package Font::TTF::Sill;

=head1 NAME

Font::TTF::Sill - Graphite language mapping table

=head1 DESCRIPTION

=head1 INSTANCE VARIABLES

=over 4

=item version

Table version number.

=item langs

Contains a hash where the key is the language id and the value is an array of
language records

=back

=head2 Language Records

Each language record is itself an array of two values [fid, val]. fid is the
feature id and is held as a long.

=cut

use Font::TTF::Utils;
require Font::TTF::Table;

@ISA = qw(Font::TTF::Table);

sub read
{
    my ($self) = @_;
    my ($num, $i, $j);

    return $self if ($self->{' read'});
    $self->SUPER::read_dat or return $self;

    ($self->{'version'}, $num) = TTF_Unpack("vS", $self->{' dat'});

    foreach $i (1 .. $num)        # ignore bogus entry at end
    {
        my ($lid, $numf, $offset) = unpack("A4nn", substr($self->{' dat'}, $i * 8 + 4));      # 12 - 8 = 4 since i starts at 1. A4 strips nulls
        my (@settings);

        foreach $j (1 .. $numf)
        {
            my ($fid, $val) = TTF_Unpack("Ls", substr($self->{' dat'}, $offset + $j * 8 - 8));
            push (@settings, [$fid, $val]);
        }
        $self->{'langs'}{$lid} = [@settings];
    }
    delete $self->{' dat'};
    $self->{' read'} = 1;
    $self;
}

sub out
{
    my ($self, $fh) = @_;
    my ($num, $range, $select, $shift) = TTF_bininfo(scalar keys %{$self->{'langs'}}, 1);
    my ($offset) = $num * 8 + 20;   #header = 12, dummy = 8
    my ($k, $s);

    return $self->SUPER::out($fh) unless ($self->{' read'});
    $fh->print(TTF_Pack("vSSSS", $self->{'version'}, $num, $range, $select, $shift));
    foreach $k (sort (keys %{$self->{'langs'}}), '+1')
    {
        my ($numf) = scalar @{$self->{'langs'}{$k}} unless ($k eq '+1');
        $fh->print(pack("a4nn", $k, $numf, $offset));
        $offset += $numf * 8;
    }

    foreach $k (sort keys %{$self->{'langs'}})
    {
        foreach $s (@{$self->{'langs'}{$k}})
        { $fh->print(TTF_Pack("LsS", @{$s}, 0)); }
    }
    $self;
}

sub XML_element
{
    my ($self) = shift;
    my ($context, $depth, $key, $dat) = @_;
    my ($fh) = $context->{'fh'};
    my ($k, $s);

    return $self->SUPER::XML_element(@_) unless ($key eq 'langs');
    foreach $k (sort keys %{$self->{'langs'}})
    {
        $fh->printf("%s<lang id='%s'>\n", $depth, $k);
        foreach $s (@{$self->{'langs'}{$k}})
        {
            my ($fid) = $s->[0];
            if ($fid > 0x00FFFFFF)
            { $fid = unpack("A4", pack ("N", $fid)); }
            else
            { $fid = sprintf("%d", $fid); }
            $fh->printf("%s%s<feature id='%s' value='%d'/>\n",
                $depth, $context->{'indent'}, $fid, $s->[1]);
        }
        $fh->printf("%s</lang>\n", $depth);
    }
    $self;
}

=head2 $t->minsize()

Returns the minimum size this table can be. If it is smaller than this, then the table
must be bad and should be deleted or whatever.

=cut

sub minsize
{
    return 6;
}

1;

=head1 AUTHOR

Martin Hosken L<Martin_Hosken@sil.org>



=head1 LICENSING

Copyright (c) 1998-2013, 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.

The test suite contains test fonts released under the SIL Open Font License 1.1, see OFL.txt.

=cut