#======================================================================= # ____ ____ _____ _ ____ ___ ____ # | _ \| _ \| ___| _ _ / \ | _ \_ _| |___ \ # | |_) | | | | |_ (_) (_) / _ \ | |_) | | __) | # | __/| |_| | _| _ _ / ___ \| __/| | / __/ # |_| |____/|_| (_) (_) /_/ \_\_| |___| |_____| # # 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: Hmtx.pm,v 1.5 2004/06/15 09:13:37 fredo Exp $ # #======================================================================= package PDF::API2::Basic::TTF::Hmtx; =head1 NAME PDF::API2::Basic::TTF::Hmtx - Horizontal Metrics =head1 DESCRIPTION Contains the advance width and left side bearing for each glyph. Given the compressability of the data onto disk, this table uses information from other tables, and thus must do part of its output during the output of other tables =head1 INSTANCE VARIABLES The horizontal metrics are kept in two arrays by glyph id. The variable names do not start with a space =over 4 =item advance An array containing the advance width for each glyph =item lsb An array containing the left side bearing for each glyph =back =head1 METHODS =cut use strict; use vars qw(@ISA); require PDF::API2::Basic::TTF::Table; @ISA = qw(PDF::API2::Basic::TTF::Table); =head2 $t->read Reads the horizontal metrics from the TTF file into memory =cut sub read { my ($self) = @_; my ($numh, $numg); $numh = $self->{' PARENT'}{'hhea'}->read->{'numberOfHMetrics'}; $numg = $self->{' PARENT'}{'maxp'}->read->{'numGlyphs'}; $self->_read($numg, $numh, "advance", "lsb"); } sub _read { my ($self, $numg, $numh, $tAdv, $tLsb) = @_; my ($fh) = $self->{' INFILE'}; my ($i, $dat); $self->SUPER::read or return $self; for ($i = 0; $i < $numh; $i++) { $fh->read($dat, 4); ($self->{$tAdv}[$i], $self->{$tLsb}[$i]) = unpack("nn", $dat); $self->{$tLsb}[$i] -= 65536 if ($self->{$tLsb}[$i] >= 32768); } $i--; while ($i++ < $numg) { $fh->read($dat, 2); $self->{$tAdv}[$i] = $self->{$tAdv}[$numh - 1]; $self->{$tLsb}[$i] = unpack("n", $dat); $self->{$tLsb}[$i] -= 65536 if ($self->{$tLsb}[$i] >= 32768); } $self; } =head2 $t->numMetrics Calculates again the number of long metrics required to store the information here. Returns undef if the table has not been read. =cut sub numMetrics { my ($self) = @_; my ($numg) = $self->{' PARENT'}{'maxp'}{'numGlyphs'}; my ($i); return undef unless $self->{' read'}; for ($i = $numg - 2; $i >= 0; $i--) { last if ($self->{'advance'}[$i] != $self->{'advance'}[$i + 1]); } return $i + 2; } =head2 $t->out($fh) Writes the metrics to a TTF file. Assumes that the C<hhea> has updated the numHMetrics from here =cut sub out { my ($self, $fh) = @_; my ($numg) = $self->{' PARENT'}{'maxp'}{'numGlyphs'}; my ($numh) = $self->{' PARENT'}{'hhea'}->read->{'numberOfHMetrics'}; $self->_out($fh, $numg, $numh, "advance", "lsb"); } sub _out { my ($self, $fh, $numg, $numh, $tAdv, $tLsb) = @_; my ($i, $lsb); return $self->SUPER::out($fh) unless ($self->{' read'}); for ($i = 0; $i < $numg; $i++) { $lsb = $self->{$tLsb}[$i]; $lsb += 65536 if $lsb < 0; if ($i >= $numh) { $fh->print(pack("n", $lsb)); } else { $fh->print(pack("n2", $self->{$tAdv}[$i], $lsb)); } } $self; } =head2 $t->update Updates the lsb values from the xMin from the each glyph =cut sub update { my ($self) = @_; my ($numg) = $self->{' PARENT'}{'maxp'}{'numGlyphs'}; my ($i); return undef unless ($self->SUPER::update); # lsb & xMin must always be the same, regardless of any flags! # return $self unless ($self->{' PARENT'}{'head'}{'flags'} & 2); # lsb & xMin the same $self->{' PARENT'}{'loca'}->update; for ($i = 0; $i < $numg; $i++) { my ($g) = $self->{' PARENT'}{'loca'}{'glyphs'}[$i]; if ($g) { $self->{'lsb'}[$i] = $g->read->update_bbox->{'xMin'}; } else { $self->{'lsb'}[$i] = 0; } } $self->{' PARENT'}{'head'}{'flags'} |= 2; $self; } =head2 $t->out_xml($context, $depth) Outputs the table in XML =cut sub out_xml { my ($self, $context, $depth) = @_; my ($fh) = $context->{'fh'}; my ($numg) = $self->{' PARENT'}{'maxp'}{'numGlyphs'}; my ($addr) = ($self =~ m/\((.+)\)$/o); my ($i); if ($context->{'addresses'}{$addr}) { $fh->printf("%s<%s id_ref='%s'/>\n", $depth, $context->{'name'}, $addr); return $self; } else { $fh->printf("%s<%s id='%s'>\n", $depth, $context->{'name'}, $addr); } $self->read; for ($i = 0; $i < $numg; $i++) { $fh->print("$depth$context->{'indent'}<width adv='$self->{'advance'}[$i]' lsb='$self->{'lsb'}[$i]'/>\n"); } $fh->print("$depth</$context->{'name'}>\n"); $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