text: let xPosArr = [ 20, 30, 180, 250, 462 ];
  
  function setup() {
      createCanvas( windowWidth, 400 );
  }
  
  let yPos = 0;
  function draw() {
      background( 'rgb( 200, 37, 52 )' );
      
      stroke( 255 );
      fill( 'rgb( 100, 255, 0 )' );
      
      for( let idx = 0; idx < xPosArr.length; idx++ ) {
          // draw some boxes!
          rect( xPosArr[idx], yPos, 20, 40 ); 
      }
      
      yPos = (yPos + 1) % windowHeight;  
  }