var rectX = [];

var rectY = [];

var rectWidth = [];

var rectHeight = [];



var colors = [];

var time;



function setup() {

  createCanvas(windowWidth,

               windowHeight);

  angleMode(DEGREES);

  rectMode(CENTER);



  for (var i = 90; i > 0; i = i - 5) {

    rectX[i] = windowWidth / 2;

    rectY[i] = windowHeight / 2;

    rectWidth[i] = i * (windowHeight / 90);

    rectHeight[i] = windowHeight * sin(i);

  }



  colors.push(color(25, 15, 40, 50));

  colors.push(color(90, 160, 245, 128));

  colors.push(color(120, 250, 125, 100));

  colors.push(color(170, 255, 255, 150));

  colors.push(color(255, 200, 100, 40));



  time = 0;

}



function draw() {

  background(500, 500, 500);

  strokeWeight(6);

  stroke(150, 150, 150, 50);

  

  for (var i = 90; i > 0; i = i - 5) {

    var c = getColor(i / 90);

    fill(c);

    rect(rectX[i] + 60 * sin(3.0 * i + time), rectY[i], rectWidth[i], rectHeight[i]);

  }



  time = time + 1;

}



function getColor(t) {

  t = constrain(t, 0.000, 0.9999);

  var p = t * (colors.length - 1);

  var from = floor(p);

  return lerpColor(colors[from], colors[from + 1], p - from);

}