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

@@ -0,0 +1,67 @@
+// A simple Particle class
+
+class Particle {
+  PVector loc;
+  PVector vel;
+  PVector acc;
+  float r;
+  float timer;
+  
+  // Another constructor (the one we are using here)
+  Particle(PVector l) {
+    acc = new PVector(0,0.05,0);
+    vel = new PVector(random(-1,1),random(-2,0),0);
+    loc = l.get();
+    r = 10.0;
+    timer = 100.0;
+  }
+
+  void run() {
+    update();
+    render();
+  }
+
+  // Method to update location
+  void update() {
+    vel.add(acc);
+    loc.add(vel);
+    timer -= 1.0;
+  }
+
+  // Method to display
+  void render() {
+    ellipseMode(CENTER);
+    stroke(255,timer);
+    fill(100,timer);
+    ellipse(loc.x,loc.y,r,r);
+    displayVector(vel,loc.x,loc.y,10);
+  }
+  
+  // Is the particle still useful?
+  boolean dead() {
+    if (timer <= 0.0) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+  
+   void displayVector(PVector v, float x, float y, float scayl) {
+    pushMatrix();
+    float arrowsize = 4;
+    // Translate to location to render vector
+    translate(x,y);
+    stroke(255);
+    // Call vector heading function to get direction (note that pointing up is a heading of 0) and rotate
+    rotate(v.heading2D());
+    // Calculate length of vector & scale it to be bigger or smaller if necessary
+    float len = v.mag()*scayl;
+    // Draw three lines to make an arrow (draw pointing up since we've rotate to the proper direction)
+    line(0,0,len,0);
+    line(len,0,len-arrowsize,+arrowsize/2);
+    line(len,0,len-arrowsize,-arrowsize/2);
+    popMatrix();
+  } 
+
+}
+

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

@@ -0,0 +1,50 @@
+// A class to describe a group of Particles
+// An ArrayList is used to manage the list of Particles 
+
+class ParticleSystem {
+
+  ArrayList particles;    // An arraylist for all the particles
+  PVector origin;        // An origin point for where particles are born
+
+  ParticleSystem(int num, PVector v) {
+    particles = new ArrayList();              // Initialize the arraylist
+    origin = v.get();                        // Store the origin point
+    for (int i = 0; i < num; i++) {
+      particles.add(new Particle(origin));    // Add "num" amount of particles to the arraylist
+    }
+  }
+
+  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);
+      p.run();
+      if (p.dead()) {
+        particles.remove(i);
+      }
+    }
+  }
+
+  void addParticle() {
+    particles.add(new Particle(origin));
+  }
+  
+    void addParticle(float x, float y) {
+    particles.add(new Particle(new PVector(x,y)));
+  }
+
+  void addParticle(Particle p) {
+    particles.add(p);
+  }
+
+  // A method to test if the particle system still has particles
+  boolean dead() {
+    if (particles.isEmpty()) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+}
+

java/examples/Topics/Simulate/SimpleParticleSystem/SimpleParticleSystem.pde

@@ -0,0 +1,27 @@
+/**
+ * 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);
+  colorMode(RGB, 255, 255, 255, 100);
+  ps = new ParticleSystem(1, new PVector(width/2,height/2,0));
+  smooth();
+}
+
+void draw() {
+  background(0);
+  ps.run();
+  ps.addParticle(mouseX,mouseY);
+}
+
+
+

java/examples/Topics/Simulate/SimpleParticleSystem/applet/Particle.pde

@@ -0,0 +1,49 @@
+// A simple Particle class
+
+class Particle {
+  Vector3D loc;
+  Vector3D vel;
+  Vector3D acc;
+  float r;
+  float timer;
+  
+  // Another constructor (the one we are using here)
+  Particle(Vector3D l) {
+    acc = new Vector3D(0,0.05,0);
+    vel = new Vector3D(random(-1,1),random(-2,0),0);
+    loc = l.copy();
+    r = 10.0;
+    timer = 100.0;
+  }
+
+  void run() {
+    update();
+    render();
+  }
+
+  // Method to update location
+  void update() {
+    vel.add(acc);
+    loc.add(vel);
+    timer -= 1.0;
+  }
+
+  // Method to display
+  void render() {
+    ellipseMode(CENTER);
+    stroke(255,timer);
+    fill(100,timer);
+    ellipse(loc.x,loc.y,r,r);
+    vel.display(loc.x,loc.y,10);
+  }
+  
+  // Is the particle still useful?
+  boolean dead() {
+    if (timer <= 0.0) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+}
+

java/examples/Topics/Simulate/SimpleParticleSystem/applet/ParticleSystem.pde

@@ -0,0 +1,50 @@
+// A class to describe a group of Particles
+// An ArrayList is used to manage the list of Particles 
+
+class ParticleSystem {
+
+  ArrayList particles;    // An arraylist for all the particles
+  Vector3D origin;        // An origin point for where particles are born
+
+  ParticleSystem(int num, Vector3D v) {
+    particles = new ArrayList();              // Initialize the arraylist
+    origin = v.copy();                        // Store the origin point
+    for (int i = 0; i < num; i++) {
+      particles.add(new Particle(origin));    // Add "num" amount of particles to the arraylist
+    }
+  }
+
+  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);
+      p.run();
+      if (p.dead()) {
+        particles.remove(i);
+      }
+    }
+  }
+
+  void addParticle() {
+    particles.add(new Particle(origin));
+  }
+  
+    void addParticle(float x, float y) {
+    particles.add(new Particle(new Vector3D(x,y)));
+  }
+
+  void addParticle(Particle p) {
+    particles.add(p);
+  }
+
+  // A method to test if the particle system still has particles
+  boolean dead() {
+    if (particles.isEmpty()) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+}
+

java/examples/Topics/Simulate/SimpleParticleSystem/applet/SimpleParticleSystem.java

@@ -0,0 +1,308 @@
+import processing.core.*; 
+
+import java.applet.*; 
+import java.awt.*; 
+import java.awt.image.*; 
+import java.awt.event.*; 
+import java.io.*; 
+import java.net.*; 
+import java.text.*; 
+import java.util.*; 
+import java.util.zip.*; 
+import java.util.regex.*; 
+
+public class SimpleParticleSystem extends PApplet {
+
+/**
+ * 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;
+
+public void setup() {
+  size(640, 360);
+  colorMode(RGB, 255, 255, 255, 100);
+  ps = new ParticleSystem(1,new Vector3D(width/2,height/2,0));
+  smooth();
+}
+
+public void draw() {
+  background(0);
+  ps.run();
+  ps.addParticle(mouseX,mouseY);
+}
+
+
+
+// A simple Particle class
+
+class Particle {
+  Vector3D loc;
+  Vector3D vel;
+  Vector3D acc;
+  float r;
+  float timer;
+  
+  // Another constructor (the one we are using here)
+  Particle(Vector3D l) {
+    acc = new Vector3D(0,0.05f,0);
+    vel = new Vector3D(random(-1,1),random(-2,0),0);
+    loc = l.copy();
+    r = 10.0f;
+    timer = 100.0f;
+  }
+
+  public void run() {
+    update();
+    render();
+  }
+
+  // Method to update location
+  public void update() {
+    vel.add(acc);
+    loc.add(vel);
+    timer -= 1.0f;
+  }
+
+  // Method to display
+  public void render() {
+    ellipseMode(CENTER);
+    stroke(255,timer);
+    fill(100,timer);
+    ellipse(loc.x,loc.y,r,r);
+    vel.display(loc.x,loc.y,10);
+  }
+  
+  // Is the particle still useful?
+  public boolean dead() {
+    if (timer <= 0.0f) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+}
+
+// A class to describe a group of Particles
+// An ArrayList is used to manage the list of Particles 
+
+class ParticleSystem {
+
+  ArrayList particles;    // An arraylist for all the particles
+  Vector3D origin;        // An origin point for where particles are born
+
+  ParticleSystem(int num, Vector3D v) {
+    particles = new ArrayList();              // Initialize the arraylist
+    origin = v.copy();                        // Store the origin point
+    for (int i = 0; i < num; i++) {
+      particles.add(new Particle(origin));    // Add "num" amount of particles to the arraylist
+    }
+  }
+
+  public 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);
+      p.run();
+      if (p.dead()) {
+        particles.remove(i);
+      }
+    }
+  }
+
+  public void addParticle() {
+    particles.add(new Particle(origin));
+  }
+  
+    public void addParticle(float x, float y) {
+    particles.add(new Particle(new Vector3D(x,y)));
+  }
+
+  public void addParticle(Particle p) {
+    particles.add(p);
+  }
+
+  // A method to test if the particle system still has particles
+  public boolean dead() {
+    if (particles.isEmpty()) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+}
+
+// Simple Vector class
+
+class Vector3D {
+  float x;
+  float y;
+  float z;
+
+  Vector3D(float x_, float y_, float z_) {
+    x = x_; 
+    y = y_; 
+    z = z_;
+  }
+
+  Vector3D(float x_, float y_) {
+    x = x_; 
+    y = y_; 
+    z = 0f;
+  }
+
+  Vector3D() {
+    x = 0f; 
+    y = 0f; 
+    z = 0f;
+  }
+
+  public void setX(float x_) {
+    x = x_;
+  }
+
+  public void setY(float y_) {
+    y = y_;
+  }
+
+  public void setZ(float z_) {
+    z = z_;
+  }
+
+  public void setXY(float x_, float y_) {
+    x = x_;
+    y = y_;
+  }
+
+  public void setXYZ(float x_, float y_, float z_) {
+    x = x_;
+    y = y_;
+    z = z_;
+  }
+
+  public void setXYZ(Vector3D v) {
+    x = v.x;
+    y = v.y;
+    z = v.z;
+  }
+  public float magnitude() {
+    return (float) Math.sqrt(x*x + y*y + z*z);
+  }
+
+  public Vector3D copy() {
+    return new Vector3D(x,y,z);
+  }
+
+  public Vector3D copy(Vector3D v) {
+    return new Vector3D(v.x, v.y,v.z);
+  }
+
+  public void add(Vector3D v) {
+    x += v.x;
+    y += v.y;
+    z += v.z;
+  }
+
+  public void sub(Vector3D v) {
+    x -= v.x;
+    y -= v.y;
+    z -= v.z;
+  }
+
+  public void mult(float n) {
+    x *= n;
+    y *= n;
+    z *= n;
+  }
+
+  public void div(float n) {
+    x /= n;
+    y /= n;
+    z /= n;
+  }
+
+  /* float dot(Vector3D v) {
+   //implement DOT product
+   }*/
+
+  /* Vector3D cross(Vector3D v) {
+   //implement CROSS product
+   }*/
+
+  public void normalize() {
+    float m = magnitude();
+    if (m > 0) {
+      div(m);
+    }
+  }
+
+  public void limit(float max) {
+    if (magnitude() > max) {
+      normalize();
+      mult(max);
+    }
+  }
+
+  public float heading2D() {
+    float angle = (float) Math.atan2(-y, x);
+    return -1*angle;
+  }
+
+  public Vector3D add(Vector3D v1, Vector3D v2) {
+    Vector3D v = new Vector3D(v1.x + v2.x,v1.y + v2.y, v1.z + v2.z);
+    return v;
+  }
+
+  public Vector3D sub(Vector3D v1, Vector3D v2) {
+    Vector3D v = new Vector3D(v1.x - v2.x,v1.y - v2.y,v1.z - v2.z);
+    return v;
+  }
+
+  public Vector3D div(Vector3D v1, float n) {
+    Vector3D v = new Vector3D(v1.x/n,v1.y/n,v1.z/n);
+    return v;
+  }
+
+  public Vector3D mult(Vector3D v1, float n) {
+    Vector3D v = new Vector3D(v1.x*n,v1.y*n,v1.z*n);
+    return v;
+  }
+
+  public float distance (Vector3D v1, Vector3D v2) {
+    float dx = v1.x - v2.x;
+    float dy = v1.y - v2.y;
+    float dz = v1.z - v2.z;
+    return (float) Math.sqrt(dx*dx + dy*dy + dz*dz);
+  }
+
+  public void display(float x, float y, float scayl) {
+    pushMatrix();
+    float arrowsize = 4;
+    // Translate to location to render vector
+    translate(x,y);
+    // stroke(255);
+    // Call vector heading function to get direction (note that pointing up is a heading of 0) and rotate
+    rotate(heading2D());
+    // Calculate length of vector & scale it to be bigger or smaller if necessary
+    float len = magnitude()*scayl;
+    // Draw three lines to make an arrow (draw pointing up since we've rotate to the proper direction)
+    line(0,0,len,0);
+    line(len,0,len-arrowsize,+arrowsize/2);
+    line(len,0,len-arrowsize,-arrowsize/2);
+    popMatrix();
+  } 
+
+}
+
+
+  static public void main(String args[]) {
+    PApplet.main(new String[] { "SimpleParticleSystem" });
+  }
+}

java/examples/Topics/Simulate/SimpleParticleSystem/applet/SimpleParticleSystem.pde

@@ -0,0 +1,27 @@
+/**
+ * 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);
+  colorMode(RGB, 255, 255, 255, 100);
+  ps = new ParticleSystem(1,new Vector3D(width/2,height/2,0));
+  smooth();
+}
+
+void draw() {
+  background(0);
+  ps.run();
+  ps.addParticle(mouseX,mouseY);
+}
+
+
+