Re: [CSS21] os/2 and hhea tables

Cross-plattform toolkit:
http://sourceforge.net/projects/fonttools/

Written in Python, allows direct readout of any field of any table, alternatively you can use the "ttx" commandline tool which converts OpenType fonts or any of their tables into XML, which allows easy parsing/reading of the contents.

http://code.google.com/p/sfntly/
http://opensource.adobe.com/wiki/display/tin/Tin
are two alternatives -- libraries that can be integrated into C, C++ or Java tools for reading OpenType tables and their fields.

(And a big clarification: in terms of OpenType .otf or .ttf fonts and TrueType .ttf fonts, the term "table" refers to a data structure referred by a 4-letter tag which is included in the container referred to as "SFNT" -- which are stored in files with the .otf or .ttf file, or, wrapped once more and compressed, in a .woff or .eot file.)

Adam

Sent from my mobile phone.

On 24.06.2012, at 17:44, Roger Baker <tstartme@hotmail.com> wrote:

> Thanks very much Adam. On cursory glance these links look to be of great educational value -- I look forward to digging in...
> Roger
> > Date: Sat, 23 Jun 2012 21:35:54 +0200
> > From: list.adam@twardoch.com
> > To: www-style@w3.org
> > CC: tstartme@hotmail.com
> > Subject: Re: [CSS21] os/2 and hhea tables
> > 
> > Recommended reading:
> > 
> > http://www.kltf.de/downloads/FontMetrics-kltf.pdf
> > http://typophile.com/node/13081
> > http://code.google.com/p/googlefontdirectory/wiki/VerticalMetricsRecommendations
> > http://typophile.com/node/77906
> > 
> > Regards,
> > Adam
> > 
> > On 12-06-23 14:55, Roger Baker wrote:
> > > I'm trying to better understand/predict font-size versus content area
> > > for various fonts, and it seems I need a better understanding of font
> > > metrics (for example, how a font's glyphs relate to the font's em
> > > square). From the CSS2.1 spec (section 10.8.1):
> > >
> > > "Note. It is recommended that implementations that use OpenType or
> > > TrueType fonts use the metrics "sTypoAscender" and "sTypoDescender"
> > > from the font's OS/2 table for A and D (after scaling to the current
> > > element's font size). In the absence of these metrics, the "Ascent"
> > > and "Descent" metrics from the HHEA table should be used."
> > >
> > > I'm usually pretty good at "Googling", but in this case I haven't been
> > > able to locate OS/2 and HHEA tables for particular fonts. I'll I've
> > > found is general information explaining what the variables such as
> > > sTypoAscender mean. Can someone please point me in the right direction
> > > in terms of how to find *specific* font metric information for a given
> > > font?
> > >
> > > Thank you
> > 
> > 
> > -- 
> > 
> > May success attend your efforts,
> > -- Adam Twardoch
> > (Remove "list." from e-mail address to contact me directly.)
> > 
> >