play-note   scheme

(define play-note
  (lambda (time inst pitch vol dur . args)
    (let* ((nargs (length args))
           (duration dur)
           (dargs (sys:make-cptr (* (if (audio_64bit) 8 4) nargs))) ;; doubles
           (native (if (closure? inst)
                       (llvm:get-native-closure (symbol->string (apply inst (list 'xtlang))))
                       (if (symbol? inst)
                           (llvm:get-native-closure (eval (string->symbol (string-append (symbol->string inst) "_xtlang_name"))))
                           (if (cptr? inst)
                               inst
                               #f)))))
      (if (= (audio_64bit) 1)
          (dotimes (i nargs) (cptr:set-double dargs (* i 8) (eval (list-ref args i))))
          (dotimes (i nargs) (cptr:set-float dargs (* i 4) (eval (list-ref args i)))))
      (if (cptr? native)
          (if (list? pitch)
              (for-each (lambda (p)
                          (xtm_play_note (real->integer time)
                          native
                          (midi2frq (* 1.0 p))
                          (/ (exp (/ vol 26.222)) 127.0)
                          (real->integer duration)
                          nargs
                          dargs))
                        pitch)
            (xtm_play_note (real->integer time)
                        native
                        (midi2frq (* 1.0 pitch))
                        (/ (exp (/ vol 26.222)) 127.0)
                        (real->integer duration)
                        nargs
                        dargs))
          (log-error 'No 'inst 'named (symbol->string inst))))))