File Coverage

blib/lib/Barcode/DataMatrix/Reed.pm

Criterion	Covered	Total	%
statement	31	32	96.8
branch	7	12	58.3
condition			n/a
subroutine	7	8	87.5
pod	4	4	100.0
total	49	56	87.5

package Barcode::DataMatrix::Reed;

=head1 Barcode::DataMatrix::Reed

This is just a renamed version of Algorithm::DataMatrix::Reed
by Mons Anderson
from http://code.google.com/p/perl-ex/

For a rough explanation of the structure of this code, see
L.
Note that the link is not the basis of the implementation (this is unknown),
however it helps explain how Reed-Solomon encoding is implemented and hence
how the code below works.

=cut

use strict;
use warnings;
use Carp;

our (@GFI,@GFL,%POLY,$DEBUG);
our $N = 255;

=head2 DEBUG

Control whether or not debugging output is printed.

=cut

sub DEBUG { 0 }

=head2 mult (x, y)

Multiply two Galois field element values and return the result.

=cut

sub mult {
    my ($x, $y) = @_;
	return 0 unless $x * $y;
	return $GFI[($GFL[$x] + $GFL[$y]) % $N];
}

=head2 encode (ai, j)

Encode the message array and return it.

=cut

sub encode {
	my ($ai,$j) = @_;
	my $i = @$ai;
	for (0..$#$ai) {
		( $ai->[$_] & 0xFF ) != $ai->[$_] and warn("number $ai->[$_] at index $_ is not a byte size"), $ai->[$_] = $ai->[$_] & 0xFF;
	}
	warn "CalcReed: ai [@$ai], $j\n" if DEBUG;
	my $p = exists $POLY{$j} ? $POLY{$j} : $POLY{68};
	warn "CalcReed: poly [@$p]\n" if DEBUG;
	@$ai[ $i .. $i + $j - 1 ] = (0) x $j;
	for my $l(0 .. $i - 1) {
		my $word0 = ($ai->[$i] ^ $ai->[$l]);
		for my $i1 (0 .. $j - 2) {
			$ai->[$i + $i1] = ( $ai->[$i + $i1 + 1] ^ mult($word0, $p->[$i1]) );
		}
		$ai->[$i+$j-1] = mult($word0, $p->[$j - 1]);
	}
	warn "CalcReed: result [@$ai]\n" if DEBUG;
	return $ai;
}

=head2 decode

Decode the message array.  Currently not implemented.

=cut

sub decode {
	croak "not implemented";
}

BEGIN {
	@GFI = ( 1, 2, 4, 8, 16, 32, 64, 128, 45, 90, 180, 69, 138, 57, 114, 228, 229, 231, 227, 235, 251, 219, 155, 27, 54, 108, 216, 157, 23, 46, 92, 184, 93, 186, 89, 178, 73, 146, 9, 18, 36, 72, 144, 13, 26, 52, 104, 208, 141, 55, 110, 220, 149, 7, 14, 28, 56, 112, 224, 237, 247, 195, 171, 123, 246, 193, 175, 115, 230, 225, 239, 243, 203, 187, 91, 182, 65, 130, 41, 82, 164, 101, 202, 185, 95, 190, 81, 162, 105, 210, 137, 63, 126, 252, 213, 135, 35, 70, 140, 53, 106, 212, 133, 39, 78, 156, 21, 42, 84, 168, 125, 250, 217, 159, 19, 38, 76, 152, 29, 58, 116, 232, 253, 215, 131, 43, 86, 172, 117, 234, 249, 223, 147, 11, 22, 44, 88, 176, 77, 154, 25, 50, 100, 200, 189, 87, 174, 113, 226, 233, 255, 211, 139, 59, 118, 236, 245, 199, 163, 107, 214, 129, 47, 94, 188, 85, 170, 121, 242, 201, 191, 83, 166, 97, 194, 169, 127, 254, 209, 143, 51, 102, 204, 181, 71, 142, 49, 98, 196, 165, 103, 206, 177, 79, 158, 17, 34, 68, 136, 61, 122, 244, 197, 167, 99, 198, 161, 111, 222, 145, 15, 30, 60, 120, 240, 205, 183, 67, 134, 33, 66, 132, 37, 74, 148, 5, 10, 20, 40, 80, 160, 109, 218, 153, 31, 62, 124, 248, 221, 151, 3, 6, 12, 24, 48, 96, 192, 173, 119, 238, 241, 207, 179, 75, 150 );
	@GFL = ( 0, 0, 1, 240, 2, 225, 241, 53, 3, 38, 226, 133, 242, 43, 54, 210, 4, 195, 39, 114, 227, 106, 134, 28, 243, 140, 44, 23, 55, 118, 211, 234, 5, 219, 196, 96, 40, 222, 115, 103, 228, 78, 107, 125, 135, 8, 29, 162, 244, 186, 141, 180, 45, 99, 24, 49, 56, 13, 119, 153, 212, 199, 235, 91, 6, 76, 220, 217, 197, 11, 97, 184, 41, 36, 223, 253, 116, 138, 104, 193, 229, 86, 79, 171, 108, 165, 126, 145, 136, 34, 9, 74, 30, 32, 163, 84, 245, 173, 187, 204, 142, 81, 181, 190, 46, 88, 100, 159, 25, 231, 50, 207, 57, 147, 14, 67, 120, 128, 154, 248, 213, 167, 200, 63, 236, 110, 92, 176, 7, 161, 77, 124, 221, 102, 218, 95, 198, 90, 12, 152, 98, 48, 185, 179, 42, 209, 37, 132, 224, 52, 254, 239, 117, 233, 139, 22, 105, 27, 194, 113, 230, 206, 87, 158, 80, 189, 172, 203, 109, 175, 166, 62, 127, 247, 146, 66, 137, 192, 35, 252, 10, 183, 75, 216, 31, 83, 33, 73, 164, 144, 85, 170, 246, 65, 174, 61, 188, 202, 205, 157, 143, 169, 82, 72, 182, 215, 191, 251, 47, 178, 89, 151, 101, 94, 160, 123, 26, 112, 232, 21, 51, 238, 208, 131, 58, 69, 148, 18, 15, 16, 68, 17, 121, 149, 129, 19, 155, 59, 249, 70, 214, 250, 168, 71, 201, 156, 64, 60, 237, 130, 111, 20, 93, 122, 177, 150 );
	%POLY = (
	5   => [62, 111, 15, 48, 228],
	7   => [254, 92, 240, 134, 144, 68, 23],
	10  => [61, 110, 255, 116, 248, 223, 166, 185, 24, 28],
	11  => [120, 97, 60, 245, 39, 168, 194, 12, 205, 138, 175],
	12  => [242, 100, 178, 97, 213, 142, 42, 61, 91, 158, 153, 41],
	14  => [185, 83, 186, 18, 45, 138, 119, 157, 9, 95, 252, 192, 97, 156],
	18  => [188, 90, 48, 225, 254, 94, 129, 109, 213, 241, 61, 66, 75, 188, 39, 100, 195, 83],
	20  => [172, 186, 174, 27, 82, 108, 79, 253, 145, 153, 160, 188, 2, 168, 71, 233, 9, 244, 195, 15],
	24  => [193, 50, 96, 184, 181, 12, 124, 254, 172, 5, 21, 155, 223, 251, 197, 155, 21, 176, 39, 109, 205, 88, 190, 52],
	28  => [255, 93, 168, 233, 151, 120, 136, 141, 213, 110, 138, 17, 121, 249, 34, 75, 53, 170, 151, 37, 174, 103, 96, 71, 97, 43, 231, 211],
	36  => [112, 81, 98, 225, 25, 59, 184, 175, 44, 115, 119, 95, 137, 101, 33, 68, 4, 2, 18, 229, 182, 80, 251, 220, 179, 84, 120, 102, 181, 162, 250, 130, 218, 242, 127, 245],
	42  => [5, 9, 5, 226, 177, 150, 50, 69, 202, 248, 101, 54, 57, 253, 1, 21, 121, 57, 111, 214, 105, 167, 9, 100, 95, 175, 8, 242, 133, 245, 2, 122, 105, 247, 153, 22, 38, 19, 31, 137, 193, 77],
	48  => [19, 225, 253, 92, 213, 69, 175, 160, 147, 187, 87, 176, 44, 82, 240, 186, 138, 66, 100, 120, 88, 131, 205, 170, 90, 37, 23, 118, 147, 16, 106, 191, 87, 237, 188, 205, 231, 238, 133, 238, 22, 117, 32, 96, 223, 172, 132, 245],
	56  => [46, 143, 53, 233, 107, 203, 43, 155, 28, 247, 67, 127, 245, 137, 13, 164, 207, 62, 117, 201, 150, 22, 238, 144, 232, 29, 203, 117, 234, 218, 146, 228, 54, 132, 200, 38, 223, 36, 159, 150, 235, 215, 192, 230, 170, 175, 29, 100, 208, 220, 17, 12, 238, 223, 9, 175],
	62  => [204, 11, 47, 86, 124, 224, 166, 94, 7, 232, 107, 4, 170, 176, 31, 163, 17, 188, 130, 40, 10, 87, 63, 51, 218, 27, 6, 147, 44, 161, 71, 114, 64, 175, 221, 185, 106, 250, 190, 197, 63, 245, 230, 134, 112, 185, 37, 196, 108, 143, 189, 201, 188, 202, 118, 39, 210, 144, 50, 169, 93, 242],
	68  => [186, 82, 103, 96, 63, 132, 153, 108, 54, 64, 189, 211, 232, 49, 25, 172, 52, 59, 241, 181, 239, 223, 136, 231, 210, 96, 232, 220, 25, 179, 167, 202, 185, 153, 139, 66, 236, 227, 160, 15, 213, 93, 122, 68, 177, 158, 197, 234, 180, 248, 136, 213, 127, 73, 36, 154, 244, 147, 33, 89, 56, 159, 149, 251, 89, 173, 228, 220],
	);
}

1;