Demonstration of snow falling /Processing による雪の降下デモ

snowfalling2.pde

class Crystal {
  float x, y, phi;
  
  Crystal(float x0, float y0, float phi0) {
    x = x0;
    y = y0;
    phi = phi0;
  }
  
  void fall() {
    y++;
  }
  
  void show() {
    noStroke();
    ellipse(x, y, phi, phi);
  }
}

ArrayList<Crystal> crystals = new ArrayList<Crystal>(100);

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

  for (int i = 0; i < 100; i++) {
    crystals.add(new Crystal(random(width), random(height), 20));
  }
}

void draw() {
  background(180);
  for (Crystal x: crystals) {
    x.show();
    x.fall();
  }
}

void mouseReleased() {
  crystals.add(new Crystal(mouseX, mouseY, 20));
}