Game Development

Since Windows Phone 7 doesn’t have multitask, at least for now, Microsoft implemented a Tombstone notion in WP7 apps. It’s basically a suspended state where you receive a notification that it’s going to suspend but there is no guarantee that it will resume, it might be terminated so you must treat this as an exit and a might start again state. So depending on you app you might want to save the current state just in case the app really closes. ...

Finally and after several weeks locked inside Different Pixel “dungeon” making my engine compatible with iOS, namely with iPhone/iPod touch I submitted today my first App to the Apple Store. The binary didn’t reported any issues so as of 15 September 2010 it’s “Waiting For Review” I have mixed feelings about either it’s going to be approved or rejected. On one hand we tested as much as we could, handed to some testers using iPhone 3, iPhone 4 and iPod touches. The only issues reported were usability or with game logic itself. No one reported any crashes, so I’m a little reassured on that part. On the other hand I’ve heard and read some major horror stories surrounding the submission process. Crashes that you can’t reproduce, people resubmitting same build again after failure being accepted, meaning that something is wrong there. Right now it’s a shot in the dark… ...

When loading an application on an iPhone or iPad, a launch image can be shown to provide feedback to the user that the application is loading. On the iPhone a Default.png was used, with the iPad we need to anticipate the device being started in any orientation. Filename Dimensions Default-Portrait.png * 768w x 1024h Default-PortraitUpsideDown.png 768w x 1024h Default-Landscape.png ** 1024w x 768h Default-LandscapeLeft.png 1024w x 768h Default-LandscapeRight.png 1024w x 768h Default.png Not recommended * If you have not specified a Default-PortraitUpsideDown.png file, this file will take precedence. ...

This had me scratching my head for awhile. At first I thought that glGetRenderbufferParameterivOES would properly detect Retina screen at 960×640 but it keeps returning 480×320. A little explanation on Retina screen first. Older devices have 320×480 screen resolution. With new iPhone 4 and iPod Touch 4G the screen has 640×960 but on the same physical area. This means that each pixel is 4 times as small. To properly simulate older games resolutions iOS will replace each of your 320×480 game pixel by 4, this way your game will look identical. ...

I decided to compile all iOS devices specs here so we can get a better glimpse on their hardware and what we can expect from them. This covers iPhones, iPod Touches and iPad. iPhone/iPhone 3G – 412 MHz / 128MB / 320×480 iPhone 3GS – 600 MHz / 256MB / 320×480 iPhone 4 -~800MHz / 512MB / 640×960 iPod Touch 1G – 412 MHz / 128MB / 320×480 iPod Touch 2G – 532 MHz / 128MB / 320×480 iPod Touch 3G – 600 MHz / 256MB / 320×480 iPod Touch 4G – 800 MHz / 256MB / 640×960 ...

Even tough it’s not mandatory to support all screen orientations it’s always nice to support at least 2 of them. Let’s imagine your game is landscaped, by some reason the user may want to use either with the home button on the left or on the right. Most games support this, if you flip the device, the game will too. I’ve been using OpenGL to support the device orientation, most people on forums want an automatic solution, but belive me, it’s best that you have control on this. ...

It’s been awhile since I last updated this, I’ve have my hands full with Vizati iPhone. Ever since I got an IPod Touch 2G it was easier for Rita to get a sense of the screen size (although we knew to be 320×480) it’s different when you are testing on the real thing, text looks smaller, other stuff looks way too big. Here’s a picture she took after a few adjustments. ...

I decided to run a little poll to track what platforms do you target as a game developer. I think this should be interesting. Please share this post link or the direct link to the poll (http://twtpoll.com/dar51l) so that we can have more accurate results. The poll closes in about 6 days and you can select various options of course.

I ran into this issue a couple hours ago working on the iPhone sdk: See the darker borders around the image? It’s a png image and that’s was supposed to be a gradient of alpha. So why am I getting this strange stuff around it? Well that’s because that alpha isn’t 0 or 1 or 0 or 255. The first thing I found out is that XCode grabs the png images and multiplies the RGB component with the alpha. So you can understand now why only 0 or 1 works right? Everything in between get’s changed. This is why Apple recommends using PNG over JPGS, although they consume more space they are altered for speed. ...

It’s been around two weeks since my last post. Basically because I’ve been busy porting my engine Basalt to iPhone/iPad. If you follow me on twitter you might have known this already since I ranted pretty much at start, moving platform and language is always painful if you are used to other conventions/shortcuts etc. So it all started with my wish to port Vizati to the iPhone, since the game is already running on PC, Xbox360 and Windows Phone 7 one can only wish for an easy and quick port since pretty much all base code is done. ...