-package Font::TTF::Head;
-
-=head1 NAME
-
-Font::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 Font::TTF::Table;
-use Font::TTF::Utils;
-
-@ISA = qw(Font::TTF::Table);
-@field_info = (
- 'version' => 'v',
- '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<Font::TTF::Font> for copyright and
-licensing.
-
-=cut
-