text: define([], function () {
      function VolumeMenu(windowfield) // constructor. 
      {
          PIXI.Container.call(this);
          this.fadetime = 1000;
          this.visible = false;
          this.alpha = 1;
          this.t0 = 0;
  
          this.mastertext = new PIXI.Text('MASTER', {fontFamily: 'Comfortaa', fontSize: 20, fill: ['#ffffff']});
          this.mastertext.anchor.set(0.5);
          this.volumetext = new PIXI.Text('', {fontFamily: 'Comfortaa', fontSize: 40, fill: ['#ffffff']});
          this.volumetext.anchor.set(0.5);
          this.addChild(this.mastertext);
          this.addChild(this.volumetext);
  
          this.resize = function (windowfield) {
              this.mastertext.x = windowfield.width - 100;
              this.mastertext.y = windowfield.height / 2 - 30;
              this.volumetext.x = windowfield.width - 100;
              this.volumetext.y = windowfield.height / 2 + 10;
          }
          this.resize(windowfield);
  
          this.setVolume = function (volume) {
              this.changed = true;
              this.volumetext.text = Math.round(volume).toString();
          }
  
          this.update = function (timestamp) {
              if (this.changed) {
                  this.visible = true;
                  this.t0 = timestamp;
                  this.changed = false;
              }
              if (!this.visible)
                  return;
              let dt = timestamp - this.t0;
              if (dt > this.fadetime) {
                  this.visible = false;
              } else {
                  this.alpha = 1 - Math.pow(dt / this.fadetime, 5);
              }
          }
  
      }
  
      if (PIXI.Container) {
          VolumeMenu.__proto__ = PIXI.Container;
      }
      VolumeMenu.prototype = Object.create(PIXI.Container && PIXI.Container.prototype);
      VolumeMenu.prototype.constructor = VolumeMenu;
  
  
      VolumeMenu.prototype.destroy = function destroy(options) {
          PIXI.Container.prototype.destroy.call(this, options);
      };
  
      return VolumeMenu;
  
  });