+++ /dev/null
-package Font::TTF::GSUB;
-
-=head1 NAME
-
-Font::TTF::GSUB - Module support for the GSUB table in conjunction with TTOpen
-
-=head1 DESCRIPTION
-
-Handles the GSUB subtables in relation to Ttopen tables. Due to the variety of
-different lookup types, the data structures are not all that straightforward,
-although I have tried to make life easy for myself when using this!
-
-=head1 INSTANCE VARIABLES
-
-The structure of a GSUB table is the same as that given in L<Font::TTF::Ttopen>.
-Here we give some of the semantics specific to GSUB lookups.
-
-=over 4
-
-=item ACTION_TYPE
-
-This is a string taking one of 4 values indicating the nature of the information
-in the ACTION array of the rule:
-
-=over 8
-
-=item g
-
-The action contains a string of glyphs to replace the match string by
-
-=item l
-
-The action array contains a list of lookups and offsets to run, in order, on
-the matched string
-
-=item a
-
-The action array is an unordered set of optional replacements for the matched
-glyph. The application should make the selection somehow.
-
-=item o
-
-The action array is empty (in fact there is no rule array for this type of
-rule) and the ADJUST value should be added to the glyph id to find the replacement
-glyph id value
-
-=back
-
-=item MATCH_TYPE
-
-This indicates which type of information the various MATCH arrays (MATCH, PRE,
-POST) hold in the rule:
-
-=over 8
-
-=item g
-
-The array holds a string of glyph ids which should match exactly
-
-=item c
-
-The array holds a sequence of class definitions which each glyph should
-correspondingly match to
-
-=item o
-
-The array holds offsets to coverage tables
-
-=back
-
-=back
-
-=head1 CORRESPONDANCE TO LAYOUT TYPES
-
-The following table gives the values for ACTION_TYPE and MATCH_TYPE for each
-of the 11 different lookup types found in the GSUB table definition I have:
-
- 1.1 1.2 2 3 4 5.1 5.2 5.3 6.1 6.2 6.3
- ACTION_TYPE o g g a g l l l l l l
- MATCH_TYPE g g c o g c o
-
-Hopefully, the rest of the uses of the variables should make sense from this
-table.
-
-=head1 METHODS
-
-=cut
-
-use strict;
-use vars qw(@ISA);
-use Font::TTF::Utils;
-use Font::TTF::Ttopen;
-
-@ISA = qw(Font::TTF::Ttopen);
-
-=head2 $t->read_sub($fh, $lookup, $index)
-
-Asked by the superclass to read in from the given file the indexth subtable from
-lookup number lookup. The file is positioned ready for the read.
-
-=cut
-
-sub read_sub
-{
- my ($self, $fh, $main_lookup, $sindex) = @_;
- my ($type) = $main_lookup->{'TYPE'};
- my ($loc) = $fh->tell();
- my ($lookup) = $main_lookup->{'SUB'}[$sindex];
- my ($dat, $s, @subst, $t, $fmt, $cover, $count, $mcount, $scount, $i, $gid);
- my (@srec);
-
- if ($type == 6)
- {
- $fh->read($dat, 4);
- ($fmt, $cover) = TTF_Unpack('S2', $dat);
- if ($fmt < 3)
- {
- $fh->read($dat, 2);
- $count = TTF_Unpack('S', $dat);
- }
- } else
- {
- $fh->read($dat, 6);
- ($fmt, $cover, $count) = TTF_Unpack("S3", $dat);
- }
- unless ($fmt == 3 && ($type == 5 || $type == 6))
- { $lookup->{'COVERAGE'} = $self->read_cover($cover, $loc, $lookup, $fh, 1); }
-
- $lookup->{'FORMAT'} = $fmt;
- if ($type == 1 && $fmt == 1)
- {
- $count -= 65536 if ($count > 32767);
- $lookup->{'ADJUST'} = $count;
- $lookup->{'ACTION_TYPE'} = 'o';
- } elsif ($type == 1 && $fmt == 2)
- {
- $fh->read($dat, $count << 1);
- @subst = TTF_Unpack('S*', $dat);
- foreach $s (@subst)
- { push(@{$lookup->{'RULES'}}, [{'ACTION' => [$s]}]); }
- $lookup->{'ACTION_TYPE'} = 'g';
- } elsif ($type == 2 || $type == 3)
- {
- $fh->read($dat, $count << 1); # number of offsets
- foreach $s (TTF_Unpack('S*', $dat))
- {
- $fh->seek($loc + $s, 0);
- $fh->read($dat, 2);
- $t = TTF_Unpack('S', $dat);
- $fh->read($dat, $t << 1);
- push(@{$lookup->{'RULES'}}, [{'ACTION' => [TTF_Unpack('S*', $dat)]}]);
- }
- $lookup->{'ACTION_TYPE'} = ($type == 2 ? 'g' : 'a');
- } elsif ($type == 4)
- {
- $fh->read($dat, $count << 1);
- foreach $s (TTF_Unpack('S*', $dat))
- {
- @subst = ();
- $fh->seek($loc + $s, 0);
- $fh->read($dat, 2);
- $t = TTF_Unpack('S', $dat);
- $fh->read($dat, $t << 1);
- foreach $t (TTF_Unpack('S*', $dat))
- {
- $fh->seek($loc + $s + $t, 0);
- $fh->read($dat, 4);
- ($gid, $mcount) = TTF_Unpack('S2', $dat);
- $fh->read($dat, ($mcount - 1) << 1);
- push(@subst, {'ACTION' => [$gid], 'MATCH' => [TTF_Unpack('S*', $dat)]});
- }
- push(@{$lookup->{'RULES'}}, [@subst]);
- }
- $lookup->{'ACTION_TYPE'} = 'g';
- $lookup->{'MATCH_TYPE'} = 'g';
- } elsif ($type == 5 || $type == 6)
- { $self->read_context($lookup, $fh, $type, $fmt, $cover, $count, $loc); }
- $lookup;
-}
-
-
-=head2 $t->extension
-
-Returns the table type number for the extension table
-
-=cut
-
-sub extension
-{ return 7; }
-
-
-=head2 $t->out_sub($fh, $lookup, $index)
-
-Passed the filehandle to output to, suitably positioned, the lookup and subtable
-index, this function outputs the subtable to $fh at that point.
-
-=cut
-
-sub out_sub
-{
- my ($self, $fh, $main_lookup, $index, $ctables, $base) = @_;
- my ($type) = $main_lookup->{'TYPE'};
- my ($lookup) = $main_lookup->{'SUB'}[$index];
- my ($fmt) = $lookup->{'FORMAT'};
- my ($out, $r, $t, $i, $j, $offc, $offd, $numd);
- my ($num) = $#{$lookup->{'RULES'}} + 1;
-
- if ($type == 1)
- {
- $out = pack("nn", $fmt, Font::TTF::Ttopen::ref_cache($lookup->{'COVERAGE'}, $ctables, 2 + $base));
- if ($fmt == 1)
- { $out .= pack("n", $lookup->{'ADJUST'}); }
- else
- {
- $out .= pack("n", $num);
- foreach $r (@{$lookup->{'RULES'}})
- { $out .= pack("n", $r->[0]{'ACTION'}[0]); }
- }
- } elsif ($type == 2 || $type == 3)
- {
- $out = pack("nnn", $fmt, Font::TTF::Ttopen::ref_cache($lookup->{'COVERAGE'}, $ctables, 2 + $base),
- $num);
- $out .= pack('n*', (0) x $num);
- $offc = length($out);
- for ($i = 0; $i < $num; $i++)
- {
- $out .= pack("n*", $#{$lookup->{'RULES'}[$i][0]{'ACTION'}} + 1,
- @{$lookup->{'RULES'}[$i][0]{'ACTION'}});
- substr($out, ($i << 1) + 6, 2) = pack('n', $offc);
- $offc = length($out);
- }
- } elsif ($type == 4 || $type == 5 || $type == 6)
- { $out = $self->out_context($lookup, $fh, $type, $fmt, $ctables, $out, $num, $base); }
-# Font::TTF::Ttopen::out_final($fh, $out, [[$ctables, 0]]);
- $out;
-}
-
-=head1 AUTHOR
-
-Martin Hosken Martin_Hosken@sil.org. See L<Font::TTF::Font> for copyright and
-licensing.
-
-=cut
-
-1;
-
fnp / librarian.git / blobdiff