Plaster

common-lisp
(defun rgb->hsv (a) (declare (optimize speed)) (declare (type rgb a)) (let* ((r (* (aref a 0) (coerce 1/255 'float))) (g (* (aref a 1) (coerce 1/255 'float))) (b (* (aref a 2) (coerce 1/255 'float))) (max (max r g b)) (min (min r g b)) (v max)) (if (= max min) (make-array '(3) :element-type '(float 0.0e0 1.0e0) :initial-contents (list 0.0 0.0 v)) (let ((s (/ (- max min) max)) (h 0)) (cond ((= r max) (setf h (- (/ (- max b) (- max min)) (/ (- max g) (- max min))))) ((= g max) (setf h (+ 2.0 (- (/ (- max r) (- max min)) (/ (- max b) (- max min)))))) (t (setf h (+ 4.0 (- (/ (- max g) (- max min)) (/ (- max r) (- max min))))))) (setf h (mod (* h (coerce 1/6 'float)) 1)) (hsv h s v))))) ; Line 23: (mod (* h (coerce 1/6 'float)) 1) ; note: forced to do full call ; unable to do inline float truncate (cost 5) because: ; The result is a (VALUES INTEGER &OPTIONAL), not a (VALUES ; (SIGNED-BYTE 64) &REST ; T).