再散一贴 | 天下站长网

http://expert.csdn.net/Expert/topic/1665/1665572.xml

对画直线部分做了一点纯学术意义上的优化呵呵，并且把基本的绘画函数分离出来了。

文件名：
emu_draw.js
//-----------------------------------------------------------------------
// emu's dhtml painting functions

function drawLine(x0,y0,x1,y1,color){
x0 = Math.round(x0);
x1 = Math.round(x1);
y0 = Math.round(y0);
y1 = Math.round(y1);
var rs = "";
if (y0 == y1){ //»ºáÏß
if (x0>x1){var t=x0;x0=x1;x1=t}
rs = "

1<p class="emuH" style='top:"+y0+";left:"+x0+";background-color:"+color+"; width:"+Math.abs(x1-x0)+"'></p>

";
}
else if (x0 == x1){ //»ÊúÏß
if (y0>y1){var t=y0;y0=y1;y1=t}
rs = "

1<p class="emuW" style='top:"+y0+";left:"+x0+";background-color:"+color+";height:"+Math.abs(y1-y0)+"'></p>

";
}
else{
var lx = x1-x0;
var ly = y1-y0;
if (Math.abs(lx)>Math.abs(ly)){
if (ly<0){
var t=x0;x0=x1;x1=t;
t=y0;y0=y1;y1=t;
lx = -lx;
ly = -ly;
}
var dx = lx/ly;
rs = new Array(ly);
for (var i=0;i

  1<ly;i++){ (dx="" if="" left,width;="" var="">0){   
  2left = Math.round(i*dx);   
  3width = Math.round((i+1)*dx)-left;   
  4left += x0;   
  5if (width+left&gt;x1) width = x1-left;   
  6}else{   
  7left = Math.round((i+1)*dx);   
  8width = Math.round((i)*dx)-left;   
  9left += x0;   
 10if (left<x1) +(y0+i)+";left:"+left+";width:"+width+";background-color:"+color+"'="" left="x1;" rs[i]="&lt;p class=emuH style='top:" width="width+left-x1;" {="" }=""></x1)>";   
 11}   
 12}else{   
 13if (lx&lt;0){   
 14var t=x0;x0=x1;x1=t;   
 15t=y0;y0=y1;y1=t;   
 16lx = -lx;   
 17ly = -ly;   
 18}   
 19var dy = ly/lx;   
 20rs = new Array(lx);   
 21for (var i=0;i<lx;i++){ (dy="" if="" top,height;="" var="">0){   
 22top = Math.round(i*dy);   
 23height = Math.round((i+1)*dy)-top;   
 24top += y0;   
 25if (height+top&gt;y1) height = y1-top;   
 26}else{   
 27top = Math.round((i+1)*dy);   
 28height = Math.round((i)*dy)-top;   
 29top += y0;   
 30if (top<y1) +top+";left:"+(x0+i)+";height:"+height+";background-color:"+color+"'="" height="height+top-y1;" rs[i]="&lt;p class=emuW style='top:" top="y1;" {="" }=""></y1)>";   
 31}   
 32}   
 33rs = rs.join("");   
 34}   
 35return rs   
 36}   
 37function drawRectangle(x0,y0,x1,y1,color,title)   
 38{   
 39if (x0 == x1 ¦ ¦ y0 == y1) return;   
 40if (x0&gt;x1) {var t=x0;x0=x1;x1=t}   
 41if (y0&gt;y1) {var t=y0;y0=y1;y1=t}   
 42return "<table style='top:"+y0+";left:"+x0+";position:absolute' title="+title+"><td bgcolor="+color+" height="+(y1-y0)+" width="+(x1-x0)+"> </td></table>";   
 43}   
 44function outText(x0,y0,text,fontSize,color){   
 45return "<p style='top:"+y0+";left:"+x0+";position:absolute;color:"+color+";font-size:"+fontSize+"'>"+text+"</p>";   
 46}   
 47var points = new Array(1000);   
 48function drawPie(x0,y0,radius,startAngle,endAngle,color){   
 49if (points.length<radius<<2) (maxx<x)="" (minx="" (var="" ;="" arc="" endangle="endAngle*Math.PI/180;" for="" get="" i="startAngle;i&lt;endAngle;i+=step){" if="" lines="" maxx="x;" points="" points.length="radius&lt;&lt;2;" points[pointslength++]="[x,y];" pointslength="0;" startangle="startAngle*Math.PI/180;" step="1/radius;" var="" x="Math.round(Math.sin(i)*radius);" y="Math.round(Math.cos(i)*radius)">x) minX=x;   
 50if (maxY<y) (miny="" if="" maxy="y;">y) minY=y;   
 51}   
 52  
 53// get radius points   
 54var dx1=Math.sin(startAngle)*radius;   
 55var dy1=Math.cos(startAngle)*radius;   
 56var dx2=Math.sin(endAngle)*radius;   
 57var dy2=Math.cos(endAngle)*radius;   
 58var L = Math.sqrt(dx1*dx1+dy1*dy1);   
 59var stepx1 = dx1/L , stepy1 = dy1/L ,stepx2 = dx2/L , stepy2 = dy2/L ;   
 60for (var i=0;i<l;i+=.99){ (dx="" dx="maxX-minX+1;" dy="maxY-minY+1;" if="" points[pointslength++]="[Math.round(stepx2*i),Math.round(stepy2*i)]" var="" }="">dy){   
 61lines = new Array(dy);   
 62for (var i=pointsLength-1;i&gt;-1;i--){   
 63var p0 = points[i];   
 64var px = p0[0];   
 65var y = p0[1]-minY;   
 66if (lines[y]){   
 67if (lines   
 68\---------------------------------------------------------------   
 69  
 70顶   
 71\---------------------------------------------------------------   
 72  
 73我只有看的份了.   
 74\---------------------------------------------------------------   
 75  
 76请问大侠，   
 77对于现实中的应用有何以意呢？   
 78可否举下例子先？   
 79\---------------------------------------------------------------   
 80  
 81大虾的学问太精深，我要好好的研究。   
 82\---------------------------------------------------------------   
 83  
 84分   
 85\---------------------------------------------------------------   
 86  
 87复杂，收藏   
 88\---------------------------------------------------------------   
 89  
 90结贴时通知一声哦,此乃珍品,应入精华.   
 91\---------------------------------------------------------------   
 92  
 93呵呵   
 94\---------------------------------------------------------------   
 95  
 96再收……   
 97看看会不会再有update……   
 98\---------------------------------------------------------------   
 99  
100偶像……：）   
101\---------------------------------------------------------------   
102  
103可惜csdn不能上传图片。不然就有直观的了。   
104\---------------------------------------------------------------   
105  
106up   
107\---------------------------------------------------------------   
108  
109收藏！：）   
110\---------------------------------------------------------------   
111  
112绘图?   
113为什么不用vml语言?   
114\---------------------------------------------------------------   
115  
116emu做得好东西啊，收藏之   
117\---------------------------------------------------------------   
118  
119果然是大侠！不错，收藏!   
120\---------------------------------------------------------------   
121  
122在此学习也能得分啊！一举两得啊！   
123\---------------------------------------------------------------   
124  
125嘿嘿……在我的ie5.0下面报错。ie版本：5.00.2920.0000   
126日文win2000下的自带ie，没有升级过。   
127\---------------------------------------------------------------   
128  
129好啊，   
130\---------------------------------------------------------------   
131  
132好,留着</l;i+=.99){></y)></radius<<2)></lx;i++){></ly;i++){>