nd_lemniscate.pde

// ND Lemniscate rainbow curve in Processing: https://processing.org/

int iterations = 360;
int alphaDelta = 40;
int saturation = 170;

void setup(){
  size(800, 600);
  noStroke();
  colorMode(HSB);
  background(180);
}

void draw(){
  
  float x = sin(radians(frameCount));
  float y = sin(radians(frameCount)) * cos(radians(frameCount));
  
  if(frameCount < iterations){
    fill(map(frameCount, 0, iterations, 0, 255), saturation, 255);
  }else{
    alphaDelta += 10;
    fill(map(frameCount-iterations, 0, iterations, 0, 255), saturation, 255, 255 - alphaDelta);
  }
  
  translate(width/2, height/2);
  ellipse(x * 275, y * 205, 75, 75);
  
  if (frameCount == iterations + 30){
    noLoop();
  }
}