//float bright = 100;
float bright;
float bright2;
float bright3;
float bright4;
float change = -10;
long myTime = 0;

void setup(){
 size(900,200); 
}

void draw() {
  background(0);
  myTime = millis();
  //fill(0, bright, 0);
  //noStroke();
  //ellipse(width/2 - 300, height/2, 100, 100);
  
   // bright += change;
  //if(bright <= 0){ //<>//
    //change = 5; //<>//
  //} else if (bright >= 255){ //<>//
    //change = -5; //<>//
  //}
  bright = 200.0*(sin(myTime/2000.0) + 1.0);
  bright += 40.0*(sin(myTime/200.0) + 1.0);
  fill(bright, 0, 100);
  noStroke();
  ellipse(width/2 -300, height/2, 100, 100);
  
  bright2 = 128.0*(sin(myTime/900.0) + 1.0);
  bright2 += 40.0*(sin(myTime/20.0) + 1.0);
  fill(0, 0, bright2);
  noStroke();
  ellipse(width/2 -100, height/2, 100, 100);
  
  bright3 = 900.0*(sin(myTime/700.0) + 1.0);
  bright3 += 20.0*(sin(myTime/900.0) + 1.0);
  fill(bright3, 0, 0);
  noStroke();
  ellipse(width/2 +100, height/2, 100, 100);
  
  bright4 = 100*(sin(myTime/3000.0) + 1.0);
  bright4 += 10*(cos(myTime/300.0) + 1.0);
  fill(0, bright4, 0);
  noStroke();
  ellipse(width/2 +300, height/2, 100, 100);
}