Man pages matching name quat_interpolate in section 3alleg4:

quat_interpolate.3alleg4.en	debian 10 / allegro4-doc
quat_interpolate.3alleg4.en	debian 11 / allegro4-doc
quat_interpolate.3alleg4.en	debian 12 / allegro4-doc
quat_interpolate.3alleg4.en	debian 13 / allegro4-doc