+ given ($version) {
+ when (97) {
+ # current @FORMAT
+ }
+ $offsetbase = 0xF400;
+ when (96) {}
+ ref $_ and splice(@$_, -8, 2) for @{ $FORMAT[11] }; # no multifood
+ splice @FORMAT, 12, 2; # no reserved byte
+ when (95) {}
+ splice @FORMAT, 6, 2; # no description
+ when (94) {}
+ when (90) {
+ $FORMAT[5] = 'C/a'; # length-preceding name
+ splice @FORMAT, 10, 2; # no default sprite
+ ref $_ and do {
+ $_->[5] = $_->[7]; # no tron; deathmatch instead
+ $_->[7] = $_->[9]; # foodmatch instead
+ $_->[9] = 'linkmatch'; # replaces timematch
+ $_->[11] = $_->[13]; # race
+ $_->[13] = $_->[15]; # ctf
+ $_->[15] = 'domination';
+ } for @{ $FORMAT[9] }; # no multifood
+ push @LEVELFORM, "object$_" => ['C',
+ map {$_ => 'C'} qw(x1 y1 x2 y2)
+ ] for qw(lines boxes);
+ }
+ default {
+ die "Unsupported level version $version\n";
+ }
+ }
+
+ my $data = Shiar_Parse::Nested->unpack(\@FORMAT, $input);
+ my $offset = 0;
+ $offsetbase += 1 + @{ $data->{sprite} } if $data->{sprite};
+ $data->{moderef}->{offset}->{single} == $offsetbase
+ or warn "First singleplayer level is not in front\n";
+
+ my $slots = sum(
+ $data->{moderef}->{end}->{single} > 0, # singleplayer slot if any levels
+ $data->{moderef}->{end}->{peaworm}, # one for each peaworm arena
+ $data->{moderef}->{end}->{tron}, # idem for tron
+ );
+ $data->{hinames} = [ unpack '(x2a3)*', substr($data->{leveldata}, -5 * $slots) ];
+ $data->{format} = '86s';
+
+ my @VARMODES = (
+ [qw'single single'],
+ [qw'multi peaworm tron deathmatch foodmatch multifood timematch'],
+ [qw'race race'],
+ [qw'ctf ctf'],
+ );
+
+ $data->{levels} = [];
+ for my $modes (@VARMODES) {
+ my $variant = shift @$modes;
+ my @modeoffsets = grep {defined} #TODO: comment
+ map { $data->{moderef}->{offset}->{$_} } @$modes;
+ @modeoffsets or next;
+ $data->{levelcount}->{$variant} = 0;
+ $offset = min(grep {$_} @modeoffsets) or next;
+ $offset -= $offsetbase;
+ my $amount = $variant eq 'single' ? 100
+ : max(grep {defined} map { $data->{moderef}->{end}->{$_} } @$modes);
+
+ my @varform = @LEVELFORM;
+ $varform[13]->[0] = $variant eq 'single' ? 1 : 4;
+ unshift @varform, name => 'Z*' unless $variant eq 'single' or $version <= 91;
+ $varform[-1]->[0] = 1 if $variant eq 'race' and $version > 91;
+ $varform[-1]->[0] = 2 if $variant eq 'ctf';
+
+ while ($offset < length $data->{leveldata}) {
+ last if substr($data->{leveldata}, $offset, 1) eq chr(255);
+
+ # find references to this level offset, and set start number to matching modes
+ while (my ($mode, $location) = each %{ $data->{moderef}->{offset} }) {
+ $location == $offset + $offsetbase or next;
+ $data->{moderef}->{start}->{$mode} = 1 + scalar @{ $data->{levels} };
+ }
+
+ my $level = Shiar_Parse::Nested->unpack(
+ [@varform], substr $data->{leveldata}, $offset
+ );
+ my $size = 8 # unpack length (ugh, ugly recalculation)
+ + (defined $level->{name} ? 1 + length $level->{name} : 0)
+ + 3 * (ref $level->{worms} eq 'ARRAY' ? scalar @{$level->{worms}} : 1)
+ + 2 * ($level->{flags} ? ref $level->{flags} eq 'ARRAY' ? scalar @{$level->{flags}} : 1 : 0)
+ + ($level->{sprite} ? scalar @{$level->{sprite}} : 0)
+ + ($level->{balls} ? 3 * scalar @{$level->{balls}} : 0);
+ $level->{size} = $size;
+ $level->{offset} = $offset + $offsetbase;
+
+ # add objects until terminator
+ $level->{objects} = [];
+ if ($version <= 91) {
+ push @{ $level->{objects} }, { %$_, type => 2 } for map { $level->{$_} ? @{ $level->{$_} } : () } qw(objectlines);
+ push @{ $level->{objects} }, { %$_, type => 3 } for map { $level->{$_} ? @{ $level->{$_} } : () } qw(objectboxes);
+ $size += 1 + 4 * scalar @{ $level->{objects} };
+ }
+ else {
+ while (my $object = ord substr($data->{leveldata}, $offset+$size, 1)) {
+ push @{ $level->{objects} }, Shiar_Parse::Nested->unpack(
+ [@OBJECTFORM], substr($data->{leveldata}, $offset+$size, 5)
+ );
+ $size += 5;
+ }
+ }
+
+ # add parsed level and advance
+ push @{ $data->{levels} }, $level;
+ $offset += ++$size;
+ last if ++$data->{levelcount}->{$variant} >= $amount;
+ }
+
+ if ($variant eq 'single') {
+ $offset++;
+ $data->{finish}->{code} =
+ my $code = substr $data->{leveldata}, $offset, -5*$slots;
+
+ my %FINISHCODE = (
+ 0 => chr 0xC9, # ret
+ 1 => join('',
+ chr 0x21, # ld hl, MESSAGE
+ pack('v', $offsetbase + $offset + 9),
+ (map {chr}
+ 0xCD, 0x37, 0x4A, # call _puts
+ 0xC3, 0xAA, 0x55, # jp _getkey
+ ),