let inc;

let margin;

let vertOffset;

// extra flat line at either end

let extraLine = 70;

// steps between vertexes

let step = 3;

// spacing between lines

let ySpacing = 2.6

​

// noise settings

let offset = 0;

let offsetInc = 0.09

let rowOffset = 40

let lineMultiplier = 27

​

// fuzz settings

let fuzzOffset = 1000;

let fuzzInc = offsetInc

let fuzzMultiplier = 3.5

​

function setup() {

  createCanvas(600, 600);

  background(200)

​

  margin = width / 3;

  vertOffset = width / 4.6;

  spread = width - margin * 2

  inc = TWO_PI * step / spread;

  stroke(255)

  strokeWeight(1.2)

  fill(0)

  // noFill()

  frameRate(24)

}

​

function draw() {

  background(0);

​

  // make rows

  for (let y = 0; y <= 50 * ySpacing; y += ySpacing) {

    let a = 0.0;

    // begin the line

    beginShape();

    for (let x = -extraLine; x <= spread + extraLine; x += step) {

      // perlin noise

      let n = noise(offset + x / rowOffset + y) * lineMultiplier;

      // flatten the line if not in the 'spread' area

      if (x < 0 || x > spread) a = 0;

      // use a sine wave to multiply the noise

      let vert = ((1 - sin(a + PI / 2)) * n)

      // add some extra fuzz to the line

      let fuzz = noise(fuzzOffset + x / rowOffset + y) * fuzzMultiplier;

      // draw the line

      vertex(x + margin, height - vert - (height - y * ySpacing) + vertOffset + fuzz);

      //increment the angle for the sine wave.

      a = a + inc;

    }

    endShape()

  }

  // increment the noise and fuzz

  offset += offsetInc;

  fuzzOffset += fuzzInc

}