// Dartmouth CS 2, Winter 2009, Chris Bailey-Kellogg
// Notes 13 | Sketch 3
// Based on R&F 50-08 and Processing example Topics | Simulate | SimpleParticleSystem

int num = 100;  // total number of particles
int curr = 1;   // how many are active
Particle[] particles = new Particle[num];

void setup()
{
  size(200,200);
  smooth();
  noStroke();
  background(0);
  
  // Create the particles
  for (int i=0; i<num; i++)
    particles[i] = new Particle(width/2, height/2); 
}

void draw()
{
  fill(0,10);
  rect(0,0,width,height);
  // Draw and update however many have been allowed to enter
  // (one per frame, till all have entered)
  for (int i=0; i<curr; i++) particles[i].draw();
  for (int i=0; i<curr; i++) particles[i].update();
  if (curr<num) curr++;  // bring in the next
}