// boop.c
// 6c -FTVw boop.c && 6l -o boop boop.6 && ./boop | audio/pcmconv -i f32c1r44100 >/dev/audio 

#include <u.h>
#include <libc.h>

#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))
#define RATE 44100.0
#define SZ(x) (int)(x*RATE)
#define S(n,d) float n[SZ(d)]
#define FS(n) for(i = 0; i < nelem(n); i++)
#define NS(n) nelem(n)
#define TRW(f,i) (PI*2*(f)/RATE*(i))
#define LF(n) ((double)(NS(n) - i) / NS(n))
#define CF(n) cos(PI*(1.0-LF(n))/2.0)
#define SA(x,n) (((x) & (n)) ? -1 : 1)

void
main(int, char **)
{
	int i, j, k;
	S(s₀, 0.09);
	S(s₁, 0.04);
	S(s₂, 0.03);

	for(k = 0; k < 1024; k++){
		for(j = 0; j < 4; j++){
			FS(s₁) s₁[i]  = 0.7 * fabs(sin(TRW(800+20*j + 200*SA(k,3) + 120*SA(k,8) - 160*SA(k,16), i))*CF(s₁))*CF(s₁);
			FS(s₀) s₀[i]  = sin(TRW(60+20*j + 10*(k % 4), i))*CF(s₀);
			FS(s₁) s₀[i] += s₁[i];
			FS(s₂) s₂[i]  = 0.2 * cos(TRW(100+500*sin(TRW(1 + (k % 8)*((k % 16)+j), i)), i));
			FS(s₂) s₀[i] += s₂[i];
			FS(s₀) s₀[i] /= 3.0;

			write(1, s₀, sizeof(s₀));
		}
	}

	exits(nil);
}