#=======================================================================
# ____ ____ _____ _ ____ ___ ____
# | _ \| _ \| ___| _ _ / \ | _ \_ _| |___ \
# | |_) | | | | |_ (_) (_) / _ \ | |_) | | __) |
# | __/| |_| | _| _ _ / ___ \| __/| | / __/
# |_| |____/|_| (_) (_) /_/ \_\_| |___| |_____|
#
# 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: Head.pm,v 2.0 2005/11/16 02:16:00 areibens Exp $
#
#=======================================================================
package PDF::API2::Basic::TTF::Head;
=head1 NAME
PDF::API2::Basic::TTF::Head - The head table for a TTF Font
=head1 DESCRIPTION
This is a very basic table with just instance variables as described in the
TTF documentation, using the same names. One of the most commonly used is
C<unitsPerEm>.
=head1 INSTANCE VARIABLES
The C<head> table has no internal instance variables beyond those common to all
tables and those specified in the standard:
version
fontRevision
checkSumAdjustment
magicNumber
flags
unitsPerEm
created
modified
xMin
yMin
xMax
yMax
macStyle
lowestRecPPEM
fontDirectionHint
indexToLocFormat
glyphDataFormat
The two dates are held as an array of two unsigned longs (32-bits)
=head1 METHODS
=cut
use strict;
use vars qw(@ISA %fields @field_info);
require PDF::API2::Basic::TTF::Table;
use PDF::API2::Basic::TTF::Utils;
@ISA = qw(PDF::API2::Basic::TTF::Table);
@field_info = (
'version' => 'f',
'fontRevision' => 'f',
'checkSumAdjustment' => 'L',
'magicNumber' => 'L',
'flags' => 'S',
'unitsPerEm' => 'S',
'created' => 'L2',
'modified' => 'L2',
'xMin' => 's',
'yMin' => 's',
'xMax' => 's',
'yMax' => 's',
'macStyle' => 'S',
'lowestRecPPEM' => 'S',
'fontDirectionHint' => 's',
'indexToLocFormat' => 's',
'glyphDataFormat' => 's');
sub init
{
my ($k, $v, $c, $i);
for ($i = 0; $i < $#field_info; $i += 2)
{
($k, $v, $c) = TTF_Init_Fields($field_info[$i], $c, $field_info[$i + 1]);
next unless defined $k && $k ne "";
$fields{$k} = $v;
}
}
=head2 $t->read
Reads the table into memory thanks to some utility functions
=cut
sub read
{
my ($self) = @_;
my ($dat);
$self->SUPER::read || return $self;
init unless defined $fields{'Ascender'};
$self->{' INFILE'}->read($dat, 54);
TTF_Read_Fields($self, $dat, \%fields);
$self;
}
=head2 $t->out($fh)
Writes the table to a file either from memory or by copying. If in memory
(which is usually) the checkSumAdjustment field is set to 0 as per the default
if the file checksum is not to be considered.
=cut
sub out
{
my ($self, $fh) = @_;
return $self->SUPER::out($fh) unless $self->{' read'}; # this is never true
# $self->{'checkSumAdjustment'} = 0 unless $self->{' PARENT'}{' wantsig'};
$fh->print(TTF_Out_Fields($self, \%fields, 54));
$self;
}
=head2 $t->XML_element($context, $depth, $key, $value)
Handles date process for the XML exporter
=cut
sub XML_element
{
my ($self) = shift;
my ($context, $depth, $key, $value) = @_;
my ($fh) = $context->{'fh'};
my ($output, @time);
my (@month) = qw(JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC);
return $self->SUPER::XML_element(@_) unless ($key eq 'created' || $key eq 'modified');
@time = gmtime($self->getdate($key eq 'created'));
$output = sprintf("%d/%s/%d %d:%d:%d", $time[3], $month[$time[4]], $time[5] + 1900,
$time[2], $time[1], $time[0]);
$fh->print("$depth<$key>$output</$key>\n");
$self;
}
=head2 $t->update
Updates the head table based on the glyph data and the hmtx table
=cut
sub update
{
my ($self) = @_;
my ($num, $i, $loc, $hmtx);
my ($xMin, $yMin, $xMax, $yMax, $lsbx);
return undef unless ($self->SUPER::update);
$num = $self->{' PARENT'}{'maxp'}{'numGlyphs'};
return undef unless (defined $self->{' PARENT'}{'hmtx'} && defined $self->{' PARENT'}{'loca'});
$hmtx = $self->{' PARENT'}{'hmtx'}->read;
$self->{' PARENT'}{'loca'}->update;
$hmtx->update; # if we updated, then the flags will be set anyway.
$lsbx = 1;
for ($i = 0; $i < $num; $i++)
{
$loc = $self->{' PARENT'}{'loca'}{'glyphs'}[$i];
next unless defined $loc;
$loc->read->update_bbox;
$xMin = $loc->{'xMin'} if ($loc->{'xMin'} < $xMin || $i == 0);
$yMin = $loc->{'yMin'} if ($loc->{'yMin'} < $yMin || $i == 0);
$xMax = $loc->{'xMax'} if ($loc->{'xMax'} > $xMax);
$yMax = $loc->{'yMax'} if ($loc->{'yMax'} > $yMax);
$lsbx &= ($loc->{'xMin'} == $hmtx->{'lsb'}[$i]);
}
$self->{'xMin'} = $xMin;
$self->{'yMin'} = $yMin;
$self->{'xMax'} = $xMax;
$self->{'yMax'} = $yMax;
if ($lsbx)
{ $self->{'flags'} |= 2; }
else
{ $self->{'flags'} &= ~2; }
$self;
}
=head2 $t->getdate($is_create)
Converts font modification time (or creation time if $is_create is set) to a 32-bit integer as returned
from time(). Returns undef if the value is out of range, either before the epoch or after the maximum
storable time.
=cut
sub getdate
{
my ($self, $is_create) = @_;
my ($arr) = $self->{$is_create ? 'created' : 'modified'};
$arr->[1] -= 2082844800; # seconds between 1/Jan/1904 and 1/Jan/1970 (midnight)
if ($arr->[1] < 0)
{
$arr->[1] += 0xFFFFFFF; $arr->[1]++;
$arr->[0]--;
}
return undef if $arr->[0] != 0;
return $arr->[1];
}
=head2 $t->setdate($time, $is_create)
Sets the time information for modification (or creation time if $is_create is set) according to the 32-bit
time information.
=cut
sub setdate
{
my ($self, $time, $is_create) = @_;
my (@arr);
$arr[1] = $time;
if ($arr[1] >= 0x83DA4F80)
{
$arr[1] -= 0xFFFFFFFF;
$arr[1]--;
$arr[0]++;
}
$arr[1] += 2082844800;
$self->{$is_create ? 'created' : 'modified'} = \@arr;
$self;
}
1;
=head1 BUGS
None known
=head1 AUTHOR
Martin Hosken Martin_Hosken@sil.org. See L<PDF::API2::Basic::TTF::Font> for copyright and
licensing.
=cut