PDF::API3::Compat::API2::Basic::TTF::Cmap - Character map table

PDF-API3 documentation Contained in the PDF-API3 distribution.

Index

Code Index:

NAME

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PDF::API3::Compat::API2::Basic::TTF::Cmap - Character map table

DESCRIPTION

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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 $code should be a true value (0x1234) rather than a string representation.

INSTANCE VARIABLES

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The instance variables listed here are not preceeded by a space due to their emulating structural information in the font.

Num

Number of subtables in this table

Tables

An array of subtables ([0..Num-1])

Each subtables also has its own instance variables which are, again, not preceeded by a space.

Platform

The platform number for this subtable

Encoding

The encoding number for this subtable

Format

Gives the stored format of this subtable

Ver

Gives the version (or language) information for this subtable

val

A hash keyed by the codepoint value (not a string) storing the glyph id

METHODS

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$t->read

Reads the cmap into memory. Format 4 subtables read the whole subtable and fill in the segmented array accordingly.

Format 2 subtables are not read at all.

$t->ms_lookup($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.

$t->find_ms

Finds the a Unicode table, giving preference to the Microsoft one, and sets the mstable instance variable to it if found. Returns the table it finds.

$t->ms_enc

Returns the encoding of the microsoft table (0 => symbol, etc.). Returns undef if there is no Microsoft cmap.

$t->out($fh)

Writes out a cmap table to a filehandle. If it has not been read, then just copies from input file to output

$t->XML_element($context, $depth, $name, $val)

Outputs the elements of the cmap in XML. We only need to process val here

@map = $t->reverse([$num])

Returns a reverse map of the table of given number or the Unicode cmap. I.e. given a glyph gives the Unicode value for it.

is_unicode($index)

Returns whether the table of a given index is known to be a unicode table (as specified in the specifications)

BUGS

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AUTHOR

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Martin Hosken Martin_Hosken@sil.org. See PDF::API3::Compat::API2::Basic::TTF::Font for copyright and licensing.

PDF-API3 documentation Contained in the PDF-API3 distribution. 
#=======================================================================
#    ____  ____  _____              _    ____ ___   ____
#   |  _ \|  _ \|  ___|  _   _     / \  |  _ \_ _| |___ \
#   | |_) | | | | |_    (_) (_)   / _ \ | |_) | |    __) |
#   |  __/| |_| |  _|    _   _   / ___ \|  __/| |   / __/
#   |_|   |____/|_|     (_) (_) /_/   \_\_|  |___| |_____|
#
#   A Perl Module Chain to faciliate the Creation and Modification
#   of High-Quality "Portable Document Format (PDF)" Files.
#
#=======================================================================
#
#   THIS IS A REUSED PERL MODULE, FOR PROPER LICENCING TERMS SEE BELOW:
#
#
#   Copyright Martin Hosken <Martin_Hosken@sil.org>
#
#   No warranty or expression of effectiveness, least of all regarding
#   anyone's safety, is implied in this software or documentation.
#
#   This specific module is licensed under the Perl Artistic License.
#
#
#   $Id: Cmap.pm,v 2.1 2007/08/27 20:06:02 areibens Exp $
#
#=======================================================================
package PDF::API3::Compat::API2::Basic::TTF::Cmap;


use strict;
use vars qw(@ISA);
use PDF::API3::Compat::API2::Basic::TTF::Table;
use PDF::API3::Compat::API2::Basic::TTF::Utils;

@ISA = qw(PDF::API3::Compat::API2::Basic::TTF::Table);



sub read
{
    my ($self) = @_;
    my ($dat, $i, $j, $k, $id, @ids, $s);
    my ($start, $end, $range, $delta, $form, $len, $num, $ver, $sg);
    my ($fh) = $self->{' INFILE'};

    $self->SUPER::read or return $self;
    $fh->read($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)
        {
# no idea what to do here yet
        } 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);
                }
            }
        } elsif ($form == 8 || $form == 12)
        {
            $fh->read($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} = $sg++; }
            }
        } elsif ($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;
}



sub ms_lookup
{
    my ($self, $uni) = @_;

    $self->find_ms || return undef unless (defined $self->{' mstable'});
    return $self->{' mstable'}{'val'}{$uni};
}




sub find_ms
{
    my ($self,$iso) = @_;
    my ($i, $s, $alt, $found);
	my %cmap_pref=(
		'3:10' => 100,
		'3:1' => 75,
		'3:0' => 25,
		'2:0' => 50,
		'0:4' => 80,
		'0:3' => 30,
	);
	
    return($self->{' mstable'}) if(defined $self->{' mstable'});

    $self->read unless($self->{' read'});

    $self->{' mstable'} = $self->{Tables}[0];
	$self->{' mstable'}->{Pref}=$cmap_pref{$self->{' mstable'}->{Platform}.':'.$self->{' mstable'}->{Encoding}};
    foreach $i (0..($self->{Num}-1))
    {
        $s = $self->{Tables}[$i];
		$s->{Pref}=$cmap_pref{$s->{Platform}.':'.$s->{Encoding}};
        
        if($s->{Pref} > $self->{' mstable'}->{Pref})
        {
            $self->{' mstable'} = $s;
            $found = 1;
        }
        elsif (($s->{'Platform'} == 3 && ($s->{'Encoding'} == 1 || $s->{'Encoding'} == 0)) 
        	|| $s->{'Platform'} == 0 
        	|| ($s->{'Platform'} == 2 && $s->{'Encoding'} == 1))
        { 
        	$alt = $s; 
        }
    }
    $self->{' mstable'} = $alt unless $found;

    if($iso)
    {
        foreach $i (0..($self->{Num}-1))
        {
            if ($s->{'Platform'} == 0)
            {
                if(!$self->{' mstable'} || $self->{' mstable'}->{'Platform'} != 0)
                {
                    $self->{' mstable'} = $s;
                }
                else
                {
                    $self->{' mstable'} = $s if($s->{'Encoding'} >= $self->{' mstable'}->{'Encoding'});
                }
            }
        }
    }

    return($self->{' mstable'});
}



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;
}



sub out
{
    my ($self, $fh) = @_;
    my ($loc, $s, $i, $base_loc, $j, @keys);

    return $self->SUPER::out($fh) unless $self->{' read'};

    $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];
        @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)
        {
            $fh->print(pack("C256", @{$s->{'val'}}{0 .. 255}));
        } elsif ($s->{'Format'} == 6)
        {
            $fh->print(pack("n2", $keys[0], $keys[-1] - $keys[0] + 1));
            $fh->print(pack("n*", @{$s->{'val'}}{$keys[0] .. $keys[-1]}));
        } elsif ($s->{'Format'} == 2)
        {
        } elsif ($s->{'Format'} == 4)
        {
            my ($num, $sRange, $eSel, $eShift, @starts, @ends, $doff);
            my (@deltas, $delta, @range, $flat, $k, $segs, $count, $newseg, $v);

            push(@keys, 0xFFFF) unless ($keys[-1] == 0xFFFF);
            $newseg = 1; $num = 0;
            for ($j = 0; $j <= $#keys && $keys[$j] <= 0xFFFF; $j++)
            {
                $v = $s->{'val'}{$keys[$j]};
                if ($newseg)
                {
                    $delta = $v;
                    $doff = $j;
                    $flat = 1;
                    push(@starts, $keys[$j]);
                    $newseg = 0;
                }
                $delta = 0 if ($delta + $j - $doff != $v);
                $flat = 0 if ($v == 0);
                if ($j == $#keys || $keys[$j] + 1 != $keys[$j+1])
                {
                    push (@ends, $keys[$j]);
                    push (@deltas, $delta ? $delta - $keys[$doff] : 0);
                    push (@range, $flat);
                    $num++;
                    $newseg = 1;
                }
            }

            ($num, $sRange, $eSel, $eShift) = PDF::API3::Compat::API2::Basic::TTF::Utils::TTF_bininfo($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));

            $count = 0;
            for ($j = 0; $j < $num; $j++)
            {
                $delta = $deltas[$j];
                if ($delta != 0 && $range[$j] == 1)
                { $range[$j] = 0; }
                else
                {
                    $range[$j] = ($count + $num - $j) << 1;
                    $count += $ends[$j] - $starts[$j] + 1;
                }
            }

            $fh->print(pack("n*", @range));

            for ($j = 0; $j < $num; $j++)
            {
                next if ($range[$j] == 0);
                $fh->print(pack("n*", @{$s->{'val'}}{$starts[$j] .. $ends[$j]}));
            }
        } elsif ($s->{'Format'} == 8 || $s->{'Format'} == 12)
        {
            my (@jobs, $start, $current, $curr_glyf, $map);

            $map = "\000" x 8192;
            foreach $j (@keys)
            {
                if ($j > 0xFFFF)
                {
                    if (defined $s->{'val'}{$j >> 16})
                    { $s->{'Format'} = 12; }
                    vec($map, $j >> 16, 1) = 1;
                }
                if ($j != $current + 1 || $s->{'val'}{$j} != $curr_glyf + 1)
                {
                    push (@jobs, [$start, $current, $curr_glyf]) if (defined $start);
                    $start = $j; $current = $j; $curr_glyf = $s->{'val'}{$j};
                }
            }
            $fh->print($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;
}



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;
}


sub reverse
{
    my ($self, $tnum) = @_;
    my ($table) = defined $tnum ? $self->{'Tables'}[$tnum] : $self->find_ms;
    my (@res, $code, $gid);

    while (($code, $gid) = each(%{$table->{'val'}}))
    { $res[$gid] = $code unless (defined $res[$gid] && $res[$gid] > 0 && $res[$gid] < $code); }
    @res;
}



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;