Secrets of an iPhone Developer Brian Robbins Founder, Riptide Games Slides at FITC Mobile – September 14, 2009

Today Programming – AudioSession – Accelerometer Input – Accelerometer Calibration – Prevent screen darkening – OS 3.0/2.0 compatibility – Anti-Hacking – NSZombieEnabled – Xcode 3.2 Errors / Warnings – Xcode 3.2 Static Analyzer – Demo App Development – Provisioning Profile tips – iTunes Connect – App Submission Tips – Analytics tracking – Score / Networking Tools – iPhone Configuration Utility (iPCU) – Other Useful Tools Brian Robbins - slides available: 14, 2009

Today’s Goal Most useful session you attend Sept 14, 2009Brian Robbins - slides available:

Programming

AudioSession Can use AudioSession APIs – C-based Or AVAudioSession (SDK 3.0) – Obj-C wrapper into same C calls Categories: – Ambient – Games, allows background iPod Music Playback and follows ringer switch – SoloAmbient – Same as ambient, but stops iPod Music Playback so use this if you have your own background music – Playback – Use for audio playback apps – Record & PlayAndRecord – For recording and playback Brian Robbins - slides available: 14, 2009

Accelerometer Input Use an adaptive Low-Pass filter, for better response Full Implementation in the AccelerometerGraph sample application #define FILTERFACTOR0.1 #define ATTENUATION3.0 #define MINSTEP0.02 // Start with the value from a basic low-pass filter basevalue = (newAcceleration * FILTERFACTOR) + (previousValue * (1.0 - FILTERFACTOR)); // Smooth more for small movement to filter out noised = Clamp(ABS(Normalize(basevalue)-Normalize(newAcceleration))/MINSTEP - 1., 0., 1.); // Calculate a proportional factor alpha = (1.-d) * FILTERFACTOR / ATTENUATION + d * FILTERFACTOR; // Use the new factor to offset smoothed values value = newAcceleration * alpha + basevalue * (1. - alpha); Brian Robbins - slides available: 14, 2009

Accelerometer Calibration Map to the user’s starting orientation when doing heavy accelerometer control Do this when action starts, and ideally tell the user Sorry (James) no example Sept 14, 2009Brian Robbins - slides available:

Prevent Screen Darkening Turn on during gameplay Turn off in menus [UIApplication sharedApplication].idleTimerDisabled = YES; Brian Robbins - slides available: 14, 2009

OS 3.0 / 2.0 compatibility Use OS 3.0 features like MPMusicPicker, without requiring OS 3.0 – Why? OS upgrades on iPod Touch is very low 4 technical steps Business rules for behavior Brian Robbins - slides available: 14, 2009

OS 3.0 / 2.0 Compatibility 1.Target > Info > General – Set Framework Linked Library from “Required” to “Weak” 2.Target > Info > Build – Set Base SDK to latest SDK (ie 3.0) 3.Target > Info > Build – Set iPhone OS Deployment Target to oldest SDK (ie 2.1) 4.Check for availability of class before using it – if ([MPMusicPickerController]) Brian Robbins - slides available: 14, 2009

Anti-Hacking Very simple detection, can go a lot more complex NSBundle *bundle = [NSBundle mainBundle]; NSDictionary *info = [bundle infoDictionary]; if ([info != nil) { /* do something */ } Can also look to see if app is encrypted, check size of info.plist, call home, etc. Brian Robbins - slides available: 14, 2009

NSZombieEnabled Executables > Info > Arguments – NSZombieEnabled value YES Good for EXC_BAD_ACCESS BAD for memory!!! Sept 14, 2009Brian Robbins - slides available:

Xcode 3.2 Errors & Warnings Use the tabs to see from last build or all builds Can also group by type instead of by class Brian Robbins - slides available: 14, 2009

Xcode 3.2 Static Analyzer Uses Open Source Clang analyzer Good for memory references and Obj-C coding compliance Freaking awesome! Brian Robbins - slides available: 14, 2009

Live Demo Sept 14, 2009Brian Robbins - slides available:

App Development

Provisioning Profile Tips Make and use a single “wildcard” App ID – Nothing but a single * – Use that for all development and provisioning profiles – Unless you’re doing in-app purchase or Push Notification When adding devices or users make a new Provisioning Profile – ie Riptide_Dev_01, Riptide_Dev_02 Brian Robbins - slides available: 14, 2009

iTunes Connect Release Date – When submit, set it to whatever, probably 1-2 weeks in the future – The moment you get approval set the release date to today – For Updates, leave release date as is when submit Setting to future will remove you from store! – Moment approved, set release date to today Brian Robbins - slides available: 14, 2009

iTunes Connect App Submission Taking ~2 weeks for approval – Every time, even if rejected for app description problem! Plan for keywords, but don’t use competitor names Don’t put pricing in your app description Don’t put keywords in your app title Brian Robbins - slides available: 14, 2009

Analytics Tracking Simple, cheap (free) and very easy to implement PinchMedia is good Other major one is Flurry Analytics Not something you need to pay for! Brian Robbins - slides available: 14, 2009

Score / Networking Good idea, especially for games Use an existing network to borrow traffic/users OpenFeint, ScoreLoop are biggest open ones Plus+ from ngMoCo is picking up steam, but you have to talk to ngMoCo to use it. Brian Robbins - slides available: 14, 2009

iPhone Configuration Utility Search for iPhone Configuration Utility on Apple Site (2.1 latest version) Basically the Xcode Organizer without Xcode Much easier for AdHoc users to install and manage apps Brian Robbins - slides available: 14, 2009

Other Useful Tools MajicRank – AppViz – MobClix for rank tracking – AppShopper for price history – Sept 14, 2009Brian Robbins - slides available:

Recap Programming – AudioSession – Accelerometer Input – Accelerometer Calibration – Prevent screen darkening – OS 3.0/2.0 compatibility – Anti-Hacking – NSZombieEnabled – Xcode 3.2 Errors / Warnings – Xcode 3.2 Static Analyzer – Demo App Development – Provisioning Profile tips – iTunes Connect – App Submission Tips – Analytics tracking – Score / Networking Tools – iPhone Configuration Utility (iPCU) – Other Useful Tools Brian Robbins - slides available: 14, 2009

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