pangoAscent(),
pangoDescent(), pangoLbearing(), and pangoRbearing() can be used to convert
from the extents rectangle to more traditional font metrics. The units
of the rectangles are in 1/PANGO_SCALE of a device unit.pangoFontGetGlyphExtents(object, glyph)glyphink.rectPangoRectangle] rectangle used to store the extents of the glyph as drawn
or NULL to indicate that the result is not needed.logical.rectPangoRectangle] rectangle used to store the logical extents of the glyph
or NULL to indicate that the result is not needed.font is NULL, this function gracefully sets some sane values in the
output variables and returns.