bugs item #199, was opened at 2004-09-23 02:43
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Category: hz
Group: v1.20a
Status: Closed
Resolution: Fixed
Priority: 5
Submitted By: Nobody (None)
Assigned to: The Thanh Han (hanthethanh)
Summary: font expansion: characters may vanish

Initial Comment:

For extremely large shrink values, characters may not
be visible in the pdf output (although the fonts seem
to be embedded), e.g. in the following file:

%----------------------------------------------
\hsize220pt
\font\testfont=cmr17 at 90pt\testfont
\pdffontexpand\font 0 1000 100 autoexpand
\efcode\font`\s=500
\efcode\font`\e=500
\efcode\font`\y=500

see what you get\penalty-10000

\bye
%----------------------------------------------

or even worse:

%----------------------------------------------
\hsize180pt
\font\testfont=cmr17 at 90pt\testfont
\pdffontexpand\font 0 1000 100 autoexpand

see what you get\penalty-10000

\bye
%----------------------------------------------

The font `cmr17-Extend_100' will not be visible.

I only managed to achieve this effect with extremely
large font sizes, which may or may not be related (it
could also be that I didn't find the `magic' \hsize).

If you force the characters to shrink even more, for
example by setting \hsize to 120pt in the latter test
file, the unexpanded font will be used, thus printing
the characters over each other.

Regards,
Robert  <w.m.l at gmx.net>

PS. I didn't bother to create expanded fonts, so I
cannot tell whether it depends on the autoexpand feature.

----------------------------------------------------------------------

Comment By: Nobody (None)
Date: 2005-01-31 07:29

Message:
Logged In: NO

It seems as if Hartmut's patch hasn't been applied, as the
following test file will still produce incorrect output for
both pdftex 1.20b and 1.20c-beta:

%-------------------------------------------------
\font\testfont=cmr10 \testfont
\pdffontexpand\font 0 1000 100 autoexpand
\hsize40pt

OK: text text text text\break

not OK: text text text text\break

\bye

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

Regards,
Robert  <w.m.l[at]gmx.net>

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Comment By: Martin Schröder (oneiros)
Date: 2004-12-22 20:23

Message:
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user_id=421

This has been fixed in 1.20b

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Comment By: Hartmut Henkel (hhenkel)
Date: 2004-10-02 00:11

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user_id=929

tiny patch tries to solve this bug. See README and PDF test
file included.

Regards, Hartmut

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Comment By: Martin Schröder (oneiros)
Date: 2004-10-01 20:47

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I you mean the effect in the attached pdf: This is either a
bug in Jaws (png attached) or a bug in pdftex. gs 8.30,
harlequin 5.3.4a and AR 5 all display the file distorted. :-(

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Comment By: Nobody (None)
Date: 2004-09-29 03:36

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But the problem I mentioned above in the last paragraph
isn't related to Acrobat Reader, is it?
% ------------------------------------------
\hsize35pt
\font\testfont=cmr12\testfont
\pdffontexpand\font 0 1000 100 autoexpand

text text text text\penalty-10000

\bye
% ------------------------------------------

Seems like a sanity check is missing somewhere. If my guess
is right, pdftex tries to use the font `cmr17-Extend_0',
which (incorrectly) translates into the base font. What it
should probably do is use the smallest available expanded
font, i.e. in this case Extend_100, and make the line overfull.

Regards,
Robert.

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Comment By: Martin Schröder (oneiros)
Date: 2004-09-27 20:57

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Logged In: YES
user_id=421

----------------------------------------------------------------------

Comment By: Nobody (None)
Date: 2004-09-23 03:32

Message:
Logged In: NO

Obviously, I filed this report too early. Sorry about that.

It is not a pdftex bug, but appears to be a bug in Acrobat
Reader 6. (Just to tell you what I saw:) At zoom level 200%
or larger, the font most shrunk (Extend_100) is not visible
on screen. That is, in the first example, I only see "See y
e", in the second, nothing at all. However, if I zoom out,
the characters re-appear.

Sorry for not zooming out earlier.

Regards,
Robert.

----------------------------------------------------------------------

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