class Bullet extends ParticleWrapper2D { int maxAge; Bullet(Particle p) { super(p); maxAge = 25; } void update() { if ( age() > maxAge ) { kill(); } } void draw() { float r = random(0.5, 2.5); float a = map(age(), 0, maxAge, 255, 10); stroke(200, 255, 255, a); noFill(); ellipse(x(), y(), r, r); } }