let button2X, button2Y, button2Width, button2Height; //variables for button 2

let button3X, button3Y, button3Width, button3Height; //variables for button 3

​

let currentPage = 1; //initialize the current page to 1

​

function setup() {

  createCanvas(windowWidth, windowHeight);

//   button 1 size and placement

  button1Width = 200; 

  button1Height = 100; 

  button1X = width / 2 - button1Width / 2; 

  button1Y = height / 2 - button1Height / 2 - 50; 

​

//   button 2 size and placement

  button2Width = 200; 

  button2Height = 100;

  button2X = width / 2 - button2Width / 2; 

  button2Y = height / 2 + button2Height / 2 + 50; 

//   button 3 size and placement

  button3Width = 100; 

  button3Height = 50; 

  button3X = width / 2 - button3Width / 2;

  button3Y = height - button3Height - 50; 

}

​

function draw() {

  background(0); 

​

  if (currentPage == 1) {

    //if the current page is 1, draw the buttons for page 1

    fill(255); 

    rect(button1X, button1Y, button1Width, button1Height); 

    rect(button2X, button2Y, button2Width, button2Height); 

  } else if (currentPage == 2) {

    //if the current page is 2, draw the button for page 2

    fill(255); 

    rect(button3X, button3Y, button3Width, button3Height); 

  }

}

​

function mouseClicked() {

  if (currentPage == 1) {

    //if the current page is 1

    if (

      mouseX > button1X &&

      mouseX < button1X + button1Width &&

      mouseY > button1Y &&

      mouseY < button1Y + button1Height

    ) {

      //if button 1 is clicked

      currentPage = 2; //change the current page to 2

    } else if (

      mouseX > button2X &&

      mouseX < button2X + button2Width &&

      mouseY > button2Y &&

      mouseY < button2Y + button2Height

    ) {

      //if button 2 is clicked

      currentPage = 2; //change the current page to

    }

  } else if (currentPage == 2) {

    //if the current page is 2

    if (

      mouseX > button3X &&

      mouseX < button3X + button3Width &&

      mouseY > button3Y &&

      mouseY < button3Y + button3Height

    ) {

      //if button 3 is clicked

      currentPage = 1; //change the current page back to 1

    }

  }

}

​