下面是预览画面。
制作流程
首先你需要下载html5开源库件lufylegend-1.4.0
魔方分为6个面，每个面由9个小矩形组成，现在我把每个小矩形当做一个类封装起来，
因为现在建立的是一个3d魔方，所以要画出每个小矩形，需要知道小矩形的4个定点，而这4个定点会根据空间的旋转角度而变换，所以为了计算出这4个定点坐标，需要知道魔方绕x轴和z轴旋转的角度。
所以，建立矩形类如下
function rect(pointa,pointb,pointc,pointd,anglex,anglez,color){ base(this,lsprite,[]); this.pointz=[(pointa[0]+pointb[0]+pointc[0]+pointd[0])/4,(pointa[1]+pointb[1]+pointc[1]+pointd[1])/4,(pointa[2]+pointb[2]+pointc[2]+pointd[2])/4]; this.z = this.pointz[2]; this.pointa=pointa,this.pointb=pointb,this.pointc=pointc,this.pointd=pointd,this.anglex=anglex,this.anglez=anglez,this.color=color; } rect.prototype.setangle = function(a,b){ this.anglex = a; this.anglez = b; this.z=this.getpoint(this.pointz)[2]; };
pointa,pointb,pointc,pointd是小矩形的四个顶点，anglex,anglez分别是x轴和z轴旋转的角度，color是小矩形的颜色。
魔方分为6个面，先看一下最前面的一面，如果以立方体的中心作为3d坐标系的中心，那么9个小矩形的各个定点所对应的坐标如下图所示
所以，前面这个面的9个小矩形可以由下面的代码来建立
for(var x=0;x<3;x++){ for(var y=0;y<3;y++){ z = 3; var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,"#ff0000"); backlayer.addchild(rect); } }
其中backlayer是一个lsprite类，step是半个小矩形的长，同样的道理，可以也得到其他5个面。
6个面都建立了，在绘制这6个面之前，首先要根据旋转的角度来计算各个定点的坐标，看下面的图
根据上面的图，用下面的公式即可得到变换后的定点坐标
rect.prototype.getpoint = function(p){ var u2,v2,w2,u=p[0],v=p[1],w=p[2]; u2 = u * math.cos(this.anglex) - v * math.sin(this.anglex); v2 = u * math.sin(this.anglex) + v * math.cos(this.anglex); w2 = w; u = u2; v = v2; w = w2; u2 = u; v2 = v * math.cos(this.anglez) - w * math.sin(this.anglez); w2 = v * math.sin(this.anglez) + w * math.cos(this.anglez); u = u2; v = v2; w = w2; return [u2,v2,w2]; };
最后根据小矩形的四个定点坐标，来绘制这个矩形，
rect.prototype.draw = function(layer){ this.graphics.clear(); this.graphics.drawvertices(1,"#000000",[this.getpoint(this.pointa),this.getpoint(this.pointb),this.getpoint(this.pointc),this.getpoint(this.pointd)],true,this.color); };
其中drawvertices是lufylegend.js库件中lgraphics类的一个方法，它可以根据传入的定点坐标数组来绘制一个多边形。
最后，给出完整代码，代码很少，js代码一共91行。
一，index.html
<!doctype html> <html> <head> <meta charset="utf-8"> <title>3d魔方</title> </head> <body> <p id="mylegend">loading……</p> <script type="text/javascript" src="../lufylegend-1.4.0.min.js"></script> <script type="text/javascript" src="./main.js"></script> <script type="text/javascript" src="./rect.js"></script> </body> </html>
二，rect类
function rect(pointa,pointb,pointc,pointd,anglex,anglez,color){ base(this,lsprite,[]); this.pointz=[(pointa[0]+pointb[0]+pointc[0]+pointd[0])/4,(pointa[1]+pointb[1]+pointc[1]+pointd[1])/4,(pointa[2]+pointb[2]+pointc[2]+pointd[2])/4]; this.z = this.pointz[2]; this.pointa=pointa,this.pointb=pointb,this.pointc=pointc,this.pointd=pointd,this.anglex=anglex,this.anglez=anglez,this.color=color; } rect.prototype.draw = function(layer){ this.graphics.clear(); this.graphics.drawvertices(1,#000000,[this.getpoint(this.pointa),this.getpoint(this.pointb),this.getpoint(this.pointc),this.getpoint(this.pointd)],true,this.color); }; rect.prototype.setangle = function(a,b){ this.anglex = a; this.anglez = b; this.z=this.getpoint(this.pointz)[2]; }; rect.prototype.getpoint = function(p){ var u2,v2,w2,u=p[0],v=p[1],w=p[2]; u2 = u * math.cos(this.anglex) - v * math.sin(this.anglex); v2 = u * math.sin(this.anglex) + v * math.cos(this.anglex); w2 = w; u = u2; v = v2; w = w2; u2 = u; v2 = v * math.cos(this.anglez) - w * math.sin(this.anglez); w2 = v * math.sin(this.anglez) + w * math.cos(this.anglez); u = u2; v = v2; w = w2; return [u2,v2,w2]; };
三，main.js
init(50,mylegend,400,400,main); var a = 0,b=0,backlayer,step = 20,key = null; function main(){ backlayer = new lsprite(); addchild(backlayer); backlayer.x = 120,backlayer.y = 120; //后 for(var x=0;x<3;x++){ for(var y=0;y<3;y++){ z = 0; var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,#ff4500); backlayer.addchild(rect); } } //前 for(var x=0;x<3;x++){ for(var y=0;y<3;y++){ z = 3; var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,#ff0000); backlayer.addchild(rect); } } //上 for(var x=0;x<3;x++){ for(var z=0;z<3;z++){ y = 0; var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],0,0,#ffffff); backlayer.addchild(rect); } } //下 for(var x=0;x<3;x++){ for(var z=0;z<3;z++){ y = 3; var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],0,0,#ffff00); backlayer.addchild(rect); } } //左 for(var y=0;y<3;y++){ for(var z=0;z<3;z++){ x = 0; var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,#008000); backlayer.addchild(rect); } } //右 for(var y=0;y<3;y++){ for(var z=0;z<3;z++){ x = 3; var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,#0000ff); backlayer.addchild(rect); } } backlayer.addeventlistener(levent.enter_frame,onframe); } function onframe(){ a += 0.1 , b += 0.1; backlayer.childlist = backlayer.childlist.sort(function(a,b){return a.z - b.z;}); for(key in backlayer.childlist){ backlayer.childlist[key].setangle(a,b); backlayer.childlist[key].draw(backlayer); } }
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