What roman author described the technique of Opus quadratum?
Vitruvius Marcus Vitruvius Pollio (born c. 80–70 BC, died after c. 15 BC), commonly known as Vitruvius, was a Roman author, architect, civil engineer and military engineer during the 1st century BC, known for his multi-volume work entitled "De architectura". His discussion of perfect proportion in architecture and the human body, led to the famous Renaissance drawing by Da Vinci of "Vitruvian Man".
De Arte Gladiatoria Dimicandi De Arte Gladiatoria Dimicandi was written by Italian fencing master Filippo Vadi at some time between 1482 and 1487. It consists of an opening prologue describing the art of fencing followed by colored plates illustrating specific techniques for the longsword, dagger, pollaxe, spear and club. While much of what he describes closely follows the work of Fiore dei Liberi, author of "Flos Duellatorum", Vadi's work also differs in some respects, including his footwork and several original techniques of his own.