fftr_config   xtlang

;; fftr config (real config) not the same as cpx config above!
(bind-func fftr_config:[FFTR_Config*,i64]*
  (lambda (len)
    (let ((sz:i64 0)
          (findSize (kiss_fftr_alloc (i64toi32 len) 0 null (ref sz)))
          (config:i8* (alloc sz))
          (res:kiss_fft_cfg (kiss_fftr_alloc (i64toi32 len) 0 config (ref sz))))
      (if (null? res) (println "error constructing fftr config!"))
      (FFTR_Config res))))