a port of the Processing Visualization Language

AdditiveWave

by Daniel Shiffman. Create a more complex wave by adding two waves together.

Original Processing.org Example: AdditiveWave

// All Examples Written by Casey Reas and Ben Fry

// unless otherwise stated.

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);

  }

}
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