zig Tryit Editor

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<style>
canvas {
    border:1px solid #d3d3d3;
    background-color: #f1f1f1;
}
</style>
</head>
<body onload="startGame()">
<script>
  var myGamePiece;
  function startGame() {
    myGamePiece = new component(30, 30, "smiley.gif", 10, 120, "image");
    myGameArea.start();
  }
  var myGameArea = {
    canvas: document.createElement("canvas"),
    start: function () {
      this.canvas.width = 480;
      this.canvas.height = 270;
      this.context = this.canvas.getContext("2d");
      document.body.insertBefore(this.canvas, document.body.childNodes[0]);
      this.frameNo = 0;
      this.interval = setInterval(updateGameArea, 20);
    },
    clear: function () {
      this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
    },
    stop: function () {
      clearInterval(this.interval);
    }
  }
  function component(width, height, color, x, y, type) {
    this.type = type;
    if (type == "image") {
      this.image = new Image();
      this.image.src = color;
    }
    this.width = width;
    this.height = height;
    this.speedX = 0;
    this.speedY = 0;
    this.x = x;
    this.y = y;
    this.update = function () {
      ctx = myGameArea.context;
      if (type == "image") {
        ctx.drawImage(this.image,
          this.x,
          this.y,
          this.width, this.height);
      } else {
        ctx.fillStyle = color;
        ctx.fillRect(this.x, this.y, this.width, this.height);
      }
    }
    this.newPos = function () {
      this.x += this.speedX;
      this.y += this.speedY;
    }
  }
  function updateGameArea() {
    myGameArea.clear();
    myGamePiece.newPos();
    myGamePiece.update();
  }
  function move(dir) {
    myGamePiece.image.src = "angry.gif";
    if (dir == "up") { myGamePiece.speedY = -1; }
    if (dir == "down") { myGamePiece.speedY = 1; }
    if (dir == "left") { myGamePiece.speedX = -1; }
    if (dir == "right") { myGamePiece.speedX = 1; }
  }
  function clearmove() {
    myGamePiece.image.src = "smiley.gif";
    myGamePiece.speedX = 0;
    myGamePiece.speedY = 0;
  }
</script>
<div style="text-align:center;width:480px;">
  <button onmousedown="move('up')" onmouseup="clearmove()" ontouchstart="move('up')">UP</button><br><br>
  <button onmousedown="move('left')" onmouseup="clearmove()" ontouchstart="move('left')">LEFT</button>
  <button onmousedown="move('right')" onmouseup="clearmove()" ontouchstart="move('right')">RIGHT</button><br><br>
  <button onmousedown="move('down')" onmouseup="clearmove()" ontouchstart="move('down')">DOWN</button>
</div>
<p>See the image changes when you click on a button.</p>
</body>

</html>

 
<!DOCTYPE html><html><head><meta name="viewport" content="width=device-width, initial-scale=1.0"/><style>canvas {    border:1px solid #d3d3d3;    background-color: #f1f1f1;}</style></head><body onload="startGame()"><script>  var myGamePiece;  function startGame() {    myGamePiece = new component(30, 30, "smiley.gif", 10, 120, "image");    myGameArea.start();  }  var myGameArea = {    canvas: document.createElement("canvas"),    start: function () {      this.canvas.width = 480;      this.canvas.height = 270;      this.context = this.canvas.getContext("2d");      document.body.insertBefore(this.canvas, document.body.childNodes[0]);      this.frameNo = 0;      this.interval = setInterval(updateGameArea, 20);    },    clear: function () {      this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);    },    stop: function () {      clearInterval(this.interval);    }  }  function component(width, height, color, x, y, type) {    this.type = type;    if (type == "image") {      this.image = new Image();      this.image.src = color;    }    this.width = width;    this.height = height;    this.speedX = 0;    this.speedY = 0;    this.x = x;