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",18);
  textFont(font);
  
  msgs[0] ="Set anchor 1";
  msgs[3] ="Set anchor 2";
  msgs[1] = "Set control 1";
  msgs[2] = "Set control 2";
  fill(0,255,0);
  text(msgs[0],10,50);
  drawbuttons();
}
void draw() {
  }
void mousePressed() {
  if ((mouseX>650)&&(mouseX<716)&&(mouseY>50)&&(mouseY<80)) {
         turn=0;
          //erasing old message
    fill(255);
    noStroke();
    rect(5,20,120,80);
    fill(0,255,0);
     text(msgs[turn],10,50);    
  }
  else if ((mouseX>740)&&(mouseX<790)&&(mouseY>50)&&(mouseY<80)){
      
        //erase everything
        background(255);
        drawbuttons();
        turn=0;
        //erasing old message
    fill(255);
    noStroke();
    rect(5,20,120,80);
    fill(0,255,0);
     text(msgs[turn],10,50);     
         
      }
  else {
  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 3:
      a2[0] = mouseX;
      a2[1] = mouseY;
      break;
     case 1:
      c1[0] = mouseX;
      c1[1] = mouseY;
      break;
    case 2:
      c2[0] = mouseX;
      c2[1] = mouseY;
      break;
  }
  turn++;
  if (turn<4) {
    //erasing old message
    fill(255);
    noStroke();
    rect(5,20,120,80);
    fill(0,255,0);
     text(msgs[turn],10,50);    
  }
  else {
    turn=1;
    //erasing old message
    fill(255);
    noStroke();
    rect(5,20,120,80);
    stroke(0,0,255);
   noFill();
    bezier(a1[0],a1[1],c1[0],c1[1],c2[0],c2[1],a2[0],a2[1]);
    a1[0] = a2[0];
    a1[1] = a2[1];
    fill(0,255,0);
    text(msgs[1],10,50);
  }
}
}
void drawbuttons() {
  fill(0);
  text("Click mouse to set anchor and control points for continuous Bezier curve.",50,20);
   noFill();
  rect(650,50,66,30);
  rect(740,50,50,30);
  fill(0);
  text("Re-start",652,68);
  text("Clear",742,68);
  
}