<HTML><HEAD>
<!--
------------------
GROOVY COLOR THING
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-->
<SCRIPT LANGUAGE="JavaScript"><!-- hide from old browsers
/*
THE JAVASCRIPT COOKBOOK by Erica Sadun, webrx@mindspring.com
Copyright (c)2000 by Charles River Media. All Rights Reserved.
This applet can only be re-used or modifed by license holders of the
JavaScript Cookbook CD-ROM. Credit must be given in the source
code and this copyright notice must be maintained. If you do
not hold a license to the JavaScript Cookbook, you may NOT
duplicate or modify this code for your own use.
Use at your own risk. No warranty is given or implied of the suitability
of this applet for any specific application. Neither Erica Sadun nor
Charles River Media will be held responsible for any unwanted effects
due to the use of this applet or any derivative.
*/
//------------------RANDOM NUMBERS----------------------------
var js_mult1=3141
var js_mult2=5821
var js_m1=100000000
var js_m2=10000
var js_iseed=0
var js_iseed1=0
var js_iseed2=0
// Return a Random Integer between 0 and N-1
function random(n)
{
if (js_iseed == 0)
{
now = new Date()
js_iseed = now.getHours() + now.getMinutes() * 60
+ now.getSeconds() * 3600
}
js_iseed1 = js_iseed / js_m2
js_iseed2 = js_iseed % js_m2
var tmp = (((js_iseed2 * js_mult1 + js_iseed1 * js_mult2) % js_m2) *
js_m2 + (js_iseed2 * js_mult2)) % js_m1
js_iseed = (tmp + 1) % js_m1
return (Math.floor((js_iseed/js_m1) * n))
}
// --------------------Hexadecimal Conversion---------------------
// convert a single digit (0 - 16) into hex
function enHex(aDigit)
{
return("0123456789ABCDEF".substring(aDigit, aDigit+1))
}
// convert a hex digit into decimal
function deHex(aDigit)
{
return("0123456789ABCDEF".indexOf(aDigit))
}
// Convert a 24bit number to hex
function toHex(n)
{
return (enHex((0xf00000 & n) >> 20) +
enHex((0x0f0000 & n) >> 16) +
enHex((0x00f000 & n) >> 12) +
enHex((0x000f00 & n) >> 8) +
enHex((0x0000f0 & n) >> 4) +
enHex((0x00000f & n) >> 0))
}
// Convert a six character hex to decimal
function toDecimal(hexNum)
{
var tmp = ""+hexNum.toUpperCase()
while (tmp.length < 6) tmp = "0"+tmp
return ((deHex(tmp.substring(0,1)) << 20) +
(deHex(tmp.substring(1,2)) << 16) +
(deHex(tmp.substring(2,3)) << 12) +
(deHex(tmp.substring(3,4)) << 8) +
(deHex(tmp.substring(4,5)) << 4) +
(deHex(tmp.substring(5,6))))
}
// --------------------JSCcolor Object---------------------
// Returns a JavaScript integer representing a JSCcolor object's color
function rawColor()
{
return (this.red << 16) + (this.green << 8) + this.blue
}
// Returns a hex string representing a JSCcolor object's color
function hexColor()
{
return toHex(this.rawColor())
}
// Set the JSCcolor object's color to that in a hex string.
// This routine does not add the Ox prefix.
function setColor(aString)
{
var tmp = toDecimal(aString)
this.red = (0xff0000 & tmp) >> 16
this.green = (0xff00 & tmp) >> 8
this.blue = (0xff & tmp)
return this
}
// Set the JSCcolor object's color to an integer
function setDecimalColor(aNumber)
{
var tmp = toHex(aNumber)
this.red = eval('0x'+tmp.substring(0,2))
this.green = eval('0x'+tmp.substring(2,4))
this.blue = eval('0x'+tmp.substring(4,8))
return this
}
// Adjust a JSCcolor object's color (red, green or blue) by an offset
function adjustColor(aColor, anOffset)
{
this[aColor] += anOffset
if (this[aColor] > 0xff) this[aColor] = 0xff
if (this[aColor] < 0x0) this[aColor] = 0x0
}
// Adjust one or more of a JSCcolor object's colors by an offset
function adjustColors(colString, anOffset)
{
var cs = colString.toUpperCase()
if (cs.indexOf('R') != -1) this.adjustColor('red', anOffset)
if (cs.indexOf('G') != -1) this.adjustColor('green', anOffset)
if (cs.indexOf('B') != -1) this.adjustColor('blue', anOffset)
}
// JSCcolor object constructor
function JSCcolor(r, g, b)
{
// set properties
this.red = r
this.green = g
this.blue = b
// set methods
this.rawColor = rawColor
this.hexColor = hexColor
this.adjustColor = adjustColor
this.adjustColors = adjustColors
this.setColor = setColor
this.setDecimalColor = setDecimalColor
return this
}
// --------------------Kaleidoscope Functions---------------------
// This color object will store our current color
var myColor = new JSCcolor(0x80, 0x80, 0x80)
// Do the actual adjustment
function doAdjust(aColor, anOffset)
{
myColor.adjustColor(aColor, anOffset)
parent.JCGroovyI.document.bgColor = myColor.hexColor()
}
function startColor()
{
// select a component to vary
var which = random(3) + 1
// select a direction to vary the component
var direction = ((random(2) == 1) ? -1 : 1)
// select an amount to vary the component
var amount = random(128)
var theColor
if (which == 1) theColor = 'red'
if (which == 2) theColor = 'green'
if (which == 3) theColor = 'blue'
// perform the color adjustment
for (var i = 0; i < amount; i++) doAdjust(theColor, direction)
// reset the timeout
JSCTimeOutID = window.setTimeout('startColor()', 200)
}
<!-- done hiding --></SCRIPT></HEAD>
<BODY bgcolor="ffffff" link="0000ff" vlink="770077"
onload="JSCTimeOutID = window.setTimeout('startColor()',500);">
<FONT COLOR="007777"><H1><IMG SRC="../GRAFX/SPICE.JPG" WIDTH=37 HEIGHT=72
ALIGN = LEFT>JavaScript Groovy Color Thing</H1></FONT>
<BLOCKQUOTE><FONT SIZE=4>
This small applet randomly adjusts the upper window's red, green or blue
channels up and down to provide a pleasant (if useless) color
animation using
<A HREF='../CLOCK/TIMEOVR.HTM' TARGET='JCcontent'>timeouts</A>.<p>
<CENTER><FORM>
<INPUT TYPE="BUTTON" VALUE="Turn Off Color Animation"
onClick="clearTimeout(JSCTimeOutID)">
<INPUT TYPE="BUTTON" VALUE="Restart Color Animation"
onClick="startColor()">
</FORM></CENTER>
</FONT></BLOCKQUOTE>
<h5>Copyright ©1996 by Charles River Media, All Rights Reserved</h5>
</BODY>
</HTML>