(module (engine math) ()
(import scheme
	(chicken base)
	(chicken module))

(export PI PI/2)
(define PI
  3.141592653589793238462643383279502884197169399375105820974944592307816406286)

(define PI/2
  (/ PI 2))

(export rad-to-deg deg-to-rad)
;; Radians and degrees conversion
(define (rad-to-deg rad)
  (* rad
     (/ 180 PI)))
(define (deg-to-rad deg)
  (* deg
     (/ PI 180)))

(export *float-precision* approx-=)
(define *float-precision* (make-parameter 0.001))
;; Approximately equal - for real number comparison
(define (approx-= x y)
  (< (abs (- x y)) (*float-precision*)))
)