Finds the gravity that best matches the rotation component in a #PangoMatrix.
Based on the script, base gravity, and hint, returns actual gravity to use in laying out a single #PangoItem.
Based on the script, East Asian width, base gravity, and hint, returns actual gravity to use in laying out a single character or #PangoItem.
Converts a #PangoGravity value to its natural rotation in radians. @gravity should not be %PANGO_GRAVITY_AUTO.