javascript游戏开发之《三国志曹操传》零部件开发(四)用地图块拼成大地图

小时候我们玩过拼图游戏，是用自己的手去拼的。今天我们来研究研究用javascript来拼图。同样是拼图，但用js拼图要比用手拼图麻烦多了，因此以后我要把它优化成引擎。

一、前言

以上是一段导语，话不扯远，对《三国志曹操传》熟悉的玩家知道，《三国志曹操传》的地图是由小地图块拼成的，那要实现它就和导语说得一样：很麻烦。不过即使麻烦也是一门技术，因此在此分享给大家，希望大家喜欢。

二、代码讲解

今天我要换换讲解方式，先不给代码，我们先来想想原理。现在，假如你有一幅图片，把它裁开成若干份，并打乱。现在如果让你用js把他们组织起来，如何做呢？先不说图的顺序，首先来看把它们弄在一起就很难了。这时我减少难度，给你几个选择：
A.用margin慢慢调        B.用数组把它们排列好        C.放弃

在这道题中，选A是很不明智的，选C就代表你也拿不定主意。看来选B是最好的。既然都告诉大家用数组，那就先上代码吧。免得消磨大家兴致。
js代码：

/* 
*Prompt: 
*If you want to add hurdle, find string: "{{Add hurdle above." and "{{After add hurdle, add the hurdle to the vector above." please. 
*If you want to add or change type of grid, find string: "{{Add new grid above.". 
*If you want to change position of map, please find string: "{{Change map margin above.". 
*If the icon of crid is changed, you have to change the size of icon. Find "{{Change icon size above." to change size. 
*/ //Map of hurdle or military or resource. 
var vView = []; 
/*Remarks: 
*L: land *S: sea *R: river *W: swamp *A: lawn *B: bridge *H: house *h: hospital *w: warehouse *b: bourse *M: military academy *m: military factories 
*r: research Center *P: port *D: dock *s: Shipyard 
*/ 
var mScene = { 
'L': ['./land.png', '陆地'] 
, 'S': ['./sea.png', '河流'] 
, 'T': ['./tree.png', '树木'] 
, 'B': ['./bridge.png', '桥'] 
, 'C': ['./beach.png', '沙滩'] 
}; 
//{{Add new grid above. 
var mCurrent = { 
Margin: { 
left: -1 
, top: -1 
, right: -1 
, bottom: -1 
} 
, Position: { 
X: -1 
, Y: -1 
} 
, Type: 'NONE' 
}; 
var mTitle = {}; 
var sHurdleONE = 
'S,S,S,S,S,S,S,S,S,S,S' 
+ ';T,L,T,T,T,T,S,S,S,S,T' 
+ ';T,L,L,T,S,S,S,S,S,L,T' 
+ ';T,L,L,L,C,C,C,S,S,T,S' 
+ ';T,L,L,L,C,C,C,B,B,L,T' 
+ ';T,L,L,C,C,C,C,S,S,L,T' 
+ ';T,L,L,C,C,T,S,S,L,L,T' 
//{{Add hurdle above. 
var vHurdles = [sHurdleONE]; 
//{{After add hurdle, add the hurdle to the vector above. 
function _createGrid(nWidthBasic, nHeightBasic, nPicWidth, nPicHeight, cType, mMargin) 
{ 
var mCoordMember = { 
left: nWidthBasic 
, top: nHeightBasic 
, right: nWidthBasic + nPicWidth 
, bottom: nHeightBasic + nPicHeight 
}; 
var mPositionMember = { 
X: (mCoordMember.left - mMargin.x) / nPicWidth 
, Y: (mCoordMember.top - mMargin.y) / nPicHeight 
}; 
var mItem = { 
Coord: mCoordMember 
, Position: mPositionMember 
, Type: cType 
}; 
return mItem; 
} 
function _loadHurdle(sHurdle) 
{ 
var nBasic = 0; 
var nWidthBasic = nBasic; //margin-left. 
var nHeightBasic = 0; //margin-top. 
//{{Change map margin above. 
var nPicWidth = 45; //Picture width is nBasic. 
var nPicHeight = 45; //Picturn height is nHeightBasic. 
//{{Change icon size above. 
var nSub; 
var nRow; 
var nCol; 
var v = sHurdle.split(';'); 
var vRec = []; 
for(nSub = 0; nSub < v.length; nSub++){ 
var vCrid = v[nSub].split(','); 
vRec[vRec.length] = vCrid; 
} 
for(nRow = 0; nRow < vRec.length; nRow++){ 
var vCol = vRec[nRow]; 
for(nCol = 0; nCol < vCol.length; nCol++){ 
var cType = vCol[nCol]; 
var mMargin = {x: nBasic, y: nBasic}; 
vView[vView.length] = _createGrid(nWidthBasic, nHeightBasic, nPicWidth, nPicHeight, cType, mMargin); 
nWidthBasic += nPicWidth; 
} 
nHeightBasic += nPicHeight; 
nWidthBasic = nBasic; 
} 
} 

//Show map with vector 'vView'. 
function _showMap(sID) 
{ 
var xDiv=document.getElementById(sID); 
var xGrid; 
var xImg; 

var nTop = 0; 
var nSub; 
var sIdPrefix = 'ID_IMG_NUM_'; 
var sIdGrid = 'ID_A_NUM_'; 
for(nSub = 0; nSub < vView.length; nSub++){ 
var mGrid = vView[nSub]; 
if(mGrid){ 
var xMargin = mGrid.Coord; 
var cType = mGrid.Type; 
var xProper = mScene[cType]; 
if(xProper){ 
xGrid = document.createElement('a'); 
xImg = document.createElement('img'); 
xImg.style.position = 'absolute'; 
xImg.style.marginLeft = xMargin.left; 
xImg.style.marginTop = xMargin.top; 
xImg.src = xProper[0]; 
xImg.style.border = '0px solid #000000'; 
xImg.id = sIdPrefix + nSub; 
xImg.style.width = 45; 
xImg.style.height = 45; 
xImg.style.display = 'block'; 
xGrid.onclick = function(e){ 
var xCurrentGrid = e.target; 
var sId = xCurrentGrid.id; 
var nIdAsSub = parseInt(sId.substring(sIdPrefix.length, sId.length)); 
mCurrent = vView[nIdAsSub]; 
if(!mCurrent){ 
alert("Error 0004."); 
} 
}; 
xGrid.title = xProper[1] + '(' + parseInt(mGrid.Position.X) + ', ' + parseInt(mGrid.Position.Y+2) + ')'; 
xGrid.id = sIdGrid + nSub; 
xGrid.appendChild(xImg); 
xDiv.appendChild(xGrid); 
}else{ 
alert("Error: 0003."); 
} 
}else{ 
alert("Error: 0002."); 
} 
} 
} 
//Show map of hurdle. 
function _showHurdle(nHurdle) 
{ 
if(vHurdles[nHurdle - 1]){ 
_loadHurdle(vHurdles[nHurdle - 1]); 
_showMap('ID_DIV_BATTLEFIELD'); 
}else{ 
alert("Error: 0001."); 
} 
}

看看，这点程序就用了195行，而且这还是一张地图，看来还很有点麻烦哦。没关系，慢慢解释。
首先还是把素材放在这里：

素材不是来自《三国志曹操传》，因为没整理好《三国志曹操传》的地图素材，所以就随便找了些。不过也照样可以用。希望大家不要介意。

麻烦的代码最容易弄得乱七八糟，因此在此时要良好的区分开样式设置和拼图核心。
拼图核心在哪里呢？在这里：

var mScene = { 
'L': ['./land.png', '陆地'] 
, 'S': ['./sea.png', '河流'] 
, 'T': ['./tree.png', '树木'] 
, 'B': ['./bridge.png', '桥'] 
, 'C': ['./beach.png', '沙滩'] 
}; 
//{{Add new grid above. var mCurrent = { 
Margin: { 
left: -1 
, top: -1 
, right: -1 
, bottom: -1 
} 
, Position: { 
X: -1 
, Y: -1 
} 
, Type: 'NONE' 
}; 
var mTitle = {}; 
var sHurdleONE = 
'S,S,S,S,S,S,S,S,S,S,S' 
+ ';T,L,T,T,T,T,S,S,S,S,T' 
+ ';T,L,L,T,S,S,S,S,S,L,T' 
+ ';T,L,L,L,C,C,C,S,S,T,S' 
+ ';T,L,L,L,C,C,C,B,B,L,T' 
+ ';T,L,L,C,C,C,C,S,S,L,T' 
+ ';T,L,L,C,C,T,S,S,L,L,T' 
//{{Add hurdle above. 
var vHurdles = [sHurdleONE]; 
//{{After add hurdle, add the hurdle to the vector above.

首先我把S,T,B,C,L定义好，使S代表河流，T代表树木，B代表桥，C代表沙滩，L代表陆地。var mCurrent后面有用，暂不解释。然后是var mTitle，这个专门是用来显示title的，所以也不解释了。关键是在下：

var sHurdleONE = 
'S,S,S,S,S,S,S,S,S,S,S' 
+ ';T,L,T,T,T,T,S,S,S,S,T' 
+ ';T,L,L,T,S,S,S,S,S,L,T' 
+ ';T,L,L,L,C,C,C,S,S,T,S' 
+ ';T,L,L,L,C,C,C,B,B,L,T' 
+ ';T,L,L,C,C,C,C,S,S,L,T' 
+ ';T,L,L,C,C,T,S,S,L,L,T'

这段代码就是把定义好的S,T,B,C,L连在一起的核心。后面只用定义S,T,B,C,L的宽度高度定义就能把它们连成一块。并且只要把它们在数组里的位置调一调就能改变样式。
接下来为了能切换地图，我们把第一张地图放进了数组：

var vHurdles = [sHurdleONE]; 
//{{After add hurdle, add the hurdle to the vector above.

如果以后加了地图，只用把地图所属的数组名加到vHurdles数组就可以了，调用是就可以直接写对应下标。
样式设置在下：

function _createGrid(nWidthBasic, nHeightBasic, nPicWidth, nPicHeight, cType, mMargin) 
{ 
var mCoordMember = { 
left: nWidthBasic 
, top: nHeightBasic 
, right: nWidthBasic + nPicWidth 
, bottom: nHeightBasic + nPicHeight 
}; 
var mPositionMember = { 
X: (mCoordMember.left - mMargin.x) / nPicWidth 
, Y: (mCoordMember.top - mMargin.y) / nPicHeight 
}; 
var mItem = { 
Coord: mCoordMember 
, Position: mPositionMember 
, Type: cType 
}; return mItem; 
} 
function _loadHurdle(sHurdle) 
{ 
var nBasic = 0; 
var nWidthBasic = nBasic; //margin-left. 
var nHeightBasic = 0; //margin-top. 
//{{Change map margin above. 
var nPicWidth = 45; //Picture width is nBasic. 
var nPicHeight = 45; //Picturn height is nHeightBasic. 
//{{Change icon size above. 
var nSub; 
var nRow; 
var nCol; 
var v = sHurdle.split(';'); 
var vRec = []; 
for(nSub = 0; nSub < v.length; nSub++){ 
var vCrid = v[nSub].split(','); 
vRec[vRec.length] = vCrid; 
} 
for(nRow = 0; nRow < vRec.length; nRow++){ 
var vCol = vRec[nRow]; 
for(nCol = 0; nCol < vCol.length; nCol++){ 
var cType = vCol[nCol]; 
var mMargin = {x: nBasic, y: nBasic}; 
vView[vView.length] = _createGrid(nWidthBasic, nHeightBasic, nPicWidth, nPicHeight, cType, mMargin); 
nWidthBasic += nPicWidth; 
} 
nHeightBasic += nPicHeight; 
nWidthBasic = nBasic; 
} 
} 

//Show map with vector 'vView'. 
function _showMap(sID) 
{ 
var xDiv=document.getElementById(sID); 
var xGrid; 
var xImg; 

var nTop = 0; 
var nSub; 
var sIdPrefix = 'ID_IMG_NUM_'; 
var sIdGrid = 'ID_A_NUM_'; 
for(nSub = 0; nSub < vView.length; nSub++){ 
var mGrid = vView[nSub]; 
if(mGrid){ 
var xMargin = mGrid.Coord; 
var cType = mGrid.Type; 
var xProper = mScene[cType]; 
if(xProper){ 
xGrid = document.createElement('a'); 
xImg = document.createElement('img'); 
xImg.style.position = 'absolute'; 
xImg.style.marginLeft = xMargin.left; 
xImg.style.marginTop = xMargin.top; 
xImg.src = xProper[0]; 
xImg.style.border = '0px solid #000000'; 
xImg.id = sIdPrefix + nSub; 
xImg.style.width = 45; 
xImg.style.height = 45; 
xImg.style.display = 'block'; 
xGrid.onclick = function(e){ 
var xCurrentGrid = e.target; 
var sId = xCurrentGrid.id; 
var nIdAsSub = parseInt(sId.substring(sIdPrefix.length, sId.length)); 
mCurrent = vView[nIdAsSub]; 
if(!mCurrent){ 
alert("Error 0004."); 
} 
}; 
xGrid.title = xProper[1] + '(' + parseInt(mGrid.Position.X) + ', ' + parseInt(mGrid.Position.Y+2) + ')'; 
xGrid.id = sIdGrid + nSub; 
xGrid.appendChild(xImg); 
xDiv.appendChild(xGrid); 
}else{ 
alert("Error: 0003."); 
} 
}else{ 
alert("Error: 0002."); 
} 
} 
}

以上的代码很简单，自己可以看看，提示一下：当你在自己开发的过程中如果弹出一个Error: 0002, Error: 0003, Error: 0001什么之类的，就代表出了错，需要马上去检查。这是为了在麻烦的程序开发中有一点提醒而设计的。值得注意的是：这里的图片全是createElement弄出来的，所以请不要猜疑html代码里有什么蹊跷。
接着看：

function _showHurdle(nHurdle) 
{ 
if(vHurdles[nHurdle - 1]){ 
_loadHurdle(vHurdles[nHurdle - 1]); 
_showMap('ID_DIV_BATTLEFIELD'); 
}else{ 
alert("Error: 0001."); 
} 
}

这是在你要弄出地图的调用函数，当你在html代码里写上：<body onload="_showHurdle(nHurdle)">几可以把拼的图一下子画出来。nHurdle就是地图在数组vHurdles里的对应下标，最低是1，而不是0，也就是说要用第一张地图,那nHurdle就该赋值为1，调用是写为：<body onload="_showHurdle(1)">。

源代码下载
三、演示效果

演示图在下：

由于是静态的，所以就不给demo了。这种方法虽然很麻烦，而且地图块多了就很慢，但是毕竟是种技术，如果大家有什么好的方法也可以来告诉我。

希望大家多支持。谢谢。