Font::TTFMetrics - A parser for the TTF file.
Index
Code Index:
NAME
Font::TTFMetrics - A parser for the TTF file.
SYNOPSIS
use Font::TTFMetrics;
my $metrics = Font::TTFMetrics->new("somefont.ttf");
my $ascent = $metrics->get_ascent();
DESCRIPTION
Font::TTFMetrics encapsulates the font metrics of a true type font
file. A true type font file contains several tables which need to be
parsed before any useful information could be gathered about the
font. There is the excellent module for parsing TTF font in CPAN by
Martin Hosken, Font::TTF. But in my opinion the use of Font::TTF
requires intimate knowledge of TTF font format. This module was
written to support the use of TTF in Pastel 2D graphics library in
Perl. Three factors prompted me to write this module: first, I
required a fast module to access TTF file. Second, all the access
required was read-only. Last, I wanted a user friendly, higher level
API to access TTF file.
Each font file actually contains several informations the most
important information is how a particular character will display on
screen. The shape of a character (glyph) is determined by a series of
points. The points are generally lines or points on curved path. For
details see the TTF specification. Remember, the points actually
determines the outline of the curve.TTF file stores the glyph shape in
the "glyf" table of the font. The first glyph described in this table
will be always a particular glyph, called "missing-glyph" which is
shown in case the font file doesnot contains the glyph that a software
wants.
Each character in computer is actually a number. You can find what
number corresponds to the character, you can call ord() on the
character. This value is called the ordinal value of the character. If
you just use common english typically the number of any character
falls between 32-126, commonly called as ASCII. If you use some more
extra character not commonly found in key-board like "degree" then
your character code will fall between 0-255, commonly called LATIN-1
character set. Unicode is a way to use charaters with ordinal values
beyond 255. The good thing about it is that the UTF8 encoding in perl
works silently in the backdrop and you can intermix characters with
any ordinal value. This ofcourse does not mean that you will be able
to use character with any ordinal values for display. The font file
must contains the corresponding glyph.
The way to extract the glyph for a character is done by looking into
"cmap" table of the font. This table contains the character ordinal
number and a correspoding index. This index is used to look into the
"glyf" table to extract the shape of the character. Thar means if you
just substitute another index for a particular ordinal number you can
actually display a different character, a mechanism known as "glyph
substitution". As you can guess there is one more way to display a
particular character instead of what if should display in a more font
specific manner. If you just add a particular offset to a glyph
ordinal value and provide the index for this added value in the "cmap"
table, you can generate a completely different glyph. This mechanism
works for a particular type of fonts supplied by Microsoft called
symbol fonts. Example of these are symbol.ttf and wingding. Both these
fonts does not supply any glyphs corresponding to LATIN-1 character
sets but with ordinal values in the range of 61472-61695. But notice
if you fire up your word-processor and change the font to symbol and
type any character on the key board you get a display. For example, if
you type A (ordinal value 65) what you get is greek capital
alpha. This works this way: as soon as the word-processor find that
you are using a symbol font (you can call is_symbol() method to
find that) it just adds 61440 to any character you type and then
queries the "cmap" table for the glyph.
One more important aspect of using a TTF file is to find the width of
a string. The easiest way to find this to query "htmx" table, which
contains advanced width of each character, add up all the advance
widths of the individual characters in the string and then go look
into "kern" table, which contains the kerning value for pair of glyphs
add deduct these values from the total width. You need to deduct also
the left-side bearing of the first character and the right-side
bearing of the last character from the total width.
User of this module should keep in mind that all the values
returned from this modules are in font-units and should be converted
to pixel unit by:
fIUnits * pointsize * resolution /(72 * units_per_em)
An example from the true type specification at
http://www.microsoft.com/typography/otspec/TTCH01.htm:
A font-feature of 550 units when used with 18 pt on screen (typically
72 dpi resolution) will be
550 * 18 * 72 / ( 72 * 2048 ) = 4.83 pixels long.
Note that the units_per_em value is 2048 which is typical for a TTF
file. This value can be obtained by calling get_units_per_em() call.
This module also takes full advantage of the unicode support of
Perl. Any strings that you pass to any function call in this module
can have unicode built into into it. That means a string like:
"Something \x{70ff}" is perfectly valid.
CONSTRUCTOR
new()
Creates and returns a Font::TTFMetrics object.
Usage : my $metrics = Font::TTFMetrics->new($file);
Args : $file - TTF filename.
Returns : A Font::TTFMetrics object.
METHODS
is_symbol()
Returns true if the font is a Symbol font from Microsoft. Remember
that Wingding is also a symbol font.
Usage : $metrics->is_symbol();
Args : Nothing.
Returns : True if the font is a Symbol font, false otherwise.
char_width()
Returns the advance width of a single character, in font units.
Usage : $font->char_width('a');
Args : A single perl character. Can be even a unicode.
Returns : A scalar value. The width of the character in font units.
string_width()
Given a string the function returns the width of the string in font
units. The function at present only calculates the advanced width of
the each character and deducts the calculated kerning from the whole
length. If some one has any better idea then let me know.
Usage : $font->string_width("Some string");
Args : A perl string. Can be embedded unicode.
Returns : A scalar indicating the width of the whole string in font units.
get_leading()
"Leading" is the gap between two lines. The value is present in the
OS/2 table of the font.
Usage : $metrics->get_leading();
Args : None.
Returns : A scalar Integer.
get_units_per_em()
Get units_per_em of the font. This value is present in the head
table of the font and for TTF is generally 2048.
Usage : $metrics->get_units_per_em();
Args : None.
Returns : A scalar integer.
get_ascent()
"Ascent" is the distance between the baseline to the top of the glyph.
Usage : $metrics->get_ascent();
Args : None.
Returns : A scalar integer.
get_descent()
"Descent" is the negative distance from the baseline to the lowest
point of the glyph.
Usage : $metrics->get_descent();
Args : None.
Returns : A scalar integer.
is_bold()
Returns true if the font is a bold variation of the font. That means
if you call this function of arial.ttf, it returns false. If you call
this function on arialb.ttf it returns true.
Usage : $metrics->is_bold()
Args : None.
Returns : True if the font is a bold font, returns false otherwise.
is_italic()
Returns true if the font is italic version of the font. Thar means if
you call this function on arialbi.ttf or ariali.ttf it returns true.
Usage : $metrics->is_italic()
Args : None
Returns : True if the font italic, false otherwise
get_font_family()
Returns the family name of the font.
Usage : $metrics->get_font_family()
Args : None
Returns : A scalar
get_subfamily()
Reuturns the style variation of the font in text. Note that depending
on this description might actully be pretty confusing. Call
is_bold() and/or is_italic() to detemine the style. For example
a "demi" version of the font is not "bold" by text. But in display
this in actually bold variation. In this case is_bold() will return
true.
Usage : $metrics->get_subfamily()
Args : None
Returns : A scalar.
is_fixed_pitch()
Returns true for a fixed-pitched font like courier.
Usage : $metrics->is_fixed_pitch()
Args : None
Returns : True for a fixed-pitched font, false otherwise
SEE ALSO
Font::TTF, Pastel::Font::TTF.
COPYRIGHTS
Copyright (c) 2003 by Malay <curiouser@ccmb.res.in>. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
# $Id: TTFMetrics.pm,v 1.4 2003/06/09 13:03:04 malay Exp $
# Perl module for Font::TTFMetrics
# Author: Malay < curiouser@ccmb.res.in >
# Copyright (c) 2003 by Malay. All rights reserved.
# You may distribute this module under the same terms as perl itself
package Font::TTFMetrics;
$Font::TTFMetrics::VERSION = 0.1;
use IO::File;
use Carp;
use strict;
my @glyph_name_index = ();
my @post_glyph_name = ();
my @mac_glyph_name = ();
sub new {
my $arg = shift;
my $class = ref($arg) || $arg;
my $self = {};
bless $self, $class;
$self->_init(@_);
return $self;
}
sub _init {
my ( $self, @args ) = @_;
unless (@args) {
croak "Supply filename in Font::TTFMetrics::new()\n";
}
my ($file) = $self->_rearrange( ["FILE"], @args );
$self->{_fh} = undef;
$self->{family} = undef;
$self->{glyphs} = [];
$self->{tables} = {};
$self->{platform} = 3;
$self->{encoding} = 1;
$self->{subfamily} = undef;
$self->{glyph_index} = [];
$self->{advance_width} = [];
$self->{lsb} = [];
# $self->{number_of_glyphs} = undef;
$self->set_file_handle($file);
$self->make_directory_entry();
$self->is_symbol();
$self->make_ps_name_table();
$self->make_glyph_index();
#print STDERR "After glyph index\n";
#$self->make_advance_width();
$self->process_kern_table();
}
#sub create_from_file {
# my ( $self, @args ) = @_;
# my $mod = Pastel::Font::TTF->new();
# my ( $path, $file ) = $mod->_rearrange( [ "PATH", "FILE" ], @args );
# my $fh;
# if ( defined($path) || defined($file) ) {
# if ( defined($path) ) {
# $mod->set_file_handle($path);
# #return $mod;
# }
# if ( defined($file) ) {
# $mod->set_file_handle($file);
# #return $mod;
# }
# }
# else {
# croak "Supply filename in Pastel::Font::TTF::create_from_file()\n";
# }
# $mod->make_directory_entry();
# $mod->is_symbol();
# # print STDERR "before glyph call\n";
# #$mod->make_glyph_index();
# $mod->make_ps_name_table();
# return $mod;
#}
sub is_symbol {
my $self = shift;
if ( defined( $self->{is_symbol} ) ) {
return $self->{is_symbol};
}
my $fh = $self->get_file_handle();
my $buf = "";
my $add = $self->get_table_address("name");
seek( $fh, $add, 0 );
read( $fh, $buf, 6 );
my ( $num, $offset ) = unpack( "x2nn", $buf );
# loop through the name table whether there is an entry of
# encoding 0 of platform ID 3. If there is one the font must be a
# symbol font. I could not find a better way to do this.
for ( my $i = 0 ; $i < $num ; $i++ ) {
read( $fh, $buf, 12 );
my ( $id, $encoding, $language, $name_id, $length, $string_offset ) =
unpack( "n6", $buf );
if ( $id == $self->{platform} && $encoding == 0 ) {
$self->{is_symbol} = 1;
$self->{encoding} = 0;
return $self->{is_symbol};
}
}
$self->{is_symbol} = 0;
return $self->{is_symbol};
}
sub make_directory_entry {
my $self = shift;
my $fh = $self->get_file_handle();
my $buf = "";
eval { read( $fh, $buf, 12 ) };
if ($@) {
croak "Read error in Pastel::Font::TTF::make_directory_entry\n";
}
my ( $version, $number ) = unpack( "Nn", $buf );
#print "Version = $version, Number of tables = $number\n";
# print "\nTABLE\tOFFSET\tLENGTH\n";
for ( my $i = 0 ; $i < $number ; $i++ ) {
#print "Inside for\n";
read( $fh, $buf, 16 );
my ( $table, $offset, $length ) = unpack( "a4x4NN", $buf );
$self->{table}->{$table} = $offset;
#print "$table\t$offset\t$length\n";
}
#print $self->{table}->{'OS/2'};
}
sub get_table_address {
my $self = shift;
my $table_name = shift;
if ( defined( $self->{table}->{$table_name} ) ) {
return $self->{table}->{$table_name};
}
else {
# croak
# "Undefined table address in Font::TTFMetrics::get_table_address()\n";
return 0;
}
}
sub char_width {
my ( $self, $char ) = @_;
my $ord = ord($char);
if ( $self->is_symbol() ) {
$ord = $ord + 61440;
}
my $index = $self->get_glyph_index($ord);
return $self->get_advance_width($index);
}
sub string_width{
my ($self,$string) = @_;
my @s = split(//, $string);
my $kern = 0;
my $width = 0;
for (my $i = 0; $i <@s; $i++) {
my $ord = ord($s[$i]);
if ($self->is_symbol()) {
$ord = $ord + 61440;
}
my $index = $self->get_glyph_index($ord);
$width = $width + $self->get_advance_width($index);
if ($i < @s -1) {
my $ord_plus_one = ord($s[$i + 1]);
if ($self->is_symbol()) {
$ord_plus_one = $ord_plus_one + 61440;
}
my $index_plus_one = $self->get_glyph_index($ord_plus_one);
$kern = $kern + $self->kern_value($index, $index_plus_one);
}
}
my $start_ord = ord ($s[0]);
if ($self->is_symbol()) {
$start_ord = $start_ord + 61440;
}
my $start_index = $self->get_glyph_index($start_ord);
#print STDERR "\n****start index : $start_index\n";
#my $lsb = $self->get_lsb($start_index);
return $width + $kern;
}
# returns the glyph index for a given chracter ordinal number from the
# cmap table. The function first check whether the ordinal number
# passed to it lies in the range 0-255. If it is then it simple get
# the index number from the $self->{glyph_index} array set by
# make_glyph_index(). If the ordinal value is greater than 255 the
# function queries the cmap table itself and returns the value.
sub get_glyph_index {
my $self = shift;
my $char = shift; # ordinal number of the character
if ( $char < 256 ) {
return $self->{glyph_index}->[$char];
}
my $buf = "";
my $fh = $self->get_file_handle();
my $add = $self->get_table_address('cmap');
my $offset;
seek( $fh, $add, 0 );
read( $fh, $buf, 4 );
my $num = unpack( "x2n", $buf );
for ( my $i = 0 ; $i < $num ; $i++ ) {
read( $fh, $buf, 8 );
my ( $id, $encoding, $off ) = unpack( "nnN", $buf );
#print $id , "\n";
#print $encoding , "\n";
if ( $id == $self->{platform} && $encoding == $self->{encoding} ) {
#print "Match Found ", $id, "\n";
# print "Offset: $off\n";
$offset = $off;
last;
}
}
seek( $fh, $add + $offset, 0 );
read( $fh, $buf, 6 );
my ( $format, $length, $version ) = unpack( "nnn", $buf );
read( $fh, $buf, 8 );
#print STDERR "\nlength = $length\n";
my ( $seg_countX2, $search_range, $entry_selector, $range_shift ) =
unpack( "nnnn", $buf );
my $seg_count = $seg_countX2 / 2;
#print STDERR "\n",$seg_count,"\n";
read( $fh, $buf, 2 * $seg_count );
my (@end_count) = unpack( "n" x $seg_count, $buf );
read( $fh, $buf, 2 );
#my $reserve_pad = unpack( "n", $buf );
read( $fh, $buf, 2 * $seg_count );
my (@start_count) = unpack( "n" x $seg_count, $buf );
#print STDERR "\n", "@start_count","\n";
#print "Start Count: ", join("\t",@start_count), "\n";
read( $fh, $buf, 2 * $seg_count );
my (@id_delta) = unpack( "n" x $seg_count, $buf );
#print "idDelta: ", join("\t",@id_delta), "\n";
read( $fh, $buf, 2 * $seg_count );
my (@id_range_offset) = unpack( "n" x $seg_count, $buf );
#print "idRangeOffset: ", join("\t",@id_range_offset), "\n";
#my $num1 = read( $fh, $buf, $length - ( $seg_count * 8 ) - 16 );
#my (@glyph_id) = unpack( "n" x ( $num1 / 2 ), $buf );
#print STDERR "\n",join("\n",@glyph_id),"\n";
#my $i;
#my $j;
my $index;
my $present =
0; # boolean to indicate the char code is actually present or not
for ( my $i = 0 ; $i < $seg_count ; $i++ ) {
if ( $start_count[$i] <= $char && $end_count[$i] >= $char ) {
$index = $i;
$present = 1;
last;
}
}
#print STDERR "\nIndex: ", $index,"\n";
#print STDERR "\nId offset: ", $id_range_offset[$index],"\n";
my $glyph;
# If the char code is not there just return the missing glyph
if ( !$present ) {
return 0;
}
elsif ( $id_range_offset[$index] != 0 ) {
my $glyph_id_index =
$id_range_offset[$index] / 2 + ( $char - $start_count[$index] ) -
( $seg_count - $index );
seek( $fh, $glyph_id_index * 2, 1 );
read( $fh, $buf, 2 );
$glyph = unpack( "n", $buf );
#print STDERR "is range not 0\n";
#print STDERR "\nGlyph : $glyph\n";
}
else {
$glyph = ( $id_delta[$index] + $char ) % 65536;
}
return $glyph;
}
# Look into the cmap table and create and array of 256 glyph
# indexes. Should be called only once during the initialization of the
# module. This array is used to find quickly the index of a particulr
# glyph if the ordinal value of the character lies in the range
# 0-255. If the ordinal number in greater than 255 use
# get_glyph_index() to get the index of particular glyph.
sub make_glyph_index {
#print STDERR "**Inside glyph index\n";
my $self = shift;
my $buf;
my $offset;
my $PLATFORM_ID = $self->{platform};
my $ENCODING_ID = $self->{encoding};
my $fh = $self->get_file_handle();
my $cmap = $self->get_table_address("cmap");
my @glyph_index;
#Go there
seek( $fh, $cmap, 0 );
#'cmap' table starts with
# USHORT Table version number
# USHORT Number of encoding tables
# Read 4 bytes
read( $fh, $buf, 4 );
#Get number of tables and skip the version number
my ($num) = unpack( "x2n", $buf );
# Read the tables. There will $num tables
# Each one for a specific encoding and platform id
# There are three most important id and encoding-
# Windows : ID=3 Encoding = 1
# Windows symbol : ID=3 Encoding = 0
# Mac/Poscript : ID=1 Encoding = 0
#Each subtable:
# USHORT Platform ID
# USHORT Platform specific encoding ID
# ULONG Byte ofset from the begining of the 'cmap' table
for ( my $i = 0 ; $i < $num ; $i++ ) {
read( $fh, $buf, 8 );
my ( $id, $encoding, $off ) = unpack( "nnN", $buf );
#print $id , "\n";
#print $encoding , "\n";
if ( $id == $PLATFORM_ID && $encoding == $ENCODING_ID ) {
#print "Match Found ", $id, "\n";
# print "Offset: $off\n";
$offset = $off;
seek( $fh, $cmap + $offset, 0 );
}
}
#Goto the specific table
# Mac/Poscript table with encoding 0 use the following format
# USHORT format set to 0
# USHORT length
# USHORT version starts at 0
# BYTE glyphIdArray[256] There is no trick here just read the whole
# thing as 256 array
# If MAC/Postcript table
if ( $PLATFORM_ID == "1" && $ENCODING_ID == "0" ) {
# Skip the format, length and version information
read( $fh, $buf, 6 );
#print (unpack("nnn", $buf));
# Now read the 256 element array directly
for ( my $i = 0 ; $i < 256 ; $i++ ) {
read( $fh, $buf, 1 );
#print $buf;
$glyph_index[$i] = unpack( "C", $buf );
#print $glyph_index[$i];
#print "Char $i\t\t-> Index $glyph_index[$i]\n";
}
}
# Windows table with encoding 1 use the following format FORMAT 4
# USHORT format Format number is set to 4.
# USHORT length Length in bytes.
# USHORT version Version number (starts at 0).
# USHORT segCountX2 2 x segCount.
# USHORT searchRange 2 x (2**floor(log2(segCount)))
# USHORT entrySelector log2(searchRange/2)
# USHORT rangeShift 2 x segCount - searchRange
# USHORT endCount[segCount] End characterCode for each segment,
# last =0xFFFF.
# USHORT reservedPad Set to 0.
# USHORT startCount[segCount] Start character code for each segment.
# USHORT idDelta[segCount] Delta for all character codes in segment.
# USHORT idRangeOffset[segCount]Offsets into glyphIdArray or 0
# USHORT glyphIdArray[ ] Glyph index array (arbitrary length)
if ( $PLATFORM_ID == 3 ) {
read( $fh, $buf, 6 );
my ( $format, $length, $version ) = unpack( "nnn", $buf );
#print "Format: $format\tLength: $length\tVersion: $version\n\n";
read( $fh, $buf, 8 );
my ( $seg_countX2, $search_range, $entry_selector, $range_shift ) =
unpack( "nnnn", $buf );
my $seg_count = $seg_countX2 / 2;
#print "SegcountX2:\t\t$seg_countX2\n";
#print "Search Range:\t$search_range\n";
#print "Entry:\t$entry_selector\n";
#print "Range Shift:\t$range_shift\n";
read( $fh, $buf, 2 * $seg_count );
my (@end_count) = unpack( "n" x $seg_count, $buf );
#print "EndCount: ", join("\t",@end_count), "\n";
read( $fh, $buf, 2 );
my $reserve_pad = unpack( "n", $buf );
#print "Reserve Pad: $reserve_pad\n";
read( $fh, $buf, 2 * $seg_count );
my (@start_count) = unpack( "n" x $seg_count, $buf );
#print "Start Count: ", join("\t",@start_count), "\n";
read( $fh, $buf, 2 * $seg_count );
my (@id_delta) = unpack( "n" x $seg_count, $buf );
#print "idDelta: ", join("\t",@id_delta), "\n";
read( $fh, $buf, 2 * $seg_count );
my (@id_range_offset) = unpack( "n" x $seg_count, $buf );
#print "idRangeOffset: ", join("\t",@id_range_offset), "\n";
my $num = read( $fh, $buf, $length - ( $seg_count * 8 ) - 16 );
my (@glyph_id) = unpack( "n" x ( $num / 2 ), $buf );
#print STDERR "\n",join("\n",@glyph_id),"\n",
my $i;
my $j;
#print "Last count:", $end_count[$#end_count], "\n";
for ( $j = 0 ; $j < $seg_count ; $j++ ) {
#for ( $i = $start_count[$j] ; $i <= $end_count[$j] ; $i++ ) {
for ( $i = $start_count[$j] ; $i < 256 ; $i++ ) {
#print $start_count[$j], "****", $end_count[$j], "\n";
#if ($end_count[$j] >= $i && $start_count[$j] <= $i){
#print "ID RANGE OFFSET $id_range_offset[$j]", "\n";
if ( $id_range_offset[$j] != 0 ) {
$glyph_index[$i] = $glyph_id[ $id_range_offset[$j] / 2 +
( $i - $start_count[$j] ) - ( $seg_count - $j ) ];
}
else {
$glyph_index[$i] = ( $id_delta[$j] + $i ) % 65536;
}
if ( !defined( $glyph_index[$i] ) ) {
#$glyph_index[$i] = $glyph_id[0];
$glyph_index[$i] = 0;
}
}
}
for ( my $i = 0 ; $i < @glyph_index ; $i++ ) {
if ( !defined( $glyph_index[$i] ) ) {
$glyph_index[$i] = 0;
}
}
}
$self->{glyph_index} = \@glyph_index;
# print STDERR "\n","Number of glyphs:", scalar(@{$self->{glyph_index}}), "\n";
# print STDERR "\n","glyphs:", "@{$self->{glyph_index}}", "\n";
}
sub make_advance_width {
my $self = shift;
if ( $self->is_symbol() ) {
return;
}
my $fh = $self->get_file_handle();
my $buf;
#print STDERR "***", $self->{table}->{"hhea"}, "\n";
seek( $fh, $self->get_table_address("hhea"), 0 );
read( $fh, $buf, 36 );
my ($num) = unpack( "x34n", $buf );
my $number_of_glyphs = $self->maxp_get_number_of_glyph();
#$num = $num > 256 ? 256: $num;
#print STDERR "*** ", $num, "\n";
seek( $fh, $self->get_table_address("hmtx"), 0 );
read( $fh, $buf, 4 * $num );
my (@temp) = unpack( "n" x ( 2 * $num ), $buf );
my @advanced_width;
my @lsb;
my $index = @temp;
# if ($num > 256) {
# $index = 256 * 2;
# }
for ( my $i = 0 ; $i < $index - 1 ; $i++ ) {
$advanced_width[@advanced_width] = $temp[$i];
$lsb[@lsb] = $temp[ $i + 1 ] - ( $temp[ $i + 1 ] > 32768 ? 65536 : 0 );
$i++;
}
my $end_lsb = $number_of_glyphs;
# if ($number_of_glyphs > 256) {
# $end_lsb = 256;
# }else {
# $end_lsb = $number_of_glyphs;
# }
if ( @lsb < $end_lsb ) {
my $more_lsb = $end_lsb - scalar(@lsb);
read( $fh, $buf, 2 * $more_lsb );
@temp = unpack( "n*", $buf );
for ( my $i = 0 ; $i < @temp ; $i++ ) {
$lsb[@lsb] = $temp[$i] - ( $temp[$i] > 32768 ? 65536 : 0 );
}
}
undef(@temp);
my @ad;
my @l;
for ( my $i = 0 ; $i < 256 ; $i++ ) {
my $index = $self->get_glyph_index($i);
if ( $advanced_width[$index] ) {
$ad[$i] = $advanced_width[$index];
}
else {
$ad[$i] = $advanced_width[0];
}
if ( defined( $lsb[$index] ) ) {
$l[$i] = $lsb[$index];
}
else {
$l[$i] = $lsb[0];
}
}
$self->{advance_width} = \@ad;
$self->{lsb} = \@l;
#print STDERR "\n",$self->get_font_family(),$self->get_subfamily(),"\n";
#print STDERR "\nadv:\n@advanced_width", "\n";
#print STDERR "\nlsb\n@lsb", "\n";
}
sub get_lsb {
my ($self, $index) = @_;
my $fh = $self->get_file_handle();
my $buf;
seek( $fh, $self->get_table_address("hhea"), 0 );
read( $fh, $buf, 36 );
my ($num) = unpack( "x34n", $buf );
my $number_of_glyphs = $self->maxp_get_number_of_glyph();
#$num = $num > 256 ? 256: $num;
#print STDERR "*** ", $num, "\n";
seek( $fh, $self->get_table_address("hmtx"), 0 );
read( $fh, $buf, 4 * $num );
my (@temp) = unpack( "n" x ( 2 * $num ), $buf );
#my @advanced_width;
my @lsb;
my $loop_index = @temp;
for ( my $i = 0 ; $i < $loop_index - 1 ; $i++ ) {
#$advanced_width[@advanced_width] = $temp[$i];
$lsb[@lsb] = $temp[ $i + 1 ] - ( $temp[ $i + 1 ] > 32768 ? 65536 : 0 );
$i++;
}
my $end_lsb = $number_of_glyphs;
if ( @lsb < $end_lsb ) {
my $more_lsb = $end_lsb - scalar(@lsb);
read( $fh, $buf, 2 * $more_lsb );
@temp = unpack( "n*", $buf );
for ( my $i = 0 ; $i < @temp ; $i++ ) {
$lsb[@lsb] = $temp[$i] - ( $temp[$i] > 32768 ? 65536 : 0 );
}
}
return defined ($lsb[$index])? $lsb[$index] : undef;
}
sub get_advance_width {
my $self = shift;
my $index = shift; # glyph index
my $fh = $self->get_file_handle();
my $buf;
seek( $fh, $self->{table}->{"hhea"}, 0 );
read( $fh, $buf, 36 ) == 36 || die "reading hhea table";
my ($h_num) = unpack( "x34n", $buf );
my $num = $h_num;
seek( $fh, $self->{table}->{"hmtx"}, 0 );
read( $fh, $buf, 4 * $num ) == 4 * $num || die "reading hmtx table";
my (@h_temp) = unpack( "n" x ( 2 * $num ), $buf );
# print "******@h_temp\n";
my (@advanced_width);
#my (@lsb);
for ( my $i = 0 ; $i < @h_temp - 1 ; $i += 2 ) {
push ( @advanced_width, $h_temp[$i] );
#push ( @lsb, $h_temp[ $i + 1 ] );
}
#print @advanced_width, "\n";
#print @lsb;
if ($index > $#advanced_width && $self->is_fixed_pitch()) {
$index = $#advanced_width;
}
#if ( $index > @lsb ) { $index = @lsb; }
my $a =
$advanced_width[$index] - ( $advanced_width[$index] > 32768 ? 65536 : 0 );
#my $l = $lsb[$index] - ( $lsb[$index] > 32768 ? 65536 : 0 );
#return $a, $l;
return $a ? $a : undef;
}
sub get_leading {
my $self = shift;
if ( defined( $self->{leading} ) ) {
return $self->{leading};
}
else {
$self->_parse_os2();
#$self->{leading} = $self->_get_leading();
return $self->{leading};
}
}
sub _get_leading {
my $self = shift;
my $fh = $self->get_file_handle();
# Get the adress of the OS/2 table
my $add = $self->get_table_address('OS/2');
my $buf;
#print $add, "\n";
#Leading is sTypoLineGap in OS/2 table
seek( $fh, $add, 0 );
read( $fh, $buf, 74 ) == 74 || die "reading OS/2 table";
my ($leading) = unpack( "x72n", $buf );
#print join(" ",@panose), "\n";
#print $leading, "\n";
return $leading - ( $leading > 32768 ? 65536 : 0 );
}
sub get_units_per_em {
my $self = shift;
# Get Headtable address
my $add = $self->get_table_address("head");
my $buf;
my $fh = $self->get_file_handle();
seek( $fh, $add, 0 );
read( $fh, $buf, 54 ) == 54 || die "reading head table";
my ( $units_per_em, $index_to_loc ) = unpack( "x18nx30n", $buf );
# print "Unit/EM: $units_per_em\tIndex_to_loc: $index_to_loc\n\n";
return $units_per_em;
}
sub get_ascent {
my $self = shift;
if ( defined( $self->{ascent} ) ) {
return $self->{ascent};
}
else {
$self->_parse_os2();
#$self->{ascent} = $self->_get_ascent();
return $self->{ascent};
}
}
sub _get_ascent {
my $self = shift;
my $fh = $self->get_file_handle();
# Get the adress of the OS/2 table
my $add = $self->get_table_address('OS/2');
my $buf;
#print $add, "\n";
# Ascent is is sTypoAscender in OS/2 table
seek( $fh, $add, 0 );
read( $fh, $buf, 70 ) == 70 || die "reading OS/2 table";
my ($ascent) = unpack( "x68n", $buf );
#print join(" ",@panose), "\n";
#print $ascent, "\n";
return $ascent - ( $ascent > 32768 ? 65536 : 0 );
}
sub get_descent {
my $self = shift;
if ( defined( $self->{descent} ) ) {
return $self->{descent};
}
else {
$self->_parse_os2();
#$self->{descent} = $self->_get_descent();
return $self->{descent};
}
}
sub _parse_os2 {
my $self = shift;
my $fh = $self->get_file_handle();
my $add = $self->get_table_address('OS/2');
my $buf;
seek( $fh, $add, 0 );
read( $fh, $buf, 74 ) == 74 || die "reading OS/2 table";
#my ($ascent, $descent, $leading) =
# unpack("x68nnn", $buf);
my ( $fs, $ascent, $descent, $leading ) = unpack( "x62nx4nnn", $buf );
#print STDERR dec2bin($fs) ,"\n";
if ( $fs & 0x20 ) {
$self->{isbold} = 1;
}
else {
$self->{isbold} = 0;
}
if ( $fs & 0x01 ) {
$self->{isitalic} = 1;
}
else {
$self->{isitalic} = 0;
}
if ( $fs & 0x40 ) {
$self->{isregular} = 1;
}
else {
$self->{isregular} = 0;
}
$self->{ascent} = $ascent - ( $ascent > 32768 ? 65536 : 0 );
$self->{descent} = $descent - ( $descent > 32768 ? 65536 : 0 );
$self->{leading} = $leading - ( $leading > 32768 ? 65536 : 0 );
}
sub is_bold {
my $self = shift;
if ( defined( $self->{isbold} ) ) {
return $self->{isbold};
}
else {
$self->_parse_os2();
}
return $self->{isbold};
}
sub is_italic {
my $self = shift;
if ( defined( $self->{isitalic} ) ) {
return $self->{isitalic};
}
else {
$self->_parse_os2();
}
return $self->{isitalic};
}
sub get_font_family {
my $self = shift;
if ( defined( $self->{family} ) ) {
return $self->{family};
}
else {
$self->_parse_name_table();
}
return $self->{family};
}
sub get_subfamily {
my $self = shift;
if ( defined( $self->{subfamily} ) ) {
return $self->{subfamily};
}
else {
$self->_parse_name_table();
}
return $self->{subfamily};
}
sub _parse_name_table {
my $self = shift;
my $buf;
my $fh = $self->get_file_handle();
my $LANGUAGE_ID;
my $PLATFORM_ID = $self->{platform};
my $ENCODING_ID = $self->{encoding};
if ( $self->{platform} == "1" && $self->{encoding} == "0" ) {
$LANGUAGE_ID = 0;
}
else {
$LANGUAGE_ID = 1033;
}
my $add = $self->get_table_address("name");
seek( $fh, $add, 0 );
read( $fh, $buf, 6 );
my ( $num, $offset ) = unpack( "x2nn", $buf );
#print "*******NAME : Number of records, $num, Offset: $offset\n";
my (
$copyright_offset, $font_family_name_offset,
$subfamily_offset, $id_offset,
$full_name_offset, $version_string_offset,
$postscript_offset, $trademark_offset
);
my (
$copyright_length, $font_family_length, $subfamily_length,
$id_length, $full_name_length, $version_length,
$postscript_length, $trademark_length
);
for ( my $i = 0 ; $i < $num ; $i++ ) {
read( $fh, $buf, 12 );
my ( $id, $encoding, $language, $name_id, $length, $string_offset ) =
unpack( "n6", $buf );
#print "****NAMERECORDS: $id, $encoding, $language, $name_id, $length, $string_offset\n";
if (
( $id == $PLATFORM_ID ) && # Windows??
( $encoding == $ENCODING_ID ) && #UGL??
( $language == $LANGUAGE_ID )
)
{
if ( $name_id == 0 ) { #Copyright
$copyright_offset = $string_offset;
$copyright_length = $length;
}
if ( $name_id == 1 ) { # Familyname
$font_family_name_offset = $string_offset;
$font_family_length = $length;
}
if ( $name_id == 2 ) { # Subfamily
$subfamily_offset = $string_offset;
$subfamily_length = $length;
}
if ( $name_id == 3 ) { # Identifier
$id_offset = $string_offset;
$id_length = $length;
}
if ( $name_id == 4 ) { # Full name
$full_name_offset = $string_offset;
$full_name_length = $length;
}
if ( $name_id == 5 ) { #version string
$version_string_offset = $string_offset;
$version_length = $length;
}
if ( $name_id == 6 ) { # Postscript name
$postscript_offset = $string_offset;
$postscript_length = $length;
}
if ( $name_id == 7 ) { # Trademark
$trademark_offset = $string_offset;
$trademark_length = $length;
}
}
} # End for loop;
# Print copyright
seek( $fh, $self->get_table_address("name") + $offset + $copyright_offset,
0 );
read( $fh, $buf, $copyright_length );
# print "COPYRIGHT: $buf\n\n";
# Print familyname
seek( $fh,
$self->get_table_address("name") + $offset + $font_family_name_offset,
0 );
read( $fh, $buf, $font_family_length );
#print $s;
$self->{family} = $self->_remove_white_space( $buf, $font_family_length );
#print "\n****", "@char", "*****\n";
#return "@char";
# print "FAMILY: $buf\n\n";
#Print Subfamily
seek( $fh, $self->get_table_address('name') + $offset + $subfamily_offset,
0 );
read( $fh, $buf, $subfamily_length );
#print "SUBFAMILY: $buf\n\n";
$self->{subfamily} = $self->_remove_white_space( $buf, $subfamily_length );
# #Print Identifier
# seek( $fh, $self->get_table_address('name') + $offset + $id_offset, 0 );
# read( $fh, $buf, $id_length );
# #print "ID: $buf\n\n";
# #Print Full name
# seek( $fh, $self->get_table_address('name') + $offset + $full_name_offset,
# 0 );
# read( $fh, $buf, $full_name_length );
# #print "FULL NAME: $buf\n\n";
# #Print Version string
# seek( $fh,
# $self->get_table_address('name') + $offset + $version_string_offset,
# 0 );
# read( $fh, $buf, $version_length );
# #print "VERSION: $buf\n\n";
# #Print Postscript
# seek( $fh, $self->get_table_address('name') + $offset + $postscript_offset,
# 0 );
# read( $fh, $buf, $postscript_length );
# #print "Postscript: $buf\n\n";
# #Print Trademark
# seek( $fh, $self->get_table_address('name') + $offset + $trademark_offset,
# 0 );
# read( $fh, $buf, $trademark_length );
# #print "TRADEMARK: $buf\n\n";
}
sub _remove_white_space {
my $self = shift;
my $buf = shift;
my $font_family_length = shift;
my @char = unpack( "C*", $buf );
my $i = $font_family_length;
my $s = "";
my $j = 0;
while ( $j < $i ) {
if ( defined $char[ $j + 1 ] ) {
$s .= pack( "C", $char[ $j + 1 ] );
}
$j += 2;
}
return $s;
}
sub is_fixed_pitch {
my $self = shift;
if ( defined $self->{isfixedpitch} ) {
return $self->{isfixedpitch};
}
else {
return 0;
}
}
sub make_ps_name_table {
my $self = shift;
my $fh = $self->get_file_handle();
my $address = $self->get_table_address("post");
my $buf;
seek( $fh, $address, 0 );
read( $fh, $buf, 4 );
my $format_type = unpack( "N", $buf );
#print "Format type:$format_type\n";
if ( $format_type == 131072 ) { # Test whether 0x00020000
#print "Microsoft table! \n";
read( $fh, $buf, 30 );
my ( $italic_angle_m, $italic_angle_f, $fixed_pitched, $num_glyphs ) =
unpack( "nnx4Nx16n", $buf );
#$italic_angle_m = $italic_angle_m - ($italic_angle_m > 32768 ? 65536 :0);
#print STDERR $fixed_pitched, "\n";
if ($fixed_pitched) {
$self->{isfixedpitch} = 1;
}
#print $num_glyphs, "\n";
my $highest_glyph_index = 0;
for ( my $i = 0 ; $i < $num_glyphs ; $i++ ) {
read( $fh, $buf, 2 );
$glyph_name_index[$i] = unpack( "n", $buf );
if ( $highest_glyph_index < $glyph_name_index[$i] ) {
$highest_glyph_index = $glyph_name_index[$i];
}
}
if ( $highest_glyph_index > 257 ) {
$highest_glyph_index -= 257;
}
for ( my $i = 0 ; $i < $highest_glyph_index ; $i++ ) {
read( $fh, $buf, 1 );
my $length = unpack( "C", $buf );
read( $fh, $buf, $length );
$post_glyph_name[$i] = pack( "C*", unpack( "C*", $buf ) );
#print $post_glyph_name[$i], "\n";
}
}
elsif ( $format_type == 131077 ) {
#Do Nothing
}
}
sub make_mac_glyph_name {
@mac_glyph_name = (
".notdef", "null", "CR", "space",
"exclam", # 4
"quotedbl", # 5
"numbersign", # 6
"dollar", # 7
"percent", # 8
"ampersand", # 9
"quotesingle", # 10
"parenleft", # 11
"parenright", # 12
"asterisk", # 13
"plus", # 14
"comma", # 15
"hyphen", # 16
"period", # 17
"slash", # 18
"zero", # 19
"one", # 20
"two", # 21
"three", # 22
"four", # 23
"five", # 24
"six", # 25
"seven", # 26
"eight", # 27
"nine", # 28
"colon", # 29
"semicolon", # 30
"less", # 31
"equal", # 32
"greater", # 33
"question", # 34
"at", # 35
"A", # 36
"B", # 37
"C", # 38
"D", # 39
"E", # 40
"F", # 41
"G", # 42
"H", # 43
"I", # 44
"J", # 45
"K", # 46
"L", # 47
"M", # 48
"N", # 49
"O", # 50
"P", # 51
"Q", # 52
"R", # 53
"S", # 54
"T", # 55
"U", # 56
"V", # 57
"W", # 58
"X", # 59
"Y", # 60
"Z", # 61
"bracketleft", # 62
"backslash", # 63
"bracketright", # 64
"asciicircum", # 65
"underscore", # 66
"grave", # 67
"a", # 68
"b", # 69
"c", # 70
"d", # 71
"e", # 72
"f", # 73
"g", # 74
"h", # 75
"i", # 76
"j", # 77
"k", # 78
"l", # 79
"m", # 80
"n", # 81
"o", # 82
"p", # 83
"q", # 84
"r", # 85
"s", # 86
"t", # 87
"u", # 88
"v", # 89
"w", # 90
"x", # 91
"y", # 92
"z", # 93
"braceleft", # 94
"bar", # 95
"braceright", # 96
"asciitilde", # 97
"Adieresis", # 98
"Aring", # 99
"Ccedilla", # 100
"Eacute", # 101
"Ntilde", # 102
"Odieresis", # 103
"Udieresis", # 104
"aacute", # 105
"agrave", # 106
"acircumflex", # 107
"adieresis", # 108
"atilde", # 109
"aring", # 110
"ccedilla", # 111
"eacute", # 112
"egrave", # 113
"ecircumflex", # 114
"edieresis", # 115
"iacute", # 116
"igrave", # 117
"icircumflex", # 118
"idieresis", # 119
"ntilde", # 120
"oacute", # 121
"ograve", # 122
"ocircumflex", # 123
"odieresis", # 124
"otilde", # 125
"uacute", # 126
"ugrave", # 127
"ucircumflex", # 128
"udieresis", # 129
"dagger", # 130
"degree", # 131
"cent", # 132
"sterling", # 133
"section", # 134
"bullet", # 135
"paragraph", # 136
"germandbls", # 137
"registered", # 138
"copyright", # 139
"trademark", # 140
"acute", # 141
"dieresis", # 142
"notequal", # 143
"AE", # 144
"Oslash", # 145
"infinity", # 146
"plusminus", # 147
"lessequal", # 148
"greaterequal", # 149
"yen", # 150
"mu", # 151
"partialdiff", # 152
"summation", # 153
"product", # 154
"pi", # 155
"integral'", # 156
"ordfeminine", # 157
"ordmasculine", # 158
"Omega", # 159
"ae", # 160
"oslash", # 161
"questiondown", # 162
"exclamdown", # 163
"logicalnot", # 164
"radical", # 165
"florin", # 166
"approxequal", # 167
"increment", # 168
"guillemotleft", # 169
"guillemotright", #170
"ellipsis", # 171
"nbspace", # 172
"Agrave", # 173
"Atilde", # 174
"Otilde", # 175
"OE", # 176
"oe", # 177
"endash", # 178
"emdash", # 179
"quotedblleft", # 180
"quotedblright", # 181
"quoteleft", # 182
"quoteright", # 183
"divide", # 184
"lozenge", # 185
"ydieresis", # 186
"Ydieresis", # 187
"fraction", # 188
"currency", # 189
"guilsinglleft", # 190
"guilsinglright", #191
"fi", # 192
"fl", # 193
"daggerdbl", # 194
"middot", # 195
"quotesinglbase", #196
"quotedblbase", # 197
"perthousand", # 198
"Acircumflex", # 199
"Ecircumflex", # 200
"Aacute", # 201
"Edieresis", # 202
"Egrave", # 203
"Iacute", # 204
"Icircumflex", # 205
"Idieresis", # 206
"Igrave", # 207
"Oacute", # 208
"Ocircumflex", # 209
"", # 210
"Ograve", # 211
"Uacute", # 212
"Ucircumflex", # 213
"Ugrave", # 214
"dotlessi", # 215
"circumflex", # 216
"tilde", # 217
"overscore", # 218
"breve", # 219
"dotaccent", # 220
"ring", # 221
"cedilla", # 222
"hungarumlaut", # 223
"ogonek", # 224
"caron", # 225
"Lslash", # 226
"lslash", # 227
"Scaron", # 228
"scaron", # 229
"Zcaron", # 230
"zcaron", # 231
"brokenbar", # 232
"Eth", # 233
"eth", # 234
"Yacute", # 235
"yacute", # 236
"Thorn", # 237
"thorn", # 238
"minus", # 239
"multiply", # 240
"onesuperior", # 241
"twosuperior", # 242
"threesuperior", # 243
"onehalf", # 244
"onequarter", # 245
"threequarters", # 246
"franc", # 247
"Gbreve", # 248
"gbreve", # 249
"Idot", # 250
"Scedilla", # 251
"scedilla", # 252
"Cacute", # 253
"cacute", # 254
"Ccaron", # 255
"ccaron", # 256
"" # 257
);
}
sub get_glyph_name {
my $index = shift;
if ( $glyph_name_index[$index] > 257 ) {
#print $post_glyph_name[$glyph_name_index[$index] -258], "******\n";
return $post_glyph_name[ $glyph_name_index[$index] - 258 ];
}
else {
#print $glyph_name_index[$index], "*****\n";
#print $mac_glyph_name[$glyph_name_index[$index]], "******\n";
#print $mac_glyph_name[3], "*****\n";
return $mac_glyph_name[ $glyph_name_index[$index] ];
}
}
sub get_panose {
my $self = shift;
my $buf;
my $add = $self->get_table_address('OS/2');
my $fh = $self->get_file_handle();
seek( $fh, $add, 0 );
read( $fh, $buf, 42 );
#Throw away first 32 bytes and take last 10
my (@panose) = unpack( "x32c10", $buf );
return @panose;
}
sub kern_value{
my ($self,$left, $right) = @_;
unless ($self->{kern}) {
return 0;
}
if (exists ($self->{kern}->{$left}->{$right}) ) {
return $self->{kern}->{$left}->{$right};
}else {
return 0;
}
}
sub process_kern_table {
my $self = shift;
my $buf;
#print STDERR $self->get_font_family(), "\n";
#my $s = "";
unless ( defined( $self->get_table_address("kern") ) ) {
return 0;
}
my $add = $self->get_table_address("kern");
my $fh = $self->get_file_handle();
my %kern;
seek( $fh, $add, 0 );
read( $fh, $buf, 4 );
my $num_of_tables = unpack( "x2n", $buf );
#print $num_of_tables, "\n";
for ( my $i = 0 ; $i < $num_of_tables ; $i++ ) {
read( $fh, $buf, 4 );
my $length = unpack( "x2n", $buf );
read( $fh, $buf, 2 );
my $coverage = unpack( "n", $buf );
my $format = $coverage >> 8;
#print $format, "\n";
if ( ( $format == 0 ) && ( ( $coverage & 1 ) != 0 ) ) {
#print "FORMAT 0\n";
read( $fh, $buf, 2 );
my $npairs = unpack( "n", $buf );
#print $npairs, "\n";
read( $fh, $buf, 6 );
for ( my $j = 0 ; $j < $npairs ; $j++ ) {
read( $fh, $buf, 4 );
# my $right_and_left = unpack("N", $buf);
my ( $left, $right ) = unpack( "nn", $buf );
if ( $left > 255 ) {
last;
}
read( $fh, $buf, 2 );
my $kern_data = unpack( "n", $buf );
$kern_data = $kern_data - ( $kern_data > 32768 ? 65536 : 0 );
# $kern_data = $kern_data * ( -1);
# if(exists($kern_to_print{$left})){
# $s .= write_kern_data($left, $right, $kern_data);
# }
$kern{$left}->{$right} = $kern_data;
#print STDERR $left,"\t",$right, "\t", $kern_data,"\n";
#print get_glyph_name($left), ":", get_glyph_name($right);
#print "$right_and_left ";
# $kern{$right_and_left} = $kern_data;
#print $kern_data, "\n";
}
}
else {
read( $fh, $buf, $length - 6 );
}
}
$self->{kern} = \%kern;
#return $s;
}
sub DESTROY {
my $self = shift;
close $self->{_fh};
}
sub set_file_handle {
my $self = shift;
my $path = shift;
my $fh = IO::File->new();
if ( $fh->open("< $path") ) {
binmode($fh);
$self->{_fh} = $fh;
}
else {
croak "Could not open $path in Pastel::Font::TTF::set_file_handle\n";
}
}
sub get_file_handle {
my $self = shift;
if ( defined( $self->{_fh} ) ) {
return $self->{_fh};
}
else {
return 0;
}
}
sub _rearrange {
my ( $self, $order, @param ) = @_;
return unless @param;
return @param unless ( defined( $param[0] ) && $param[0] =~ /^-/ );
for ( my $i = 0 ; $i < @param ; $i += 2 ) {
$param[$i] =~ s/^\-//;
$param[$i] =~ tr/a-z/A-Z/;
}
# Now we'll convert the @params variable into an associative array.
local ($^W) = 0; # prevent "odd number of elements" warning with -w.
my (%param) = @param;
my (@return_array);
# What we intend to do is loop through the @{$order} variable,
# and for each value, we use that as a key into our associative
# array, pushing the value at that key onto our return array.
my ($key);
foreach $key ( @{$order} ) {
my ($value) = $param{$key};
delete $param{$key};
push ( @return_array, $value );
}
# print "\n_rearrange() after processing:\n";
# my $i; for ($i=0;$i<@return_array;$i++) { printf "%20s => %s\n", ${$order}[$i], $return_array[$i]; } <STDIN>;
return (@return_array);
}
sub maxp_get_number_of_glyph {
my $self = shift;
my $fh = $self->get_file_handle();
my $buf;
seek( $fh, $self->get_table_address("maxp"), 0 );
read( $fh, $buf, 6 );
my ($num_glyph) = unpack( "x4n", $buf );
return $num_glyph;
}
1;