Returns the gravity to use in laying out a `PangoItem`.
The gravity is determined based on the script, base gravity, and hint.
If base_gravity is pango_gravity_auto, it is first replaced with the preferred gravity of
script. To get the preferred gravity of a script, pass pango_gravity_auto and
pango_gravity_hint_strong in.
| script |
`PangoScript` to query |
| base_gravity |
base gravity of the paragraph |
| hint |
orientation hint |
|
resolved gravity suitable to use for a run of text with |