chaikin.pde

// chaikin takes an array of points Pn and calculates points QRn
// [PVector] -> [PVector]
ArrayList<PVector> chaikin(ArrayList<PVector> P) {
  ArrayList<PVector> CP = new ArrayList<PVector>();
  
  for(int i = 0; i < P.size() - 1; i++) {
    PVector p = P.get(i);
    PVector p2 = P.get(i + 1);
    
    float qx = lerp(p.x, p2.x, .25); // lerp() == linear interpolation between 2 values at point T where 0 <= T <= 1
    float rx = lerp(p.x, p2.x, .75);
    
    float qy = lerp(p.y, p2.y, .25);
    float ry = lerp(p.y, p2.y, .75);
    
    PVector q = new PVector(qx, qy);
    PVector r = new PVector(rx, ry);
    
    CP.add(q); // essentially Array.push(q)
    CP.add(r);
  }
  
  return CP;
}