<script language="JavaScript">
<!-- Ball Intro - Kurt Grigg http://website.lineone.net/~kurt.grigg/javascript
--> <!-- Distributed by http://www.hypergurl.com //Change link url here
to the page you want to go to on click. goTo="easyhtml.html"; //Size
of stationary ball. This is a transparent gif. F=90; //Moving ball sizes. Add
to array for more balls, min 2. S=new Array(90,20,30,40,50) //Speeds. min=10;
max=30; //Alter nothing past here. Co-ordinates will be lost! n6=(document.getElementById&&!document.all);
n4=(document.layers); ie=(document.all); d=(n4||ie)?'document.':'document.getElementById("';
a=(n4||n6)?'':'all.'; n6r=(n6)?'")':''; s=(n4)?'':'.style'; TY=0; TX=0; I=new
Array(); P=new Array(); HT=new Array(); HY=new Array(); HX=new Array(); Y=new
Array(); X=new Array(); A=new Array(); PY=new Array(); PX=new Array(); CR=new
Array(); D=new Array(); B=new Array(); SP=new Array(); SP2=new Array(); Q=new
Array(); CY=new Array(); CX=new Array(); IL=new Array(); ILS=new Array(); TD=new
Array(); SH=new Array(); L=new Array(); p1x=new Array(); p1y=new Array(); p2x=new
Array(); p2y=new Array(); CY=new Array(); CX=new Array(); FDS=new Array(); DS=new
Array(); if (ie){ document.write("<a href='"+goTo+"'><img
src='ballB.gif' border='0' height='"+F+"' width='"+F+"' id='still'
style='position:absolute;top:300px;left:438px;width:"+F+";height:"+F+"'></a>");
} if (n6){ document.write("<div id='still' style='position:absolute;top:179px;left:438px;width:"+F+";height:"+F+";cursor:move'>");
document.write("<a href='"+goTo+"'><img src='ballB.gif'
border='0' height='"+F+"' width='"+F+"'></a>");
document.write("</div>"); } if (n4){ document.write("<layer
name='still' top=200 left=450>"); document.write("<a href='"+goTo+"'><img
src='ballB.gif' border='0' height='"+F+"' width='"+F+"'></a>");
document.write("</layer>"); } for (i=0; i < S.length; i++){
if (ie){ document.write("<img id='move"+i+"' src='ballA.gif'
height='"+S[i]+"' width='"+S[i]+"' style='position:absolute;top:0px;left:0px;height:"+S[i]+";width:"+S[i]+"'>");
} if (n6){ document.write("<div id='move"+i+"' style='position:absolute;top:0px;left:0px;height:"+S[i]+";width:"+S[i]+"'>");
document.write("<img src='ballA.gif' height='"+S[i]+"' width='"+S[i]+"'>");
document.write("</div>"); } if (n4){ document.write("<layer
name='move"+i+"' top=0 left=0>"); document.write("<img
src='ballA.gif' height='"+S[i]+"' width='"+S[i]+"'>");
document.write("</layer>"); } Y[i]=10; X[i]=10; D[i]=30; SP[i]=min+Math.floor(Math.random()*max);
SP2[i]=SP[i]; } function Move(){ H=(n4||n6)?window.innerHeight:document.body.clientHeight;
W=(n4||n6)?window.innerWidth:document.body.clientWidth; T1=eval(d+a+"still"+n6r+s);
R1=F/2; T1.top=H/2-R1; T1.left=W/2-R1; //center of stationary ball!! TY=(ie)?T1.pixelTop+F/2:parseInt(T1.top)+F/2;
TX=(ie)?T1.pixelLeft+F/2:parseInt(T1.left)+F/2; for (i=0; i < S.length; i++){
T2=eval(d+a+"move"+i+n6r+s); R2=S[i]/2; CR[i]=R2+R1; //center of moving
balls!! PY[i]=(ie)?T2.pixelTop+S[i]/2:parseInt(T2.top)+S[i]/2; PX[i]=(ie)?T2.pixelLeft+S[i]/2:parseInt(T2.left)+S[i]/2;
//Angle between center of balls and still!! ay=PY[i]-TY; ax=PX[i]-TX; A[i]=Math.atan2(ay,ax)*180/Math.PI;
if (A[i] < 0) A[i]+=360; //Shortest distance between centre's of stationary
and moving balls!! dx=TY-PY[i]; dy=TX-PX[i]; DS[i]=Math.sqrt(dx*dx+dy*dy); FDS[i]
= Math.floor(DS[i]); Q[i]=(FDS[i]-CR[i]); if (Q[i] < 0) Q[i]=0; //The following
is based on a standard line/circle intersection routine. B[i]=R1/R2+1; CY[i]=PY[i]-(DS[i]/B[i])*Math.sin(A[i]*Math.PI/180);
CX[i]=PX[i]-(DS[i]/B[i])*Math.cos(A[i]*Math.PI/180); //Line start point!! p1y[i]=CY[i];
p1x[i]=CX[i]; //Line end point!! p2y[i]=CY[i]+1*Math.sin(D[i]*Math.PI/180); p2x[i]=CX[i]+1*Math.cos(D[i]*Math.PI/180);
L[i]=(p2x[i]-p1x[i])*(p2x[i]-p1x[i])+(p2y[i]-p1y[i])*(p2y[i]-p1y[i]); //Travelling
towards if SH is less than zero. SH[i]=2*((p2x[i]-p1x[i])*(p1x[i]-TX)+(p2y[i]-p1y[i])*(p1y[i]-TY));
TD[i]=TX*TX+TY*TY+p1x[i]*p1x[i]+p1y[i]*p1y[i]-2*(TX*p1x[i]+TY*p1y[i])-R1*R1;//OK!
//Contact possible if IL is greater than zero! IL[i]=SH[i]*SH[i]-4*L[i]*TD[i];
ILS[i]=Math.sqrt(IL[i]); HT[i]=(-SH[i]-ILS[i])/(2*L[i]); HX[i]=p1x[i]+HT[i]*(p2x[i]-p1x[i]);//Contact
point x. HY[i]=p1y[i]+HT[i]*(p2y[i]-p1y[i]);//Contact point y. //Required angle.
a1= HY[i]-TY; a2= HX[i]-TX; I[i]=Math.atan2(a1,a2)*180/Math.PI; if (I[i] <
0) I[i]+=360; //Distance to impact point. d1=HY[i]-CY[i]; d2=HX[i]-CX[i]; P[i]=Math.floor(Math.sqrt(d1*d1+d2*d2)*2);
//Error adjust. For this situation only! if (Q[i] <= 0) Q[i]=0; if (SP[i] ==
0) Q[i]=0; E=(R1 > R2)?SP[i]*2:SP[i]; if ((P[i] <= E) && (IL[i]
> 1) && (SH[i] < 0)){ SP[i]=0; Y[i]=(TY-R2)+CR[i]*Math.sin(I[i]*Math.PI/180);
X[i]=(TX-R2)+CR[i]*Math.cos(I[i]*Math.PI/180); } if ((Q[i] == 0) && (SH[i]
<= -1)){ D[i]=A[i]*2-180-D[i]; SP[i]=SP2[i]; } if (D[i] < 0) D[i]+=360;
Y[i]+=SP[i]*Math.sin(D[i]*Math.PI/180); X[i]+=SP[i]*Math.cos(D[i]*Math.PI/180);
VB=180-D[i]; HB=0-D[i]; //Edge rebounds! if(Y[i]<1){Y[i]=1;D[i]=HB} if(Y[i]+S[i]>H){Y[i]=H-S[i];D[i]=HB}
if(X[i]<1){X[i]=1;D[i]=VB} if(X[i]+S[i]>W){X[i]=W-S[i];D[i]=VB} //Corner
rebounds! not necessary but looks nice. if((Y[i]<1)&&(X[i]<1)){Y[i]=1;X[i]=1;D[i]=45}
if((Y[i]<1)&&(X[i]+S[i]>W)){Y[i]=1;X[i]=W-S[i];D[i]=135} if((Y[i]+S[i]>H)&&(X[i]<1)){Y[i]=H-S[i];X[i]=1;D[i]=315}
if((Y[i]+S[i]>H)&&(X[i]+S[i]>W)){Y[i]=H-S[i];X[i]=W-S[i];D[i]=225}
T2.top=Y[i]; T2.left=X[i]; }//end loop! setTimeout('Move()',20); } //--> </script
