WordPress custom post types prev and next logic

thing.php

		<?php
		$projects = array();
        $loop = new WP_Query(array('post_type' => array('work'), 'posts_per_page' => -1, 'order' => 'ASC'));
        $i = 1;
        $current = FALSE;
        $current_post_id = $post->ID;
        while ($loop->have_posts()) : $loop->the_post();

            $projects[$i]['title'] = get_field('grid_title');
            $projects[$i]['url'] = get_permalink();

            if ($current_post_id == $post->ID) {
                $current = $i;
            }

        $i++;
        endwhile;
        wp_reset_postdata();


        $count = count($projects);

        // First in lineup
        if ($current == 1)
        {
            $prev = $projects[$current + 1];
            $next = $projects[$count];
        }
        // Last in lineup
        elseif ($current == $count)
        {
            $prev = $projects[1];
            $next = $projects[$count - 1];
        }
        // Normal
        else
        {
            $prev = $projects[$current + 1];
            $next = $projects[$current - 1];
        }
        ?>