typedef gint32 PangoGlyphUnit
PangoGlyphUnit type is used to store dimensions within Pango.
Dimensions are stored in 1/
PANGO_SCALE of a device unit.
(A device unit might be a pixel for screen display, or
a point on a printer.)
PANGO_SCALE is currently 1024, and
may change in the future (unlikely though), but you should not
depend on its exact value. The
PANGO_PIXELS() macro can be used
to convert from glyph units into device units with correct rounding.