a port of the Processing Visualization Language

SineWave

by Daniel Shiffman. Render a simple sine wave.

Original Processing.org Example: SineWave

// 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



float theta = 0.0;       // Start angle at 0

float amplitude = 75.0;  // Height of wave

float period = 500.0;    // How many pixels before the wave repeats

float dx;                 // 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;

  dx = (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;



  // For every x value, calculate a y value with sine function

  float x = theta;

  for (int i = 0; i < yvalues.length; i++) {

    yvalues[i] = sin(x)*amplitude;

    x+=dx;

  }

}



void renderWave() {

  // A simple way to draw the wave with an ellipse at each location

  for (int x = 0; x < yvalues.length; x++) {

    noStroke();

    fill(255,50);

    ellipseMode(CENTER);

    ellipse(x*xspacing,width/2+yvalues[x],16,16);

  }

}
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