試一試 - HTML Games obstacles

<!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;
var myObstacles = [];

function startGame() {
   myGamePiece = new component(30, 30, "red", 10, 120);
   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) {
   this.width = width;
   this.height = height;
   this.speedX = 0;
   this.speedY = 0;
   this.x = x;
   this.y = y;
   this.update = function() {
   ctx = myGameArea.context;
   ctx.fillStyle = color;
   ctx.fillRect(this.x, this.y, this.width, this.height);
   }
   this.newPos = function() {
   this.x += this.speedX;
   this.y += this.speedY;
   }
   this.crashWith = function(otherobj) {
   var myleft = this.x;
   var myright = this.x + (this.width);
   var mytop = this.y;
   var mybottom = this.y + (this.height);
   var otherleft = otherobj.x;
   var otherright = otherobj.x + (otherobj.width);
   var othertop = otherobj.y;
   var otherbottom = otherobj.y + (otherobj.height);
   var crash = true;
   if ((mybottom < othertop) || (mytop > otherbottom) || (myright < otherleft) || (myleft > otherright)) {
   crash = false;
   }
   return crash;
   }
}

function updateGameArea() {
   var x, y;
   for (i = 0; i < myObstacles.length; i += 1) {
   if (myGamePiece.crashWith(myObstacles[i])) {
   myGameArea.stop();
   return;
   }
   }
   myGameArea.clear();
   myGameArea.frameNo += 1;
   if (myGameArea.frameNo == 1 || everyinterval(150)) {
   x = myGameArea.canvas.width;
   y = myGameArea.canvas.height - 200;
   myObstacles.push(new component(10, 200, "green", x, y));
   }
   for (i = 0; i < myObstacles.length; i += 1) {
   myObstacles[i].x += -1;
   myObstacles[i].update();
   }
   myGamePiece.newPos();
   myGamePiece.update();
}

function everyinterval(n) {
   if ((myGameArea.frameNo / n) % 1 == 0) {return true;}
   return false;
}

function moveup() {
   myGamePiece.speedY = -1;
}

function movedown() {
   myGamePiece.speedY = 1;
}

function moveleft() {
   myGamePiece.speedX = -1;
}

function moveright() {
   myGamePiece.speedX = 1;
}

function clearmove() {
   myGamePiece.speedX = 0;
   myGamePiece.speedY = 0;
}
</script>
<div style="text-align:center;width:480px;">
  <button onmousedown="moveup()" onmouseup="clearmove()" ontouchstart="moveup()">UP</button><br><br>
  <button onmousedown="moveleft()" onmouseup="clearmove()" ontouchstart="moveleft()">LEFT</button>
  <button onmousedown="moveright()" onmouseup="clearmove()" ontouchstart="moveright()">RIGHT</button><br><br>
  <button onmousedown="movedown()" onmouseup="clearmove()" ontouchstart="movedown()">DOWN</button>
</div>
<p>Here comes a new obstacle at every 150. frame, and we have 50 frames per second, so one obstacle every third second!</p>

</body>
</html>

var myGamePiece;
var myObstacles = [];

function startGame() {
    myGamePiece = new component(30, 30, "red", 10, 120);
    myGameArea.start();
}

function everyinterval(n) {
    if ((myGameArea.frameNo / n) % 1 == 0) {return true;}
    return false;
}

function moveup() {
    myGamePiece.speedY = -1; 
}

function movedown() {
    myGamePiece.speedY = 1; 
}

function moveleft() {
    myGamePiece.speedX = -1; 
}

function moveright() {
    myGamePiece.speedX = 1; 
}

function clearmove() {
    myGamePiece.speedX = 0; 
    myGamePiece.speedY = 0; 
}
</script>
<div style="text-align:center;width:480px;">
  <button onmousedown="moveup()" onmouseup="clearmove()" ontouchstart="moveup()">UP</button><br><br>
  <button onmousedown="moveleft()" onmouseup="clearmove()" ontouchstart="moveleft()">LEFT</button>
  <button onmousedown="moveright()" onmouseup="clearmove()" ontouchstart="moveright()">RIGHT</button><br><br>
  <button onmousedown="movedown()" onmouseup="clearmove()" ontouchstart="movedown()">DOWN</button>
</div>
<p>Here comes a new obstacle at every 150. frame, and we have 50 frames per second, so one obstacle every third second!</p>

</body>
</html>