這是一個特別簡單的用原生js實現的一個小鳥游戲，比較簡單，適合新手練習
這是html結構
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title></title> </head> <body> <div id="game"> <div id="bird"></div> </div> <script src="flappybird.js"></script> <script src="animate.js"></script> </body> </html>
整個案例結構並不多，下面是css樣式
body {
margin: 0;
padding: 0;
}
#game {
width: 800px;
height: 600px;
border: 1px solid #000;
background: url(images/sky.png);
overflow: hidden;
position: relative;
}
#game .pipeD {
background: url(images/pipe1.png) top center;
position: absolute;
}
#game .pipeU {
background: url(images/pipe2.png) bottom center;
position: absolute;
}
#bird {
width: 34px;
height: 25px;
/*border-radius: 10px;*/
/*background-color: red;*/
position: absolute;
top: 100px;
left: 100px;
background: url(images/birds.png) -8px -10px no-repeat;
}
下面就是原生js代碼了，這個小案例還運用了自己前期封裝的一個小的動畫方法
function animate(obj, json, fn) {
clearInterval(obj.timer);
obj.timer = setInterval(function () {
var flag = true;
for (var k in json) {
if (k === "opacity") {
var leader = getStyle(obj, k) * 100;
var target = json[k] * 100;
var step = (target - leader) / 10;
step = step > 0 ? Math.ceil(step) : Math.floor(step);
leader = leader + step;
obj.style[k] = leader / 100;
} else if (k === "zIndex") {
obj.style.zIndex = json[k];
} else {
var leader = parseInt(getStyle(obj, k)) || 0;
var target = json[k];
var step = (target - leader) / 10;
step = step > 0 ? Math.ceil(step) : Math.floor(step);
leader = leader + step;
obj.style[k] = leader + "px";
}
if (leader !== target) {
flag = false;
}
}
if (flag) {
clearInterval(obj.timer);
if (fn) {
fn();
}
}
}, 15);
}
function getStyle(obj, attr) {
if (window.getComputedStyle) {
return window.getComputedStyle(obj)[attr];
} else {
return obj.currentStyle[attr];
}
}
下面就是控制游戲的js代碼了
var birdElement = document.getElementById("bird");
var game = document.getElementById("game");
var gameover = false;
var g = 1;
var i = 0;
var timer=null;
var bird = {
x: birdElement.offsetLeft,
y: birdElement.offsetTop,
speedX: 5,
speedY: 0,
entity: birdElement
};
var sky = {
x: 0
};
//var timer=setInterval(function(){
// birdElement.style.backgroundPositionX=-52*i+"px";
// i++;
// if(i===3){
// i=0;
// }
//},100);
setInterval(function () {
//游戲沒有結束的時候運行代碼
if (!gameover) {
//整個游戲背景x軸移動的距離
sky.x = sky.x - bird.speedX;
game.style.backgroundPositionX = sky.x + "px";
//小鳥下落時y軸的坐標
bird.speedY = bird.speedY + g;
//設置一個變量用來接收小鳥下落時y軸的坐標，用來設置小鳥下降時的速度
var step = bird.speedY;
bird.y = bird.y + step;
//用一個變量來設定小鳥下落的最低高度，用來 判斷游戲是否結束
var overY = game.offsetHeight - birdElement.offsetHeight;
//小鳥的y軸坐標大於最低高度，所以游戲停止
if (bird.y > overY) {
bird.y = overY;
stop();
}
//小鳥的y軸坐標小於0，說明碰到頂部邊框，所以游戲結束
if (bird.y < 0) {
bird.y = 0;
stop();
}
//設置游戲開始時小鳥出現的位置
bird.entity.style.top = bird.y + "px";
}
}, 25);
//添加鍵盤事件，實現鍵盤上下鍵控制小鳥
document.onkeyup = function (e) {
if (e.keyCode === 38) {
bird.speedY = -10;
}
}
function Pipe(positonX) {
//管子的坐標
this.x = positonX;
this.upPipeY = 0;
this.width = 52;
this.upPipeH = parseInt(Math.random() * 175 + 100);
this.downPipeY = this.upPipeH + 200;
this.downPipeH = game.offsetHeight - this.downPipeY;
// 動態添加管子
var divUp = document.createElement("div");
divUp.className = "pipeU";
divUp.style.width = this.width + "px";
divUp.style.height = this.upPipeH + "px";
divUp.style.left = this.x + "px";
divUp.style.top = this.upPipeY + "px";
game.appendChild(divUp);
var divDown = document.createElement("div");
divDown.className = "pipeD";
divDown.style.width = this.width + "px";
divDown.style.height = this.downPipeH + "px";
divDown.style.left = this.x + "px";
divDown.style.top = this.downPipeY + "px";
game.appendChild(divDown);
//因為定時器會混亂this的指向問題，所以提前保存this的指向，這里的this指向調用該方法的實例
var that = this;
// 設置定時器讓管子向后移動
this.timer=setInterval(function () {
that.x = that.x - 1;
//簡單實現管子無縫滾動
if (that.x < -52) {
that.x = 800;
}
if (!gameover) {
divUp.style.left = that.x + "px";
divDown.style.left = that.x + "px";
}
// 設置變量，進行游戲碰撞檢測，並停止游戲
var downCrash = (bird.x + 34 > that.x) && (bird.x < that.x + 52) && (bird.y + 25 > that.downPipeY);
var upCrash = (bird.x + 34 > that.x) && (bird.x < that.x + 52) && (bird.y < that.upPipeH);
if (downCrash || upCrash) {
//gameover = true;
stop();
}
}, 10);
}
//執行上面的函數方法
var arr=[];
for (var i = 0; i < 4; i++) {
arr[i]=new Pipe(i * 200 + 400);
}
//封裝一個用來停止游戲的方法，
function stop(){
gameover=true;
clearInterval(timer);
for(var i=0;i<arr.length;i++){
clearInterval(arr[i].timer);
}
}
注釋都寫在了了代碼里，一個簡單小游戲就完成了