float offset = 0;

void setup() {
  size(1200, 800);
}

void draw() {
  background(0);
  stroke(255);
  noFill();

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

  offset += 0.05;
}