either the delta handed to show handler is wrong, or mis-documented

[wchristian]

The documentation on the topic says:

The first argument passed is the time, in seconds, since the previous call.

However, the code handling that looks like the following. Notable there is that between delta_time being determined, 1 or more runs of the move handler are done, which can take up considerable time. So either delta_time should be calculated specifically for the show handler, or the documentation amended to explain this better.

                my $new_time   = Time::HiRes::time;
                my $delta_time = $new_time - $_current_time{ $ref };
                next if $delta_time < $min_t;
                $_current_time{ $ref} = $new_time;
                my $delta_copy = $delta_time;

                while ( $delta_copy > $dt ) {
                        $self->_move( $ref, 1, $t ); #a full move
                        $delta_copy -= $dt;
                        $t += $dt;
                }
                my $step = $delta_copy / $dt;
                $self->_move( $ref, $step, $t ); #a partial move
                $t += $dt * $step;

                $self->_show( $ref, $delta_time );