If you are looking for a bit of escapist Science Fiction/Fantasy stuff then take a look at Chris Wooding. I’ve just read the first of his Ketty Jay series and it is a rollicking good fun. If you enjoy Harry Harrison, Blake's Seven, Firefly kind of stuff then you’ll like this. A well written take on the “ship of misfits freebooting around falling into danger and adventure” kind of thing with plenty of action and a quite a few laughs.
Here’s a tip. If you are buying a digital camera which is not completely new, point it at a white piece of paper and take a photo. Then look at the result. The photograph will show you if there is any dirt on the sensor or the lens.
I didn’t do this today, which is why I had to take the camera back to the shop……..
We are doing objects and references in the First Year tutorial today. Great fun. Well, at least I thought so. I asked the class whether big objects in memory have larger references than small ones. They don’t – the size of the tag is always the same – no matter what it is connected to. I went on to explain that a reference tag contains a bunch of information about the thing it is referring to, including the type that it has, for example string, BankAccount, AlienSprite or whatever class you have created.
Then someone asked a great question: “What happens if the type has a very long name? Does the reference tag get bigger?”. Aha! What a great question. The answer is no. This is because the type of a reference is managed in terms of a reference from the tag to the type object that describes that reference. In other words, a reference to a BankAccount will also contain a reference to an object that describes the BankAccount class.
I was very pleased with this question, because it let me start to explain how, by using objects, you can build up structures of data that are genuinely useful. I’ve been explaining structures and objects all week and several times I’ve had the sensible question “What’s the point of objects and references? They just seem to make life harder for us.” This little allows me to show how easy it is to use references to allow the system running the program to track and mange the type of the objects it is using.
I reckon that a good tutorial is when the students learn something. A great tutorial is when the tutor learns something as well. I’ve now got a lovely new example to use next year…
Pop quiz. What would the following C# code do?
float x = 1; float y = 0; float result = x / y; Console.WriteLine(result);
Here’s the thing, the code prints the word “Infinity”. Dividing any floating point variable by zero gives a special result which is encoded into the floating point variable range as “Infinity”. Now what about this?
float y = 0; float result = y / y; Console.WriteLine(result);
This time we get the message “NaN”, which means “Not a Number”. Dividing zero by zero does not give a number as a result. There just isn’t a value for this quantity. The value is not as big as as infinity or as small as zero its just, well, not a number. You get the same non-result if you divide infinity by infinity.
The C# runtimes are based on .NET which uses an IEEE (Institute of Electrical Electronics Engineers) standard that contains representations for negative infinity, positive infinity and “not a number”. Calculations in a C# program will produce these results when given dodgy values to work on. This is very important. You might think if you do silly things with numbers in your program you are going to get an exception thrown. Like this would.
int i = 1; int j = 0; int Result = i / j; Console.WriteLine(Result);
Run this code and it throws a “Divide by Zero” exception when it tries to, er, divide by zero. But this does not happen with floating point calculations. This is probably because the range of values for the int type does not include one to represent “infinity”.
The bottom line here is that if you do sums involving floating point values you can’t expect exceptions to be thrown if the calculations go wrong. The good news is that you can use methods provided by the float type to test results of calculations:
if (float.IsNaN(fresult)) Console.WriteLine("Welcome to the Twilight Zone");
This prints the enigmatic message if the value in fresult is not a number.
Lovers of fine literature (and those who read my books) will be thrilled to know that my XNA 4.0 book is half price today on the O’Reilly site. This is the latest version, that also covers Windows Phone game development and features words of wisdom from “The Great Programmer”.
Find out more here.
I actually own this single on 12” vinyl. I bet it is worth a fortune now….
One of the nice things about having a Zune Pass is that I can track down old bands that I used to listen to in the old days. Like Living in a Box. I’m sure you’ve heard the title track of album and band. Good stuff. The rest of the album is 80’s synth pop, but none the worse for that.
I’m off on my travels again next month. I’m doing sessions about Windows Phone and Kinect at TechDays in Belgium and the Netherlands and then hopping over to SIGCSE in the USA to give some sessions there too.
The plan is to develop and maybe even publish a complete Windows Phone application during one session and then play some rather silly games during the Kinect one. Should be fun.
The students came back to lectures today. A chance to use all those great jokes that I’ve been practicing over the break.
Or something.
Drawing with your fingers on an iPad is fine, but not natural. The Crayola colouring pen gives you something to hold on to as you draw, which is nice. I first thought it was just a pen that works on a touch screen, but there is more to it than that. The pen does something with the connection to the screen (I think it turns it on and off quickly) that enables the software in the iPad to detect when the pen is touching it, and ignore fingers. This means that if you accidently touch the screen with your hand while drawing the program ignores this. If you (or a very small friend) want to get to grips with colouring and free hand drawing the program is worth a look. The pen works fairly reliably, although I had to press quite hard to make it work sometimes.
The pen comes with a colouring and drawing application with pictures you can colour in which are quite fun. It has a really nice option you can set. I’ve always wanted something that helps me stay inside the lines..
Lego Star Wars Battle of Hoth is a neat little game which they say is for up to four players but works best with just two, light against dark. You take it in turns to move and attack your little Lego snow speeders and AT-ATs in an attempt to wipe out your opponents or storm their defences. It was getting quite strategic until number one son had a run of phenomenal luck (I suspect the force) and I lost.
Probably not worth the asking price really unless you are a Star Wars fanatic. You could spend around the same amount of money on the Creationary game which has a lot more to it. Having said that, if you have someone little in your family who is a Star Wars nut and you want to get them used to strategy games, perhaps on the way to chess, then it is a good starting point. And being Lego they encourage you to change the rules and board shape to make it more interesting.
Did my Graduands Marshal thing this morning. As usual I took a picture of the audience and it mostly came out OK, sorry if you are in the blurry part of the audience… There are some more of the other ceremonies on Flickr. Click on the right to find my photostream and take a look. I should have set a faster shutter speed really. I tend to fret about noise (which you get when you make the camera more sensitive to light) whereas I should remember that you can always get rid of noise, but you can’t do anything if the picture is blurred….
Both ceremonies were really good ones, I hope you had a good time if you were there. For me one of the the best bits was finding the chap next to me had a Nokia Lumia 800, and was liking it.
I have a few hero/heroines in my life. One of them is Verity Stob. She has been writing about computers for about as long as I’ve been playing with them. I’ve mentioned her before, and now I’ve discovered to my great joy that she is still writing for The Register. Her piece on exceptions is one of the best I’ve read on the subject. If you have any interest in computers you should read her stuff and treasure it.
Had a chat with Jon Moss today. He’s one of the movers and shakers behind Hull Digital. I’ve been to a few of their events, which are usually (and very sensibly) held at one of my favourite eating places in Hull, Fudge in Princes Ave. If you want to sync up with what’s happening with developers in Hull they are a great way to do this.
Jon was telling me about future events, including a regular programme of Digital Breakfast MeetUps, where like minded folk get together for “the most important meal of the day” every month. The next one is on Friday this week, which is a shame for me because I’m not able to go. I’m helping out with the Graduation Ceremony on the Hull campus. However, if you want to go along and meet up with digital folk - if you see what I mean- and enjoy some fantastic food (my advice, go for the omelette) then you should pop along.
Jon was also telling me about TEDx at Hull, which brings together a bunch of interesting folk for a day of discussion and debate about the future of, well, everything..
What with that and Platform Expo coming along it looks like it is going to be an interesting few months around here.
If you’ve wondered where I’ve been for a week. Or why I’ve suddenly just had time to suddenly produce seven blog updates (ahem) it’s because I’ve been writing. Book stuff. Twelve chapters on having fun with your Kinect using the Kinect SDK and your PC. I’ve been squashing pretend bugs with virtual mallets, taking pictures of ghosts and creating all kinds of funky pictures. I even made the computer talk to itself.
The book will be out in late spring. And now I’ve written all the words.
Keep your diaries free for the weekend of 17th 18th March folks. You know why….
Last week I sold a MacBook and bought a camera. And got a free copy of Adobe Lightroom. And it is wonderful. Up until now I’ve been muddling through managing my many photographs, keeping them in folders and using Windows explorer to find and look after them. This mostly works, but it is a bit of a pain.
Lightroom provides a really good way to find and then fix your pictures. It works really well with raw files and the noise reduction abilities are awesome. It also has some rather cool picture styles built in. And it will upload directly to Facebook, Flickr and SmugMug, among other places. It also takes care of the importing and has very good tagging and metadata management.
If you are serious about your photography, then I think you should take a good look at it. The trial download runs for 30 days or so, by which time you should be hooked.
These are really neat usb-hubs from Red5. I got the red one. Now I feel a need to own one of each….
I think my Lumia 800 is turning me into a fashion victim. I got the Nokia blue case today. Looks pretty good too, as you can see. Special prize for naming the person in the back of the picture. I love the way that the case doesn’t look like a case, it just looks like I have a cool, blue phone. Which I have.
If you want to be cool too, Amazon have them in stock in a range of colours, look for the magic stock number Nokia CC-1031.
I’m making a sister application for the PlayMusic application. The PlayMusic program doesn’t do much, it just starts playing a random playlist when you run it. Not a lot of functionality, but it does mean you can start music playing by issuing a spoken command. I’ve had nearly a thousand downloads up to now, so a few people must find it useful.
The PlayMeMore application will do something similar. When you run it the program will find the album that the currently playing song is part of, and then play that album. I want this because frequently on random play I hear a track that I’ve not heard for a while, and fancy hearing the album it came from. I thought it would be nice to be able to say “Start PlayMeMore” and have it do this for you.
I’ve written the program in XNA because I like XNA and I might add a visualisation or two later. The program displays the name of the album when it starts it. By a wonderful quick of fate the first album it tried to play was Bête Noire by Bryan Ferry (darned good album too). And the program crashed. Any idea why? Took me a few minutes to work it out. It has to do with SpriteFonts.
When you use a font in XNA it builds a raster with the character designs on it. The font requirements are given in an little XML file that specifies the TrueType font to be used for the character designs. This font also specifies which character codes are rendered. And the default character codes don’t include the character ê. The fix is simple enough, open the file and make the end value a bit bigger.
<CharacterRegions> <CharacterRegion> <Start> </Start> <End>ÿ</End> </CharacterRegion> </CharacterRegions>
Normally the end value is 126, but this does not include accented characters like ê. Making the value 255 seems to fix the problem. And I’ve put a try-catch around my DrawString calls in case I hit any music info that has any weird characters in it. Like the artist formally known as Prince….
I had one of those happy/sad moments today. Someone showed me a stunning little game they’d written for Windows Phone. Snappy graphics and fun to play. “Is it in the Marketplace?” I asked. “No” was the reply.
Some people hold back until their game is “finished”. This is a bad idea. There is no such thing as finished as far as a developer is concerned. You can always add bits, make it better, tidy up the class design, make all the curly brackets line up. But if you keep on like that you never get anything out there. I’m not saying that you should push out broken programs, I’m saying that things like on-line high score tables, multi-player, extra levels, a level editor etc can always be added later.
The faster you can get something out there the faster you can start getting feedback and recognition. So go for it.
Rob Miles is technology author and educator who spent many years as a lecturer in Computer Science at the University of Hull. He is also a Microsoft Developer Technologies MVP. He is into technology, teaching and photography. He is the author of the World Famous C# Yellow Book and almost as handsome as he thinks he is.
