How to make a new bezier in processing on arduino button press?

appie

Alright, I realize this is gonna be a little abstract but please bear with me;

I'm using this code:

    int pts = 4;
    int ptSize = 6;
    float[]x = new float[4];
    float[]y = new float[4];
    boolean[]isDragSafe = new boolean[4];

void setup(){
  size(300, 300);
  smooth();
  // fill coordinate arrays
  x[0] = x[1] =  50;
  x[2] = x[3] = width-50;
  y[0] = height/2-50;
  y[3] = height/2+50;
  y[1] = y[2] = height/2;

  //initialize dragging flags to false
  for (int i =0; i< pts; i++){
    isDragSafe[i] = false;
  }
}

void draw(){
  background(255);
  noFill();
  //draw curves and control handles
  strokeWeight(2);
  //spline curve
  stroke(0, 200, 30);
  curve (x[0], y[0],x[0], y[0], x[1], y[1], x[2], y[2]);
  curve (x[0], y[0], x[1], y[1], x[2], y[2], x[3], y[3]);
  curve (x[1], y[1], x[2], y[2], x[3], y[3], x[0], y[0]);
  //bezier curve
  stroke(0, 30, 200);
  bezier (x[1], y[1],x[0], y[0], x[3], y[3], x[2], y[2]);
  // draw bezier handles
  strokeWeight(1);
  stroke(100);
  line(x[0], y[0], x[1], y[1]);
  line(x[2], y[2], x[3], y[3]);
  // draw anchor/control points
  stroke(0);
  fill(0);
  for (int i =0; i< pts; i++){
    if (i ==0 || i==3){
  fill(255, 100, 10);
  rectMode(CENTER);
  rect(x[i], y[i], ptSize, ptSize);
    }  
    else {
  fill(0);
  ellipse(x[i], y[i], ptSize, ptSize);
    }
  }

  // start dragging if flag true
  for (int i =0; i< pts; i++){
    if (isDragSafe[i]){
  x[i] = mouseX;
  y[i] = mouseY;
    }  
  }
}

// release any point attached to the mouse
void mouseReleased (){
  for (int i =0; i< pts; i++){
    isDragSafe[i] = false;
  }
}

// for dragg'n dem points
void mousePressed (){
  for (int i =0; i< pts; i++){
    if (mouseX>=x[i]-5 && mouseX<=x[i]+ptSize+5 &&  
  mouseY>=y[i]-5 && mouseY<=y[i]+ptSize+5){
  isDragSafe[i] = true;
    }
  }
}

// show hand when over draggable points
void mouseMoved (){
  cursor(ARROW);
  for (int i =0; i< pts; i++){
    if (mouseX>=x[i]-5 && mouseX<=x[i]+ptSize+5 &&  
  mouseY>=y[i]-5 && mouseY<=y[i]+ptSize+5){
  cursor(HAND);
    }
  }
}

What I want to do is connect an arduino to it, I want to use some potentiometers to change the value of the anchor/control points, this is not the problem; I know how to connect arduino to processing etc. But the next step is: I want to have a button, that when pressed, creates a new bezier, with new anchor/control points to control with the potmeters.

So you start off with one bezier (as the current code shows), then you can tweak the curve of the bezier, once you press the button, it creates a new bezier, connected to the old bezier, so you can continue your drawing.

The idea is that it'll be a drawing machine kind of thing with potmeters and fancy buttons and stuff. I've been googling some but I can't find any info on how to make it draw a new bezier, any help or pointers are appreciated! Thanks for reading.