Added new OpenGL examples for desktop

java/libraries/opengl/examples/Advanced/Particles/ParticleSystem.pde

@@ -0,0 +1,36 @@
+class ParticleSystem {
+  ArrayList<Particle> particles;
+
+  PShape particleShape;
+
+  ParticleSystem(int n) {
+    particles = new ArrayList<Particle>();
+    particleShape = createShape(PShape.GROUP);
+
+    for (int i = 0; i < n; i++) {
+      Particle p = new Particle();
+      particles.add(p);
+      particleShape.addChild(p.getShape());
+    }
+  }
+
+  void update() {
+    for (Particle p : particles) {
+      p.update();
+    }
+  }
+
+  void setEmitter(float x, float y) {
+    for (Particle p : particles) {
+      if (p.isDead()) {
+        p.rebirth(x, y);
+      }
+    }
+  }
+
+  void display() {
+
+    shape(particleShape);
+  }
+}
+