Width for bounding box of highly tilted characters

[mathog <mathog caltech edu>]

This Inkscape bug:

  https://bugs.launchpad.net/inkscape/+bug/1283194

has been tracked down to an issue with the Queensland font (and some 
other highly tilted fonts) and Pango.

The problem is this, we need to calculate a bounding box on one of these 
tilted characters, but the width currently being used is too small.  The 
ascend and descend values from the face are fine.  The width from the 
font itself is also fine, here are the values (using FreeType to open 
the font and pull out the characters):

   letter:J advance = 1472 width = 4928

The problem is that it looks like what we need to use for the width of 
this bounding box is MAX(advance,width), but what is currently being 
used is PangoGlyphGeometry which holds the advance only (I think).  On a 
normal font like Arial that would be fine, as the advance is larger than 
the width:

  letter:J advance = 1600 width = 1280

For Queensland though, it is the other way around.  We don't want the 
bounding
box for the entire string, just the one glyph.  If all one has to work 
with is

  glyphs[glyph_index]

and

  glyphs[glyph_index].geometry.width

is the wrong value (advance, narrower than the glyph), how does one 
retrieve from Pango the width (bounding box xmax - xmin) of the glyph?

Thank you,

David Mathog
mathog caltech edu
Manager, Sequence Analysis Facility, Biology Division, Caltech