TSM_TIM_OLA   xtlang

(bind-func TSM_TIM_OLA
  (lambda ()
  (let ((in_offset_ptr:i64 0)
        (out_offset_ptr:i64 0)
        (output_sample:float 0.0)
        (in_size:i64 (bitwise-shift-left 2 20)) ;increase the second argument if audio is wrapping around circular buffer to soon
        (window_size:i64 1024) ;This is split between the number of input channels.  FFT size is window_size/IN_CHANNELS
        (out_size:i64 (* window_size 2))
        (input_buffer:float* (zalloc in_size))
        (output_buffer:float* (zalloc out_size))
        (window_buffer:float* (zalloc window_size))
        (framing (store_frame_OLA window_size))
        (first:i64 1))
  (lambda (in:float)
    (let ((overlap_factor:i64 4)
          (sample_Ss:i64 (/ window_size overlap_factor))
          (sample_Sa:i64 (ftoi64 (+ (% (round (* (i64tof sample_Ss) speed)) 2.0)(round (* (i64tof sample_Ss) speed)))))) ;speed is a global variable adding the modulus ensure even number
    (pset! input_buffer in_offset_ptr in) ;Set 'in' to whatever you want to be time stretched
    (if (= (% in_offset_ptr sample_Ss) 0)
      (if (= first 0)
          (framing input_buffer in_size output_buffer out_size sample_Sa sample_Ss)))
    (if (= in_offset_ptr window_size) ;Start the TSM process after window_size number of samples
          (set! first 0))
    (set! in_offset_ptr (% (+ in_offset_ptr 1) in_size))
    (cond ((= TSM_active 0)
            (set! output_sample 0.0))
          (else (set! output_sample (pref output_buffer out_offset_ptr))
                (set! out_offset_ptr (% (+ out_offset_ptr 1) out_size))
                output_sample)))))))