package Font::TTF::Cmap;
=head1 NAME
Font::TTF::Cmap - Character map table
=head1 DESCRIPTION
Looks after the character map. For ease of use, the actual cmap is held in
a hash against codepoint. Thus for a given table:
$gid = $font->{'cmap'}{'Tables'}[0]{'val'}{$code};
Note that C<$code> should be a true value (0x1234) rather than a string representation.
=head1 INSTANCE VARIABLES
The instance variables listed here are not preceded by a space due to their
emulating structural information in the font.
=over 4
=item Num
Number of subtables in this table
=item Tables
An array of subtables ([0..Num-1])
Each subtable also has its own instance variables which are, again, not
preceded by a space.
=over 4
=item Platform
The platform number for this subtable
=item Encoding
The encoding number for this subtable
=item Format
Gives the stored format of this subtable
=item Ver
Gives the version (or language) information for this subtable
=item val
A hash keyed by the codepoint value (not a string) storing the glyph id
=back
=back
The following cmap options are controlled by instance variables that start with a space:
=over 4
=item allowholes
By default, when generating format 4 cmap subtables character codes that point to glyph zero
(normally called .notdef) are not included in the subtable. In some cases including some of these
character codes can result in a smaller format 4 subtable. To enable this behavior, set allowholes
to non-zero.
=back
=head1 METHODS
=cut
use strict;
use vars qw(@ISA);
use Font::TTF::Table;
use Font::TTF::Utils;
@ISA = qw(Font::TTF::Table);
=head2 $t->read
Reads the cmap into memory. Format 4 subtables read the whole subtable and
fill in the segmented array accordingly.
=cut
sub read
{
my ($self, $keepzeros) = @_;
$self->SUPER::read or return $self;
my ($dat, $i, $j, $k, $id, @ids, $s);
my ($start, $end, $range, $delta, $form, $len, $num, $ver, $sg);
my ($fh) = $self->{' INFILE'};
$fh->read($dat, 4);
$self->{'Num'} = unpack("x2n", $dat);
$self->{'Tables'} = [];
for ($i = 0; $i < $self->{'Num'}; $i++)
{
$s = {};
$fh->read($dat, 8);
($s->{'Platform'}, $s->{'Encoding'}, $s->{'LOC'}) = (unpack("nnN", $dat));
$s->{'LOC'} += $self->{' OFFSET'};
push(@{$self->{'Tables'}}, $s);
}
for ($i = 0; $i < $self->{'Num'}; $i++)
{
$s = $self->{'Tables'}[$i];
$fh->seek($s->{'LOC'}, 0);
$fh->read($dat, 2);
$form = unpack("n", $dat);
$s->{'Format'} = $form;
if ($form == 0)
{
my $j = 0;
$fh->read($dat, 4);
($len, $s->{'Ver'}) = unpack('n2', $dat);
$fh->read($dat, 256);
$s->{'val'} = {map {$j++; ($_ ? ($j - 1, $_) : ())} unpack("C*", $dat)};
} elsif ($form == 6)
{
my ($start, $ecount);
$fh->read($dat, 8);
($len, $s->{'Ver'}, $start, $ecount) = unpack('n4', $dat);
$fh->read($dat, $ecount << 1);
$s->{'val'} = {map {$start++; ($_ ? ($start - 1, $_) : ())} unpack("n*", $dat)};
} elsif ($form == 2) # Contributed by Huw Rogers
{
$fh->read($dat, 4);
($len, $s->{'Ver'}) = unpack('n2', $dat);
$fh->read($dat, 512);
my ($j, $k, $l, $m, $n, @subHeaderKeys, @subHeaders, $subHeader);
$n = 1;
for ($j = 0; $j < 256; $j++) {
my $k = unpack('@'.($j<<1).'n', $dat)>>3;
$n = $k + 1 if $k >= $n;
$subHeaders[$subHeaderKeys[$j] = $k] ||= [ ];
}
$fh->read($dat, $n<<3); # read subHeaders[]
for ($k = 0; $k < $n; $k++) {
$subHeader = $subHeaders[$k];
$l = $k<<3;
@$subHeader = unpack('@'.$l.'n4', $dat);
$subHeader->[2] = unpack('s', pack('S', $subHeader->[2]))
if $subHeader->[2] & 0x8000; # idDelta
$subHeader->[3] =
($subHeader->[3] - (($n - $k)<<3) + 6)>>1; # idRangeOffset
}
$fh->read($dat, $len - ($n<<3) - 518); # glyphIndexArray[]
for ($j = 0; $j < 256; $j++) {
$k = $subHeaderKeys[$j];
$subHeader = $subHeaders[$k];
unless ($k) {
$l = $j - $subHeader->[0];
if ($l >= 0 && $l < $subHeader->[1]) {
$m = unpack('@'.(($l + $subHeader->[3])<<1).'n', $dat);
$m += $subHeader->[2] if $m;
$s->{'val'}{$j} = $m;
}
} else {
for ($l = 0; $l < $subHeader->[1]; $l++) {
$m = unpack('@'.(($l + $subHeader->[3])<<1).'n', $dat);
$m += $subHeader->[2] if $m;
$s->{'val'}{($j<<8) + $l + $subHeader->[0]} = $m;
}
}
}
} elsif ($form == 4)
{
$fh->read($dat, 12);
($len, $s->{'Ver'}, $num) = unpack('n3', $dat);
$num >>= 1;
$fh->read($dat, $len - 14);
for ($j = 0; $j < $num; $j++)
{
$end = unpack("n", substr($dat, $j << 1, 2));
$start = unpack("n", substr($dat, ($j << 1) + ($num << 1) + 2, 2));
$delta = unpack("n", substr($dat, ($j << 1) + ($num << 2) + 2, 2));
$delta -= 65536 if $delta > 32767;
$range = unpack("n", substr($dat, ($j << 1) + $num * 6 + 2, 2));
for ($k = $start; $k <= $end; $k++)
{
if ($range == 0 || $range == 65535) # support the buggy FOG with its range=65535 for final segment
{ $id = $k + $delta; }
else
{ $id = unpack("n", substr($dat, ($j << 1) + $num * 6 +
2 + ($k - $start) * 2 + $range, 2)) + $delta; }
$id -= 65536 if $id >= 65536;
$s->{'val'}{$k} = $id if ($id || $keepzeros);
}
}
} elsif ($form == 8 || $form == 12 || $form == 13)
{
$fh->read($dat, 10);
($len, $s->{'Ver'}) = unpack('x2N2', $dat);
if ($form == 8)
{
$fh->read($dat, 8196);
$num = unpack("N", substr($dat, 8192, 4)); # don't need the map
} else
{
$fh->read($dat, 4);
$num = unpack("N", $dat);
}
$fh->read($dat, 12 * $num);
for ($j = 0; $j < $num; $j++)
{
($start, $end, $sg) = unpack("N3", substr($dat, $j * 12, 12));
for ($k = $start; $k <= $end; $k++)
{ $s->{'val'}{$k} = $form == 13 ? $sg : $sg++; }
}
} elsif ($form == 10)
{
$fh->read($dat, 18);
($len, $s->{'Ver'}, $start, $num) = unpack('x2N4', $dat);
$fh->read($dat, $num << 1);
for ($j = 0; $j < $num; $j++)
{ $s->{'val'}{$start + $j} = unpack("n", substr($dat, $j << 1, 2)); }
}
}
$self;
}
=head2 $t->ms_lookup($uni)
Finds a Unicode table, giving preference to the MS one, and looks up the given
Unicode codepoint in it to find the glyph id.
=cut
sub ms_lookup
{
my ($self, $uni) = @_;
$self->find_ms || return undef unless (defined $self->{' mstable'});
return $self->{' mstable'}{'val'}{$uni};
}
=head2 $t->find_ms
Finds the a Unicode table, giving preference to the Microsoft one, and sets the C<mstable> instance variable
to it if found. Returns the table it finds.
=cut
sub find_ms
{
my ($self) = @_;
my ($i, $s, $alt, $found);
return $self->{' mstable'} if defined $self->{' mstable'};
$self->read;
for ($i = 0; $i < $self->{'Num'}; $i++)
{
$s = $self->{'Tables'}[$i];
if ($s->{'Platform'} == 3)
{
$self->{' mstable'} = $s;
return $s if ($s->{'Encoding'} == 10);
$found = 1 if ($s->{'Encoding'} == 1);
} elsif ($s->{'Platform'} == 0 || ($s->{'Platform'} == 2 && $s->{'Encoding'} == 1))
{ $alt = $s; }
}
$self->{' mstable'} = $alt if ($alt && !$found);
$self->{' mstable'};
}
=head2 $t->ms_enc
Returns the encoding of the microsoft table (0 => symbol, etc.). Returns undef if there is
no Microsoft cmap.
=cut
sub ms_enc
{
my ($self) = @_;
my ($s);
return $self->{' mstable'}{'Encoding'}
if (defined $self->{' mstable'} && $self->{' mstable'}{'Platform'} == 3);
foreach $s (@{$self->{'Tables'}})
{
return $s->{'Encoding'} if ($s->{'Platform'} == 3);
}
return undef;
}
=head2 $t->out($fh)
Writes out a cmap table to a filehandle. If it has not been read, then
just copies from input file to output
=cut
sub out
{
my ($self, $fh) = @_;
my ($loc, $s, $i, $base_loc, $j, @keys);
return $self->SUPER::out($fh) unless $self->{' read'};
$self->{'Tables'} = [sort {$a->{'Platform'} <=> $b->{'Platform'}
|| $a->{'Encoding'} <=> $b->{'Encoding'}
|| $a->{'Ver'} <=> $b->{'Ver'}} @{$self->{'Tables'}}];
$self->{'Num'} = scalar @{$self->{'Tables'}};
$base_loc = $fh->tell();
$fh->print(pack("n2", 0, $self->{'Num'}));
for ($i = 0; $i < $self->{'Num'}; $i++)
{ $fh->print(pack("nnN", $self->{'Tables'}[$i]{'Platform'}, $self->{'Tables'}[$i]{'Encoding'}, 0)); }
for ($i = 0; $i < $self->{'Num'}; $i++)
{
$s = $self->{'Tables'}[$i];
if ($s->{'Format'} < 8)
{ @keys = sort {$a <=> $b} grep { $_ <= 0xFFFF} keys %{$s->{'val'}}; }
else
{ @keys = sort {$a <=> $b} keys %{$s->{'val'}}; }
$s->{' outloc'} = $fh->tell();
if ($s->{'Format'} < 8)
{ $fh->print(pack("n3", $s->{'Format'}, 0, $s->{'Ver'})); } # come back for length
else
{ $fh->print(pack("n2N2", $s->{'Format'}, 0, 0, $s->{'Ver'})); }
if ($s->{'Format'} == 0)
{
$fh->print(pack("C256", map {defined $_ ? $_ : 0} @{$s->{'val'}}{0 .. 255}));
} elsif ($s->{'Format'} == 6)
{
$fh->print(pack("n2", $keys[0], $keys[-1] - $keys[0] + 1));
$fh->print(pack("n*", map {defined $_ ? $_ : 0} @{$s->{'val'}}{$keys[0] .. $keys[-1]}));
} elsif ($s->{'Format'} == 2) # Contributed by Huw Rogers
{
my ($g, $k, $h, $l, $m, $n);
my (@subHeaderKeys, @subHeaders, $subHeader, @glyphIndexArray);
$n = 0;
@subHeaderKeys = (-1) x 256;
for $j (@keys) {
next unless defined($g = $s->{'val'}{$j});
$h = int($j>>8);
$l = ($j & 0xff);
if (($k = $subHeaderKeys[$h]) < 0) {
$subHeader = [ $l, 1, 0, 0, [ $g ] ];
$subHeaders[$k = $n++] = $subHeader;
$subHeaderKeys[$h] = $k;
} else {
$subHeader = $subHeaders[$k];
$m = ($l - $subHeader->[0] + 1) - $subHeader->[1];
$subHeader->[1] += $m;
push @{$subHeader->[4]}, (0) x ($m - 1), $g - $subHeader->[2];
}
}
@subHeaderKeys = map { $_ < 0 ? 0 : $_ } @subHeaderKeys;
$subHeader = $subHeaders[0];
$subHeader->[3] = 0;
push @glyphIndexArray, @{$subHeader->[4]};
splice(@$subHeader, 4);
{
my @subHeaders_ = sort {@{$a->[4]} <=> @{$b->[4]}} @subHeaders[1..$#subHeaders];
my ($f, $d, $r, $subHeader_);
for ($k = 0; $k < @subHeaders_; $k++) {
$subHeader = $subHeaders_[$k];
$f = $r = shift @{$subHeader->[4]};
$subHeader->[5] = join(':',
map {
$d = $_ - $r;
$r = $_;
$d < 0 ?
sprintf('-%04x', -$d) :
sprintf('+%04x', $d)
} @{$subHeader->[4]});
unshift @{$subHeader->[4]}, $f;
}
for ($k = 0; $k < @subHeaders_; $k++) {
$subHeader = $subHeaders_[$k];
next unless $subHeader->[4];
$subHeader->[3] = @glyphIndexArray;
push @glyphIndexArray, @{$subHeader->[4]};
for ($l = $k + 1; $l < @subHeaders_; $l++) {
$subHeader_ = $subHeaders_[$l];
next unless $subHeader_->[4];
$d = $subHeader_->[5];
if ($subHeader->[5] =~ /\Q$d\E/) {
my $o = length($`)/6; #`
$subHeader_->[2] +=
$subHeader_->[4]->[$o] - $subHeader->[4]->[0];
$subHeader_->[3] = $subHeader->[3] + $o;
splice(@$subHeader_, 4);
}
}
splice(@$subHeader, 4);
}
}
$fh->print(pack('n*', map { $_<<3 } @subHeaderKeys));
for ($j = 0; $j < 256; $j++) {
$k = $subHeaderKeys[$j];
$subHeader = $subHeaders[$k];
}
for ($k = 0; $k < $n; $k++) {
$subHeader = $subHeaders[$k];
$fh->print(pack('n4',
$subHeader->[0],
$subHeader->[1],
$subHeader->[2] < 0 ?
unpack('S', pack('s', $subHeader->[2])) :
$subHeader->[2],
($subHeader->[3]<<1) + (($n - $k)<<3) - 6
));
}
$fh->print(pack('n*', @glyphIndexArray));
} elsif ($s->{'Format'} == 4)
{
my (@starts, @ends, @deltas, @range);
# There appears to be a bug in Windows that requires the final 0xFFFF (sentry)
# to be in a segment by itself -- otherwise Windows 7 and 8 (at least) won't install
# or preview the font, complaining that it doesn't appear to be a valid font.
# Therefore we can't just add 0XFFFF to the USV list as we used to do:
# push(@keys, 0xFFFF) unless ($keys[-1] == 0xFFFF);
# Instead, for now *remove* 0xFFFF from the USV list, and add a segement
# for it after all the other segments are computed.
pop @keys if $keys[-1] == 0xFFFF;
# Step 1: divide into maximal length idDelta runs
my ($prevUSV, $prevgid);
for ($j = 0; $j <= $#keys; $j++)
{
my $u = $keys[$j];
my $g = $s->{'val'}{$u};
if ($j == 0 || $u != $prevUSV+1 || $g != $prevgid+1)
{
push @ends, $prevUSV unless $j == 0;
push @starts, $u;
push @range, 0;
}
$prevUSV = $u;
$prevgid = $g;
}
push @ends, $prevUSV;
# Step 2: find each macro-range
my ($start, $end); # Start and end of macro-range
for ($start = 0; $start < $#starts; $start++)
{
next if $ends[$start] - $starts[$start] > 7; # if count > 8, we always treat this as a run unto itself
for ($end = $start+1; $end <= $#starts; $end++)
{
last if $starts[$end] - $ends[$end-1] > ($self->{' allowholes'} ? 5 : 1)
|| $ends[$end] - $starts[$end] > 7; # gap > 4 or count > 8 so $end is beyond end of macro-range
}
$end--; #Ending index of this macro-range
# Step 3: optimize this macro-range (from $start through $end)
L1: for ($j = $start; $j < $end; )
{
my $size1 = ($range[$j] ? 8 + 2 * ($ends[$j] - $starts[$j] + 1) : 8); # size of first range (which may now be idRange type)
for (my $k = $j+1; $k <= $end; $k++)
{
if (8 + 2 * ($ends[$k] - $starts[$j] + 1) <= $size1 + 8 * ($k - $j))
{
# Need to coalesce $j..$k into $j:
$ends[$j] = $ends[$k];
$range[$j] = 1; # for now use boolean to indicate this is an idRange segment
splice @starts, $j+1, $k-$j;
splice @ends, $j+1, $k-$j;
splice @range, $j+1, $k-$j;
$end -= ($k-$j);
next L1; # Note that $j isn't incremented so this is a redo
}
}
# Nothing coalesced
$j++;
}
# Finished with this macro-range
$start = $end;
}
# Ok, add the final segment containing the sentry value
push(@keys, 0xFFFF);
push @starts, 0xFFFF;
push @ends, 0xFFFF;
push @range, 0;
# What is left is a collection of segments that will represent the cmap in mimimum-sized format 4 subtable
my ($num, $count, $sRange, $eSel, $eShift);
$num = scalar(@starts);
$count = 0;
for ($j = 0; $j < $num; $j++)
{
if ($range[$j])
{
$range[$j] = ($count + $num - $j) << 1;
$count += $ends[$j] - $starts[$j] + 1;
push @deltas, 0;
}
else
{
push @deltas, ($s->{'val'}{$starts[$j]} || 0) - $starts[$j];
}
}
($num, $sRange, $eSel, $eShift) = Font::TTF::Utils::TTF_bininfo($num, 2);
$fh->print(pack("n4", $num * 2, $sRange, $eSel, $eShift));
$fh->print(pack("n*", @ends));
$fh->print(pack("n", 0));
$fh->print(pack("n*", @starts));
$fh->print(pack("n*", @deltas));
$fh->print(pack("n*", @range));
for ($j = 0; $j < $num; $j++)
{
next if ($range[$j] == 0);
$fh->print(pack("n*", map {$_ || 0} @{$s->{'val'}}{$starts[$j] .. $ends[$j]}));
}
} elsif ($s->{'Format'} == 8 || $s->{'Format'} == 12 || $s->{'Format'} == 13)
{
my (@jobs, $start, $current, $curr_glyf, $map);
$current = 0; $curr_glyf = 0;
$map = "\000" x 8192;
foreach $j (@keys)
{
if ($j > 0xFFFF && $s->{'Format'} == 8)
{
if (defined $s->{'val'}{$j >> 16})
{ $s->{'Format'} = 12; }
vec($map, $j >> 16, 1) = 1;
}
if ($j != $current + 1 || $s->{'val'}{$j} != ($s->{'Format'} == 13 ? $curr_glyf : $curr_glyf + 1))
{
push (@jobs, [$start, $current, $s->{'Format'} == 13 ? $curr_glyf : $curr_glyf - ($current - $start)]) if (defined $start);
$start = $j; $current = $j; $curr_glyf = $s->{'val'}{$j};
}
$current = $j;
$curr_glyf = $s->{'val'}{$j};
}
push (@jobs, [$start, $current, $s->{'Format'} == 13 ? $curr_glyf : $curr_glyf - ($current - $start)]) if (defined $start);
$fh->print($map) if ($s->{'Format'} == 8);
$fh->print(pack('N', $#jobs + 1));
foreach $j (@jobs)
{ $fh->print(pack('N3', @{$j})); }
} elsif ($s->{'Format'} == 10)
{
$fh->print(pack('N2', $keys[0], $keys[-1] - $keys[0] + 1));
$fh->print(pack('n*', $s->{'val'}{$keys[0] .. $keys[-1]}));
}
$loc = $fh->tell();
if ($s->{'Format'} < 8)
{
$fh->seek($s->{' outloc'} + 2, 0);
$fh->print(pack("n", $loc - $s->{' outloc'}));
} else
{
$fh->seek($s->{' outloc'} + 4, 0);
$fh->print(pack("N", $loc - $s->{' outloc'}));
}
$fh->seek($base_loc + 8 + ($i << 3), 0);
$fh->print(pack("N", $s->{' outloc'} - $base_loc));
$fh->seek($loc, 0);
}
$self;
}
=head2 $t->XML_element($context, $depth, $name, $val)
Outputs the elements of the cmap in XML. We only need to process val here
=cut
sub XML_element
{
my ($self, $context, $depth, $k, $val) = @_;
my ($fh) = $context->{'fh'};
my ($i);
return $self if ($k eq 'LOC');
return $self->SUPER::XML_element($context, $depth, $k, $val) unless ($k eq 'val');
$fh->print("$depth<mappings>\n");
foreach $i (sort {$a <=> $b} keys %{$val})
{ $fh->printf("%s<map code='%04X' glyph='%s'/>\n", $depth . $context->{'indent'}, $i, $val->{$i}); }
$fh->print("$depth</mappings>\n");
$self;
}
=head2 $t->minsize()
Returns the minimum size this table can be in bytes. If it is smaller than this, then the table
must be bad and should be deleted or whatever.
=cut
sub minsize
{
return 4;
}
=head2 $t->update
Tidies the cmap table.
Removes MS Fmt12 cmap if it is no longer needed.
Removes from all cmaps any codepoint that map to GID=0. Note that such entries will
be re-introduced as necessary depending on the cmap format.
=cut
sub update
{
my ($self) = @_;
my ($max, $code, $gid, @keep);
return undef unless ($self->SUPER::update);
foreach my $s (@{$self->{'Tables'}})
{
$max = 0;
while (($code, $gid) = each %{$s->{'val'}})
{
if ($gid)
{
# remember max USV
$max = $code if $max < $code;
}
else
{
# Remove unneeded key
delete $s->{'val'}{$code}; # nb: this is a safe delete according to perldoc perlfunc.
}
}
push @keep, $s unless $s->{'Platform'} == 3 && $s->{'Encoding'} == 10 && $s->{'Format'} == 12 && $max <= 0xFFFF;
}
$self->{'Tables'} = [ @keep ];
delete $self->{' mstable'}; # Force rediscovery of this.
$self;
}
=head2 @map = $t->reverse(%opt)
Returns a reverse map of the Unicode cmap. I.e. given a glyph gives the Unicode value for it. Options are:
=over 4
=item tnum
Table number to use rather than the default Unicode table
=item array
Returns each element of reverse as an array since a glyph may be mapped by more
than one Unicode value. The arrays are unsorted. Otherwise store any one unicode value for a glyph.
=back
=cut
sub reverse
{
my ($self, %opt) = @_;
my ($table) = defined $opt{'tnum'} ? $self->{'Tables'}[$opt{'tnum'}] : $self->find_ms;
my (@res, $code, $gid);
while (($code, $gid) = each(%{$table->{'val'}}))
{
if ($opt{'array'})
{ push (@{$res[$gid]}, $code); }
else
{ $res[$gid] = $code unless (defined $res[$gid] && $res[$gid] > 0 && $res[$gid] < $code); }
}
@res;
}
=head2 is_unicode($index)
Returns whether the table of a given index is known to be a unicode table
(as specified in the specifications)
=cut
sub is_unicode
{
my ($self, $index) = @_;
my ($pid, $eid) = ($self->{'Tables'}[$index]{'Platform'}, $self->{'Tables'}[$index]{'Encoding'});
return ($pid == 3 || $pid == 0 || ($pid == 2 && $eid == 1));
}
1;
=head1 BUGS
=over 4
=item *
Format 14 (Unicode Variation Sequences) cmaps are not supported.
=back
=head1 AUTHOR
Martin Hosken L<http://scripts.sil.org/FontUtils>.
=head1 LICENSING
Copyright (c) 1998-2014, SIL International (http://www.sil.org)
This module is released under the terms of the Artistic License 2.0.
For details, see the full text of the license in the file LICENSE.
=cut