--- /dev/null
+package Font::TTF::Hmtx;
+
+=head1 NAME
+
+Font::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 Font::TTF::Table;
+
+@ISA = qw(Font::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'}{'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<Font::TTF::Font> for copyright and
+licensing.
+
+=cut
+
fnp / librarian.git / blobdiff