javascript实现的三维正方体(兼容ie7,ff)

2020-05-12 我要评论

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.

<!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></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></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></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></div>

<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>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

javascript实现的三维正方体(兼容ie7,ff)

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