<?php
/**
 * Hide Posts Rendered by Featured Posts Area from Main Query
 */

//Create an Array to Store Post Ids of all posts that have been displayed already.
$berkeley_fpost_ids = array();
if ( get_theme_mod('berkeley_featposts_enable') ) :

    $args = array(
        'posts_per_page' => 3,
        'cat' => esc_html(get_theme_mod('berkeley_featposts_cat')),
        'ignore_sticky_posts' => true,
    );

    $lastposts = new WP_Query($args);

    while ( $lastposts->have_posts() ) :
        $lastposts->the_post();

        global $berkeley_fpost_ids;
        $berkeley_fpost_ids[] = get_the_id();

    endwhile;
    wp_reset_postdata();
endif;

add_action('pre_get_posts', 'berkeley_exclude_single_posts_home');
function berkeley_exclude_single_posts_home($query) {
    global $berkeley_fpost_ids;

    if ($query->is_home() && $query->is_main_query()) {
        $query->set('post__not_in', $berkeley_fpost_ids);
    }
}