lassList.add("hidden");
      },
      canvas: (() => {
        var canvas = document.getElementById('canvas');

        // As a default initial behavior, pop up an alert when webgl context is lost. To make your
        // application robust, you may want to override this behavior before shipping!
        // See http://www.khronos.org/registry/webgl/specs/latest/1.0/#5.15.2
        // output("Add event listener to canvas")
        canvas.addEventListener("webglcontextlost", (e) => {
          output('WebGL 