topical media & game development

talk show tell print

#javascript-processing-example-basic-objects-inheritance.htm / htm



  <!DOCTYPE html>
  <html><head>
  <script src="javascript-processing-example-processing.js"></script>
  <script src="javascript-processing-example-init.js"></script>
  <link rel="stylesheet" href="javascript-processing-example-style.css">
  </head><body><h1><a href="http://ejohn.org/blog/processingjs/">Processing.js</a></h1>
  <h2>Inheritance</h2>
  
  <p>A class can be defined using another class as a foundation. In object-oriented
  programming terminology, one class can inherit fi elds and methods from another. 
  An object that inherits from another is called a subclass, and the object it 
  inherits from is called a superclass. A subclass extends the superclass.</p>
  
  <p><a href="http://processing.org/learning/basics/inheritance.html"><b>Original Processing.org Example:</b> Inheritance</a><br>
  <script type="application/processing">
  SpinSpots spots;
  SpinArm arm;
  
  void setup() 
  {
    size(200, 200);
    smooth();
    arm = new SpinArm(width/2, height/2, 0.01);
    spots = new SpinSpots(width/2, height/2, -0.02, 33.0);
  }
  
  void draw() 
  {
    background(204);
    arm.update();
    arm.display();
    spots.update();
    spots.display();
  }
  
  class Spin 
  {
    float x, y, speed;
    float angle = 0.0;
    Spin(float xpos, float ypos, float s) {
      x = xpos;
      y = ypos;
      speed = s;
    }
    void update() {
      angle += speed;
    }
  }
  
  class SpinArm extends Spin 
  {
    SpinArm(float x, float y, float s) {
      super(x, y, s);
    }
    void display() {
      strokeWeight(1);
      stroke(0);
      pushMatrix();
      translate(x, y);
      angle += speed;
      rotate(angle);
      line(0, 0, 66, 0);
      popMatrix();
    }
  }
  
  class SpinSpots extends Spin 
  {
    float dim;
    SpinSpots(float x, float y, float s, float d) {
      super(x, y, s);
      dim = d;
    }
    void display() {
      noStroke();
      pushMatrix();
      translate(x, y);
      angle += speed;
      rotate(angle);
      ellipse(-dim/2, 0, dim, dim);
      ellipse(dim/2, 0, dim, dim);
      popMatrix();
    }
  }
  </script><canvas width="200" height="200"></canvas></p>
  <div style="overflow: hidden; height: 0px; width: 0px;"></div>
  
  <pre><b>// All Examples Written by <a href="http://reas.com/">Casey Reas</a> and <a href="http://benfry.com/">Ben Fry</a>
  // unless otherwise stated.</b>
  SpinSpots spots;
  SpinArm arm;
  
  void setup() 
  {
    size(200, 200);
    smooth();
    arm = new SpinArm(width/2, height/2, 0.01);
    spots = new SpinSpots(width/2, height/2, -0.02, 33.0);
  }
  
  void draw() 
  {
    background(204);
    arm.update();
    arm.display();
    spots.update();
    spots.display();
  }
  
  class Spin 
  {
    float x, y, speed;
    float angle = 0.0;
    Spin(float xpos, float ypos, float s) {
      x = xpos;
      y = ypos;
      speed = s;
    }
    void update() {
      angle += speed;
    }
  }
  
  class SpinArm extends Spin 
  {
    SpinArm(float x, float y, float s) {
      super(x, y, s);
    }
    void display() {
      strokeWeight(1);
      stroke(0);
      pushMatrix();
      translate(x, y);
      angle += speed;
      rotate(angle);
      line(0, 0, 66, 0);
      popMatrix();
    }
  }
  
  class SpinSpots extends Spin 
  {
    float dim;
    SpinSpots(float x, float y, float s, float d) {
      super(x, y, s);
      dim = d;
    }
    void display() {
      noStroke();
      pushMatrix();
      translate(x, y);
      angle += speed;
      rotate(angle);
      ellipse(-dim/2, 0, dim, dim);
      ellipse(dim/2, 0, dim, dim);
      popMatrix();
    }
  }</pre>
  </body></html>
  


(C) Æliens 20/2/2008

You may not copy or print any of this material without explicit permission of the author or the publisher. In case of other copyright issues, contact the author.