1declare name 		"karplus";
2declare version 	"1.0";
3declare author 		"Grame";
4declare license 	"BSD";
5declare copyright 	"(c)GRAME 2006";
6
7//-----------------------------------------------
8// 				karplus-strong
9//-----------------------------------------------
10
11import("music.lib");
12
13// Excitator
14//--------
15
16upfront(x) 	= (x-x') > 0.0;
17decay(n,x)	= x - (x>0.0)/n;
18release(n)	= + ~ decay(n);
19trigger(n) 	= upfront : release(n) : >(0.0);
20
21size 		= hslider("excitation (samples)", 128, 2, 512, 1);
22
23
24
25
26// resonator
27//-----------------
28
29dur 		= hslider("duration (samples)", 128, 2, 512, 1);
30att 		= hslider("attenuation", 0.1, 0, 1, 0.01);
31average(x)	= (x+x')/2;
32
33resonator(d, a) = (+ : delay(4096, d-1.5)) ~ (average : *(1.0-a)) ;
34
35process = noise * hslider("level", 0.5, 0, 1, 0.1)
36		: vgroup("excitator", *(button("play"): trigger(size)))
37		: vgroup("resonator", resonator(dur, att));
38