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SnakeBasic.html
125 lines (108 loc) · 2.63 KB
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SnakeBasic.html
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<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Snake Basic 1</title>
<style type='text/css'>
canvas { border: 1px solid black; }
</style>
</head>
<body>
<canvas id='canvas' width='800' height='600'></canvas>
<script type='text/javascript'>
var WIDTH = 800;
var HEIGHT = 600;
var FPS = 60;
var LENGTH = 7;
var head = {
x: 50,
y: 50,
w: 10,
h: 10,
dx: 5,
dy: 5,
};
var tail = [];
for ( var i = 0; i<LENGTH; i++ ) {
var tailpiece = {
x: head.x,
y: head.y,
};
tail.push(tailpiece);
}
var left = false;
var right = false;
var up = false;
var down = false;
var canvasElement = document.getElementById('canvas');
canvasElement.width = WIDTH;
canvasElement.height = HEIGHT;
var canvas = canvasElement;
if (canvasElement.getContext) {
canvas = canvasElement.getContext("2d");
setInterval(function() {
update();
draw();
}, 1000/FPS);
}
else {
alert("Your browser doesn't seem to support the <canvas> element. Sorry.");
}
function update() {
if ( up || down || left || right ) {
var copy = {
x: head.x,
y: head.y,
};
tail.push(copy);
tail.shift();
}
if ( up )
head.y -= head.dy;
if ( down )
head.y += head.dy;
if ( left )
head.x -= head.dx;
if ( right )
head.x += head.dx;
}
function draw() {
canvas.clearRect(0, 0, WIDTH, HEIGHT);
canvas.fillStyle = "#0000FF";
for ( var i=0; i<tail.length; i++ ) {
canvas.fillRect(tail[i].x, tail[i].y, head.w, head.h);
}
canvas.fillStyle = "#00FF00";
canvas.fillRect(head.x, head.y, head.w, head.h);
}
function handleKeyDown(evt) {
if ( evt.keyCode == 38 ) /* UP */
up = true;
if ( evt.keyCode == 40 ) /* DOWN */
down = true;
if ( evt.keyCode == 37 ) /* LEFT */
left = true;
if ( evt.keyCode == 39 ) /* RIGHT */
right = true;
if ( 37 <= evt.keyCode && evt.keyCode <= 40 )
evt.preventDefault();
}
function handleKeyUp(evt) {
if ( evt.keyCode == 38 ) /* UP */
up = false;
if ( evt.keyCode == 40 ) /* DOWN */
down = false;
if ( evt.keyCode == 37 ) /* LEFT */
left = false;
if ( evt.keyCode == 39 ) /* RIGHT */
right = false;
if ( 37 <= evt.keyCode && evt.keyCode <= 40 )
evt.preventDefault();
}
document.addEventListener('keydown', handleKeyDown);
document.addEventListener('keyup', handleKeyUp);
document.addEventListener('mousedown', handleMouseDown);
document.addEventListener('mouseup', handleMouseUp);
</script>
</body>
</html>