old_contents: // Copyright 2018, University of Colorado Boulder
  
  /**
   * Utility type for rendering to a canvas via putImageData.
   *
   * @author Sam Reid (PhET Interactive Simulations)
   */
  define( require => {
    'use strict';
  
    // modules
    const waveInterference = require( 'WAVE_INTERFERENCE/waveInterference' );
  
    class ImageDataRenderer {
  
      /**
       * @param {Lattice} lattice
       * @param {number} width
       */
      constructor( lattice, width ) {
        const height = lattice.height - lattice.dampY * 2;
  
        // @public {HTMLCanvasElement}
        this.canvas = document.createElement( 'canvas' );
        this.canvas.width = width;
        this.canvas.height = height;
  
        // @private
        this.context = this.canvas.getContext( '2d' );
  
        // @private
        this.imageData = this.context.createImageData( width, height );
  
        // @public {Uint8ClampedArray} - One-dimensional array containing the data in the RGBA order, with integer values
        // between 0 and 255 (inclusive).
        this.data = this.imageData.data;
      }
  
      /**
       * Paints image data onto the canvas.
       * @param {number} x
       * @param {number} y
       */
      putImageData( x = 0, y = 0 ) {
        this.context.putImageData( this.imageData, x, y );
      }
    }
  
    return waveInterference.register( 'ImageDataRenderer', ImageDataRenderer );
  } );
new_contents: // Copyright 2018, University of Colorado Boulder
  
  /**
   * Utility type for rendering to a canvas via putImageData.
   *
   * @author Sam Reid (PhET Interactive Simulations)
   */
  define( require => {
    'use strict';
  
    // modules
    const waveInterference = require( 'WAVE_INTERFERENCE/waveInterference' );
  
    class ImageDataRenderer {
  
      /**
       * @param {width} width
       * @param {number} width
       */
      constructor( width, height ) {
  
        // @public {HTMLCanvasElement}
        this.canvas = document.createElement( 'canvas' );
        this.canvas.width = width;
        this.canvas.height = height;
  
        // @private
        this.context = this.canvas.getContext( '2d' );
  
        // @private
        this.imageData = this.context.createImageData( width, height );
  
        // @public {Uint8ClampedArray} - One-dimensional array containing the data in the RGBA order, with integer values
        // between 0 and 255 (inclusive).
        this.data = this.imageData.data;
      }
  
      /**
       * Paints image data onto the canvas.
       * @param {number} x
       * @param {number} y
       */
      putImageData( x = 0, y = 0 ) {
        this.context.putImageData( this.imageData, x, y );
      }
    }
  
    return waveInterference.register( 'ImageDataRenderer', ImageDataRenderer );
  } );
subject: Change signature of ImageDataRenderer constructor to (width, height), see https://github.com/phetsims/wave-interference/issues/277