add custom fields to post

// Add Custom Fields
add_action ('genesis_entry_content', 'rp_painting' );
function rp_painting() {
	if ( ! ( is_single() ) ) {
		return;
	}
	
	// These are the custom field keys defined in the dashboard:
	$metas_painting = array(
		'painting-image', 
		'painting-alt-text', 
		'painting-video', 
		'painting-archive-image', 
		'painting-medium', 
		'painting-signed',
		'painting-size',
		'painting-year',
		'painting-price',
	);
	
	// If _any_ ACF field is filled in, it's a go.
	$has_meta = false; // init
	foreach ($metas_painting as $test ) {
		if ( get_field($test) ) {
			$has_meta = true;
			continue; // Just need one meta field filled to create the div.
		}
	}
	if ( $has_meta ) {
		echo '<div class="custom-data painting-custom-data">';
		echo '<h2>Painting Details:</h2>';
		foreach ( $metas_painting as $meta_painting ) {
			$$meta_painting = get_field($meta_painting);
			if ( $$meta_painting ) {
				$f_object = get_field_object($meta_painting);
				$label = $f_object['label'];
				echo '<div class="' . $meta_painting . '">' .
				'<span class="label">' . $label . ':</span> ' . 
				'<span class="value">' . $$meta_painting . '</span>' . 
				'</div>';
			}
		}
		echo '</div><!-- /.custom-data -->';
	}
}