burst

int num=60, framesAmount=120;
float t, dx;
float[] r = new float[num];
float[] x = new float[num];
void setup() {
  size(500, 500);
  background(0);
  for (int i=0; i<num; i++) {
    x[i]=0;
    r[i]=TWO_PI/num*i;
    dx=1.0/framesAmount;
  }
}

void draw() {
  fill(#322030, 30);
  noStroke();
  rect(0, 0, width, height);
  stroke(#FCFDEB, 100);
  strokeWeight(2);
  t+=dx;
  translate(width/2, height/2);
  for (int i=0; i<num; i++) {
    float offSet=TWO_PI/num*i;
    pushMatrix();
    rotate(offSet);
    float sz = 100;
    x[i] = ease(t, 1.0, 4.0)*(sqrt(sq(width/2)+sq(height/2)));
    pushMatrix();
    translate(x[i], 0);
    rotate(r[i]);
    line(0, sz/2, 0, -sz/2);
    popMatrix();
    popMatrix();
    r[i] += 0.1;
  }
  //if (frameCount%2==0 && frameCount>240 && frameCount<361) saveFrame("image-##.gif");
  if (frameCount%framesAmount==0) {
    t=0;
    for (int i=0; i<num; i++) x[i]=0;    //noLoop();
  }
}

float ease(float t, float e) {
  return t<0.5? 0.5*pow(2*t, e) : 1 - 0.5*pow(2*(1 - t), e);
}
float ease(float t, float in, float out) {
  return (1-t)*ease(t, in) + t*ease(t, out);
}