use strict;
use MIDI;
use Math::Trig;
use warnings;

my $tick_length = 1536;
my $z = 8;
my $num_cycles = 8;
my $track_length = 16*$num_cycles*$tick_length*4;

my @score_events;

my $track1_dur = (sub {
    my $t = $_[0] <= $track_length/2 ? $_[0] : $track_length-$_[0];
    my $m = $_[0] <= $track_length/2 ? 1 : -1;
    return 3.0*2.0**($z+$m*($t/($track_length/$num_cycles))
             *sin($t*2.0*pi/($track_length/$num_cycles)));});

my $track2_dur = (sub {
    my $t = $_[0] <= $track_length/2 ? $_[0] : $track_length-$_[0];
    my $m = $_[0] <= $track_length/2 ? -1 : 1;
    return 3.0*2.0**($z+$m*($t/($track_length/$num_cycles))
             *sin($t*2.0*pi/($track_length/$num_cycles)));});

my $track3_dur = (sub {
    my $t = $_[0] <= $track_length/2 ? $_[0] : $track_length-$_[0];
    return 3.0*2.0**($z+($t/($track_length/$num_cycles))
             *cos($t*2.0*pi/($track_length/$num_cycles)));});

my $track4_dur = (sub {
    my $t = $_[0] <= $track_length/2 ? $_[0] : $track_length-$_[0];
    return 3.0*2.0**($z-($t/($track_length/$num_cycles))
             *cos($t*2.0*pi/($track_length/$num_cycles)));});


for ([0,$track1_dur],[1,$track2_dur],[2,$track3_dur],[3,$track4_dur]) {
    my ($channel,$f) = @{$_};
    my $i = 0;
    my @channel_starts;
    while ($i < $track_length) {
    push @channel_starts,int($i);
    $i+=&{$f}($i);
    }
    for (my $j = 0; $j < $#channel_starts-1; $j++) {
    push @score_events, ['note',$channel_starts[$j],$channel_starts[$j+1]- $channel_starts[$j],$channel,60,120];
    }
}

sub midi_note {
    my $raw = 57+12*log($_[0]/440.0)/log(2);
    my $offset = $raw - int($raw);
    my $note = sprintf("%.0f",$raw);
    return [$note,$offset >=0.5 ? $offset-1 : $offset];
}

my @colundi_freqs = (70,105,172,210,264,342,431,528,630,685,852,1052);
my %all_freqs_hash;
for my $i (1..4) {
    for my $f (@colundi_freqs) {
    my $note_info = midi_note($f*$i);
    $all_freqs_hash{sprintf "%d %.2f", @{$note_info}}=1;
    }}
my @all_freqs = sort {$a cmp $b} keys %all_freqs_hash;

do {
    my @sub_events;
    my $j = int ($#all_freqs/2);
    my $k = int ($#all_freqs/2);
    for (my $i = 0; $i < $track_length/2; $i+=$track_length/$num_cycles/2) {
    my ($note1,$offset1) = split /\s/,$all_freqs[$j];
    my ($note2,$offset2) = split /\s/,$all_freqs[$k];
    push @sub_events,
        ['note',$i,$tick_length,4,$note1,120],
        ['control_change',$i,4,0,int(64*(1-$offset1))],
        ['note',$i,$tick_length,5,$note2,120],
        ['control_change',$i,5,0,int(64*(1-$offset2))];
    #printf "%s %s\n", $all_freqs[$j],$all_freqs[$k];
    $j+=2; $k-=2;
    }
    for (my $i = $track_length/2; $i < $track_length; $i+=$track_length/$num_cycles/2) {
    my ($note1,$offset1) = split /\s/,$all_freqs[$j];
    my ($note2,$offset2) = split /\s/,$all_freqs[$k];
    push @sub_events,
        ['note',$i,$tick_length,4,$note1,120],
        ['control_change',$i,4,0,int(64*(1-$offset1))],
        ['note',$i,$tick_length,5,$note2,120],
        ['control_change',$i,5,0,int(64*(1-$offset2))];
    #printf "%s %s\n", $all_freqs[$j],$all_freqs[$k];
    $j-=2; $k+=2;
    }
    $j=int ($#all_freqs/2)+1;
    $k=int ($#all_freqs/2)-1;
    for (my $i = $tick_length*16; $i < $track_length; $i+=$track_length/$num_cycles/2) {
    my ($note1,$offset1) = split /\s/,$all_freqs[$j];
    my ($note2,$offset2) = split /\s/,$all_freqs[$k];
    push @sub_events,
        ['note',$i,$tick_length,6,$note1,120],
        ['control_change',$i,6,0,int(64*(1-$offset1))],
        ['note',$i,$tick_length,7,$note2,120],
        ['control_change',$i,7,0,int(64*(1-$offset2))];
    $j+=($i<$track_length/2) ? 2 : -2;
    $k-=($i<$track_length/2) ? 2 : -2;
    }
    push @score_events,@sub_events;
};

my $track = MIDI::Track->new;
$track->events(@{MIDI::Score::score_r_to_events_r(\@score_events)});
my $opus = MIDI::Opus->new({ 'tracks' => [ $track ], 'ticks' => $tick_length });
$opus->write_to_file('cycle1.mid');

#print &{$note_dur_fn1}($tick_length*4*$_),"\n" for 0..40;

#do {my $i = $_; print( join " ", map {my $f = $_;  sprintf("%.2f",&{$f}($i*4*$tick_length));} ($track1_dur,$track2_dur,$track3_dur,$track4_dur));print "\n"} for (0..40);