changes to simulate examples

java/examples/Topics/Simulate/SmokeParticleSystem/Particle.pde

@@ -5,26 +5,16 @@ class Particle {
   PVector loc;
   PVector vel;
   PVector acc;
-  float timer;
+  float lifespan;
   PImage img;
 
-  // One constructor
-  Particle(PVector a, PVector v, PVector l, PImage img_) {
-    acc = a.get();
-    vel = v.get();
-    loc = l.get();
-    timer = 100.0;
-    img = img_;
-  }
-
-  // Another constructor (the one we are using here)
   Particle(PVector l,PImage img_) {
-    acc = new PVector(0.0,0.0,0.0);
-    float x = (float) generator.nextGaussian()*0.3f;
-    float y = (float) generator.nextGaussian()*0.3f - 1.0f;
-    vel = new PVector(x,y,0);
+    acc = new PVector(0,0);
+    float vx = (float) generator.nextGaussian()*0.3;
+    float vy = (float) generator.nextGaussian()*0.3 - 1.0;
+    vel = new PVector(vx,vy);
     loc = l.get();
-    timer = 100.0;
+    lifespan = 100.0;
     img = img_;
   }
 
@@ -35,7 +25,7 @@ class Particle {
   
   // Method to apply a force vector to the Particle object
   // Note we are ignoring "mass" here
-  void add_force(PVector f) {
+  void applyForce(PVector f) {
     acc.add(f);
   }  
 
@@ -43,20 +33,20 @@ class Particle {
   void update() {
     vel.add(acc);
     loc.add(vel);
-    timer -= 2.5;
-    acc.mult(0);
+    acc.mult(0); // clear Acceleration
+    lifespan -= 2.5;
   }
 
   // Method to display
   void render() {
-    imageMode(CORNER);
-    tint(255,timer);
-    image(img,loc.x-img.width/2,loc.y-img.height/2);
+    imageMode(CENTER);
+    tint(255,lifespan);
+    image(img,loc.x,loc.y);
   }
 
   // Is the particle still useful?
   boolean dead() {
-    if (timer <= 0.0) {
+    if (lifespan <= 0.0) {
       return true;
     } else {
       return false;

java/examples/Topics/Simulate/SmokeParticleSystem/ParticleSystem.pde

@@ -3,12 +3,12 @@
 
 class ParticleSystem {
 
-  ArrayList particles;    // An arraylist for all the particles
+  ArrayList<Particle> particles;    // An arraylist for all the particles
   PVector origin;        // An origin point for where particles are birthed
   PImage img;
   
   ParticleSystem(int num, PVector v, PImage img_) {
-    particles = new ArrayList();              // Initialize the arraylist
+    particles = new ArrayList<Particle>();              // Initialize the arraylist
     origin = v.get();                        // Store the origin point
     img = img_;
     for (int i = 0; i < num; i++) {
@@ -17,21 +17,21 @@ class ParticleSystem {
   }
 
   void run() {
-    // Cycle through the ArrayList backwards b/c we are deleting
-    for (int i = particles.size()-1; i >= 0; i--) {
-      Particle p = (Particle) particles.get(i);
+    Iterator<Particle> it = particles.iterator();
+    while (it.hasNext()) {
+      Particle p = it.next();
       p.run();
       if (p.dead()) {
-        particles.remove(i);
+        it.remove();
       }
     }
   }
   
   // Method to add a force vector to all particles currently in the system
-  void add_force(PVector dir) {
-    for (int i = particles.size()-1; i >= 0; i--) {
-      Particle p = (Particle) particles.get(i);
-      p.add_force(dir);
+  void applyForce(PVector dir) {
+    // Enhanced loop!!!
+    for (Particle p: particles) {
+      p.applyForce(dir);
     }
   
   }  
@@ -55,3 +55,4 @@ class ParticleSystem {
 
 }
 
+

java/examples/Topics/Simulate/SmokeParticleSystem/SmokeParticleSystem.pde

@@ -8,48 +8,42 @@
 
 // @pjs preload must be used to preload media if the program is 
 // running with Processing.js
-/* @pjs preload="texture.gif"; */  
+/* @pjs preload="texture.png"; */  
 
 ParticleSystem ps;
 Random generator;
 
 void setup() {
-  size(640, 360);
-  colorMode(RGB, 255, 255, 255, 100);
-
-  // Using a Java random number generator for Gaussian random numbers
+  size(640,360);
   generator = new Random();
-
-  // Create an alpha masked image to be applied as the particle's texture
-  PImage msk = loadImage("texture.gif");
-  PImage img = createImage(msk.width, msk.height, RGB);
-  for (int i = 0; i < img.pixels.length; i++) {
-    img.pixels[i] = color(255);
-  }
-  img.mask(msk);
-  ps = new ParticleSystem(0, new PVector(width/2, height-20), img);
-
+  PImage img = loadImage("texture.png");
+  ps = new ParticleSystem(0,new PVector(width/2,height-60),img);
+  smooth();
 }
 
 void draw() {
-  background(75);
-
+  background(0);
+  
   // Calculate a "wind" force based on mouse horizontal position
-  float dx = (mouseX - width/2) / 1000.0;
-  PVector wind = new PVector(dx,0,0);
-  displayVector(wind,width/2,50,500);
-  ps.add_force(wind);
+  float dx = map(mouseX,0,width,-0.2,0.2);
+  PVector wind = new PVector(dx,0);
+  ps.applyForce(wind);
   ps.run();
   for (int i = 0; i < 2; i++) {
     ps.addParticle();
   }
+  
+  // Draw an arrow representing the wind force
+  drawVector(wind, new PVector(width/2,50,0),500);
+
 }
 
-void displayVector(PVector v, float x, float y, float scayl) {
+// Renders a vector object 'v' as an arrow and a location 'loc'
+void drawVector(PVector v, PVector loc, float scayl) {
   pushMatrix();
   float arrowsize = 4;
   // Translate to location to render vector
-  translate(x,y);
+  translate(loc.x,loc.y);
   stroke(255);
   // Call vector heading function to get direction (note that pointing up is a heading of 0) and rotate
   rotate(v.heading2D());