topical media & game development

topical media & game development

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

#javascript-processing-example-topic-simulate-chain.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>Chain</h2>
  
  <p>One mass is attached to the mouse position and the other 
  is attached the position of the other mass. The gravity
  in the environment pulls down on both.</p>
  
  <p><a href="http://processing.org/learning/topics/chain.html"><b>Original Processing.org Example:</b> Chain</a><br>
  <script type="application/processing">
  Spring2D s1, s2;
  
  float gravity = 6.0;
  float mass = 2.0;
  
  void setup() 
  {
    size(200, 200);
    smooth();
    fill(0);
    // Inputs: x, y, mass, gravity
    s1 = new Spring2D(0.0, width/2, mass, gravity);
    s2 = new Spring2D(0.0, width/2, mass, gravity);
  }
  
  void draw() 
  {
    background(204);
    s1.update(mouseX, mouseY);
    s1.display(mouseX, mouseY);
    s2.update(s1.x, s1.y);
    s2.display(s1.x, s1.y);
  }
  
  class Spring2D {
    float vx, vy; // The x- and y-axis velocities
    float x, y; // The x- and y-coordinates
    float gravity;
    float mass;
    float radius = 20;
    float stiffness = 0.2;
    float damping = 0.7;
    
    Spring2D(float xpos, float ypos, float m, float g) {
      x = xpos;
      y = ypos;
      mass = m;
      gravity = g;
    }
    
    void update(float targetX, float targetY) {
      float forceX = (targetX - x) * stiffness;
      float ax = forceX / mass;
      vx = damping * (vx + ax);
      x += vx;
      float forceY = (targetY - y) * stiffness;
      forceY += gravity;
      float ay = forceY / mass;
      vy = damping * (vy + ay);
      y += vy;
    }
    
    void display(float nx, float ny) {
      noStroke();
      ellipse(x, y, radius*2, radius*2);
      stroke(255);
      line(x, y, nx, ny);
    }
  }
  </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>
  Spring2D s1, s2;
  
  float gravity = 6.0;
  float mass = 2.0;
  
  void setup() 
  {
    size(200, 200);
    smooth();
    fill(0);
    // Inputs: x, y, mass, gravity
    s1 = new Spring2D(0.0, width/2, mass, gravity);
    s2 = new Spring2D(0.0, width/2, mass, gravity);
  }
  
  void draw() 
  {
    background(204);
    s1.update(mouseX, mouseY);
    s1.display(mouseX, mouseY);
    s2.update(s1.x, s1.y);
    s2.display(s1.x, s1.y);
  }
  
  class Spring2D {
    float vx, vy; // The x- and y-axis velocities
    float x, y; // The x- and y-coordinates
    float gravity;
    float mass;
    float radius = 20;
    float stiffness = 0.2;
    float damping = 0.7;
    
    Spring2D(float xpos, float ypos, float m, float g) {
      x = xpos;
      y = ypos;
      mass = m;
      gravity = g;
    }
    
    void update(float targetX, float targetY) {
      float forceX = (targetX - x) * stiffness;
      float ax = forceX / mass;
      vx = damping * (vx + ax);
      x += vx;
      float forceY = (targetY - y) * stiffness;
      forceY += gravity;
      float ay = forceY / mass;
      vy = damping * (vy + ay);
      y += vy;
    }
    
    void display(float nx, float ny) {
      noStroke();
      ellipse(x, y, radius*2, radius*2);
      stroke(255);
      line(x, y, nx, ny);
    }
  }</pre>
  </body></html>

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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