Miscellany

/* init */
vol = 7219;
fac1 = 2.0 * cos(2.0 * M_PI * (freq / 8000.0)) * 32768.0;
init_v2_1 = sin(-4.0 * M_PI * (freq / 8000.0)) * vol;
init_v3_1 = sin(-2.0 * M_PI * (freq / 8000.0)) * vol;

for(x=0; x<nsamp; x++) {
	if(first) {
		v1_1 = 0;
		v2_1 = init_v2_1;
		v3_1 = init_v3_1;
		}

	v1_1 = v2_1;
	v2_1 = v3_1;
	v3_1 = (fac1 * v2_1 >> 15) - v1_1;

	data[x] = v3_1;
	}