mono-fast

[Stephane Boussuge]

Hi,

 

here's a small function i did for one of my work in progress.

 

The idea is to process omn pitch material relating to omn length values.

 

For example, if omn length value faster than 1/8, "monodize" the melody at this point.

 

;;; ===============================================================
;;; MONO-FAST
;;; "Monodize" (remove chords) the omn parts faster than the given rhythmic value. 
;; Utility function
(defun mono-fast* (max-length-value mat)
  (let* (; disassembling the omn mat into his components
         (omn-mat (disassemble-omn mat))
         (p-mat (getf omn-mat :pitch))
         (l-mat (getf omn-mat :length))
         (v-mat (getf omn-mat :velocity))
         (a-mat (getf omn-mat :articulation))
         ; empty list for the result of pitch processing
         (re-pmat '())
         )
    (loop
      for i from 0 to (-(length p-mat)1)
      do (if (< (nth i l-mat) max-length-value)
           (push (pitch-demix 1 (list (nth i p-mat))) re-pmat)
           (push (nth i p-mat) re-pmat)
           )
      )
    ; re-assembling the omn material
    (make-omn
     :pitch (reverse (flatten re-pmat))
     :length l-mat
     :velocity v-mat
     :articulation a-mat
     )))

;; Main function
(defun mono-fast (max-length-value mat)
  (if (listp (car mat))
    (mapcar (lambda(x) (mono-fast* max-length-value x)) mat)
    (mono-fast* max-length-value mat)))

(setf test-seq '(q c4e4 p d4f4 e4g4 s f4a4 g4b4 a4c5 b4d5 q c5e5))
(setf test-seq2 '((q c4e4 p d4f4 e4g4) (s f4a4 g4b4 a4c5 b4d5 q c5e5)))

(mono-fast '1/8 test-seq)
(mono-fast '1/8 test-seq2)

SB.