void setup() {
 size(500,500);
 noStroke();
}

float t=0;
int[][] colors={
 {255,0,0},
 {0,255,0},
 {0,0,255}
};

int[] modes={SUBTRACT,ADD};

void draw() {
 t+=0.01;
 
// background(0);
 
 float dt=t*1.2;
 int phase=int(dt)%2;
 int jk=3;
 for (int j=0;j<jk;j++){
  blendMode(modes[(j+phase)%2]);
   
  float k=1-((float(j)-dt%1)/float(jk-1));
  for (int i=0;i<3;i++){
   fill(colors[i][0],colors[i][1],colors[i][2]);
  
   float r=k*500;
   float l=max(250.0-(k+i*0.1)*400.0,0.0);
   float a=dt*1.97+i*TWO_PI/3;
   float x=250+l*cos(a*4);
   float y=250+l*sin(a*4);
   ellipse(x,y,r,r);
  }
 }
 
 //if (dt>=2 && dt<6){
 // saveFrame("frames/frame#####.png");
 //}
}