Rotating rectangles(blue stroke)

//-----------------------------------------------
// Processing - processing.org
// Rotating rectangles(blue stroke) - by iomikron
//-----------------------------------------------

int numOfRectangles = 250;
Rectangle [] rectArray = new Rectangle[numOfRectangles];

void setup()
{
  size(300, 300);

  for(int i = 0; i <= numOfRectangles-1; i++)
  {
    rectArray[i] =
       new Rectangle(
                     random(20, width - 20), //coordinate X
                     random(20,height - 20), //coordinate Y
                     133, //color
                     20., //width
                     20., //height
                     PI/(random(i,i*i)), //angle (initial)
                     random(2.75,5.8), //angular Velocity (initial)
                     random(0.1,0.25)//rotate speed (initial)
                     );
  }
}

void draw()
{
  background(0);
   for(int i = 0; i <= numOfRectangles-1; i++)
  {
    rectArray[i].move();
  }
}

//--------------------------
//Rectangle CLASS DEFINITION
//--------------------------
class Rectangle
{
  float coordX;//horizontal coordinate for the center
  float coordY;//vertical coordinate for the center
  float rectColor;//color filling
 // float rectAlpha; Uncomment for opacity
  float rectWidth;//parameter for the width
  float widthConst;
  float rectHeight;//parameter for the height
  float angle;
  float angularVelocity;
  float rotationSpeed;

  //Constructor
  Rectangle(float X, float Y,
            float C,
            float W, float H,
            float a, float angV, float rotS)
  {
    coordX = X;
    coordY = Y;
    rectColor = C;
    rectWidth = W;
    widthConst = W;
    rectHeight = H;
    angle = a;
    angularVelocity = angV;
    rotationSpeed = rotS;
  }
  //FUNCTIONS FOR THE CLASS
  void display()
  {
    rectMode(CENTER);
    //define color and opacity
    stroke(color(0,133,255));
    fill(changeColor());
    //create the rectangle
    rect(0, 0, widthConst*changeWidth(), rectHeight);
  }

  void move()
  {
    pushMatrix();
    translate(coordX, coordY);
    rotate(radians(angle));

    display();

    popMatrix();

    changeAngle();

    changeWidth();
  }

  float changeAngle()
  {
    angle = angle + angularVelocity;
    return(angle);
  }

  float changeWidth()
  {
    float w;
    rectWidth = rectWidth + rotationSpeed;
    w = cos(rectWidth);
    return(w);
  }

  float changeColor()
  {
    float c;
    c = rectColor*cos(rectWidth)*cos(rectWidth) + 120;
    return(c);
  }

}