modSin

float y;
float a, f;

void setup() {
  size(1080, 720);
  background(34);
  a = random(2,10);
  f = random(0.05);
}

void draw() {
  //background(34);
  stroke(238, 10);
  float amplitude = a; //10;
  float frequency = f; //0.01;
  beginShape();
  noFill();
  for (int x=0; x<width; x+=2) {
    y = sin(x*frequency);
    float t = 0.000001*(-millis()*130);
    t = -frameCount/500.0;
    y += sin(x*frequency*2.1 + t)*4.5;
    y += sin(x*frequency*1.72 + t*1.121)*4.0;
    y += sin(x*frequency*2.221 + t*0.437)*5.0;
    y += sin(x*frequency*3.1122+ t*4.269)*2.5;
    y *= amplitude;
    vertex(x, height/2+y);
  }
  endShape();
}

void keyPressed() {
  save(random(9999)+".png");
}