librarian/font-optimizer/ext/Font-TTF/lib/Font/TTF/GrFeat.pm

   1 package Font::TTF::GrFeat;
   2
   3 =head1 NAME
   4
   5 Font::TTF::GrFeat - Graphite Font Features
   6
   7 =head1 DESCRIPTION
   8
   9 =head1 INSTANCE VARIABLES
  10
  11 =over 4
  12
  13 =item version
  14
  15 =item features
  16
  17 An array of hashes of the following form
  18
  19 =over 8
  20
  21 =item feature
  22
  23 feature id number
  24
  25 =item name
  26
  27 name index in name table
  28
  29 =item exclusive
  30
  31 exclusive flag
  32
  33 =item default
  34
  35 the default setting number
  36
  37 =item settings
  38
  39 hash of setting number against name string index
  40
  41 =back
  42
  43 =back
  44
  45 =head1 METHODS
  46
  47 =cut
  48
  49 use strict;
  50 use vars qw(@ISA);
  51
  52 use Font::TTF::Utils;
  53
  54 require Font::TTF::Table;
  55
  56 @ISA = qw(Font::TTF::Table);
  57
  58 =head2 $t->read
  59
  60 Reads the features from the TTF file into memory
  61
  62 =cut
  63
  64 sub read
  65 {
  66         my ($self) = @_;
  67         my ($featureCount, $features);
  68
  69         return $self if $self->{' read'};
  70         $self->SUPER::read_dat or return $self;
  71
  72         ($self->{'version'}, $featureCount) = TTF_Unpack("vS", $self->{' dat'});
  73
  74         $features = [];
  75         foreach (1 .. $featureCount) {
  76                 my ($feature, $nSettings, $settingTable, $featureFlags, $nameIndex, $reserved);
  77                 if ($self->{'version'} == 1)
  78                 {
  79                         ($feature, $nSettings, $settingTable, $featureFlags, $nameIndex)
  80                                 = TTF_Unpack("SSLSS", substr($self->{' dat'}, $_ * 12, 12));
  81                         #The version 1 Feat table ends with a feature (id 1) named NoName
  82                         #with zero settings but with an offset to the last entry in the setting
  83                         #array. This last setting has id 0 and an invalid name id. This last
  84                         #feature is changed to have one setting.
  85                         if ($_ == $featureCount && $nSettings == 0) {$nSettings = 1;}
  86                 }
  87                 else #version == 2
  88                         {($feature, $nSettings, $reserved, $settingTable, $featureFlags, $nameIndex)
  89                                 = TTF_Unpack("LSSLSS", substr($self->{' dat'}, 12 + ($_ - 1) * 16, 16))};
  90                 my $feature =
  91                         {
  92                                 'feature'       => $feature,
  93                                 'name'          => $nameIndex,
  94                         };
  95
  96                 #interpret the featureFlags & store settings
  97                 $feature->{'exclusive'} = (($featureFlags & 0x8000) != 0);
  98
  99                 my @settings = TTF_Unpack("S*", substr($self->{' dat'}, $settingTable, $nSettings * 4));
 100                 if ($featureFlags & 0x4000)
 101                         {$feature->{'default'} = $featureFlags & 0x00FF;}
 102                 else
 103                         {$feature->{'default'} = @settings[0];}
 104                 $feature->{'settings'} = {@settings};
 105
 106                 push(@$features, $feature);
 107         }
 108
 109         $self->{'features'} = $features;
 110
 111         delete $self->{' dat'}; # no longer needed, and may become obsolete
 112         $self->{' read'} = 1;
 113         $self;
 114 }
 115
 116 =head2 $t->out($fh)
 117
 118 Writes the features to a TTF file
 119
 120 =cut
 121
 122 sub out
 123 {
 124         my ($self, $fh) = @_;
 125         my ($features, $numFeatures, $settings, $featureFlags, $featuresData, $settingsData);
 126
 127         return $self->SUPER::out($fh) unless $self->{' read'};
 128
 129         $features = $self->{'features'};
 130         $numFeatures = @$features;
 131         $featuresData, $settingsData = ('', '');
 132
 133         foreach (@$features) {
 134                 $settings = $_->{'settings'};
 135                 $featureFlags = ($_->{'exclusive'} ? 0x8000 : 0x0000);
 136
 137 #               output default setting first instead of using the featureFlags (as done below)
 138 #               $featureFlags = ($_->{'exclusive'} ? 0x8000 : 0x0000) |
 139 #                                                               ($_->{'default'} != 0 ? 0x4000 | ($_->{'default'} & 0x00FF)
 140 #                                                                                                               : 0x0000);
 141                 if ($self->{'version'} == 1)
 142                 {
 143                         $featuresData .= TTF_Pack("SSLSS",
 144                                                                                 $_->{'feature'},
 145                                                                                 scalar keys %$settings,
 146                                                                                 12 + 12 * $numFeatures + length $settingsData,
 147                                                                                 $featureFlags,
 148                                                                                 $_->{'name'});
 149                 }
 150                 else #version == 2
 151                 {
 152                         $featuresData .= TTF_Pack("LSSLSS",
 153                                                                                 $_->{'feature'},
 154                                                                                 scalar keys %$settings,
 155                                                                                 0,
 156                                                                                 12 + 16 * $numFeatures + length $settingsData,
 157                                                                                 $featureFlags,
 158                                                                                 $_->{'name'});
 159                 }
 160
 161                 #output default setting first
 162                 #the settings may not be in their original order
 163                 my $defaultSetting = $_->{'default'};
 164                 $settingsData .= TTF_Pack("SS", $defaultSetting, $settings->{$defaultSetting});
 165                 foreach (sort {$a <=> $b} keys %$settings) {
 166                         if ($_ == $defaultSetting) {next;} #skip default setting
 167                         $settingsData .= TTF_Pack("SS", $_, $settings->{$_});
 168                 }
 169         }
 170
 171         $fh->print(TTF_Pack("vSSL", $self->{'version'}, $numFeatures, 0, 0));
 172         $fh->print($featuresData);
 173         $fh->print($settingsData);
 174
 175         $self;
 176 }
 177
 178 =head2 $t->print($fh)
 179
 180 Prints a human-readable representation of the table
 181
 182 =cut
 183
 184 sub print
 185 {
 186         my ($self, $fh) = @_;
 187         my ($names, $features, $settings);
 188
 189         $self->read;
 190
 191         $names = $self->{' PARENT'}->{'name'};
 192         $names->read;
 193
 194         $fh = 'STDOUT' unless defined $fh;
 195
 196         $features = $self->{'features'};
 197         foreach (@$features) {
 198                 $fh->printf("Feature %d, %s, default: %d name %d # '%s'\n",
 199                                         $_->{'feature'},
 200                                         ($_->{'exclusive'} ? "exclusive" : "additive"),
 201                                         $_->{'default'},
 202                                         $_->{'name'},
 203                                         $names->{'strings'}[$_->{'name'}][3][1]{1033});
 204                 $settings = $_->{'settings'};
 205                 foreach (sort { $a <=> $b } keys %$settings) {
 206                         $fh->printf("\tSetting %d, name %d # '%s'\n",
 207                                                 $_, $settings->{$_}, $names->{'strings'}[$settings->{$_}][3][1]{1033});
 208                 }
 209         }
 210
 211         $self;
 212 }
 213
 214 sub settingName
 215 {
 216         my ($self, $feature, $setting) = @_;
 217
 218         $self->read;
 219
 220         my $names = $self->{' PARENT'}->{'name'};
 221         $names->read;
 222
 223         my $features = $self->{'features'};
 224         my ($featureEntry) = grep { $_->{'feature'} == $feature } @$features;
 225         my $featureName = $names->{'strings'}[$featureEntry->{'name'}][3][1]{1033};
 226         my $settingName = $featureEntry->{'exclusive'}
 227                         ? $names->{'strings'}[$featureEntry->{'settings'}->{$setting}][3][1]{1033}
 228                         : $names->{'strings'}[$featureEntry->{'settings'}->{$setting & ~1}][3][1]{1033}
 229                                 . (($setting & 1) == 0 ? " On" : " Off");
 230
 231         ($featureName, $settingName);
 232 }
 233
 234 1;
 235
 236 =head1 BUGS
 237
 238 The version 1 Feat table ends with a feature (id 1) named NoName
 239 with zero settings but with an offset to the last entry in the setting
 240 array. This last setting has id 0 and an invalid name id. This last
 241 feature is changed to have one setting.
 242
 243 =head1 AUTHOR
 244
 245 Alan Ward (derived from Jonathan Kew's Feat.pm).
 246 See L<Font::TTF::Font> for copyright and licensing.
 247
 248 =cut
 249