        onclick="toggleOpacity()"
                id="toggleOpacity"
              />
              <div class="button" title="Opacity">
                <i class="off material-icons">opacity</i>
                <i class="on material-icons">opacity</i>
              </div>
            </label>
            <!--Scale/zoom toggle-->
            <label for="toggleScale">
              <input type="checkbox" onclick="toggleScale()" id="toggleScale" />
              <div class="button" title="Scale">
             