SineLines.pde

float octaves;

void setup() {
  size(800, 800, P2D);
  smooth(8);
}

void draw() {
  background(0);
  float t = radians(frameCount*.5);
  /*
   float lineCount = slider("count", 0, 160, 65);
   strokeWeight(slider("weight", 1, 10, 1.5));
   float margin = slider("margin", 0, 400);
   float yOff = slider("y offset", -100, 100, -50);
   float padding = slider("padding", 0, 200, 160);
   octaves = slider("octaves", 1, 12, 6);
   */
   
  float lineCount = 65;
  strokeWeight(1.5);
  float margin = 200;
  float yOff = -50;
  float padding = 160;
  octaves = 3;
  
  for (int i = 0; i < lineCount; i++) {
    float iN = map(i, 0, lineCount-1, 0, 1);
    float y = map(iN, 0, 1, margin, height-margin);
    y -= yOff/2;
    float x0 = margin;
    float x2 = width-margin;
    float x1 = map(fbm(iN*6-t), 0, 1, x0+padding, x2-padding);
    beginShape();
    noFill();
    stroke(0);
    vertex(x0, y);
    stroke(255);
    vertex(x1, y+yOff);
    stroke(100);
    vertex(x1, y+yOff);
    stroke(0);
    vertex(x2, y);
    endShape();
  }
}

float fbm(float x) {
  float sum = 0;
  float freq = 1;
  float amp = 1;
  for (int i = 0; i < floor(octaves); i++) {
    sum += amp*(sin(x*freq));
    freq *= 2;
    amp *= .5;
  }
  return .5+.5*sum;
}