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

@title{Pavaroh}
 applying ascending and descending scales to event stream@section{categories}
  Streams-Patterns-Events>Patterns>Math

@section{description}


Basic classical indian scale pattern. Allowing to apply an ascending scale (aroh) and a descending scale (avaroh).

Note that no special pakads (movements) or vakras (twists) are applied.

The pakad is often a natural consequence of the notes of arohana / avarohana (ascending and descending structures). This is the purpose of this pattern.

@section{Examples}
 


@racketblock[
(
Pbind(\note, Pavaroh(
			Pseq([1, 2, 3, 2, 5, 4, 3, 4, 2, 1], 2),
			#[0, 2, 3, 6, 7, 9],
			#[0, 1, 3, 7, 8, 11]
		),
	\dur, 0.25
).play;
)


//___indian video game (1)
(
SynthDef("ivg", { arg out, freq=900, pan;
	var trig, snd;
	trig = Impulse.kr(LFClipNoise.kr(4, 3, LFClipNoise.kr(0.2, 2, 7)));
	snd = RLPF.ar(
		SinOsc.ar(freq, 0, Decay.kr(trig, 1.8)).distort
		, 554, 0.3)
	* 0.1;
	Out.ar(out, Pan2.ar(snd, pan))
 }).add;
)

(
	var aroh, avaroh, synth, str, pat;

	//gandhari raga.  vadi: dha (7) samvadi: ga (3)

	aroh = #[0, 2, 5, 7, 10];
	avaroh =  #[0, 1, 3, 5, 7, 9, 10];

	synth = Synth.head(s, \ivg);
	pat = Prand([0, 2, 3, 4, 2, 1, 0, -1, -2], inf);
	str = Pavaroh(pat, aroh, avaroh).asStream;
	Routine({

		loop({
			synth.set(\freq, midicps(str.next + 60) );
			rrand([0.1,1.0].choose, 0.5).wait;
		});

	}).play;
)
::
]