added csound-play method and csound helper functions

Hello Michael,

I finally found some time to implement a csound-play method. As depicted in the code documentation, it is aimed at creating Csound-scores from sc-objects for one or more players and writing it to a .sco-file. All p-fields other than p1-p3 (i.e. the Csound-instrument name, the onset and the duration) will be generated either by a list of lists (for static values) or a user defined function. The latter is the reason why I created a csound.lsp-file and included a simple helper function for creating p-fields for the frequency and amplitude values derived from the events processed by csound-play. Some work might be necessary in order to implement sndfile-palette compatibility. Albeit there is already a draft of this feature on my hard drive, I decided to keep things straightforward and just push this first working version.

Here is an example call of the method:

(in-package :sc)

(let ((mini
        (make-slippery-chicken
         '+mini+
         :ensemble '(((pno (piano :midi-channel 1))
                      (vln (violin :midi-channel 2))))
         :set-palette '((1 ((f3 g3 as3 a3 bf3 b3 c4 d4 e4 f4 g4 a4 bf4 cs5))))
         :set-map '((1 (1 1 1 1 1 1 1))
                    (2 (1 1 1 1 1 1 1))
                    (3 (1 1 1 1 1 1 1)))
         :tempo-map '((1 (q 60)))
         :rthm-seq-palette '((1 ((((4 4) h (q) e (s) s))
                                 :pitch-seq-palette ((1 (2) 3))))
                             (2 ((((4 4) (q) e (s) s h))
                                 :pitch-seq-palette ((1 2 3))))
                             (3 ((((4 4) e (s) s h (q)))
                                 :pitch-seq-palette ((2 3 3))))
                             (4 ((((4 4) (s) s h (q) e))
                                 :pitch-seq-palette ((3 1 (2))))))
         :rthm-seq-map '((1 ((pno (1 2 1 2 1 2 1))
                             (vln (1 2 1 2 1 2 1))))
                         (2 ((pno (3 4 3 4 3 4 3))
                             (vln (3 4 3 4 3 4 3))))
                         (3 ((pno (1 2 1 2 1 2 1))
                             (vln (1 2 1 2 1 2 1))))))))
  (csound-play mini
               '(pno vln)
               '(1 "fmsynth")
               :csound-file "/tmp/weird-piece.sco"
               :chords 1
               :delimiter #\tab
               :comments t))

I tested it with a set of my own compositions and with some of the tutorial compositions in your manual and, so far, did not encounter any inconvenience.

Hope you like it…

Greetings Ruben

mdedwards / slippery-chicken

added csound-play method and csound helper functions #62