package GFX::Enhancer::SingleLineAntialias;
sub new {
        my ($class, $imgrepr) = @_;
        my $self = { imgrepr => $imgrepr, };
        $class = ref($class) || $class;
        bless $self, $class;
}
sub filter {
        my ($self, $imgrepr, @rgba_points) = @_;
        my @non_return_rgba_points = @rgba_points;
        my @return_rgba_points = ();
        my @indexl = ();
        for (my $i = 0; $i < length(@rgba_points); $i++) {
                push (@indexl, @rgba_points[$i]->{index});
        }
        for (my $i = 0; $i < length(@rgba_points); $i++) {
                for (my $j = 0; $j < length(@rgba_points); $j++) {
                        ### grep points to be deleted  
                        my @non_return_rgba_points = grep { $_ != $self->grep(@indexl, @rgba_points) } @non_return_rgba_points;
                }
        }
        ### delete grepped points from resulting list
        for (my $i = 0; $i < length(@rgba_points); $i++) {
                if (not (@rgba_points[$i] ~~ @non_rgba_rgba_points)) {
                        push (@return_rgba_points, @rgba_points[$i]);
                }
        }
         
        return (@return_rgba_points);
}
sub grep {
        my ($self, @indexl, @rgbasl) = @_;
        my @grepped_points = (); ### these are scheduled for deletion
        for (my $i = 0; $i < length(@rgbasl); $i++) {
                if ((@rgbasl[$i]->{@rgbasl[$i]->{index} - $self->{imgrepr}->{width}}) % $self->{imgrepr}->{width} ~~ @indexl
                        and (@rgbasl[$i]->{@rgbasl[$i]->{index} - $self->{imgrepr}->{width} - 1}) % $self->{imgrepr}->{width} ~~ @indexl
                        and (@rgbasl[$i]->{@rgbasl[$i]->{index} - $self->{imgrepr}->{width} + 1}) % $self->{imgrepr}->{width} ~~ @indexl) {
                push (@grepped_points, @rgbasl[$i]);
                }
        }
        return (@grepped_points);       
}
1;