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package GD::Barcode::EAN13;
use strict;
use warnings;
use GD::Barcode;
our $VERSION = '2.00';
use parent qw(Exporter);
use vars qw($VERSION @ISA $errStr);
@ISA     = qw(GD::Barcode Exporter);
my $leftOddBar = {
    '0' => '0001101',
    '1' => '0011001',
    '2' => '0010011',
    '3' => '0111101',
    '4' => '0100011',
    '5' => '0110001',
    '6' => '0101111',
    '7' => '0111011',
    '8' => '0110111',
    '9' => '0001011'
};
my $leftEvenBar = {
    '0' => '0100111',
    '1' => '0110011',
    '2' => '0011011',
    '3' => '0100001',
    '4' => '0011101',
    '5' => '0111001',
    '6' => '0000101',
    '7' => '0010001',
    '8' => '0001001',
    '9' => '0010111'
};
my $rightBar = {
    '0' => '1110010',
    '1' => '1100110',
    '2' => '1101100',
    '3' => '1000010',
    '4' => '1011100',
    '5' => '1001110',
    '6' => '1010000',
    '7' => '1000100',
    '8' => '1001000',
    '9' => '1110100'
};
my $guardBar    = 'G0G';
my $centerBar   = '0G0G0';
my $oddEven4EAN = {
    0 => 'OOOOOO',
    1 => 'OOEOEE',
    2 => 'OOEEOE',
    3 => 'OOEEEO',
    4 => 'OEOOEE',
    5 => 'OEEOOE',
    6 => 'OEEEOO',
    7 => 'OEOEOE',
    8 => 'OEOEEO',
    9 => 'OEEOEO'
};
sub new {
    my ( $sClass, $sTxt ) = @_;
    $errStr = '';
    my $oThis = {};
    bless $oThis, $sClass;
    return if ( $errStr = $oThis->init($sTxt) );
    return $oThis;
}
sub init {
    my ( $oThis, $sTxt ) = @_;
    #Check
    return 'Invalid Characters' if ( $sTxt =~ /[^0-9]/ );
    #CalcCd
    if ( length($sTxt) == 12 ) {
        $sTxt .= calcEAN13CD($sTxt);
    }
    elsif ( length($sTxt) == 13 ) {
        ;
    }
    else {
        return 'Invalid Length';
    }
    $oThis->{text} = $sTxt;
    return '';
}
sub calcEAN13CD {
    my ($sTxt) = @_;
    my ( $i, $iSum );
    my @aWeight = ( 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3 );
    $iSum = 0;
    for ( $i = 0 ; $i < 12 ; $i++ ) {
        $iSum += substr( $sTxt, $i, 1 ) * $aWeight[$i];
    }
    $iSum %= 10;
    $iSum = ( $iSum == 0 ) ? 0 : ( 10 - $iSum );
    return "$iSum";
}
sub barcode {
    my ($oThis) = @_;
    my ($sTxt);
    my ( $oddEven, $i, $sBar );
    my ($sRes);
    #(1)Init
    $sTxt = $oThis->{text};
    $sRes = $guardBar;        #GUARD
    #(2)Left 7 letters
    $oddEven = $oddEven4EAN->{ substr( $sTxt, 0, 1 ) };
    for ( $i = 1 ; $i < 7 ; $i++ ) {
        $sBar =
          ( substr( $oddEven, $i - 1, 1 ) eq 'O' ) ? $leftOddBar : $leftEvenBar;
        $sRes .= GD::Barcode::barPtn( substr( $sTxt, $i, 1 ), $sBar );
    }
    #(4)Center
    $sRes .= $centerBar;
    #(5)Right
    for ( $i = 7 ; $i < 13 ; $i++ ) {
        $sRes .= GD::Barcode::barPtn( substr( $sTxt, $i, 1 ), $rightBar );
    }
    #(6)GUARD
    $sRes .= $guardBar;
    return $sRes;
}
sub plot {
    my ( $oThis, %hParam ) = @_;
    #Barcode Pattern
    my $sPtn = $oThis->barcode();
    #Create Image
    require GD;
    my $iHeight = ( $hParam{Height} ) ? $hParam{Height} : 50;
    my ( $oGd, $cBlack );
    if ( $hParam{NoText} ) {
        ( $oGd, $cBlack ) =
          GD::Barcode::plot( $sPtn, length($sPtn), $iHeight, 0, 0 );
    }
    else {
        my ( $fW, $fH ) = ( GD::Font->Small->width, GD::Font->Small->height );
        my $iWidth = length($sPtn) + $fW + 1;
        ( $oGd, $cBlack ) =
          GD::Barcode::plot( $sPtn, $iWidth, $iHeight, $fH, $fW + 1 );
        $oGd->string(
            GD::Font->Small, 0,
            $iHeight - $fH,
            substr( $oThis->{text}, 0, 1 ), $cBlack
        );
        $oGd->string(
            GD::Font->Small, $fW + 8,
            $iHeight - $fH,
            substr( $oThis->{text}, 1, 6 ), $cBlack
        );
        $oGd->string(
            GD::Font->Small, $fW + 55,
            $iHeight - $fH,
            substr( $oThis->{text}, 7, 6 ), $cBlack
        );
    }
    return $oGd;
}
1;
__END__
HideShow 89 lines of Pod
=head1 NAME
GD::Barcode::EAN13 - Create EAN13(JAN13) barcode image with GD
=head1 SYNOPSIS
I<ex. CGI>
  use GD::Barcode::EAN13;
  binmode(STDOUT);
  print "Content-Type: image/png\n\n";
  print GD::Barcode::EAN13->new('123456789012')->plot->png;
I<with Error Check>
  my $oGdBar = GD::Barcode::EAN13->new('123456789');
  die $GD::Barcode::EAN13::errStr unless($oGdBar);      #Invalid Length
=head1 DESCRIPTION
GD::Barcode::EAN13 is a subclass of GD::Barcode and allows you to
create EAN13(JAN13) barcode image with GD.
This module based on "Generate Barcode Ver 1.02 By Shisei Hanai 97/08/22".
=head2 new
I<$oGdBar> = GD::Barcode::EAN13->new(I<$sTxt>);
Constructor.
Creates a GD::Barcode::EAN13 object for I<$sTxt>.
I<$sTxt> has 12 or 13 numeric characters([0-9]).
If I<$sTxt> has 12 characters, this module calacurates CD for you.
=head2 plot()
I<$oGd> = $oGdBar->plot([Height => I<$iHeight>, NoText => I<0 | 1>]);
creates GD object with barcode image for the I<$sTxt> specified at L<new> method.
I<$iHeight> is height of the image. If I<NoText> is 1, the image has no text image of I<$sTxt>.
 ex.
  my $oGdB = GD::Barcode::EAN13->new('123456789012');
  my $oGD = $oGdB->plot(NoText=>1, Height => 20);
  # $sGD is a GD image with Height=>20 pixels, with no text.
=head2 barcode()
I<$sPtn> = $oGdBar->barcode();
returns a barcode pattern in string with '1', 'G' and '0'.
'1' means black, 'G' also means black but little bit long,
'0' means white.
 ex.
  my $oGdB = GD::Barcode::EAN13->new('123456789012');
  my $sPtn = $oGdB->barcode();
  # $sPtn = '';
=head2 $errStr
$GD::Barcode::EAN13::errStr
has error message.
=head2 $text
$oGdBar->{$text}
has barcode text based on I<$sTxt> specified in L<new> method.
=head1 AUTHOR
Kawai Takanori GCD00051@nifty.ne.jp
=head1 COPYRIGHT
The GD::Barocde::EAN13 module is Copyright (c) 2000 Kawai Takanori. Japan.
All rights reserved.
You may distribute under the terms of either the GNU General Public
License or the Artistic License, as specified in the Perl README file.
=head1 SEE ALSO
GD::Barcode
=cut