21.02.2012

BoB bug

posted by Karsten

I was teaching Android Game App development today. The session where I go through all of the code. The session as such went quite well IMHO.

Except, I “obviously” plugged my own games, as examples of game representations within a game. A student of mine downloaded BoB, and played it hanging about while waiting for a mate finishing asking me questions. To my surprise BoB crashed on him!

Apart from being only “slightly” embarrassing this was a great opportunity for a more in depth bug report. Not only had I observed him play a normal game, but also seen him finish, so I knew that the bug was in the transition between playing and finishing a game. So, I got him to file a bug report, and my was it interesting!

I can now locate the bug in the Scoreloop API, perhaps not surprising as the BoB game is using an old’ish version of the library, but nonetheless it is reassuring to know that the bug is related to failing to sending the highscore correctly, and not timing out, therefore not allowing the surfacedeletion to happen. This makes Android timeout, and that seemingly blows up everything within the system, as my code relies on the normal OS life cycle of an app. I must find a proper solution to this problem, but at least I now know the cause of the problem.

Oh, and btw, how we can teach Computer Science in a lecture hall with no adequate internet / 3g access is beyond me…

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13.02.2012

Farseer engine “bug”

posted by Karsten

I’m working on a game project for the Microsoft Phone / xbox. I decided to try out the box2d library for this one, and found the Farseer engine, which is a well supported library with many developers using it.

Things have been working well, but over the week-end I ran into a strange behaviour. Shapes (called body(ies) in the box2d world) got stuck to static shapes. So if a ball slowly approach a static wall it would be stuck to the wall, and it wouldn’t get away again (at least not by bouncing other balls into it). The ball would only move along the static wall.

Now this isn’t really expected behaviour in an environment simulating physics in the normal world! I have searched high and low to find a solution to this, and in the end my curious mind got into the Settings class, and I found the VelocityThreshold, which was set to 0.3f. This is indeed the culprit, as it treat any velocity below this threshold as inelastic. When set to 0.0f (zero point zero) the world starts to behave normally. This might be ok in a senario with non-static bodies, but in an world with static walls, not so great…

That was then that Sunday afternoon… 😉

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12.02.2012

Rune Escape – changed format

posted by Karsten

I’ve decided to test how the download rates are with a traditional ad supported/full version model on Google market. Seemingly it works well on Amazon market where I have a steady – albeit low – sales rate.

Therefore, if you cannot find the adfreeable version on the market it’s because it has gone. You can follow the links to the new version to the right, or still get the adfreeable version from slideme.

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10.02.2012

Rune Escape Free – Windows Phone

posted by Karsten

I’ve had an interesting start to my Windows Phone explorations. Rune Escape is currently #15 for “paid apps” in the card/board games category, unfortunately not as lucrative as being #15 on the Android or iPhone markets. hi ho!

So I thought it was time to see how a free (add sponsored – with less functionalities) version would do…

Today it got published and can it be found here.

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29.01.2012

Google Market vs. Windows App Hub – a review

posted by Karsten

Yesterday evening I uploaded Rune Escape to App Hub – The Windows Phone Market backoffice – and I am now awaiting certification by MS! Following is a comparative analysis of that process and the Google Market process: (1 – Google, 2 – MS)

Coding:

  1. Coding the Menu’ing was easy. The game engine was hard. I struggled getting a smooth game play (Java isn’t exactly the first choice of language for most game developers…)
  2. Coding the game was easy (converted the game in an afternoon). The menu’ing was hard (using api 7.1, under 7.5 this should be easier by combining silverlight and xna)

IDE Environment including emulation and debugging on phone:

  1. Eclipse works fine and emulation and connection to handsets is easily set up. Emulation is slow even on fast computers.
  2. Visual Studio 2010 express works well. Perhaps a bit more “polished” (I hate to say) than Eclipse. Emulation works much faster than on Android. Setting up a handset for testing is a hassle though! It took me about 4 days from starting on the journey until I had the game on a phone for debugging. Not technical problems but redtape (see below)

Registering for markets

  1. Easy – just used my google account, and as google has a registered EU entity there are no need for any US tax forms to set up money transactions in either direction.
  2. Hard – First you have to pay £65 for a year’s membership of App Hub, then a 3rd party company has to verify you exist, and are who you say you are, and then after that they cannot activate the account, MS does that, which takes and extra 2-3 days. (All of this time you aren’t allowed to debug…) After that they still have to receive a US tax form by snail mail to their US entity of the corporation. This is strange as the EU headquarters are less than 10 miles from my home, and I literally drive past them every day going to work! So they must be set up to deal with UK/EU tax authorities directly. (But it gets stranger still – see below)

App Business model

  1. It is hard making money on Android. There are many developers fighting for the pot, and after Google removed the “Just In” section on the market, new apps don’t get exposure automatically, so you need to be big to make an easy entrance. Additionally few players buy paid for games, and ad-support and in-game purchase  seemingly are the two models that work well.
  2. We’ll see about this once the game is published. But there are definitely less games, and the NEW section automatically creates exposure to new apps. The trial versioning of MS phone games is interesting to test out, which I do in my first game. Ads can be used (which I do in the trial version), and this was reasonably simple to set up. Only MS’s ad service seemed to support XNA apps, so I use them. Setting up an account required me to create an electronic US tax form, which took about 30 mins to do, but once done, fine, I had a working account on the spot. WHY oh WHY can’t MS use this within the App Hub. The method clearly works, and is efficient! Or even better – set up a system where it is not necessary? Being multinational should come with such perks….

All-in-all an ok experience to convert Rune Escape, but I can understand if the redtape acts as a deterrent for some international developers. Now that I have done most of it, I cannot wait to compare how the market models compare to each other…

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22.01.2012

Rune Escape – Windows 7 phone

posted by Karsten

I’ve been wanting to test how other mobile phone platforms work. So over the last 3 weeks all of my hobby code efforts have been put into creating a version of Rune Escape for Windows 7 phone. The following is a screenshot of the game from the emulator.

image of the Rune Escape windows 7 phone version

I decided to create it fully in XNA, because it is the “normal” way of creating games. Also Microsoft has only recently enabled development of XNA inside Silverlight for mobile phones, and I was unsure how/if that works on xbox360 apps, and ultimately I want to create a version of it for xbox as well. Everything is prepared for the xbox, and I “just” need to create menu system and online scoring. The Ultimate reason for non-Silverlight – I have used Scoreloop’s API for online scores, awards, and online fights, which on iPhone and Android comes with a nice UI. Because it is the pre-“Silverlight/XNA marriage” the Windows version doesn’t, so I figure as I had to develop a UI myself, I could just as well do it from first principles. I do this for fun and to learn, so first principles is fine with me!

What I’ve learned is that without Silverlight, creating menus is a hassle, and most of the development efforts is put into this. But the end-result is a product where I as the developer has full control. No problems with strange UI modification by the OS (Android is notorious at that), and I actually am quite proud of my end result.

I now have to test it on a real phone, which I expect to finish doing this week, and then I’ll upload a free version (ad supported) to the Microsoft Market place. If I get many download, then I’ll also add a paid for version, and perhaps a version of Runes’n’Dragons.

We’ll see – my next big project is an iPhone version…

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28.11.2011

Santa’s Mess – review

posted by Karsten

Yay – my game Santa’s Mess have been nicely reviewed by gametrender.net. It is nice when someone else likes your game…

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13.11.2011

Runes’n’Dragons

posted by Karsten

I’ve just published my latest games. This is an All-Year version of Santa’s Mess using my rune graphics. It has more levels and awards than Santa’s Mess. Good fun!

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05.11.2011

Santa’s Mess

posted by Karsten

I’m on a roll! I’ve just created a new Mahjong styled game using a Cristmas theme, just to get people in to that seasonal spirit! I hope you guys enjoy it, you can download it here!

 

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17.10.2011

Woim Attack has arrived!

posted by Karsten

I’ve just published the newest game Woim Attack on the Android Market. It is a game where you have to kill some AI Worms – called Woims – using bombs.

The reason I’ve created this game was to show the usage of a swarming algorithm, which I’m going to teach in next term, and I though it was a fun way to showcase it, and also code it up for myself, as I had never used the Boid algorithm before.

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