Monday, 31 August 2009

Help for BlueOnyx Server Maintenance

My last post looked at setting up a testing server for web designers. One of the options included building your own server running BlueOnyx for easy set-up and easy server management.

The thing that makes server management so easy is the web based interface. Originally the interface was only available for Sun Cobalt hardware, but once Cobalt was discontinued Sun Microsystems released the source code as open source. Since then others have developed it to work with any hardware (great news for us) and is most currently available as BlueOnyx.

PDF Manual

Because the BlueOnyx server management interface is based heavily on the sourceode for the Cobalt RaQ 550 the old RaQ 550 manual still contains some useful instruction on managing the system, and you can download it in PDF format here:


The great thing about the BlueOnyx (and Cobalt RaQ) is how easy the server management interface made server management for non-techies.

Server managment after all was traditionally done through a shell interface (not unlike the windows command prompt). Setting up a web site involved manually creating users and folders, manually setting permissions and quotas, and manually editing several config files without making mistakes.

What the BlueOnyx interface does (and what the Cobalt RaQ interface did) is turn this process into an interface. You simply fill in the blanks and press "go" and scripts automatically create the folders and permissions and update the config files. Happiness.

There are other web based server management systems such as Plesk or Webmin.

Plesk is perhaps the easiest (it really is aimed at hosting companies, providing an interface for customers), but it costs money.

Webmin, is secure and powerful and popular with techies, but IMHO much more difficult to use than BlueOnyx because you still have to do many things manually. You still need to create the folders, set the permissions etc... albeit through a browser rather than a command prompt. And that requires a fair amount of technical knowledge.

BlueOnyx arranges things differently. It assumes you have limited technical know-how, but that you do know what you want at the end, and arranges the interface into tasks rather than tools. So much easier.

Setting Up Your Own Testing Server

Call it what you like, a "testbed", a "testing server", a "sandbox server", it all amounts to the same thing - a server for testing your sites, scripts, databases before you "go live".

When it comes to web design I prefer to use Dreamweaver (in conjunction with Flash, Fireworks and occasionally Photoshop). And when it comes to static websites that's all fine, you can test them in Dreamweaver by hitting F12 and getting a preview in your browser. But for more advanced sites this will not do...

3 good reasons why you need a testing server

Going beyond static sites, to sites that include server-side scripts (such as PHP or Perl (CGI)) or database connections such as discussion forums, content management systems or shopping carts, it is really useful having a place to test before you "go live". Having your own server allows you to regularly test as you develop without long upload times, and without your client getting glimpses of half finished work.

It's also great for designers wanting to learn or improve their dynamic web skills. So you want to learn some PHP? So you want to learn how to get Flash to talk to a database? So you want to practice setting up and customising a content management system or shopping cart? You're going to need a server - it's a handy place to practice without needing to buy webspace.

Finally, if you want to use Dreamweaver's testing server facility when you set up your site in the "manage sites" window... you need a testing server.

Admittedly, if you have a website of your own you could use your own website host for testing and practice by shoving it in a folder separate from the rest of your site. But this is far from ideal, since your testing site will be running from a folder below the web root, when you intend to run it from the web root when you "go live". Much better is to test it as it will run when live.


I confess that if I had not learned what I now know, the whole idea of setting up a server would be enough to send me back to bed for another couple of hours. It sounds complex, but some very clever and generous people have made it much easier than it used to be - read on.

Before we go any further - LAMP or WAMP?

Before we go further let me introduce the server platforms I will be discussing today - LAMP and WAMP.

L - Linux
A - Apache


W - Windows
A - Apache

You will already be aware that Linux and Windows are operating systems, and really that is the only major distinction between the platforms above.

Apache is FREE open source web server software.

MySQL is FREE open source database server software.

PHP is a FREE open source server-side scripting language/engine.

Loads of websites run on LAMP or WAMP. Loads of web hosting companies use LAMP or WAMP to host websites commercially. In fact, last time I checked, Apache was the most installed web server in the world.

Loads of free web software runs on LAMP or WAMP too:

Zen Cart
To name but a few...

All free and all running on free server software. At some point I guarantee you will want to install at least one of these for a client or for your own use, you need some practice, you will need to test it as you "skin" or "theme" it, you need a testing server running Apache, MySQL and PHP.

(Although I am not going to explain commercial alternatives in this post, you should be aware that you don't have to use FREE open source server software, a popular proprietary alternative would be Microsoft's Internet Information Server (IIS), MSSQL a database server and ASP or ASP.NET for server-side scripting. The drawback is that this all requires a commercial license. the other drawback it that I won't be explaining these today.)

A couple of approaches

There are probably many approaches you can take, but I am going to discuss what are to me 2 of the easiest options:

1. Install a server on your development computer
2. Set-up a server using an old computer

Let's start with the first...

Install a server on your development computer - WAMP

This is my least favourite of the two options, but if you want something quick, and you don't have an old computer kicking around it's a good alternative. I use a Windows XP machine for web design and development, so this solution is effectively a WAMP solution.

The easiest way is to get a pre-configured bundle of Apache, MySQL and PHP and install it as an application onto your Windows machine. There are several free options, but I recommend:



Download the installer, run it, and voila, you are done.

The installer sets up all the server software you need, and creates a web root folder. To test your site all you need to do is copy the files into the web root folder and start browsing. Your new installation of Apache, MySQL and PHP will process files in or below the web root folder as though they were on a web server (in fact they are on a web server at this point).

Couldn't be simpler.

Although I have used this type of approach many moons ago with Apache Triad, and while it is quick and easy, I recently built a server on a totally separate computer, rather than installing it on my development machine, and I prefer it - I guess I just don't like to clutter my graphics workstation up with too much other software (it's sucking my resources dry man, I can feel it) - just a little harmless paranoia. Which brings me to...

Set-up a server using an old computer - LAMP - the "real deal"

I did this just last week as the culmination of sporadic research over several months. You might think that setting up your own server hardware and software is the stuff of IT technitians and not the realm of designers, and depending on the type of designer you are, or your background you may still want to leave it to your techie friend. But I managed it so I urge you to read on.

And of course the great thing about this approach is that you are not making a simulation of a web server, you will end up with an actual web server in every sense. Stick it in a datacentre and you really could use it to host yours and your clients websites and email (if you wanted), this is the "real deal".

And being the "real deal" it has several advantages:

1. More than one person can use it as a testing server simultaneously - which makes it ideal for web design studios with several designers, and ideal for schools/colleges/universities/education allowing more than one student to upload and test their projects.

2. Each user can have their own login and testing server space. In fact each project can have it's own server space and login.

3. FTP, HTTP, HTTPS, PHP and MySQL all work the way they should.

As a testing server it is ideal because it is a real server.

There are loads of LAMP options out there, but being designers, not technitians we want one that is:

1. Easy to set-up
2. Easy to operate once set-up
3. Free - we're on a budget

Which, after my research and experience, leaves me with one option that ticks all boxes:

It is described as a turnkey solution (meaning it is as easy as turning a key to get up and running) and it really is straightforward.


1. Is your network suitable?

Before we go any further you need to check that you are the right kind of network to have a server. Answer the following questions with a "YES" and you can go ahead:

Do you have a network hub or router with a spare LAN socket?
Do your other computers connect to the hub or router using ethernet cable or wireless?
Does the router connect to your broadband connection?

If you answered "YES" to all 3 questions, then you can go ahead. Hoorah.

2. Get your machine

First you need an old computer that works, but which you no longer need. the computer should have at least the following:

Processor (CPU): Reasonable speed
RAM: At least 256Mb
HDD (at least 40Gb)
Graphics Card: (spec irrelevant)
Network Card: 10/100 Mbps
Other Drives: Floppy, CD ROM

The higher the spec the better, but don't worry too much, I am running a working testing server with BlueOnyx on the following very low spec machine:

Processor: PII 266MHz
RAM: 256Mb
HDD: 80Gb
Graphics: 8Mb
Network Card: 10/100 Mbps
Other Drives: Floppy, CD ROM
Sound: None

And it all works like a dream. The fact is that my testing server doesn't have to put up with much load. It won't be experiencing thousands of visitors, only me, and in most situations a testing server probably won't have more simulaneous users than the number of designers using it. Obviously, the more users the the better your computer needs to be but the main areas of concern are:

HDD - Improve this to hold more files

RAM and Processor - Improve these to handle more simultaneous visitors

Web servers DO NOT need a good graphics card, they spend most of their time without a monitor plugged in because they are managed over the web via a web browser or shell client. Nor do they need a sound card.

3. Check you don't need it

Make sure you really don't need the machine for anything else.

Make sure you don't need any of the information on the Hard Drive. What we do next will wipe it completely. You will lose all data, software, downloads, accounts information, everything.

If you are using an old windows machine with an OEM Windows XP sticker on it, you need to know that we will be wiping Windows off the machine, and you won't be able to transfer the Windows licence to another machine. OEM licenses stay with the machine.

Are you sure you can spare this machine?

OK, let's move on.

4. Set up the machine for install

For installation you need to temporarily hook up a monitor and keyboard to the computer you plan to use. Make sure it has power but don't turn it on yet. Make sure it is connected to your network hub via the ethernet port in the network card.

5. Download and burn the BlueOnyx server set-up disk

The BlueOnyx set-up disc needs downloading as an ISO file and then burning to a blank CD.

Download the ISO file here:

Once downloaded you need to burn the ISO to a blank CD.

If you don't have software to burn the ISO to a blank CD, I recommend:

Burn baby burn.

6. Install the server software

This is the really exciting bit. Your old computer becomes useful again as a testing server.

Open the CD ROM drawer and insert the set-up disc.

Reboot the machine.

Booting from CD :-)

In most cases your computer will check the CD drive first, to see if it can boot from CD. If this is the case follow the on-screen prompts until installation is complete.

MAKE SURE you write down or remember usernames, passwords and IP addresses you put in during installation. You will need them later.

Not booting from CD :-(

You will know if the computer does not boot from CD if you see Windows starting up, or nothing happens and it complains it cannot boot. If this is the case you need to make sure the computer boots from the CD ROM drive before it boots from HDD by changing the "boot order" or "boot priority" in the BIOS.

Do this by pressing reset or restarting the machine, then hitting the F8 or F10 keys as soon as it starts booting up (a note on the screen should tell you which key).

Then the BIOS menu will appear and you need to hunt around for the "boot order" or "boot priority" and set CD or Optical Drive to be FIRST.

I would show you in detail but all BIOS menus are different (get your techie friend to help if you are not sure).

7. After installation

Once the server has finished installing (you will know because it will reboot and tell you to remove the CD) it is ready to begin acting like a server.

At this point you can unhook the monitor and then find a place where it won't get in anybody's way and plug it into the network there and switch it back on.

After a few minutes it will have booted up and you will be able to access the server via the web browser of any computer on the network and finish the set-up.

To do this simply input the IP address you gave to the server into your web browser.

You will then get lovely web interface to the server and be able to finish setting up.

And that's a wrap

At this point you have a web server. Look out for a future post on how to set-up "sites" on the server so you can test your work.

If you want to have a go on your own. Check my next post.

Monday, 24 August 2009

Descartes Day

In these modern times with such a rapid pace of progress we often mistake old or antiquated as meaning irrelevant. But we couldn't be more wrong.

I learned yesterday, from a child's book, that major principles on which much of my Actionscript is based were invented (or discovered) 372 years ago in the year 1637. The man we have to thank for bothering to write his discovery (or invention) down is the mathematician and philosopher Rene Descartes (pronounced day-cart).

And what was this great principle? What we now take for granted, the Cartesian Coordinate System (what we refer to as X and Y coordinates).

Allow me to quote that kid's book:

"Graphs turn pairs of numbers represented by x and y into meaningful shapes. This idea was invented by the French philosopher Rene Descartes, who is perhaps more famous for saying "I think, therefore I am." It allowed people to solve geometric problems with algebra and algebraic problems with geometry."
(Bridgman, R, 1000 Inventions and Discoveries, Dorling Kindersley Limited,
2002, pp 90)

If Descartes hadn't invented the system no doubt someone else would at some point - such is human ingenuity - so I don't for one minute suggest that _xmouse or _root.movieclip._y would not be possible without him. But the fact that Descartes was at least one of the independent inventors, and could be bothered to record and share his invention way back in 1637, deserves him some credit. So, today I briefly doff my cap to Descartes for his coordinate system (in much the same way I might tip my hat to Sir Tim Berners-Lee (inventor of the WWW) or Thomas Knoll (a founder developer of Photoshop) were I to pass them on the street).

The Wikipedia article on Cartesian Coordinates is an excellent introduction, and even gives formulas for transformation, reflection and rotation of geometry (all of which could form the basis of some useful Actionscript).

Just remember that with Flash the (0,0) point of the cartesian coordinate system is the top left hand corner (not the bottom left hand corner as it is with graphs).

Moving on...

Wednesday, 12 August 2009

Mouse Control for Flash Games - Part 2 - (Top Down Driving Game with Steering)

A couple of months ago I posted a solution for getting a MovieClip to follow the mouse, with easing. It was a quick solution for controlling the 'player' in a top-down car game.

Since then I have revised the code to also make the 'player' rotate in the direction of travel, to simulate the effect of the car steering.

Take a look:

Original Movie (without steering) - Demo SWF

Modified Code (with steering) - Demo SWF

As you can see the rotation produced by the modified code offers more realistic looking game play, allowing the 'player' car to appear to swerve as the player moves the mouse, and making the 'player' car straighten up as it comes to the end of its movement.

The Code

The code is actually remarkably simple, much simpler than I expected. As I look back through my development versions it gets progressively simpler as I cut out all the redundant code and am left with only what matters.

I will give you the code below, the comments explain how it works. Just paste it into your Flash Actionscript panel, and click the format button to make it nice and easy to read:

/* Includes code from */
/* This code works best if your movie is set to run at 30fps. */

/* The higher the frame rate the lower this number must be. */

var easing = 10;

/* Influences how far the player_mc rotates in response to the mouse distance from the player_mc. The lower the number the greater the rotation. */

var rotatefactor = 4.5;

/* This function animates the player_mc in response to mouse moving. */

onEnterFrame = function () {

/* Works out the current distance between the X coordinate of the mouse and the X coordinate of the player_mc */

mousediff = _root._xmouse-_root.player_mc._x;

/* Moves the player_mc along the X axis towards the location of the mouse with easing to provide some delay and smooth movement. */

_root.player_mc._x += mousediff/easing;

/* Rotates the player_mc towards the mouse. The amount of rotation is determined by the difference between the player_mc location and the mouse location along the X axis, and the rotation factor defined in the variable at the top. The closer they are together the smaller the amount of rotation, the further apart the larger the rotation.
With the _rotation method a negative number means anti-clockwise (counter-clockwise) and a positive number means clockwise. Even so, we do NOT need to test which side of the player_mc the mouse is on to determine whether the angle of rotation should be positive or negative. This is because we base the rotation on the distance between the mouse and the player_mc, and if the mouse is to the left of the player_mc this code will return a negative number which in turn will give us a negative rotation factor. Cool.*/

_root.player_mc._rotation = mousediff/rotatefactor;

As you can see, the whole affect is achieved without trigonometry. As such it simulates the visual appearance of the 'player' car steering, but is not a mathematically accurate model of steering. But it is only intended to provide user mouse control of a car for a simple top-down driving game - accurate physics are not necessary.

The thing I am most pleased about (apart from the cool effect) is how little code it takes. Without comments, it is a mere 7 lines long. And yet it provides so much more engaging game play (I think so anyway). If you find it helpful, leave a comment.


Monday, 10 August 2009

Now Includes Demo SWF Files

I have a fair number of posts on here that describe funky uses of actionscript, but without showing examples of what I am talking about.

The good news is that I have now started adding demo SWFs to previous blog posts, and all future posts will include working examples by default.

Hopefully this will make it that little bit easier to see if my code is doing the thing you are needing help with.

What fun.

Friday, 7 August 2009

Manipulating Colour in Flash - #4 - Building an Interactive Colour Mixer

Now we are beginning to see the end result of all my experiments with manipulating colour using Actionscript. Using the techniques from my previous posts, and a few others to get a working interface, this post explains how to make a simple RGB colour mixer that gives a preview of the colour and the hexadecimal value in a form that can be copy and pasted.

Demo SWF

The Interface

While it is very tempting for those with a graphics background to want to start by designing a groovy interface (including me), it is sometimes a good idea to get just a basic prototype working so you can get the bugs out of the code - and that's what you see here.

The demo above shows my basic interface. Before we can go much further you will need to lay out something similar on your stage. The items in the demo above are labelled, check the key below:


A = MovieClip, instance name 'colourspot_mc'
B = Input Text, instance name 'red_txt', variable 'red'
C = Input Text, instance name 'green_txt', variable 'green'
D = Input Text, instance name 'blue_txt', variable 'blue'
E = Dynamic Text, variable 'displayhex'
F = MoveiClip, instance name 'redpointer_mc'
G = MovieClip, instance name 'redclicker_mc'
H = MoveiClip, instance name 'greenpointer_mc'
I = MovieClip, instance name 'greenclicker_mc'

J = MoveiClip, instance name 'bluepointer_mc'
K = MovieClip, instance name 'blueclicker_mc'

Once you have set up your objects on the stage as above, you are ready to start coding.

The Code

I won't go into long and drawn out explanations of everything this time. The colour manipulation is explained in previous posts on this blog, and other things are explained within the code as comments.

NOTE: For some reason blogger is not treating this code very well. When you dump it into Flash make sure you hit the 'Format' button so it looks as it should.

/* set default values for R, G and B */
var red = 0;
var green = 0;
var blue = 0;
/* Create colour object to control colourspot_mc */
var my_color:Color = new Color(colourspot_mc);
/* Button triggers conversion of RGB into hex, then applies it to the colour object */
onEnterFrame = function() { /*This enables colour to be constantly updated */
/* ensures that only values between 0 and 255 can be used for red */
if (red>255) {
red = 255;
if (red<0) {
red = 0;
/* convert red decimal into hex */
var decred = new Number(red);
hexred = decred.toString(16);
if (decred<=15) {
hexredfinal = "0"+hexred;
} else {
hexredfinal = hexred;
/* ensures that only values between 0 and 255 can be used for green */
if (green>255) {
green = 255;
if (green<0) {
green = 0;
/* convert green decimal into hex */
var decgreen = new Number(green);
hexgreen = decgreen.toString(16);
if (decgreen<=15) {
hexgreenfinal = "0"+hexgreen;
} else {
hexgreenfinal = hexgreen;
/* ensures that only values between 0 and 255 can be used for blue */
if (blue>255) {
blue = 255;
if (blue<0) {
blue = 0;
/* convert blue decimal into hex */
var decblue = new Number(blue);
hexblue = decblue.toString(16);
if (decblue<=15) {
hexbluefinal = "0"+hexblue;
} else {
hexbluefinal = hexblue;
/* build the final 6 digit hex figure and prepend with 0x as needed by Flash */
hex = "0x"+hexredfinal+hexgreenfinal+hexbluefinal;
/* build the final 6 digit hex figure and prepend with # as needed by HTML */
displayhex = "#"+hexredfinal+hexgreenfinal+hexbluefinal;
/* set the colour property of the colour object controlling the MovieClip */
/* Update the location of the pointers */
_root.redpointer_mc._x = ((_root.redclicker_mc._width/256)*red)+_root.redclicker_mc._x;
_root.greenpointer_mc._x = ((_root.greenclicker_mc._width/256)*green)+_root.greenclicker_mc._x;
_root.bluepointer_mc._x = ((_root.blueclicker_mc._width/256)*blue)+_root.blueclicker_mc._x;
/* Set the red decimal value with a clicker */
_root.redclicker_mc.onPress = function () {
redleft = _root.redclicker_mc._x;
clickpos = _xmouse;
clickval = clickpos-redleft;
clickprop = (clickval/_root.redclicker_mc._width)*256;
red = Math.floor(clickprop);
/*moving the pointer
_root.redpointer_mc._x = clickpos;
/* Set the green decimal value with a clicker */
_root.greenclicker_mc.onPress = function () {
redleft = _root.greenclicker_mc._x;
clickpos = _xmouse;
clickval = clickpos-redleft;
clickprop = (clickval/_root.greenclicker_mc._width)*256;
green = Math.floor(clickprop);
/*moving the pointer */
_root.greenpointer_mc._x = clickpos;
/* Set the blue decimal value with a clicker */
_root.blueclicker_mc.onPress = function () {
/*Getting the zero point on the clicker bar */
redleft = _root.blueclicker_mc._x;
/*Capturing the location of the click on the clicker bar */
clickpos = _xmouse;
/*Calculating how far along the clicker bar the click was made */
clickval = clickpos-redleft;
/*Calculating the proportional distance along the bar at which the click was made as a figure between 0 and 1, then converting that into a value between 0 and 256. */
clickprop = (clickval/_root.blueclicker_mc._width)*256;
/*Converting the figure to an integer by rounding DOWN to the nearest whole number. Rounding DOWN ensures we can get 0 at the bottom and 255 rather than 256 at the top. */
blue = Math.floor(clickprop);
/*moving the pointer object to the position clicked on the clicker bar */
_root.bluepointer_mc._x = clickpos;

And there we have it.

Solving Issues as You Go

It is always interesting to solve some issues as you go. For instance, I hadn't quite decided whether I wanted users to be able to type RGB values, or just limit them to using the colour bars.

When I decided that some users might want to be able to type them (as it might be easier and faster in some situations) I realised that some users might enter a value greater than 255 - which would then give inaccurate results. So, at the last minute I included the code that converts any number higher than 255 into 255 and any number lower than 0 into 0. Like I say, always interesting.

Another implication was with the pointers on the colour bars (items F, H and J in my diagram). Making the RGB numbers updatem depending on where the user clicked, and moving the pointers to the place the user clicked was one thing. But now we had to also work it the other way, and get the pointers to move to the place on the colour bar representing the value the user typed. It wasn't difficult, just a case of working the equation the other way, but it needed doing.

Sometimes seemingly small decisions about user experience can have a significant impact on our code. That doesn't mean we shouldn't put the user first, but it does mean we should be prepared to modify our code when needed. After all, our interactive applications need to actually do what the user wants, if we want any users to use them.

Thursday, 6 August 2009

Google Advantages with Blogger

I have been using Blogger since August 2007 very happily. And though everyone has their favourite blog system, and although I have even been recommended that Wordpress is better, there is something that some bloggers may not be aware of - really fast Google indexing for Blogger posts.

I don't know how long it takes for someone using Wordpress to have their blog posts begin appearing in Google. No doubt it will vary depending on the rating the blog has under the highly secret Google algorithms. But as a Blogger user I can honestly say that I have had a blog post appear in the Google search results within 2 hours of posting - this very day - and not buried pages deep either.

Less than 2 hours after publishing this post:

I found it on the number 1 spot on Google (out of about 13,300 results) under this search term:

convert 2 digit hex actionscript

Of course this is obviously related to the fact that Google owns Blogger, but the reasons are less important than the results. I almost don't care what other features other blog systems may have. Until they can beat me into the Google index I will stick with Blogger.

Converting Decimal RGB Values Into a 6 Digit Hexadecimal

Recent posts have looked at the Actionscript required to convert decimal numbers into hexadecimal strings. And if we don't look any deeper everything looks hunkydory for mixing any colour we like using RGB values, and then convert to a hexadecimal number you might use to define a colour in HTML.

But we still have a problem to solve.

Low Numbers v. High Numbers

HTML and Flash can both use hexadecimal values to define colours, but the hexadecimal values must be defined as a 6 digit number - 3 pairs representing the 3 colour channels Red, Green and Blue. For example:

White: Decimal Red 255 + Green 255 + Blue 255 = Hexadecimal FFFFFF

In most cases this won't present a problem, after all decimal 255 equates to hexadecimal FF. The problem comes when the decimal value drops below 16. Lets take a look:

Decimal 255 = hex FF
Decimal 16 = hex 10
Decimal 15 = hex F
Decimal 1 = hex 1
Decimal 0 = hex 0

Notice that as soon as the decimal value drops below 16 the hexadecimal value drops into single digits. Lets see what this means in practice:

Black: Decimal Red 0 + Green 0 + Blue 0 = Hexadecimal 000

This is a problem because to convey colour values to HTML or Flash consistently we need a 6 digit hexadecimal number, but what we have here is only a 3 digit number.

To solve the problem we need to remember how hex counts. As an example let's count to thirty in hex:

0 1 2 3 4 5 6 7 8 9 A B C D E F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E

In this example values 16 and above all have 2 digits in hex. We need to find a way of making the lower numbers all have 2 digits too. This is actually very easy, in fact we do this all the time, most commonly when we write the date. Take for example 1st January 2009 written numerically - 01/01/09. We can turn a single digit number into a 2 digit number, without changing its value, very easily by placing a '0' (zero) in front (this is called prepending), like so:

1 becomes 01
2 becomes 02

All we have to do then is prepend single digit hex values with a '0' (zero), like so:

00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

If we do this we can display black as a 6 digit hex number after all:

Black: Decimal Red 0 + Green 0 + Blue 0 = Hexadecimal 000000

But how do we do this in Flash with Actionscript?

Prepending Single Digit Hexadecimal Numbers With '0' Using Actionscript

I am sure there are many and varied ways to do this, but I prefer the following method. First I will give you the code, then I will explain how it works.

/* R is defined as a value between 0-255 in a text input field by the user */

_root.calc_but.onPress = function() {
var decimalred = new Number(R);
hexred = decimalred.toString(16);
if (decimalred<=15) {
hexredfinal = "0"+hexred;
} else {
hexredfinal = hexred;


Here's how it works:

1. First we take the user inputted value (a number between 0 and 255) and pass it to 'decimalred' specifically defining it as a number.

2. Then we convert the 'decimalred' number into a hexadecimal string and pass the result to 'hexred'.

3. Then we test to see if the original value inputted by the user was 15 or less. We do this because we already know that any decimal between 0 and 15 will convert to a single digit hex number.

4. If the original value inputted by the user was 15 or less, then we use Actionscript to prepend a '0' to the converted 'hexred' value like so:

hexredfinal = "0"+hexred;

Then we pass the result to 'hexredfinal'.

5. If the original value inputted by the user was not 15 or less, then we don't prepend anything, we just pass the 'hexred' value straight to 'hexredfinal' untouched.

In this way we can make sure that in the conversion from decimal to hexadecimal, all values between 0 and 255 are shown as 2 digit hex numbers. This allows us to produce the 6 digit numbers required in HTML and by Flash.

What fun.

Manipulating Colour in Flash - #3 - Successfully Converting Decimal to Hexadecimal Using the toString Method (even with user defined variables)

My last two posts looked at how you can use Actionscript to change the colour of a MovieClip, and to convert decimal colour values into hexadecimal.

Teething Trouble

But as I work towards harnessing these techniques to make a simple colour mixer in Flash I suddenly ran into difficulty converting decimal to hexadecimal when the user defines the decimal values in text input fields.

I must confess that to begin with I spent a while being stumped by this. As I Googled around for a solution there were similar questions, but no answers. Anyway, I am happy to say, there is a solution.

No doubt some of you will have a similar problem, so let me talk you through the problem I experienced and then the solution (I hope it helps).

The Problem

In my tests the toString method easily converted a decimal defined as a variable in a keyframe to a hexadecimal as follows:

/* This works */
var R = 255;

mybutton_but.onPress = function () {
hex = R.toString(16);
trace(hex); //Returns FF

However, when the value of R was defined by the user through a text input box it suddenly stopped working, as follows:

/* This DOESN'T work */
/* value of R is defined as 255 in a text input field by the user */

mybutton_but.onPress = function () {
hex = R.toString(16);
trace(hex); //Returns 255

For some reason, when the value of R was defined in the keyframe the toString method successfully converted the decimal value 255 and returned FF, but when the value of R was defined in a text input field the toString method failed to perform any conversion on the decimal value 255 and returned 255.

Preparing to Find a Solution

When I struggle with solving these niggly little problems I often find that taking some time out and doing something else gives the mind time to unwind (and also mull over the problem without having to try out every idea instantly). The brain is a fantastic problem solver, if it is given the right conditions. As a college lecturer I know that the ideal conditions come when an individual is relaxed but alert. So, if needed, take a break, unwind, get some sleep or remove distractions. I spent the morning cutting the grass and sorting out the chickens, then in the afternoon found the solution.

The Solution

As I said before, none of my Googling revealed an answer to my problem, but as I hunted around for anything I could find that might give me a hint, or prompt an idea I came across this snippet on

var i = new Number(555);

I must have seen several similar examples yesterday evening and got nothing from them (too tired no doubt). But having taken a break from the problem since then, and relaxed, my brain was ready to spot the significant detail that was the solution:

var i = new Number(555);

And there it was, staring out at me. Something I had not yet tried. So I modified my code as follows:

/* This DOES work */
/* value of R is defined as 255 in a text input field by the user */

mybutton_but.onPress = function () {
var decimalred = new Number(R);
hexred = decimalred.toString(16);
trace(hexred); //Returns FF

Why it Works

So why didn't it work before, and what's the big difference that makes it work this time?

I suspect that the reason it did not work before was because the user defined variable 'R' was already being treated by Flash as a string and so using the toString method to convert to a string did nothing, because it was already a string to start with.

Result: 255 (string) in, 255 (string) out.

The solution is really hidden within the problem (as are so many design solutions). We are converting a decimal value (representing a colour channel intensity) into its hexadecimal equivalent. We want to do this using the toString method. However, the toString method is for datatype conversion. This means converting one datatype to another datatype, in this case a non-string into a string. For this to work we need to force Flash to treat the user input 'R' as a number so that we can use toString to convert it into a string in hex format.

The script above does this by passing the user defined decimal value 'R' to a new variable 'decimalred' - with 'decimalred' specifically defined as being a new Number. This forces Flash to treat the user defined value as a number datatype thereby allowing toString to work as expected and convert the decimal number value to a hexadecimal string.

Result: 255 (number) in, FF (string) out.

And that's a wrap.

It is precisely this kind of problem that I see as being the drawback of having come to Flash and Actionscript from a graphic design, rather than a programming background. Nevertheless, I hope that by posting my solution I have helped at least one other poor designer get to grips with with one small area of Actionscript. If my Googling is anything to go by, this may well be the only explanation of this problem on the web (at time of posting of course).

Happy coding.

Tuesday, 4 August 2009

Manipulating Colour in Flash - #2 - Dynamically Changing MovieClip Colour

Converting decimal colour values into hexadecimal is one part of the puzzle, but then we have to use the result to dynamically change the colour of a MovieClip.

One of the inconsistent(?), and certainly annoying things about Flash is the way you modify the colour of a MovieClip with Actionscript. We already know you can modify various attributes of a MovieClip such as _height, _width, _x, _y, _rotation... but there is no attribute for colour.

The Colour Object

What you have to do instead is create a create a colour Object which in turn controls the colour of the MovieClip. It's not difficult, take this as an example:

var my_color:Color = new Color(MovieClipName_mc);

In this code we call the object 'my_color' and in the parenthesis we specify the instance name of the MovieClip the colour object will be controlling the colour of, in this case a MovieClip called 'MovieClipName_mc' - you can of course name your MovieClip differently, provided you specify its name in the parenthesis as above.

Changing the Colour

We know the name of the colour object - 'my_color' - so now we can tell Flash the colour value of that object in hexadecimal (just as we would specify a colour in HTML). Here's the code:


In HTML we prefix a hexadecimal colour value with '#' as in '#FFFFFF'. In Actionscript we prefix with '0x' as above '0xFFFFFF'.

FFFFFF of course represents the colour White (if white is a colour), if you change this value in the script above the MovieClip specified in the colour object will adopt the same colour.

Practical Use

That explains the principles of how we can use a colour object to control the colour of a MovieClip, but how about a practical example...

1. Create an object on the stage, select it and hit F8 to turn it into a MovieClip. Give the MovieClip the instance name of 'colourthing_mc'.

2. Create a new layer, name it 'Actions', then select the first frame of the layer.

3. Now create a Dynamic Text Box of the Input variety on the stage. In the properties panel set the variable to be '_root.usercolour', the reason for this will be explained in my comments below.

4. Now create a Button on the stage and give it the instance name 'calc_but'.

And that's the easy bit, now for the easy code:

/* This is one of those really silly things about Flash. Instead of having a colour attribute like they have _width and _height attributes, you have to create a colour Object which in turn controls the colour of a specified MovieClip. Here's how you do it: */

var my_color:Color = new Color(colourthing_mc);

/* This next step sets up for allowing the user to specify the colour of the MovieClip. */

/* First we create the user controlled variable */

var usercolour = "000000";

/* Then we create another variable that is the result of formatting 'usercolour' as required for Flash to understand it as a hexadecimal value by pre-pending it with '0x' */

var hexusercolour = "0x"+usercolour;

/* Then we setRGB of 'my_color' to that hexadecimal value */


/* All that remains is to create a dynamic text box that allows the user to input their own hex value for the 'usercolour' variable and a button that will update the 'my_color' value with the user value from the text box, whenever it is clicked.

The important thing to remember when setting up the text input box, is to se the variable very precisely. If the variable it is updating is in the root timeline, then you must define the variable in the text box as '_root.variablename' not simply 'variablename'. In this case the variable for the text box must be '_root.usercolour'. */

/* This code then makes the button update the colour object with the user specified value. */

_root.calc_but.onPress = function () {
var hexusercolour = "0x"+usercolour;

And that should be it.

Now we have been able to change the colour of an object through user input of the hex value. This could be developed further to allow the user to change the value by using sliders. This will require us to change 0-255 values into hex values on the fly. But knowing what we know from my previous post, this shouldn't be too hard.

Monday, 3 August 2009

Manipulating Colour in Flash - #1

Following on from my previous post, I have begun to look into how I can use Actionscript to work with colour.

This experiment looks at how we can convert decimal RGB values into hexadecimal using Actionscript.

It's very simple...

The Code

/* First we set the RGB values as decimal integers (whole numbers) from 0-255, as you would see them defined in any graphics program. This example would reproduce white, but you can change the values to be anything you like between 0-255. */

var R = 255;
var G = 255;
var B = 255;

/* Then we convert the RGB decimals to their hexadecimal equivalents. The toString method is the easiest way I have found of doing it (thanks to Colin Moock). This script takes the value of each of the variables and converts the datatype from a numeric value
(in this case 255) into a string using '16' as the radix argument of the method. As a result 255 becomes FF, the hexadecimal equivalent. The code below then simply stitches the converted values of the R, G and B variables together to form a 6 digit hex number for the colour. */

trace(R.toString(16)+G.toString(16)+B.toString(16)); //Returns FFFFFF

What I like about this method is its simplicity. It would form the basis of a very simple colour mixer program, since the R, G and B values could easily be set by sliders, or the user keying in decimal values for each of the channels.

Over to you... meanwhile, I play with colour some more.

Thoughts on Colour

Colour is a fascinating thing. As a child there was always that wonder of discovery that went with mixing colours to make new colours... always resulting in that grimy brown in the end.

I have since learned that as a child I was playing with subtractive colour, the mixing of pigments to subtract from white and make black. Meanwhile your computer monitor uses additive colour, mixing light to add to black and make white.

It gets even more interesting when you introduce colour wheels and start to notice the relationships between primary, secondary and tertiary colours. Or the difference between tint, hue and shade, or complementary colours and colours in common.

16 Million +

Computers make mixing colours so easy, in fact, with the right tools it becomes less about art or aesthetics and more about mathematics. Did you know for instance that the 16 million or so colours your monitor can display are made up of just 3 colours, red, green and blue? Each of these is called a channel, a red channel, a green channel and a blue channel. In fact your computer can display 256 increments (levels of colour strength) on each channel and by mixing those colours in different amounts you get all the colours available to your monitor.

Just think about it, 3 colour channels, 256 increments of each to mix:

256 x 256 x 256 = 16,777,216 possible colours

Decimal v. Hexadecimal

In decimal we count from 0 to 9 before starting over, giving us 10 increments. like so:

0 1 2 3 4 5 6 7 8 9

Using decimal to define colour we start with 0 as the lowest colour value, and end with 255 as the highest, giving 256 increments.

However, HTML (and at times Flash) prefers hexadecimal which differs from decimal in that we count from 0 to 15 before starting over, giving us 16 increments. Like so:

0 1 2 3 4 5 6 7 8 9 A B C D E F

Using hexadecimal to define colour we start with 00 as the lowest colour value, and end with FF as the highest, giving 256 increments also.

We can say that a decimal 255 and a hexadecimal FF are of equal value. They represent the same number. Likewise a decimal 0 and a hexadecimal 00 are also equal.

Defining Colour Values Numerically

A present we are looking at specifying RGB colour, that is colour defined by the amounts of Red, Green and Blue in their makeup.

When defining RGB colour numerically, it is vital to remember the order of the colour channels. It is always Red, then Green, then Blue. Take the following decimal example:


Knowing the order of the colour channels means we can understand that this means the Red channel is on full blast at 255, the green channel is at three-quarter strength at 192 and the blue channel is at about half strength at 128.

Using hexadecimal we would write the same colour as:


The first 2 digits are the red channel, the second 2 digits the green channel and the last 2 digits the blue channel.

Fascinating stuff.

Anyway, as a result of my interest in digital colour, I have decided to take the plunge and see how Flash can be used to manipulate colour. From my initial reading an understanding of the above will be vital to colour manipulation with Actionscript.