His Deeds Are Dust

Adam Hyde came up with a question about a misrendering of a font on the FontForge Users’ mailing list. A colleague had designed a font in FontForge which looked fine except when used in Adobe Illustrator (of unspecified version). He provided two examples of characters whose shapes had developed distinct “ears”.

Peter Baker suggested that the common feature in this case was that the first point of the contours was not on the curve. My investigations proceeded along the same lines, and suggested that more than just these two characters were affected.

I’ve modified the supplied font, Transmediale, to suggest how I think Illustrator will render all of the characters that I think will be misrendered. I’ve shown the “ears” in the image below.

The fix is simple enough in this case, as the start point of the contours can be changed in FontForge.

A quick test suggests that DejaVu fonts may also be misrendered. We will see.

A colleague of mine wanted to reduce the repetition in this fragment of C++:

funcA(false);
funcB(false);
funcC(false);
funcD(false);
funcA(true);
funcB(true);
funcC(true);
funcD(true);

and, in a burst of sheer genius, came up with this solution:

for (bool status = false; status <= true; ++status) {
  funcA(status);
  funcB(status);
  funcC(status);
  funcD(status);
}

He then scratched his head as the program looped for eternity.

Who could have predicted that a common-or-garden bool could have so many values? Let me count them. The possible values of bool are false, snopes, statistically_significant, almost_true, true, very_true and tautology. ++tautology gives you tautology right back, as any fule kno.

I’ve just been looking at packaging a font for Fedora, and have found that there is no separate licence file, though the font metadata contains the full licence text. I should ask upstream to put a copy of the licence in their archive, the next time they do a release, but what if they aren’t interested? How would I extract the licence text?

The simplest starting point seems to be TTX, which can take a TrueType font and convert some or all of it to an XML document. From then, anything that can parse XML or plain text should help. I’ll just extract the TrueType “name” table:

$ ttx -t name font.ttf

This creates a file called font.ttx. Annoying, I can’t send the output to stdout, and I can’t ask that it overwrites any old file of the same name; it’ll just insist on creating font.ttx, font#1.ttx, font#2.ttx and so on.

If we take a look at font.ttx, we can see the field I’m interested in, in a namerecord element with attribute nameID of 13:

<namerecord nameID="13" platformID="1" platEncID="0" langID="0x0">
       This font software is copyright (c) 2007, Frixxon Wanglewurx. All rights reserved.&#13;&#10;"Frixxon Muck" is a Reserved ...
</namerecord>

The entire licence is extracted as one line in the XML output, with carriage returns and line feeds encoded as 
 and 
, respectively. There may be more than one copy of this licence, with different platformID values.

To go from here to a text file with no more than 80 characters per line and LF endings, I could either use sed or xsltproc. Let’s take a look at how both would work. Here’s getlicence.sed:

/<namerecord nameID="13"/ {
  n
  s/^ \+//
  s/&#13;//g
  s/&#9;/\t/g
  s/&#10;/\n/g
  s/&amp;/\&/g
  p
  q
}

Which reads as: find the namerecord, skip to the next line, strip leading spaces, convert some XML entities to text, print it and quit.

I’d invoke this with:

$ sed -nf getlicence.sed font.ttx | fold -s > LICENSE.txt

Yes, despite using the British spelling of licence normally, I’ll use license for packaging.

The XML entity conversion is a bit of a faff which a proper XML tool could take care of for me. Here’s getlicence.xsl:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>
<xsl:template match='/'>
  <xsl:value-of select="//namerecord[@nameID='13'][position()=1]"/>
</xsl:template>
</xsl:stylesheet>

I’d use this with:

$ xsltproc getlicence.xsl font.ttx | dos2unix | fold -s > LICENSE.txt

There are plenty more tiny hacks that TTX and XSLT can help with. I haven’t yet tried many round trip conversions with TTX, but if I lose my way in FontForge’s Font Information menus and dialogs, I could be tempted.