GDC 2010: Bootstrapping Games on Android

Chris Pruett – Developer Advocate Google Japan Overview of Android * Linux based OS * First released Oct 2008 * Today 26 devices in the world * 60,000 sold daily * Android Market re: apps market for compatible devices Tech Specs * Open GL * Java shell also C++ or Java (custom VM which is called Dalvik) * Resolution is HVGA 380x320 * Media has various formats such as AAC, AMR, MP3 etc. Also H.263 format. Device Classes * How to make work on all devices? Devices break out to two or three classes – first generation, second generation and other (gaming device) As game developers, speaker recommends to concentrate on first and second generation devices. *  Most First Gen devices are pretty much the same hardware. This first gen is about 78% of the market currently. Android 1.5 and 1.6s Second gen devices cover around 21% of market currently, and is Android 2.1. The first device was shipped in December 2009. Screen Size QVGA – WVGA API provides tools such as runtime scaling, resource filtering. In worst-case scenario they suggest you can letterbox for compatibility. You can also choose which markets you don’t want to include, though they don’t specify compatibility filtering options. Real Device Differences * Some have trackball, D-Pad, keyboard, milti touch – but there is a standardized API for input events. Everything is a motion event or key event. * All devices have a touch screen, accelerometer and orientation sensor. * OpenGL Driver – different platforms support different OpenGL so need to check that out. Real Device Differences - OS Android OS version - 1.5 has all basic functionality - 1.6 screen size support - 2.0 has OpenGL ES 2.0 support. Simple 2D games might not need Open GL. Recommend to make sure you build for 1.5+ (1.5 and 1.6 have most devices in market). Minimum spec 1.5 and target spec 1.6 Market Filtering *  Look up AndroidManifest.xml. You can filter OS / version easily in this apps market. * You can also filter by country. Localization * Devices – you can program a game to auto detect localized version dependant on what language the user has set device to. You can do this for other things like, does this device have a keyboard ? Size Limit * Currently the size limit for Android is 25 megs or less. If it’s more you need to break up into different content packs. Or on first start up download materials off the web and on to SD card. They’re working on the size limit but for now this is it. Sound tools * MediaPlayer – plays everything as it streams * SoundPool – pool of short samples * JetPlayer – tool for syncing an event track to music eg. Rhythm games. * Best results with Ogg Vorbis – best compression to quality ratio. * Java-only interface Links developer.android.com code.google.com/p/apps-for-android replicaisland.net (test game build by speaker)

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