the font family is specified.
the font gravity is specified (Since: 1.16.)
the font size is specified.
the font stretch is specified.
the font style is specified.
the font variant is specified.
OpenType font variations are specified (Since: 1.42)
the font weight is specified.
The bits in a
PangoFontMask
correspond to the set fields in aPangoFontDescription
.