Introduce src dir.

[librarian.git] / src / librarian / font-optimizer / ext / Font-TTF / lib / Font / TTF / Dumper.pm

diff --git a/src/librarian/font-optimizer/ext/Font-TTF/lib/Font/TTF/Dumper.pm b/src/librarian/font-optimizer/ext/Font-TTF/lib/Font/TTF/Dumper.pm
new file mode 100644 (file)
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--- /dev/null
+++ b/src/librarian/font-optimizer/ext/Font-TTF/lib/Font/TTF/Dumper.pm
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+package Font::TTF::Dumper;
+
+=head1 NAME
+
+Font::TTF::Dumper - Debug dump of a font datastructure, avoiding recursion on ' PARENT'
+
+=head1 SYNOPSIS
+
+    Font::TTF::Dumper;
+    
+    # Print a table from the font structure:
+    print ttfdump($font->{$tag});
+    
+    # Print font table with name
+    print ttfdump($font->{'head'}, 'head');
+    
+    # Print one glyph's data:
+    print ttfdump($font->{'loca'}->read->{'glyphs'}[$gid], "glyph_$gid");
+
+=head1 DESCRIPTION
+
+Font::TTF data structures are trees created from hashes and arrays. When trying to figure
+out how the structures work, sometimes it is helpful to use Data::Dumper on them. However,
+many of the object structures have ' PARENT' links that refer back to the object's parent,
+which means that Data::Dumper ends up dumping the whole font no matter what.
+
+The purpose of this module is to do just one thing: invoke Data::Dumper with a
+filter that skips over the ' PARENT' element of any hash.
+
+To reduce output further, this module also skips over ' CACHE' elements and any 
+hash element whose value is a Font::TTF::Glyph or Font::TTF::Font object. 
+(Really should make this configurable.)
+
+=cut
+
+use strict;
+use Data::Dumper;
+
+use vars qw(@EXPORT @ISA);
+require Exporter;
+@ISA = qw( Exporter );
+@EXPORT = qw( ttfdump );
+
+my %skip = ( Font => 1, Glyph => 1 );
+
+sub ttfdump
+{
+    my ($var, $name) = @_;
+    my $res;
+    
+    my $d = Data::Dumper->new([$var]);
+    $d->Names([$name]) if defined $name;
+    $d->Sortkeys(\&myfilter);   # This is the trick to keep from dumping the whole font
+    $d->Indent(3);  # I want array indicies
+    $d->Useqq(1);   # Perlquote -- slower but there might be binary data.
+    $res = $d->Dump;
+    $d->DESTROY;
+    $res;
+}
+
+sub myfilter
+{
+    my ($hash) = @_;
+    my @a = grep {
+            ($_ eq ' PARENT' || $_ eq ' CACHE') ? 0 :
+            ref($hash->{$_}) =~ m/^Font::TTF::(.*)$/ ? !$skip{$1} :
+            1
+        } (keys %{$hash}) ;
+    # Sort numerically if that is reasonable:
+    return [ sort {$a =~ /\D/ || $b =~ /\D/ ? $a cmp $b : $a <=> $b} @a ];
+}
+
+1;
+
+=head1 See also
+
+L<Font::TTF::Font>
+
+=cut