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-basic-math-additivewave.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>AdditiveWave</h2>
  
  <p>by Daniel Shiffman. 
  
  Create a more complex wave by adding two waves together.</p>
  
  <p><a href="http://processing.org/learning/basics/additivewave.html"><b>Original Processing.org Example:</b> AdditiveWave</a><br>
  <script type="application/processing">
  int xspacing = 8;   // How far apart should each horizontal location be spaced
  int w;              // Width of entire wave
  int maxwaves = 4;   // total # of waves to add together
  
  float theta = 0.0f;
  float[] amplitude = new float[maxwaves];   // Height of wave
  float[] dx = new float[maxwaves];          // Value for incrementing X, to be calculated as a function of period and xspacing
  float[] yvalues;                           // Using an array to store height values for the wave (not entirely necessary)
  
  void setup() {
    size(200,200);
    frameRate(30);
    colorMode(RGB,255,255,255,100);
    smooth();
    w = width+16;
  
    for (int i = 0; i < maxwaves; i++) {
      amplitude[i] = random(10,30);
      float period = random(100,300); // How many pixels before the wave repeats
      dx[i] = (TWO_PI / period) * xspacing;
    }
  
    yvalues = new float[w/xspacing];
  }
  
  void draw() {
    background(0);
    calcWave();
    renderWave();
  }
  
  void calcWave() {
    // Increment theta (try different values for 'angular velocity' here
    theta += 0.02;
  
    // Set all height values to zero
    for (int i = 0; i < yvalues.length; i++) {
      yvalues[i] = 0.0f;
    }
   
    // Accumulate wave height values
    for (int j = 0; j < maxwaves; j++) {
      float x = theta;
      for (int i = 0; i < yvalues.length; i++) {
        // Every other wave is cosine instead of sine
        if (j % 2 == 0)  yvalues[i] += sin(x)*amplitude[j];
        else yvalues[i] += cos(x)*amplitude[j];
        x+=dx[j];
      }
    }
  }
  
  void renderWave() {
    // A simple way to draw the wave with an ellipse at each location
    noStroke();
    fill(255,50);
    ellipseMode(CENTER);
    for (int x = 0; x < yvalues.length; x++) {
      ellipse(x*xspacing,width/2+yvalues[x],16,16);
    }
  }
  </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>
  int xspacing = 8;   // How far apart should each horizontal location be spaced
  int w;              // Width of entire wave
  int maxwaves = 4;   // total # of waves to add together
  
  float theta = 0.0f;
  float[] amplitude = new float[maxwaves];   // Height of wave
  float[] dx = new float[maxwaves];          // Value for incrementing X, to be calculated as a function of period and xspacing
  float[] yvalues;                           // Using an array to store height values for the wave (not entirely necessary)
  
  void setup() {
    size(200,200);
    frameRate(30);
    colorMode(RGB,255,255,255,100);
    smooth();
    w = width+16;
  
    for (int i = 0; i &lt; maxwaves; i++) {
      amplitude[i] = random(10,30);
      float period = random(100,300); // How many pixels before the wave repeats
      dx[i] = (TWO_PI / period) * xspacing;
    }
  
    yvalues = new float[w/xspacing];
  }
  
  void draw() {
    background(0);
    calcWave();
    renderWave();
  }
  
  void calcWave() {
    // Increment theta (try different values for 'angular velocity' here
    theta += 0.02;
  
    // Set all height values to zero
    for (int i = 0; i &lt; yvalues.length; i++) {
      yvalues[i] = 0.0f;
    }
   
    // Accumulate wave height values
    for (int j = 0; j &lt; maxwaves; j++) {
      float x = theta;
      for (int i = 0; i &lt; yvalues.length; i++) {
        // Every other wave is cosine instead of sine
        if (j % 2 == 0)  yvalues[i] += sin(x)*amplitude[j];
        else yvalues[i] += cos(x)*amplitude[j];
        x+=dx[j];
      }
    }
  }
  
  void renderWave() {
    // A simple way to draw the wave with an ellipse at each location
    noStroke();
    fill(255,50);
    ellipseMode(CENTER);
    for (int x = 0; x &lt; yvalues.length; x++) {
      ellipse(x*xspacing,width/2+yvalues[x],16,16);
    }
  }</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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