gravity = pango.GravityForScript(script, base_gravity, 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.
This function returns resolved gravity suitable to use for a run of text
with script.
See pcontext:SetBaseGravity() for a list of gravity constants. See pcontext:SetGravityHint() for a list of gravity hints. See planguage:GetScripts() for a list of scripts.