Javascript JS游戏未在网页中呈现
我一直在跟随一个教程制作一个简单的Javascript游戏,但由于某种原因,当我在chrome中运行index.html文件时,游戏本身不会呈现,我也不知道为什么 到目前为止,我已经尝试将脚本分离到一个单独的文件中,并尝试在html文件中使用脚本元素呈现 请参阅下面的代码:Javascript JS游戏未在网页中呈现,javascript,html,canvas,Javascript,Html,Canvas,我一直在跟随一个教程制作一个简单的Javascript游戏,但由于某种原因,当我在chrome中运行index.html文件时,游戏本身不会呈现,我也不知道为什么 到目前为止,我已经尝试将脚本分离到一个单独的文件中,并尝试在html文件中使用脚本元素呈现 请参阅下面的代码: <!DOCTYPE html> <html lang='en'> <head> <meta charset='utf-8'> <t
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='utf-8'>
<title>JS Goblin Catcher</title>
</head>
<body>
<script>
// Create the canvas
var canvas = document.createElement("canvas");
var context = canvas.getContext("2d");
canvas.width = 512;
canvas.height = 480;
document.body.appendChild(canvas);
// Background image
var bgReady = false;
var bgImage = new Image();
bgImage.onload = function () {
bgReady = true;
};
bgImage.src = "background.png";
// Hero Image
var heroReady = false;
var heroImage = new Image();
heroImage.onload = function () {
heroReady = true;
};
heroImage.src = "hero.png";
// Goblin image
var goblinReady = false;
var goblinImage = new Image();
goblinImage.onload = function () {
goblinReady = true;
};
goblinImage.src = "monster.png";
// Game Objects
var hero = {
speed: 256, // pixels per second
x: 0,
y: 0
};
var goblin = {
x: 0,
y: 0
};
var goblinsCaught = 0;
// Keyboard controls
var keysDown = {};
addEventListener("keydown", function (e) {
keysDown[e.keyCode] = true;
}, false);
addEventListener("keyup", function (e) {
delete keysDown[e.keyCode];
}, false);
// Resets the game when a Goblin is caught
var reset = function () {
hero.x = canvas.width / 2;
hero.y = canvas.height / 2;
// Randomly places the Goblin
goblin.x = 32 + (Math.random() * (canvas.width - 64));
goblin.y = 32 + (Math.random() * (canvas.width - 64));
};
// Update game objects
var update = function (modifier) {
if (38 in keysDown) { // Player holding up
hero.y -= hero.speed * modifier;
}
if (40 in keysDown) { // Player holding down
hero.y += hero.speed * modifier;
}
if (37 in keysDown) { // Player holding left
hero.x -= hero.speed * modifier;
}
if (39 in keysDown) { // Player holding right
hero.x += hero.speed * modifier;
}
// Are they touching?
if (
hero.x <= (goblin.x + 32)
&& goblin.x <= (hero.x + 32)
&& hero.y <= (goblin.y + 32)
&& goblin.y <= (hero.y + 32)
) {
++goblinsCaught;
reset();
}
};
// Render objects
// Draw everything
let render = function () {
if (bgReady) {
context.drawImage(bgImage, 0, 0);
}
if (heroReady) {
context.drawImage(heroImage, hero.x, hero.y);
}
if (monsterReady) {
context.drawImage(goblinImage, goblin.x, goblin.y);
}
// Score
context.fillStyle = "rgb(250, 250, 250)";
context.font = "24px Helvetica";
context.textAlign = "left";
context.textBaseline = "top";
context.fillText("Goblins caught: " + goblinsCaught, 32, 32);
};
// Game loop
let game = function() {
let dateNow = Date.now();
let delta = dateNow - then;
update(delta/1000);
render();
then = now;
requestAnimationFrame(game);
};
// Cross-browser support for requestAnimationFrame
var w = window;
requestAnimationFrame = w.requestAnimationFrame || w.webkitRequestAnimationFrame || w.msRequestAnimationFrame || w.mozRequestAnimationFrame;
// Start the game!
let then = Date.now();
reset();
main();</script>
</body>
</html>
地精捕手
//创建画布
var canvas=document.createElement(“canvas”);
var context=canvas.getContext(“2d”);
canvas.width=512;
canvas.height=480;
document.body.appendChild(画布);
//背景图像
var bgrady=false;
var bgImage=新图像();
bgImage.onload=函数(){
bgrady=true;
};
bgImage.src=“background.png”;
//英雄形象
var-heroredy=false;
var-mage=新图像();
heroMage.onload=函数(){
heroReady=true;
};
heroMage.src=“hero.png”;
//地精形象
var goblinReady=false;
var goblinImage=新图像();
goblinImage.onload=函数(){
goblinReady=true;
};
goblinImage.src=“monster.png”;
//游戏物品
var hero={
速度:256,//像素/秒
x:0,,
y:0
};
小妖精={
x:0,,
y:0
};
var goblinscapt=0;
//键盘控制
var keysDown={};
addEventListener(“向下键控”,函数(e){
keysDown[e.keyCode]=真;
},假);
addEventListener(“键控”,函数(e){
删除keysDown[e.keyCode];
},假);
//当地精被抓到时重置游戏
变量重置=函数(){
hero.x=canvas.width/2;
hero.y=canvas.height/2;
//随机放置地精
goblin.x=32+(Math.random()*(canvas.width-64));
goblin.y=32+(Math.random()*(canvas.width-64));
};
//更新游戏对象
变量更新=函数(修饰符){
如果(38键向下){//玩家举起
hero.y-=hero.speed*修饰符;
}
如果(40英寸向下键){//玩家按住
hero.y+=hero.speed*修改器;
}
如果(37英寸向下键){//玩家左握
hero.x-=hero.speed*修改器;
}
如果(39键向下){//玩家保持右侧
hero.x+=hero.speed*修改器;
}
//他们在动吗?
如果(
hero.x打开您的浏览器调试工具并检查控制台。非常确定您会在那里出错。您在末尾调用了main()函数,但没有声明它。我删除了未声明的main()但是仍然没有任何渲染,我不是在某处调用游戏吗?我似乎不明白为什么它没有启动,现在控制台中也没有显示错误。