client_hints-8.x-1.0-alpha3/client_hints.module

<?php

/**
 * @file
 * Contains hook implementations for Client Hints.
 */

/**
 * Build an appropriately sized svg data string.
 */
function _client_hints_placeholder_svg($width, $height) {
  $source = '<svg width="' . $width . '" height="' . $height . '" xmlns="http://www.w3.org/2000/svg">
 <g>
  <rect fill="none" id="canvas_background" height="' . $height . '" width="' . $width . '" y="-1" x="-1"/>
 </g>
</svg>';

  return 'data: image/svg+xml;base64,' . base64_encode($source);
}