April 29, 2015

html5游戏制作入门系列教程（六）

By Gideon Div / Css / XML / HTML5 / SVG 0 Comments

我们继续这一系列文章，使用HTML5的canvas组件进行游戏开发。今天，我们将创建我们的第一个完整的游戏 – 打砖块。在这一课中，我会告诉你如何检测基本的碰撞和HTML5的本地存储。您可以使用鼠标和键盘（左/右按钮）来操作垫拍左右运动。我们将html5本地存储技术存储经过历史的游戏时间和碎砖（点）的数据。

这里有我们的演示和下载包：

在线演示源码下载

好吧，下载所需文件，让我们开始编码！

步骤1： HTML
这里是我演示的HTML，非常简单，对不对？

<!DOCTYPE html>
<html lang="en" >
<head>
<meta charset="utf-8" />
<title>html5游戏制作入门系列教程（六）</title>
<link href="css/main.css" rel="stylesheet" type="text/css" />
<script src="js/jquery-1.5.2.min.js"></script>
<script src="js/script.js"></script>
</head>
<body>
<header>
<h2>html5游戏制作入门系列教程（六）</h2>
<a href="http://html5gamedev.org/?p=337" class="stuts">返回原文<span>HTML5GAME</span></a>
</header>

<div class="container">
<canvas id="scene" width="800" height="600"></canvas>
</div>
</body>
</html>

步骤2：CSS
下面是使用CSS样式。
css/main.css

/* page layout styles */
*{
margin:0;
padding:0;
}
body {
background-color:#eee;
color:#fff;
font:14px/1.3 Arial,sans-serif;
}
header {
background-color:#212121;
box-shadow: 0 -1px 2px #111111;
display:block;
height:70px;
position:relative;
width:100%;
z-index:100;
}
header h2{
font-size:22px;
font-weight:normal;
left:50%;
margin-left:-400px;
padding:22px 0;
position:absolute;
width:540px;
}
header a.stuts,a.stuts:visited{
border:none;
text-decoration:none;
color:#fcfcfc;
font-size:14px;
left:50%;
line-height:31px;
margin:23px 0 0 110px;
position:absolute;
top:0;
}
header .stuts span {
font-size:22px;
font-weight:bold;
margin-left:5px;
}
.container {
margin: 20px auto;
overflow: hidden;
position: relative;
width: 800px;
}

步骤3：JS

js/script.js

// inner variables
var canvas, ctx;

var iStart = 0;
var bRightBut = false;
var bLeftBut = false;
var oBall, oPadd, oBricks;
var aSounds = [];
var iPoints = 0;
var iGameTimer;
var iElapsed = iMin = iSec = 0;
var sLastTime, sLastPoints;

// objects :
function Ball(x, y, dx, dy, r) {
this.x = x;
this.y = y;
this.dx = dx;
this.dy = dy;
this.r = r;
}
function Padd(x, w, h, img) {
this.x = x;
this.w = w;
this.h = h;
this.img = img;
}
function Bricks(w, h, r, c, p) {
this.w = w;
this.h = h;
this.r = r; // rows
this.c = c; // cols
this.p = p; // padd
this.objs;
this.colors = ['#9d9d9d', '#f80207', '#feff01', '#0072ff', '#fc01fc', '#03fe03']; // colors for rows
}

// -------------------------------------------------------------
// draw functions :

function clear() { // clear canvas function
ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);

// fill background
ctx.fillStyle = '#111';
ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
}

function drawScene() { // main drawScene function
clear(); // clear canvas

// draw Ball (circle)
ctx.fillStyle = '#f66';
ctx.beginPath();
ctx.arc(oBall.x, oBall.y, oBall.r, 0, Math.PI * 2, true);
ctx.closePath();
ctx.fill();

if (bRightBut)
oPadd.x += 5;
else if (bLeftBut)
oPadd.x -= 5;

// draw Padd (rectangle)
ctx.drawImage(oPadd.img, oPadd.x, ctx.canvas.height - oPadd.h);

// draw bricks (from array of its objects)
for (i=0; i < oBricks.r; i++) {
ctx.fillStyle = oBricks.colors[i];
for (j=0; j < oBricks.c; j++) {
if (oBricks.objs[i][j] == 1) {
ctx.beginPath();
ctx.rect((j * (oBricks.w + oBricks.p)) + oBricks.p, (i * (oBricks.h + oBricks.p)) + oBricks.p, oBricks.w, oBricks.h);
ctx.closePath();
ctx.fill();
}
}
}

// collision detection
iRowH = oBricks.h + oBricks.p;
iRow = Math.floor(oBall.y / iRowH);
iCol = Math.floor(oBall.x / (oBricks.w + oBricks.p));

// mark brick as broken (empty) and reverse brick
if (oBall.y < oBricks.r * iRowH && iRow >= 0 && iCol >= 0 && oBricks.objs[iRow][iCol] == 1) {
oBricks.objs[iRow][iCol] = 0;
oBall.dy = -oBall.dy;
iPoints++;

aSounds[0].play(); // play sound
}

// reverse X position of ball
if (oBall.x + oBall.dx + oBall.r > ctx.canvas.width || oBall.x + oBall.dx - oBall.r < 0) {
oBall.dx = -oBall.dx;
}

if (oBall.y + oBall.dy - oBall.r < 0) {
oBall.dy = -oBall.dy;
} else if (oBall.y + oBall.dy + oBall.r > ctx.canvas.height - oPadd.h) {
if (oBall.x > oPadd.x && oBall.x < oPadd.x + oPadd.w) {
oBall.dx = 10 * ((oBall.x-(oPadd.x+oPadd.w/2))/oPadd.w);
oBall.dy = -oBall.dy;

aSounds[2].play(); // play sound
}
else if (oBall.y + oBall.dy + oBall.r > ctx.canvas.height) {
clearInterval(iStart);
clearInterval(iGameTimer);

// HTML5 Local storage - save values
localStorage.setItem('last-time', iMin + ':' + iSec);
localStorage.setItem('last-points', iPoints);

aSounds[1].play(); // play sound
}
}

oBall.x += oBall.dx;
oBall.y += oBall.dy;

ctx.font = '16px Verdana';
ctx.fillStyle = '#fff';
iMin = Math.floor(iElapsed / 60);
iSec = iElapsed % 60;
if (iMin < 10) iMin = "0" + iMin;
if (iSec < 10) iSec = "0" + iSec;
ctx.fillText('Time: ' + iMin + ':' + iSec, 600, 520);
ctx.fillText('Points: ' + iPoints, 600, 550);

if (sLastTime != null && sLastPoints != null) {
ctx.fillText('Last Time: ' + sLastTime, 600, 460);
ctx.fillText('Last Points: ' + sLastPoints, 600, 490);
}
}

// initialization
$(function(){
canvas = document.getElementById('scene');
ctx = canvas.getContext('2d');

var width = canvas.width;
var height = canvas.height;

var padImg = new Image();
padImg.src = 'images/padd.png';
padImg.onload = function() {};

oBall = new Ball(width / 2, 550, 0.5, -5, 10); // new ball object
oPadd = new Padd(width / 2, 120, 20, padImg); // new padd object
oBricks = new Bricks((width / <img src="http://www.script-tutorials.com/wp-includes/images/smilies/icon_cool.gif" alt="8)" class="wp-smiley"> - 1, 20, 6, 8, 2); // new bricks object

oBricks.objs = new Array(oBricks.r); // fill-in bricks
for (i=0; i < oBricks.r; i++) {
oBricks.objs[i] = new Array(oBricks.c);
for (j=0; j < oBricks.c; j++) {
oBricks.objs[i][j] = 1;
}
}

aSounds[0] = new Audio('media/snd1.wav');
aSounds[0].volume = 0.9;
aSounds[1] = new Audio('media/snd2.wav');
aSounds[1].volume = 0.9;
aSounds[2] = new Audio('media/snd3.wav');
aSounds[2].volume = 0.9;

iStart = setInterval(drawScene, 10); // loop drawScene
iGameTimer = setInterval(countTimer, 1000); // inner game timer

// HTML5 Local storage - get values
sLastTime = localStorage.getItem('last-time');
sLastPoints = localStorage.getItem('last-points');

$(window).keydown(function(event){ // keyboard-down alerts
switch (event.keyCode) {
case 37: // 'Left' key
bLeftBut = true;
break;
case 39: // 'Right' key
bRightBut = true;
break;
}
});
$(window).keyup(function(event){ // keyboard-up alerts
switch (event.keyCode) {
case 37: // 'Left' key
bLeftBut = false;
break;
case 39: // 'Right' key
bRightBut = false;
break;
}
});

var iCanvX1 = $(canvas).offset().left;
var iCanvX2 = iCanvX1 + width;
$('#scene').mousemove(function(e) { // binding mousemove event
if (e.pageX > iCanvX1 && e.pageX < iCanvX2) {
oPadd.x = Math.max(e.pageX - iCanvX1 - (oPadd.w/2), 0);
oPadd.x = Math.min(ctx.canvas.width - oPadd.w, oPadd.x);
}
});
});

function countTimer() {
iElapsed++;
}

我为主要的代码添加了注释，希望代码是容易理解的。请注意“的localStorage对象，以了解如何使用HTML5本地存储（我使用’SetItem的方法来存储的数据，使用’getItem方法’来读取本地存储的数据）。

在线演示源码下载

结论
超级酷，不是吗？我会很高兴看到您的评论和意见。祝你好运！