#include <stdlib.h>
#include <stdio.h>
#include <math.h>

double get_base_freq(void)
{
	double base_freq;
	char *envvar = getenv("BASEFREQ");
	if (envvar) {
		base_freq = atof(envvar);
	} else {
		base_freq = 440.0;
	}
	return base_freq;
}

int main(int argc, char **argv)
{
	int sample_rate=44100;
	int count = argc-1;
	double *dat = calloc(count, sizeof(double));
	int i, j, e;
	double base_freq = get_base_freq();
	double sample_len=1; // 1 second
	double v;

	for (i=0; i<count; ++i) {
		dat[i] = pow(2.0, atof(argv[i+1])/12) * base_freq / sample_rate;
	}

	e = (int)sample_rate*sample_len;
	for (i=0; i<e; ++i) {
		v = 0;
		for (j=0; j<count; ++j) {
			v += sin(dat[j]*i*3.1415926535*2); // TODO amplitude
		}
		v = v / count;
		printf("%c%c", (int)(v * 0x7000) & 0xFF, ((int)(v * 0x7000) >> 8) & 0xFF);
	}
	exit(0);
}