A Pen by Rishi Giri on CodePen.
Created
February 4, 2015 17:13
-
-
Save CodeDotJS/308373ac50f15369b2dc to your computer and use it in GitHub Desktop.
pvWYyR
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<html> | |
<head> | |
<title> | |
JavaScript Game | |
</title> | |
<style type="text/css"> | |
body{ | |
background-color: teal; | |
position: fixed; | |
top: 0; | |
left: 0; | |
right: 0; | |
bottom: 0; | |
} | |
#screen | |
{ | |
position: relative; | |
left: 150px; | |
} | |
.poked | |
{ | |
text-align: center; | |
font-weight:bolder; | |
font-size: 50px; | |
} | |
</style> | |
</head> | |
<body> <p class="poked">JavaScript Game</p> | |
<center><canvas id="screen" width="560" height="580"></canvas></center> | |
<script src="./animate.js"></script> | |
</body> | |
</html> |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
var FPS = 600; | |
var PADDLE_SPEED = 100; | |
var BALL_SPEED = 100; | |
var canvas = document.getElementById('screen'); | |
var ctx = canvas.getContext('2d'); | |
var elements = []; | |
var Element = function(x, y, width, height, vx, vy) { | |
this.x = x; | |
this.y = y; | |
this.width = width; | |
this.height = height; | |
this.vx = vx || 0; | |
this.vy = vy || 0; | |
elements.push(this); | |
}; | |
Element.prototype.draw = function() { | |
ctx.fillRect(this.x, this.y, this.width, this.height); | |
}; | |
Element.prototype.move = function() { | |
for (var i=0; i < elements.length; i++) { | |
el = elements[i]; | |
if (elements[i] == this) { | |
continue; | |
} | |
// bounce on horizontal collision | |
if ((this.top() < el.bottom() && this.bottom() > el.top()) && | |
(this.right() < el.left() && this.right() + this.vx >= el.left() || | |
this.left() > el.right() && this.left() + this.vx <= el.right())) { | |
this.vx = -this.vx; | |
break; | |
} | |
// bounce on vertical collision | |
if ((this.left() < el.right() && this.right() > el.left()) && | |
(this.bottom() < el.top() && this.bottom() + this.vy >= el.top() || | |
this.top() > el.bottom() && this.top() + this.vy <= el.bottom())) { | |
this.vy = -this.vy; | |
break; | |
} | |
} | |
this.x += this.vx; | |
this.y += this.vy; | |
}; | |
Element.prototype.left = function() { | |
return this.x; | |
}; | |
Element.prototype.right = function() { | |
return this.x + this.width; | |
}; | |
Element.prototype.top = function() { | |
return this.y; | |
}; | |
Element.prototype.bottom = function() { | |
return this.y + this.height; | |
}; | |
// instantiate moving game elements | |
var paddle1 = new Element(5, 65, 5, 30); | |
var paddle2 = new Element(230, 65, 5, 30); | |
var ball = new Element(117, 77, 6, 6, -1 * BALL_SPEED / FPS, 0.6 * BALL_SPEED / FPS); | |
// create top and bottom walls | |
var topWall = new Element( 0, 0, 240, 1); | |
var bottomWall = new Element(0, 159, 240, 1); | |
// player one controller | |
window.onkeydown = function(event) { | |
// go up if the up key was pressed | |
if (event.keyCode === 38) { | |
paddle1.vy = -PADDLE_SPEED / FPS; | |
} | |
// go down if it was the down key was pressed | |
if (event.keyCode === 40) { | |
paddle1.vy = PADDLE_SPEED / FPS; | |
} | |
}; | |
window.onkeyup = function(e) { | |
paddle1.vy = 0; | |
}; | |
// computer player | |
var ai = function(paddle) { | |
var prediction = (ball.vy / ball.vx) * (paddle.x - ball.x) + ball.y; | |
if (prediction < paddle.top() + paddle.height * 1/3) { | |
paddle.vy = -PADDLE_SPEED / FPS; | |
} else if (prediction > paddle.top() + paddle.height * 2/3) { | |
paddle.vy = PADDLE_SPEED / FPS; | |
} else { | |
paddle.vy = 0; | |
} | |
}; | |
// game loop | |
var gameLoop = function() { | |
ctx.clearRect(0, 0, canvas.width, canvas.height); | |
for (var i = 0; i < elements.length; i++) { | |
elements[i].move(); | |
elements[i].draw(); | |
} | |
ai(paddle2); | |
// game rules | |
if (ball.right() > canvas.width) { | |
ball.x = 117; | |
ball.y = 77; | |
} else if (ball.left() < 0) { | |
ball.x = 117; | |
ball.y = 77; | |
} | |
}; | |
setInterval(gameLoop, 1000 / FPS); |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment