[CG]VitasLab3

class Point
{
  int x, y;

  Point()
  {
    x = 0;
    y = 0;
  }

  Point(int ax, int ay)
  {
    x = ax;
    y = ay;
  }
}
void setup() {
  size(500, 500);
  background(255);
}

ArrayList<Point> points = new ArrayList<Point>();
float X, Y, t;

void draw() {
  if (points.size() == 4) {
    for (t = 0; t <= 1; t += 0.0001)
    {
      X = (pow(1.0 - t, points.get(0).x)* points.get(0).x + pow(1.0 - t, 2)*3*t*points.get(1).x + 3*t*t*(1.0 - t)*points.get(2).x + pow(t, 3)*points.get(3).x)/(pow(1.0 - t, 3) + pow(1.0 - t, 2)*3*t + 3*t*t*(1.0 - t) + pow(t, 3));
      Y = (pow(1.0 - t, 3)* points.get(0).y + pow(1.0 - t, 2)*3*t*points.get(1).y + 3*t*t*(1.0 - t)*points.get(2).y + pow(t, 3)*points.get(3).y)/(pow(1.0 - t, 3) + pow(1.0 - t, 2)*3*t + 3*t*t*(1.0 - t) + pow(t, 3));
      point(X, Y);
    }
  } else
  {
    for (int i = 0; i < points.size (); i++) point(points.get(i).x, points.get(i).y);
  }
}


void mousePressed() {
  if (points.size() < 4)
  {
    if (mouseButton == LEFT)
    {
      points.add(new Point(mouseX, mouseY));
    } else if (mouseButton == RIGHT)
    {
      if (points.size() > 0)
        points.remove(points.size()-1);
    }
  }
}