#!/usr/bin/perl -w 
use strict; 
use warnings; 
use Data::Dumper; 
 
## Wave file module 
use Audio::Wav; 
 
## Pi Constants 
use Math::Trig ':pi'; 
 
my $wav = new Audio::Wav; 
 
my $sample_rate = 44100; 
my $bits_sample = 16; 
my $details = { 
    'bits_sample'   => $bits_sample, 
    'sample_rate'   => $sample_rate, 
    'channels'      => 3, 
#    'info'          => {}, 
#    'display'       => [[0,1,2],["Phase 0","Phase 1","Phase 2"]], 
    # if you'd like this module not to use a write cache, uncomment the next line 
    #'no_cache'     => 1, 
}; 
 
my $write = $wav -> write( '3ph.wav', $details ); 
 
&add_sine( 200, 1 ); 
 
sub add_sine { 
    my $f = shift; 
    my $length = shift; 
    $length *= $sample_rate; 
    my $max_no =  (2 ** ($bits_sample - 1)) - 1; 
    for my $pos ( 0 .. $length ) { 
        my $ph0 = $max_no * sin(pi2 * $f * ($pos / $sample_rate)); 
        my $ph1 = $max_no * sin(pi2 * $f * ($pos / $sample_rate) + pi2/3); 
        my $ph2 = $max_no * sin(pi2 * $f * ($pos / $sample_rate) - pi2/3); 
#        printf "tick #%d, phase0 = %.4f, phase1 = %.4f, phase2 = %.4f\n", $pos, $ph0, $ph1, $ph2; 
        $write -> write( ($ph0, $ph1, $ph2) ); 
    } 
} 
#print Dumper \$write; 
 
$write -> finish();