#lang scribble/manual
@(require (for-label racket))

@title{(grain-buf nc tr dur sndbuf rate pos interp pan envbuf)}


Granular synthesis with sound stored in a buffer

nc - the number of channels to output. If 1, mono is returned and
     pan is ignored.

tr - a kr or ar trigger to start a new grain. If ar, grains after
     the start of the synth are sample accurate.

The following args are polled at grain creation time

dur - size of the grain.

sndbuf - the buffer holding an audio signal

rate - the playback rate of the sampled sound

pos - the playback position for the grain to start with (0 is
      beginning, 1 is end of file)

interp - the interpolation method used for pitchshifting grains.
         1 = no interpolation. 2 = linear. 4 = cubic interpolation
         (more computationally intensive).

pan - a value from -1 to 1. Determines where to pan the output in
      the same manner as pan-az.

envb - the buffer number containing a singal to use for the
       grain envelope. -1 uses a built-in Hanning envelope.


@racketblock[
(with-sc3
 (lambda (fd)
   (async fd (b-alloc-read 10 "/home/rohan/audio/metal.wav" 0 0))
   (let ((g (letc ((gate 1)
		   (amp 1)
		   (sndbuf 0)
		   (envbuf -1))
	      (let* ((x (mouse-x kr -1 1 0 0.1))
		     (y (mouse-y kr 10 45 0 0.1))
		     (i (impulse kr y 0))
		     (r (lin-lin (lf-noise1 kr 500) -1 1 0.5 2))
		     (p (lin-lin (lf-noise2 kr 0.1) -1 1 0 1)))
		(out 0 (grain-buf 2 i 0.1 sndbuf r p 2 x envbuf))))))
     (send-synth fd "g" g)
     (send fd (s-new2 "g" -1 add-to-tail 1 "sndbuf" 10 "envbuf" -1)))))
]