Problem
For some time now I’ve had a problem every time my application profiles expire - I can’t build the application for the device, with the usual error:
Code Sign Error: Provisioning Profile ‘GUID’ cannot be found.
OpenAL - the Good and the Bad
Well, I went with OpenAL in the end, as AVAudioPlayer objects seemed to stall Wire Whizz randomly when they fired up, [sound prepareToPlay] seemingly having no effect.
In App Purchasing (IAP)
I am not sure, but I think I am delighted that free apps can include IAP now. I say I am not sure, because there are positives and negatives. The positives are that I don’t have to write a demo app, and that anyone can download the app and have a taste and upgrade quickly for whatever nominal fee, but on the flip side, I am competing in the free app pool, which is a pretty tough pool to be in as I understand it - we shall see!
I was quite delighted to hear Steve Jobs state that 100 million devices have been sold, so if half of those are in use and can run my game, then I’ll settle for 1% giving it a go and a good conversion ratio. The reality is, that I’ve invested so much time and energy, that I am on something of a mission to get it completed, regardless of whether it is a scorching success or a damp squib.
The State of Play
Wire Whizz looks somewhat different from the early work on the game:
The menus are entirely Cocoa Touch now, with a view containing the OpenGL rendering context as the main view and the Cocoa Touch menus all hang off a nav controller that’s a child of the root controller’s view (if you follow my drift). When in game, the child controller is hidden from view and all it’s sub views are removed.
iPhone Programming Languages
With the iPhone (and Mac) programming, you have the choice of C, C++, Objective-C and Objective-C++.
I say, Given the Choice, but the reality is that you will be forced to use some Objective-C, love or loathe. Personally, I am growing (slowly) to like the language, but I think it will depend on your background. To a C, C++ and C# programmer, Objective-C does seem a tad crazy - because from my point of view, I don’t want a method (read message) to be silently swallowed when I try and apply it to a nil object. I assume a Mac bod, would explain the reasoning to me behind this bit of design, but I imagine that, Objective-C being quite different to C and C++, it might still not make any sense. And the lack of any enforced constructor logic is a bit annoying I find.
Cross-Platform Development
For a time, I pursued the holy grail of game development, cross-platform development, and Wire Whizz was functional on the PC and on the iPhone with no change (that I can recall) to game code. I would add before going on, that maintaining any cross-platform functionality is a potentially painful process and I have had to largely abandon this for Wire Whizz (I’ll cover the reasons why later though).
There are a number of ways to achieve this:
Mathematical Short-Comings
Okay, so I should confess that my grasp of 3D maths isn’t quite as strong as it once was. I was quite a whizz (if you’ll excise the pun) when I was younger, but I pursued an alternative career back in my youth (Acting, bizarrely as it happens!) and so my maths and 3D knowledge slipped into corners of my memory I cannot now reach. Additionally I never studied higher maths, so many concepts in 3D are a little beyond me, but I am hoping to address this soon so that I can do much more mathematically intense stuff, probably with the GPU on the 3G S and iPhone 4.
That said, I will explain a little of the maths behind Wire Whizz, but no math detail (you can find ray -> plane intersection tests from more reliable sources!).
The Idea
Because the iPhone contains an accelerometer (and now a gyroscope!), and I believe I had read that games and apps were doing well that made use of the phone’s hardware, I was thinking of ideas that would work well and might appeal.
Before having worked with the iPhone’s accelerometer, I wondered if it would be possible to move the phone in space and have the phone’s view appear to move in 3D space. Now, this might be more achievable with the gyroscope (I have yet to try) but this isn’t really possible with the accelerometer.
The Puuuuurfect 3D Editor
At this time, Cheetah 3D became my friend. Cheetah 3D is an excellent little 3D package for the Mac that punches massively above it’s weight. There are a few areas in the scripting language that need work, but the lone developer (at least I believe he is a lone developer!), is working very hard to update all areas of the application.
Here’s a couple of very early screen grabs (I’ll hunt around and see if I have more!)
Early Development
For early development I wanted to see graphics on screen I bodged up the context and was drawing the ubiquitous spinning cube, to me this is the 3D analogue for “Hello World”.