how to a better and if loop for shortcode in php wordpress

I have created this wordpress module for a shortcode and was wondering if there is any better way of doing it, to make it more light weight.

below is my code

<?php

add_shortcode( 'logo_section', function($atts) {

    $output = '';

    $atts = shortcode_atts( array(
        // title
        'section-title' => '',
        'section-title-text' => '',
        'image-source' => '',
        'image-width' => '',
        'image-height' => '',
        'image-alt' => '',
        // logos
        'logo-1' => '','logo-1-image-source' => '','logo-1-alt' => '',

        'logo-2' => '','logo-2-image-source' => '','logo-2-alt' => '',

        'logo-3' => '','logo-3-image-source' => '','logo-3-alt' => '',

        'logo-4' => '','logo-4-image-source' => '','logo-4-alt' => '',

        'logo-5' => '','logo-5-image-source' => '','logo-5-alt' => '',

        'logo-6' => '','logo-6-image-source' => '','logo-6-alt' => '',

        'logo-7' => '','logo-1-image-source' => '','logo-7-alt' => '',

        'logo-8' => '','logo-2-image-source' => '','logo-8-alt' => '',

        'logo-9' => '','logo-3-image-source' => '','logo-9-alt' => '',

        'logo-10' => '','logo-4-image-source' => '','logo-10-alt' => '',

        'logo-11' => '','logo-5-image-source' => '','logo-11-alt' => '',

        'logo-12' => '','logo-6-image-source' => '','logo-12-alt' => '',    
    ), $atts );


        $output .= '<div class="logo-section clearfix">';   
            $output .= '<div class="logo-section--inner clearfix">'; 
                        if ($atts['section-title'] == 'true') {
                             $output .= '<h2 class="heading--small heading--bold heading--uppercase heading--sans-serif heading--center">'. $atts['section-title-text'] .'</h2>';
                        }  else {
                                $output .= '';
                        }
                        // first row
                        $output .= '<div class="logo-section--row clearfix">'; 
                            if ($atts['logo-1'] == 'true') {
                                 $output .= '<img src="' . $atts['logo-1-image-source'] . '" alt="' . $atts['logo-1-alt'] . '" />';
                            } else {
                                    $output .= '';
                            }

                            if ($atts['logo-2'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-2-image-source'] . '" alt="' . $atts['logo-2-alt'] . '" />';
                            }  

                            if ($atts['logo-3'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-3-image-source'] . '" alt="' . $atts['logo-3-alt'] . '" />';
                            }  else {
                                    $output .= '';
                            }

                            if ($atts['logo-4'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-4-image-source'] . '" alt="' . $atts['logo-4-alt'] . '" />';
                            } else {
                                    $output .= '';
                            }

                            if ($atts['logo-5'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-5-image-source'] . '" alt="' . $atts['logo-5-alt'] . '" />';
                            } else {
                                    $output .= '';
                            } 

                            if ($atts['logo-6'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-6-image-source'] . '" alt="' . $atts['logo-6-alt'] . '" />';
                            } else {
                                    $output .= '';
                            } 
                        $output .= '</div>'; 
                        // second row
                        $output .= '<div class="logo-section--row clearfix">'; 
                            if ($atts['logo-7'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-7-image-source'] . '" alt="' . $atts['logo-7-alt'] . '" />';
                            } else {
                                    $output .= '';
                            } 

                            if ($atts['logo-8'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-8-image-source'] . '" alt="' . $atts['logo-8-alt'] . '" />';
                            } else {
                                    $output .= '';
                            } 

                            if ($atts['logo-9'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-9-image-source'] . '" alt="' . $atts['logo-9-alt'] . '" />';
                            } else {
                                    $output .= '';
                            } 

                            if ($atts['logo-10'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-10-image-source'] . '" alt="' . $atts['logo-10-alt'] . '" />';
                            } else {
                                    $output .= '';
                            } 

                            if ($atts['logo-11'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-11-image-source'] . '" alt="' . $atts['logo-11-alt'] . '" />';
                            } else {
                                    $output .= '';
                            } 

                            if ($atts['logo-12'] == 'true') {
                                  $output .= '<img src="' . $atts['logo-12-image-source'] . '" alt="' . $atts['logo-12-alt'] . '" />';
                            } else {
                                    $output .= '';
                            }
                        $output .= '</div>'; 

            $output .= '</div>'; 
        $output .= '</div>';   

    return $output;
});

via Chebli Mohamed