let sprites = [];

let direction = 1; // 0 up

let step = 0;

let x;

let y;

let speed = 5;

let stepSpeed = 60;

let animationTimer;

​

function preload() {

  spritesheet = loadImage("walking.png");

}

​

function setup() {

  createCanvas(600, 600);

  imageMode(CENTER);

​

  // get the width and hieght of each sprite

  let w = spritesheet.width / 12;

  let h = spritesheet.height / 4;

​

  // there are four rows, create a for loop to iterate through them

  for (let y = 0; y < 4; y++) {

    // create another emoty array for that row

    sprites[y] = [];

    // there are 12 images in a row, iterate through them

    for (let x = 0; x < 12; x++) {

      // get the image subsection there and then stor in the array

      sprites[y][x] = spritesheet.get(x * w, y * h, w, h);

    }

  }

​

  x = width / 2;

  y = height / 2;

}

​

function draw() {

  background(255);

​

  //look at sprite sheet to determine which direction is which

  // use isKeyPressed here to get continuous key presses

  if (isKeyPressed == true) {

    if (keyCode == DOWN_ARROW) {

      direction = 0;

      y += speed;

    }

    if (keyCode == LEFT_ARROW) {

      direction = 1;

      x -= speed;

    }

    if (keyCode == RIGHT_ARROW) {

      direction = 2;

      x += speed;

    }

    if (keyCode == UP_ARROW) {

      direction = 3;

      y -= speed;

    }

  }

​

  // the first part choose the diretion (or row)

  // and the second part (the step) chooses the proper image from that row

  image(sprites[direction][step], x, y);

}

​

function advanceStep() {

  step = (step + 1) % 12;

}

​

function keyPressed() {

  // use the javascript setInterval function that will

  // call a function repeatedly at a given milliseconds interval

  // supply setInterval with a function that will run the animation steps

  // but first! clear any interval that already might be running

  // to account for accidental multiple keypresses

  clearInterval(animationTimer)

  // then set the interval

  animationTimer = setInterval(advanceStep, stepSpeed); // stepSpeed is our global variable that is the milliseconds for the interval

}

​

function keyReleased() {

  // when a key is released clear the interval

  clearInterval(animationTimer);

}

​