Initial Commit

Java/Processing/processing-3.3.6/modes/java/examples/Topics/Simulate/SimpleParticleSystem/Particle.pde

@@ -0,0 +1,43 @@
+// A simple Particle class
+
+class Particle {
+  PVector position;
+  PVector velocity;
+  PVector acceleration;
+  float lifespan;
+
+  Particle(PVector l) {
+    acceleration = new PVector(0, 0.05);
+    velocity = new PVector(random(-1, 1), random(-2, 0));
+    position = l.copy();
+    lifespan = 255.0;
+  }
+
+  void run() {
+    update();
+    display();
+  }
+
+  // Method to update position
+  void update() {
+    velocity.add(acceleration);
+    position.add(velocity);
+    lifespan -= 1.0;
+  }
+
+  // Method to display
+  void display() {
+    stroke(255, lifespan);
+    fill(255, lifespan);
+    ellipse(position.x, position.y, 8, 8);
+  }
+
+  // Is the particle still useful?
+  boolean isDead() {
+    if (lifespan < 0.0) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+}

Java/Processing/processing-3.3.6/modes/java/examples/Topics/Simulate/SimpleParticleSystem/ParticleSystem.pde

@@ -0,0 +1,26 @@
+// A class to describe a group of Particles
+// An ArrayList is used to manage the list of Particles 
+
+class ParticleSystem {
+  ArrayList<Particle> particles;
+  PVector origin;
+
+  ParticleSystem(PVector position) {
+    origin = position.copy();
+    particles = new ArrayList<Particle>();
+  }
+
+  void addParticle() {
+    particles.add(new Particle(origin));
+  }
+
+  void run() {
+    for (int i = particles.size()-1; i >= 0; i--) {
+      Particle p = particles.get(i);
+      p.run();
+      if (p.isDead()) {
+        particles.remove(i);
+      }
+    }
+  }
+}

Java/Processing/processing-3.3.6/modes/java/examples/Topics/Simulate/SimpleParticleSystem/SimpleParticleSystem.pde

@@ -0,0 +1,22 @@
+/**
+ * Simple Particle System
+ * by Daniel Shiffman.  
+ * 
+ * Particles are generated each cycle through draw(),
+ * fall with gravity and fade out over time
+ * A ParticleSystem object manages a variable size (ArrayList) 
+ * list of particles. 
+ */
+
+ParticleSystem ps;
+
+void setup() {
+  size(640, 360);
+  ps = new ParticleSystem(new PVector(width/2, 50));
+}
+
+void draw() {
+  background(0);
+  ps.addParticle();
+  ps.run();
+}