html5游戏制作入门系列教程（五）

huzijia

2014-12-17

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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，这是相当完整的游戏例子 – 它会回顾经典的旧电脑游戏 – 坦克大战。我会教你使用阵列地图并教你如何检测活动对象（坦克）与环境（基于阵列的地图）的碰撞。

你可以点击这里阅读这一系列教程的前一篇文章：html5游戏制作入门系列教程（四）。我们的将基于之前的程序和代码进行开发。

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（五）</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（五）</h2>
<a href="http://html5gamedev.org/?p=330" 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
今天就不把css样式贴出来了，和以前的一样，没有什么特别之处。你可以在下载包里找到它。

步骤3：JS
js/script.js

// inner variables
var canvas, context; // canvas and context objects
var imgBrick, imgSteel, imgWater, imgForest, imgTank; // images
var aMap; // map array
var oTank; // tank object

var iCellSize = 24; // cell wide
var iXCnt = 26; // amount of X cells
var iYCnt = 26; // amount of Y cells

// objects :
function Tank(x, y, w, h, image) {
this.x = x;
this.y = y;
this.w = w;
this.h = h;
this.i = 0;
this.image = image;
}

// functions
function clear() { // clear canvas function
context.clearRect(0, 0, canvas.width, canvas.height);
}

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

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

// save current context
context.save();

// walk through our array
for (var y = 0; y < iYCnt; y++) {
for (var x = 0; x < iXCnt; x++) {
switch (aMap[y][x]) {
case 0: // skip
break;
case 1: // draw brick block
context.drawImage(imgBrick, 0, 0, iCellSize, iCellSize, x*iCellSize, y*iCellSize, iCellSize, iCellSize);
break;
case 2: // draw steel block
context.drawImage(imgSteel, 0, 0, iCellSize, iCellSize, x*iCellSize, y*iCellSize, iCellSize, iCellSize);
break;
case 3: // draw forest block
context.drawImage(imgForest, 0, 0, iCellSize, iCellSize, x*iCellSize, y*iCellSize, iCellSize, iCellSize);
break;
case 4: // draw water block
context.drawImage(imgWater, 0, 0, iCellSize, iCellSize, x*iCellSize, y*iCellSize, iCellSize, iCellSize);
break;
}
}
}

// restore current context
context.restore();

// draw tank
context.drawImage(oTank.image, oTank.i*oTank.w, 0, oTank.w, oTank.h, oTank.x, oTank.y, oTank.w, oTank.h);
}
// -------------------------------------------------------------

// initialization
$(function(){
canvas = document.getElementById('scene');
canvas.width = iXCnt * iCellSize;
canvas.height = iYCnt * iCellSize;
context = canvas.getContext('2d');

// main scene Map array
aMap = ([
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0],
[0, 0, 1, 1, 4, 4, 4, 4, 0, 0, 2, 2, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 1, 1, 4, 4, 4, 4, 0, 0, 2, 2, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 4, 4, 4, 4, 1, 1, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 0, 0, 2, 2, 0, 0],
[0, 0, 0, 0, 4, 4, 4, 4, 1, 1, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 0, 0, 2, 2, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 1, 1, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 1, 1, 0, 0, 0, 0],
[0, 0, 2, 2, 0, 0, 0, 0, 4, 4, 4, 4, 0, 0, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 2, 2, 0, 0, 0, 0, 4, 4, 4, 4, 0, 0, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[3, 3, 3, 3, 1, 1, 0, 0, 4, 4, 4, 4, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0],
[3, 3, 3, 3, 1, 1, 0, 0, 4, 4, 4, 4, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0],
[3, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 2, 2],
[3, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 2, 2],
[0, 0, 1, 1, 4, 4, 4, 4, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 1, 1, 4, 4, 4, 4, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[2, 2, 0, 0, 4, 4, 4, 4, 3, 3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 3, 0, 0, 1, 1, 0, 0],
[2, 2, 0, 0, 4, 4, 4, 4, 3, 3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 3, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 4, 4, 4, 4, 3, 3, 3, 3, 4, 4, 4, 4, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 4, 4, 4, 4, 3, 3, 3, 3, 4, 4, 4, 4, 0, 0],
[0, 0, 0, 0, 0, 0, 2, 2, 3, 3, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 4, 4, 4, 4, 0, 0],
[0, 0, 0, 0, 0, 0, 2, 2, 3, 3, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3, 4, 4, 4, 4, 0, 0],
[0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 2, 2, 0, 0, 0, 0],
[1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 2, 2, 0, 0, 0, 0]
]);

// load images
imgBrick = new Image();
imgBrick.src = 'images/brick.png';
imgSteel = new Image();
imgSteel.src = 'images/steel.png';
imgWater = new Image();
imgWater.src = 'images/water.png';
imgForest = new Image();
imgForest.src = 'images/forest.png';

imgTank = new Image();
imgTank.src = 'images/tank.png';
oTank = new Tank(iCellSize*9, iCellSize*24, 48, 48, imgTank);

$(window).keydown(function(event){ // keyboard alerts
switch (event.keyCode) {
case 38: // Up key
oTank.i = 2;

// checking collisions
var iCurCelX = (2 * oTank.x) / 48;
var iCurCelY = (2 * oTank.y) / 48;
if (iCurCelY) {
var iTest1 = aMap[iCurCelY-1][iCurCelX];
var iTest2 = aMap[iCurCelY-1][iCurCelX+1];

if ((iTest1 == 0 || iTest1 == 3) && (iTest2 == 0 || iTest2 == 3)) {
oTank.y-=24;
if (oTank.y < 0) {
oTank.y = 0;
}
}
}
break;
case 40: // Down key
oTank.i = 3;

// checking collisions
var iCurCelX = (2 * oTank.x) / 48;
var iCurCelY = (2 * oTank.y) / 48;
if (iCurCelY+2 < iYCnt) {
var iTest1 = aMap[iCurCelY+2][iCurCelX];
var iTest2 = aMap[iCurCelY+2][iCurCelX+1];

if ((iTest1 == 0 || iTest1 == 3) && (iTest2 == 0 || iTest2 == 3)) {
oTank.y+=24;
if (oTank.y > 576) { //iCellSize * (iYCnt-2)
oTank.y = 576;
}
}
}
break;
case 37: // Left key
oTank.i = 1;

// checking collisions
var iCurCelX = (2 * oTank.x) / 48;
var iCurCelY = (2 * oTank.y) / 48;
var iTest1 = aMap[iCurCelY][iCurCelX-1];
var iTest2 = aMap[iCurCelY+1][iCurCelX-1];

if ((iTest1 == 0 || iTest1 == 3) && (iTest2 == 0 || iTest2 == 3)) {
oTank.x-=24;
if (oTank.x < 0) {
oTank.x = 0;
}
}
break;
case 39: // Right key
oTank.i = 0;

// checking collisions
var iCurCelX = (2 * oTank.x) / 48;
var iCurCelY = (2 * oTank.y) / 48;
var iTest1 = aMap[iCurCelY][iCurCelX+2];
var iTest2 = aMap[iCurCelY+1][iCurCelX+2];

if ((iTest1 == 0 || iTest1 == 3) && (iTest2 == 0 || iTest2 == 3)) {
oTank.x+=24;
if (oTank.x > 576) { //iCellSize * (iXCnt-2)
oTank.x = 576;
}
}
break;
}
});

setInterval(drawScene, 40); // loop drawScene
});

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！

在线演示源码下载

html5游戏制作入门系列教程（五）