<HTML xmlns:v = "urn:schemas-microsoft-com:vml"><HEAD>
<META NAME="Description" CONTENT="VML Animation - Gears within Gears">
<META NAME="Keywords" CONTENT="cogs, gears, dhtml, vml, javascript, jscript, animation">
<TITLE>VML Animation - Gears within Gears</TITLE>
<OBJECT classid=CLSID:10072CEC-8CC1-11D1-986E-00A0C955B42E
id=VMLRender></OBJECT>
<STYLE>v\:* {
BEHAVIOR: url(#VMLRender)
}
</STYLE>
</HEAD>
<BODY bgColor=#ffffff onresize=resize() scroll=no>
<div id=op></div>
<script>
//globals for HSV to RGB conversion
irpnt=new Array(2,1,0,0,3,2);
igpnt=new Array(3,2,2,1,0,0);
ibpnt=new Array(0,0,3,2,2,1);
//constants for gears
GB=100;
GD=30;
GA=20;
w=0;
h=0;
kx=0;
ky=0;
scol=new colour(57,.71,.89);
ss=new Array(500,500,500,500,500,500,500,500,500,500,500,500,500,500,500);
vs="<DIV id=kal style='position:absolute;left:"+kx+";top:"+ky+";'>";
for(j=0;j<ss.length;j++){
np=30-2*j;
sp=makegearpath(np);
hue=j*4;
dhue=8;
dr=(j+1)/2;
//if(j%2==0)dr=-dr;
vx=rnd(10)-4;if(vx==0)vx=-5;
vy=rnd(10)-4;if(vy==0)vy=-5;
vs+="<v:shape id='V"+j+"' np="+np+" hue="+hue+" dhue="+dhue+" dr="+dr+" vx="+vx+" vy="+vy+" style='position:absolute;left:"+((500-ss[j])/2)+"px;top:"+((500-ss[j])/2)+"px;height:"+ss[j]+";width:"+ss[j]+";rotation:0;' fill='true' stroke='true' coordsize='2500,2500' coordorigin '-1250,-1250' fillcolor='#fdf9ae' strokecolor='#000000' path='"+sp+"'></v:shape>"
}
vs+="</div>"
document.write(vs);
resize();
window.setInterval("frame();",20);
function frame(){
for(j=0;j<ss.length;j++){
S=document.all["V"+j];
//animate colour
hue=parseInt(S.hue);
dhue=parseInt(S.dhue);
hue+=dhue;
if(hue>=360)hue-=360;
S.hue=hue;
scol.h=hue;
scol.hsv2rgb();
S.fillcolor=scol.rgb;
//S.strokecolor=scol.rgb;
//animate rotation
r=parseFloat(S.style.rotation);
dr=parseFloat(S.dr);
r+=dr;if(r>=360)r-=360;if(r<0)r+=360;
S.style.rotation=r;
}
}
//n=number of points
//r1=outer diameter
//r2=inner diameter
//assumes coordsize='2000,2000' coordorigin '0,0'
function makegearpath(n){
var r1,r2,l1,l2
var theta,phi,alpha,beta
s="";
theta=2*Math.PI/n;
theta2=theta/2
r2=(GB*n)/(2*Math.PI);
r1=r2+GD;
l1=Math.sqrt((r1*r1+GA*GA));
l2=Math.sqrt((r2*r2+GA*GA));
alpha=Math.atan(GA/r1);
beta=Math.atan(GA/r2);
phi=Math.PI/2-theta2-beta;
s="m "+(1250+Math.round(l2*Math.cos(phi)))+","+(1250+Math.round(l2*Math.sin(phi)))+"l";
for (i=0;i<n;i++){
phi=i*theta+Math.PI/2;
if(i>0)s+=",";
s+=(1250+Math.round(l2*Math.cos(phi-theta2+beta)))+","+(1250+Math.round(l2*Math.sin(phi-theta2+beta)))+",";
s+=(1250+Math.round(l1*Math.cos(phi-alpha)))+ ","+(1250+Math.round(l1*Math.sin(phi-alpha)))+",";
s+=(1250+Math.round(l1*Math.cos(phi+alpha)))+ ","+(1250+Math.round(l1*Math.sin(phi+alpha)))+",";
s+=(1250+Math.round(l2*Math.cos(phi+theta2-beta)))+","+(1250+Math.round(l2*Math.sin(phi+theta2-beta)));
}
s+="x e"
return(s);
}
function rnd(n){
return(Math.floor((n+1)*Math.random()));
}
function resize(){
w=document.body.clientWidth;
h=document.body.clientHeight;
// bg.style.width=w;
// bg.style.height=h;
kx=w/2-250;
ky=h/2-250;
kal.style.left=kx;
kal.style.top=ky;
}
//utility object for HSV to RGB conversion
function hsv2rgb(){
pqvt=new Array(4);
with(this){
if(s==0){
r=Math.floor(255*v);
g=r;
b=r;
return;
}
if(h>=360)h=0;
nh=h/60;
i=Math.floor(nh);
f=nh-i;
pqvt[2]=255*v;
pqvt[0]=pqvt[2]*(1-s)
pqvt[1]=pqvt[2]*(1-s*f)
pqvt[3]=pqvt[2]*(1-s*(1-f))
r=Math.floor(pqvt[irpnt]);
g=Math.floor(pqvt[igpnt]);
b=Math.floor(pqvt[ibpnt]);
rgb="#"+(65536*r+256*g+b).toString(16);
}
}
function colour(h,s,v){
this.h=h; //0-359
this.s=s; //0-1
this.v=v; //0-1
this.r=0; //0-255
this.g=0; //0-255
this.b=0; //0-255
this.rgb="";
this.hsv2rgb=hsv2rgb;
//convert on construction
this.hsv2rgb();
}
</script>
</BODY></HTML>
