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

This module is deprecated

DESCRIPTION

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Looks after the character map. The primary structure used for handling a cmap is the PDF::API3::Compat::API2::Basic::TTF::Segarr which handles the segmented arrays of format 4 tables, and in a simpler form for format 0 tables.

Due to the complexity of working with segmented arrays, most of the handling of such arrays is via methods rather than via instance variables.

One important feature of a format 4 table is that it always contains a segment with a final address of 0xFFFF. If you are creating a table from scratch this is important (although PDF::API3::Compat::API2::Basic::TTF::Segarr can work quite happily without it).

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

This points to a PDF::API3::Compat::API2::Basic::TTF::Segarr which contains the content of the particular subtable.

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)

Given a Unicode value in the MS table (Platform 3, Encoding 1) locates that table and looks up the appropriate glyph number from it.

$t->find_ms

Finds the Microsoft Unicode table and sets the mstable instance variable to it if found. Returns the table it finds.

$t->out($fh)

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

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

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

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: OldCmap.pm,v 2.0 2005/11/16 02:16:00 areibens Exp $
#
#=======================================================================
package PDF::API3::Compat::API2::Basic::TTF::OldCmap;


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

@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, $ver);
    my ($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, 6);
        ($form, $len, $ver) = (unpack("n3", $dat));

        $s->{'Format'} = $form;
        $s->{'Ver'} = $ver;
        if ($form == 0)
        {
            $s->{'val'} = PDF::API3::Compat::API2::Basic::TTF::Segarr->new;
            $fh->read($dat, 256);
            $s->{'val'}->fastadd_segment(0, 2, unpack("C*", $dat));
            $s->{'Start'} = 0;
            $s->{'Num'} = 256;
        } elsif ($form == 6)
        {
            my ($start, $ecount);

            $fh->read($dat, 4);
            ($start, $ecount) = unpack("n2", $dat);
            $fh->read($dat, $ecount << 1);
            $s->{'val'} = PDF::API3::Compat::API2::Basic::TTF::Segarr->new;
            $s->{'val'}->fastadd_segment($start, 2, unpack("n*", $dat));
            $s->{'Start'} = $start;
            $s->{'Num'} = $ecount;
        } elsif ($form == 2)
        {
# no idea what to do here yet
        } elsif ($form == 4)
        {
            $fh->read($dat, 8);
            $num = unpack("n", $dat);
            $num >>= 1;
            $fh->read($dat, $len - 14);
            $s->{'val'} = PDF::API3::Compat::API2::Basic::TTF::Segarr->new;
            for ($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) + $num * 6 + 2, 2));
                @ids = ();
                for ($k = $start; $k <= $end; $k++)
                {
                    if ($range == 0)
                    { $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;
                    push (@ids, $id);
                }
                $s->{'val'}->fastadd_segment($start, 0, @ids);
            }
            $s->{'val'}->tidy;
            $s->{'Num'} = 0x10000;               # always ends here
            $s->{'Start'} = $s->{'val'}[0]{'START'};
        }
    }
    $self;
}



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

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



sub find_ms
{
    my ($self) = @_;
    my ($i, $s, $alt);

    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'} = $s;
            last if ($s->{'Encoding'} == 1);
        } elsif ($s->{'Platform'} == 0 || ($s->{'Platform'} == 2 && $s->{'Encoding'} == 1))
        { $self->{' mstable'} = $s; }
    }
    $self->{' mstable'};
}



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

    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];
        $s->{'val'}->tidy;
        $s->{' outloc'} = $fh->tell();
        $fh->print(pack("n3", $s->{'Format'}, 0, $s->{'Ver'}));       # come back for length
        if ($s->{'Format'} == 0)
        {
            $fh->print(pack("C256", $s->{'val'}->at(0, 256)));
        } elsif ($s->{'Format'} == 6)
        {
            $fh->print(pack("n2", $s->{'Start'}, $s->{'Num'}));
            $fh->print(pack("n*", $s->{'val'}->at($s->{'Start'}, $s->{'Num'})));
        } elsif ($s->{'Format'} == 2)
        {
        } elsif ($s->{'Format'} == 4)
        {
            my ($num, $sRange, $eSel);
            my (@deltas, $delta, @range, $flat, $k, $segs, $count);

            $num = $#{$s->{'val'}} + 1;
            $segs = $s->{'val'};
            for ($sRange = 1, $eSel = 0; $sRange <= $num; $eSel++)
            { $sRange <<= 1;}
            $eSel--;
            $fh->print(pack("n4", $num * 2, $sRange, $eSel, ($num * 2) - $sRange));
            $fh->print(pack("n*", map {$_->{'START'} + $_->{'LEN'} - 1} @$segs));
            $fh->print(pack("n", 0));
            $fh->print(pack("n*", map {$_->{'START'}} @$segs));

            for ($j = 0; $j < $num; $j++)
            {
                $delta = $segs->[$j]{'VAL'}[0]; $flat = 1;
                for ($k = 1; $k < $segs->[$j]{'LEN'}; $k++)
                {
                    if ($segs->[$j]{'VAL'}[$k] == 0)
                    { $flat = 0; }
                    if ($delta + $k != $segs->[$j]{'VAL'}[$k])
                    {
                        $delta = 0;
                        last;
                    }
                }
                push (@range, $flat);
                push (@deltas, ($delta ? $delta - $segs->[$j]{'START'} : 0));
            }
            $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 += $segs->[$j]{'LEN'};
                }
            }

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

            for ($j = 0; $j < $num; $j++)
            {
                next if ($range[$j] == 0);
                for ($k = 0; $k < $segs->[$j]{'LEN'}; $k++)
                { $fh->print(pack("n", $segs->[$j]{'VAL'}[$k])); }
            }
        }

        $loc = $fh->tell();
        $fh->seek($s->{' outloc'} + 2, 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 reverse
{
    my ($self, $tnum) = @_;
    my ($table) = defined $tnum ? $self->{'Tables'}[$tnum] : $self->find_ms;
    my (@res, $i, $s, $first);

    foreach $s (@{$table->{'val'}})
    {
        $first = $s->{'START'};
        map {$res[$_] = $first unless $res[$_]; $first++;} @{$s->{'VAL'}};
    }
    @res;
}

1;