float[] a1 = new float[2];
float[] a2 = new float[2];
float[] c1 = new float[2];
float[] c2 = new float[2];
PFont font;
String[] msgs = new String[4];
int turn =0;
void setup() {
  size(800,600);
  background(255);
  font = createFont("Ariel",20);
  textFont(font);
  msgs[0] ="Click to set anchor 1";
  msgs[1] ="Click to set anchor 2";
  msgs[2] = "Click to set control 1";
  msgs[3] = "Click to set control 2";
  fill(0,0,250);
  text(msgs[0],10,20);
  
}
void draw() {
  
}
void mousePressed() {
  //background(255);
  stroke(0,255,0);
  triangle(mouseX,mouseY, mouseX, mouseY+3,mouseX+3,mouseY);
  switch(turn) {
    case 0:
      a1[0] = mouseX;
      a1[1] = mouseY;
      break;
    case 1:
      a2[0] = mouseX;
      a2[1] = mouseY;
      break;
     case 2:
      c1[0] = mouseX;
      c1[1] = mouseY;
      break;
    case 3:
      c2[0] = mouseX;
      c2[1] = mouseY;
      break;
  }
  turn++;
  if (turn<4) {
    //erasing old message
    fill(255);
    noStroke();
    rect(5,3,200,30);
    fill(0,0,250);
     text(msgs[turn],10,20);    
  }
  else {
    turn=0;
     //erasing old message
    fill(255);
    noStroke();
    rect(5,3,200,30);
    fill(0,0,250);
    fill(0,0,250);
    bezier(a1[0],a1[1],c1[0],c1[1],c2[0],c2[1],a2[0],a2[1]);
    text(msgs[0],10,20);
  }
}