var x2, y2; // control point 1

var x3, y3; // point 2

var x4, y4; // control point 2

var a = 0;

​

function setup() {

  createCanvas(windowWidth,windowHeight);

  ellipseMode(CENTER); 

​

  background(0);

  strokeWeight(3);

}

​

function draw() {

    // Simulate fade-out:

  x1 = mouseX;//

  y1 = height-mouseY;

  x2 = width-mouseX;

  y2 =  map(mouseY, 0 , height,-500, height+500);;

  x3 = mouseX;

  y3 = height-mouseY;

  x4 = width-mouseX;

  y4 =  map(mouseY, 0 , height,-200, height+200);;

  noStroke();

  fill(0, 10);

  rect(0, 0, width, height);

  // Draw bezier shapes:

  fill(255, 50);

​

  x2 = 250 + (sin(radians(a)) * 355);

  x3 = 250 - (cos(radians(a)) * 355);

  noFill();

  stroke(255, 155 + sin(radians(a * 2)) * 100, 155 + cos(radians(a * 2)) * 100);

  bezier(x1, y1, x2, y2, x3, y3, x4, y4);

​

  x2 = 250 - (sin(radians(a)) * 355);

  x3 = 250 + (cos(radians(a)) * 355);

  stroke(255, 155 + sin(radians(a * 2)) * 100, 155 + cos(radians(a * 2)) * 100);

  bezier(x1, y1, x2, y2, x3, y3, x4, y4);

​

  a += 15; // increase angle (animate)

}