GUI: unable to change basedata cellsize when origin is non-zero

[shawnlaffan]

The logic is faulty when the system snaps new cellsizes to multiples of the current cellsizes, when the origin is non-zero.

The code should not even be using the origin in this case.

[shawnlaffan]

The relevant code is at

biodiverse/lib/Biodiverse/GUI/Manager/BaseDatas.pm

Lines 775 to 797 in ddc901f

	foreach my $widget (@resolution_widgets) {
	$j++;
	$widget->signal_connect (
	'value-changed' => sub {
	my $val = $widget->get_value;
	# Avoid fmod - it causes grief with 0.2 cell sizes
	# prob due to floating point issues.
	# Precision should be configurable...
	my $offset = ($val - $origins_array[$j])
	/ $cellsize_array[$j];
	if ($cellsize_array[$j] < 1) {
	$offset = ($offset * 10e10 + 0.5) / 10e10;
	}
	$offset -= int $offset;
	# effectively zero given cell size constraints
	if ($offset > 10e-10) {
	$val -= $offset;
	$widget->set_value ($val);
	}
	return;
	}
	);
	}

It can be simplified to this:

    foreach my $widget (@resolution_widgets) {
        $j++;
        $widget->signal_connect (
            'value-changed' => sub {
                my $val = $widget->get_value;
                my $remainder = fmod ($val, $cellsize_array[$j]);
                if (abs ($remainder) > 10e-10) {
                    $widget->set_value ($val - $remainder);
                }
                return;
            }
        );
    }