这是我在做的一个游戏的半成品,整理了一下发出来.
原理:
通过更新变换矩阵来记录转动(函数remx()).
利用矩阵计算出转动后的正方体顶点坐标,把各个顶点的空间坐标按”近大远小”转换成平面坐标(函数p2d()),用正方体各个面的法向量的z坐标判断该面是否可见,用高为1px的div层模拟画出四边形(函数gra2htm()).
鼠标拖曳的代码用别人的代码修改的.
运行代码框
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <title>Cube</title> <script type="text/javascript"> function gra2htm(clr,a,b,c,d){ var result=''; var maxx=Math.max(a[0],b[0],c[0],d[0]),minx=Math.min(a[0],b[0],c[0],d[0]); var maxy=Math.max(a[1],b[1],c[1],d[1]),miny=Math.min(a[1],b[1],c[1],d[1]); x=new Array(a[0],b[0],c[0],d[0],a[0],b[0],c[0],d[0],a[0],b[0]); y=new Array(a[1],b[1],c[1],d[1],a[1],b[1],c[1],d[1],a[1],b[1]); /*/begin for(var i=0;i<=3;i++){ result+='<div style="position:absolute; overflow:hidden; left:' +x[i]+'px; top:'+y[i]+'px; width:2px; height:2px; background-color:#FFF"></div>'; } //end*/ if(maxx-minx>=maxy-miny){ for(var i=3;i<=6;i++) if(y[i]==miny){ var k=l=i; break; } if(y[k]==y[k-1]) k--; xa=(x[k-1]-x[k])/(y[k-1]-y[k]); if(y[l]==y[l+1]) l++; xb=(x[l+1]-x[l])/(y[l+1]-y[l]); pl=x[k];pw=x[l]-x[k]; for(var i=miny+1;i<=maxy;i++){ if(i>y[k-1]){ k--; xa=(x[k-1]-x[k])/(y[k-1]-y[k]); } if(i>y[l+1]){ l++; xb=(x[l+1]-x[l])/(y[l+1]-y[l]); } result+='<div style="overflow:hidden; top:'+i +'px; left:'+Math.round(pl+=xa) +'px; width:'+Math.round(pw+=xb-xa) +'px; height:1px; position:absolute; background-color:'+clr +';"></div>'; } } else { for(var i=3;i<=6;i++) if(x[i]==minx){ var k=l=i; break; } if(x[k]==x[k+1]) k++; ya=(y[k+1]-y[k])/(x[k+1]-x[k]); if(x[l]==x[l-1]) l--; yb=(y[l-1]-y[l])/(x[l-1]-x[l]); pt=y[k];ph=y[l]-y[k]; for(var i=minx+1;i<=maxx;i++){ if(i>x[k+1]){ k++; ya=(y[k+1]-y[k])/(x[k+1]-x[k]); } if(i>x[l-1]){ l--; yb=(y[l-1]-y[l])/(x[l-1]-x[l]); } result+='<div style="overflow:hidden; left:'+i +'px; top:'+Math.round(pt+=ya) +'px; height:'+Math.round(ph+=yb-ya) +'px; width:1px; position:absolute; background-color:'+clr +';"></div>'; } } return result; } function remx(type,theta,omx){ var sinA=Math.sin(theta),cosA=Math.cos(theta); var m=new Array(); switch(type){ case 'rx': m[0]=omx[0];m[1]=omx[1];m[2]=omx[2]; m[3]=omx[3]*cosA-omx[6]*sinA;m[4]=omx[4]*cosA-omx[7]*sinA;m[5]=omx[5]*cosA-omx[8]*sinA; m[6]=omx[3]*sinA+omx[6]*cosA;m[7]=omx[4]*sinA+omx[7]*cosA;m[8]=omx[5]*sinA+omx[8]*cosA; break; case 'ry': m[0]=omx[0]*cosA-omx[6]*sinA;m[1]=omx[1]*cosA-omx[7]*sinA;m[2]=omx[2]*cosA-omx[8]*sinA; m[3]=omx[3];m[4]=omx[4];m[5]=omx[5]; m[6]=omx[0]*sinA+omx[6]*cosA;m[7]=omx[1]*sinA+omx[7]*cosA;m[8]=omx[2]*sinA+omx[8]*cosA; break; } return m; } function p2d(x,y,z){ var l=100,t=100; var result=new Array(); result[0]=Math.round(l+x/(z*0.004+1.25)); result[1]=Math.round(t+y/(z*0.004+1.25)); return result; } </script> <script type="text/javascript"> //const var pa=new Array(); pa[1]=new Array(50,50,-50); pa[2]=new Array(50,50,50); pa[3]=new Array(50,-50,50); pa[4]=new Array(50,-50,-50); pa[5]=new Array(-50,50,-50); pa[6]=new Array(-50,50,50); pa[7]=new Array(-50,-50,50); pa[8]=new Array(-50,-50,-50); var idx=new Array(); idx[0]=new Array(1,2,3,4); idx[1]=new Array(1,4,8,5); idx[2]=new Array(1,5,6,2); idx[3]=new Array(7,3,2,6); idx[4]=new Array(7,8,4,3); idx[5]=new Array(7,6,5,8); var clr=new Array('#03c','#c00','#fc0','#f60','#fff','#090'); //end function cube(id){ if(!document.getElementById(id)) return false; this.id=document.getElementById(id); this.angle=new Array(); this.angle2=new Array(); for(i=1;i<=8;i++) this.angle[i]=new Array(3); // alert('success'); } cube.prototype={ matrix:new Array(1,0,0,0,1,0,0,0,1), paint:function(){ var result=''; for(i=1;i<=8;i++){ this.angle[i][0]=this.matrix[0]*pa[i][0]+this.matrix[1]*pa[i][1]+this.matrix[2]*pa[i][2]; this.angle[i][1]=this.matrix[3]*pa[i][0]+this.matrix[4]*pa[i][1]+this.matrix[5]*pa[i][2]; this.angle[i][2]=this.matrix[6]*pa[i][0]+this.matrix[7]*pa[i][1]+this.matrix[8]*pa[i][2]; this.angle2[i]=p2d(this.angle[i][0],this.angle[i][1],this.angle[i][2]); } for(i=0;i<6;i++){ if((this.angle2[idx[i][2]][0]-this.angle2[idx[i][1]][0])* (this.angle2[idx[i][0]][1]-this.angle2[idx[i][1]][1])- (this.angle2[idx[i][2]][1]-this.angle2[idx[i][1]][1])* (this.angle2[idx[i][0]][0]-this.angle2[idx[i][1]][0])<0){ result+=gra2htm(clr[i],this.angle2[idx[i][3]],this.angle2[idx[i][2]],this.angle2[idx[i][1]], this.angle2[idx[i][0]]); } } // document.getElementById('aa').value=result; this.id.innerHTML=result; }, roll:function(type,theta){ this.matrix=remx(type,theta,this.matrix); // this.paint(); } } </script> <script type="text/javascript"> var tmr=(new Date()).getTime(); function drag(obj,e){ e=e?e:window.event; var setx=e.clientX,sety=e.clientY; if(document.addEventListener){ document.addEventListener('mousemove', inFmove, true); document.addEventListener('mouseup', inFup, true); } else if(document.attachEvent){ document.attachEvent('onmousemove', inFmove); document.attachEvent('onmouseup', inFup); } function inFmove(e){ tmr2=(new Date).getTime(); if(tmr2-tmr<100) return false; tmr=tmr2; cc.roll('ry',(e.clientX-setx)/50); setx=e.clientX; cc.roll('rx',(e.clientY-sety)/50); sety=e.clientY; cc.paint(); return false; } function inFup(){ if(document.removeEventListener){ document.removeEventListener('mousemove', inFmove, true); document.removeEventListener('mouseup', inFup, true); } else if(document.detachEvent){ document.detachEvent('onmousemove', inFmove); document.detachEvent('onmouseup', inFup); } } // shawl.qiu script } </script> </head> <body> <div id="t" style="width:200px;height:200px;background-color:#000000;" oncontextmenu="return false" onmousedown="drag(this,event)"></div> <br /> <input type="button" onClick="clearInterval(tt)" value="Stop" /> <input type="button" onClick="clearInterval(tt);tt=setInterval('cc.roll(\'rx\',0.2);cc.paint();',100)" value="Down" /> <input type="button" onClick="clearInterval(tt);tt=setInterval('cc.roll(\'ry\',0.2);cc.paint();',100)" value="Right" /> <script type="text/javascript"> var tt,cc=new cube('t'); cc.roll('ry',1); cc.paint(); </script> </body> </html> [提示：你可先修改部分代码，再按运行]
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