/*
 *** sin.c: sine wave ***
 *
 *** usage ***
 *	% sin [-f<frequency>] [-s<sampling rate>] [-t<length>] [-r<range>] [<wav file>]
 *
 *** compilation ***
 *	% cc -o sin sin.c wavout.o -lm
 *	(see also "make sin" in Makefile)
 */

#include "wav.h"

WAVFMT fmt;
int sampling = 44100;
double frequency = 440.0;
double tlength = 1.0;
double range = 0.8;
FILE *fd;
// FILE *fd = stdout;

void
sinewave()
{
	int it;
	int nsample = (int)((double)sampling * tlength);
	double tunit = 1.0/(double)sampling;

	for (it = 0; it < nsample; it++) {
		double t = (double)it * tunit;
		double w = sin(2.0*M_PI*frequency*t) * range;
		int iw = (int)((double)AMP2 * w);
		wavdata(fd, iw, 2);
	}
}

// void
int
main(argc, argv)
	int argc; char **argv;
{
	int i;
	fd = stdout;
	default_format(&fmt);

	for (i=1; i<argc; i++) if (argv[i][0] == '-') switch(argv[i][1]) {
		case 'f': frequency = atof(argv[i]+2); break;
		case 's': sampling = atoi(argv[i]+2); break;
		case 't': tlength = atof(argv[i]+2); break;
		case 'r': range = atof(argv[i]+2); break;
	} else if ((fd = fopen(argv[i], "wb")) == NULL) {
		fprintf(stderr, "%s: can't open\n", argv[i]);
		exit(1);
	}
	fmt.SamplingRate = sampling;
	fmt.BytesPerSec = sampling*2;

	wavopen(fd, &fmt);
	sinewave();
	wavclose(fd);
}