Wow… three months since my last post about my Android Clock Widget Project. While I’ve failed to bring stability to the clock selector during that time, I have figured out that the problem is not actually due to a deadlock. Instead, it appears that my project is tickling a bug in the Dalvik VM’s garbage collector.
Inertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion.
For me, this also describes my tendencies toward side projects like my Pingus project. When I last worked on Pingus a couple of months ago, I updated the underlying AndEngine libraries and found a ton of breaking changes. I put Pingus on the shelf until I had more time to look at the breakage and how to solve it. The AndEngine changes are pretty significant and I’m going to need to rethink portions of Pingus in order to get things running correctly again.
In my last Android Pingus post I mentioned that I was interested in getting Pingus running full screen on my Motorola Xoom. It was clear from Android Market applications that it was possible to run applications across a wide range of Android versions with full screen support for extra large screens, but it was not entirely obvious to me how to actually accomplish that.
In reading the Android supports-screen documentation, it is clear that it is necessary to set the xlargeScreens attribute to true. However, the xlargeScreens attribute is not supported below API level 9. Trying to shoehorn that attribute into my project that was attempting to support back to API level 5, resulted in the following error.
When we last met I had begun working on the ability for the Pingus character to destroy the terrain. At that point, I had managed to get the images updated for the sprites that made up the image, but since those images were shared all of the sprites that shared the image were being affected.
They say that slow and steady wins the race. In the case of this project, the only thing I have going for me is the slow part. Nicolas Gramlich, author of the AndEngine library on which this is based, referred to this part of the project as “destroyable terrain”. I really like that phrase, so I think I will continue to use it here.
In Early Digger Support I covered the initial digger support. At that point I had managed to update the in-memory collision map, but updating the actual textures driving AndEngine was proving to be a bit more difficult. I’m still not there, but I think I’m moving in a positive direction. The following video shows the current state of things. The textures are being updated with a full red fill to make it clear that they have been hit.
So, why is everything turning red? Well, that turns out to be the next item that will need to be dealt with… shared textures. To save memory, many of the sprites share common textures and texture regions. Thus, in the current implementation, changing the underlying texture information affects all sprites that share that information. This is something I knew would have to be dealt with eventually, so it appears that eventually is now.
Work and life have conspired to keep me from making a lot of progress on my Android on Pingus project. I had hoped to get further before posting here again, but instead decided to go ahead and post a minor update. In my last post I covered my early collision detection implementation.
The next step was to start implementing some behaviors for the Pingus. The digger behavior seemed a good place to start. In order to implement the digger, it is necessary to actually alter the collision map generated by the tool. In the end, this part was pretty easy to handle. The results are captured in the video capture.
While it was relatively easy to carve out a path through the in-memory collision map, updating the actual graphics is proving to be much more difficult. AndEngine implements 2D graphics using 3D/OpenGL. This implies that in order to update the graphics, the underlying texture images need to be updated. I’m in the process of building AndEngine support for altering the underlying texture images. At the moment, this appears to be slow and may need to be abandoned. Just like while I worked on the collision map, the lack of guarantee for clipping and Z buffer on Android devices further complicate the situation.
While there are times that I wonder if using AndEngine for this project is makes it more difficult, I’m not quite ready to give it up. More to come…
It is a good thing that I’m not trying to make my living with this little project, given the slow forward progress. However, there is continued progress on the collision detection compared to my last update Pingus On Android – Early Collision Detection.
As I’ve continued hiring at mFoundry (if you live in the Bay Area, check us out), I’ve been very busy non-coding. As usual, that implies the need for a non-work programming project. As I mentioned in my last post, I’ve started digging into Android programming. I decided it would be interesting to try to do a game of some sort. Given that I have zero skill with graphics, I had to cheat a bit. I’m attempting to build an Android version of the Pingus game using the graphics and levels from their source code and the very cool Android game engine AndEngine.
In my previous entries, I’ve discussed a few things that caught me off guard while learning iPhone development. In the last couple of weeks, I’ve picked up an Android device to dig into that platform a bit and probably will spend less time playing with iPhone development. Before I move too far away from iPhone, I wanted to wrap up the remaining differences I found interesting between the iPhone and Java platforms.
I’m continuing to make slow forward progress with my DAAP-based music player for the iPhone. My most recent changes have taken this in the direction of being much more like the standard music player functionality on the iPhone. In particular, I’ve switched over to using a tab view controller for the major perspectives of viewing the music database.