void setup() {
  size(400, 400);
  background(0);
  stroke(255);
  noFill();

  for (int x = 0; x < width; x += 5) {
    float angle = x * 0.05;
    float y = height / 2 + sin(angle) * 50;
    ellipse(x, y, 10, 10);
  }
}