/usr/local/CPAN/Image-Caa/Image/Caa/DitherOrdered8.pm

• package Image::Caa::DitherOrdered8
  • new
  • init
  • get
  • increment
• EOF

package Image::Caa::DitherOrdered8;

use strict;
use warnings;

sub new {
	my ($class, $args) = @_;

	my $self = bless {}, $class;

	return $self;
}

sub init {
	my ($self, $line) = @_;

	$self->{table} = [
		0x00, 0x80, 0x20, 0xa0, 0x08, 0x88, 0x28, 0xa8,
		0xc0, 0x40, 0xe0, 0x60, 0xc8, 0x48, 0xe8, 0x68,
		0x30, 0xb0, 0x10, 0x90, 0x38, 0xb8, 0x18, 0x98,
		0xf0, 0x70, 0xd0, 0x50, 0xf8, 0x78, 0xd8, 0x58,
		0x0c, 0x8c, 0x2c, 0xac, 0x04, 0x84, 0x24, 0xa4,
		0xcc, 0x4c, 0xec, 0x6c, 0xc4, 0x44, 0xe4, 0x64,
		0x3c, 0xbc, 0x1c, 0x9c, 0x34, 0xb4, 0x14, 0x94,
		0xfc, 0x7c, 0xdc, 0x5c, 0xf4, 0x74, 0xd4, 0x54,
	];

	my $skip = ($line % 8) * 8;
	shift @{$self->{table}} for 1..$skip;

	$self->{index} = 0;
}

sub get {
	my ($self) = @_;

	return $self->{table}->[$self->{index}];
}

sub increment {
	my ($self) = @_;

	$self->{index} = ($self->{index} + 1) % 8;
}

1;