Reach 4 million Unity developers with your Android library

Recording: http://www.butterflytv.net/player.html?videoId=from_pi21371431281378228

Reach 4 million Unity developers with your Android library With the 45% market share, Unity is the most popular game engine in the world. Featuring reach API exposed in C# and JavaScript, a tremendous amount of assets and libraries available and Asset Store - an open platform to sell or share them. While talk will discuss why it is time to make your Android library or SDK available to Unity developers. How to expose it to C# using Unity API, JNI and a bit of magic. What problems you'll face with while porting. And last but not least, how to publish your work to Unity Asset Store.

Transcript

1. Reach 4 million Unity developers with your Android library Vitaliy Zasadnyy Senior Unity Dev @ GetSocial Manager @ GDG Lviv Ankara Android Dev Days May 11-12 , 2015
2. Why Unity?
3. #AndroidDevDays
4. #AndroidDevDays Daily Users 0 225 450 675 900 Source: Unreleased McKinsey report; Facebook http://newsroom.fb.com/company-info/ M M M M
5. #AndroidDevDays 0 225 450 675 900 Source: Unreleased McKinsey report; Facebook http://newsroom.fb.com/company-info/ Daily Users M M M M
6. #AndroidDevDays Unity Developers Unity 4M Source: Unity Technologies
7. #AndroidDevDays Unity Developers Unity 4M 18M Worldwide Source: Global Developer Population and Demographic Study 2014
8. #AndroidDevDays Unity Developers Source: Unity Technologies
9. #AndroidDevDays Unity is Android in game engine world
10. #AndroidDevDays
11. #AndroidDevDays GetSocial Unity SDK Architecture Android SDK iOS SDK iOS Bridge Android Bridge C# API Unity SDK Java Objective C C#
12. #AndroidDevDays During Android Build Android SDK iOS SDK iOS Bridge Android Bridge C# API Unity SDK
13. #AndroidDevDays Unity Game Structure Android Mono VM Unity Core Unity C# Scripts OS Apk
14. #AndroidDevDays Android Mono VM Unity Core Unity C# Scripts Java Code ? Unity Game Structure OS Apk
15. #AndroidDevDays Android / Java Unity / C# primitive types primitive types java.lang.String string java.lang.Object AndroidJavaObject java.lang.Class AndroidJavaClass java.lang.Runnable AndroidJavaRunnable java.lang.Proxy AndroidJavaProxy Provided Wrappers
16. #AndroidDevDays Android / Java Unity / C# primitive types primitive types java.lang.String string java.lang.Object AndroidJavaObject java.lang.Class AndroidJavaClass java.lang.Runnable AndroidJavaRunnable java.lang.Proxy AndroidJavaProxy Provided Wrappers
17. Two-way communication C# ↔ Java
18. #AndroidDevDays C# → Java • AndroidJavaObject • Pure JNI (Java Native Interface) Java → C# • Unity Messaging • AndroidJavaProxy Two Way Communication
19. #AndroidDevDays Sample Java class public class Speaker { private String name; public Speaker(String name) { … } public static Speaker copy(Speaker speaker) { … } public String askQuestion(String question) { … } } Java
20. #AndroidDevDays C# var jSpeaker = new AndroidJavaObject( “com.zasadnyy.Speaker”, “Vitaliy”); var jClone = jSpeaker.CallStatic<AndroidJavaObject>( “copy”, jSpeaker); var answer = jSpeaker.Call<string>(“askQuestion”, “HDYD?”); AndroidJavaObject • Wrapper around java.lang.Object
21. #AndroidDevDays C# // var jSpeaker = new AndroidJavaObject( // “com.zasadnyy.Speaker”, “Vitaliy”); IntPtr classID = jni.FindClass("com.zasadnyy.Speaker"); IntPtr constructorID = jni.GetMethodID(classID, "<init>", "(Ljava/lang/String;)V"); IntPtr javaString = jni.NewStringUTF("Vitaliy"); IntPtr objectID = jni.NewObject(classID, constructorID, javaString); "(Ljava/lang/String;)V" Pure JNI
22. #AndroidDevDays B byte S short C char V void F float Z boolean I int Lclass; class J long [type> array of type JNI Cheatsheet
23. #AndroidDevDays B byte S short C char V void F float Z boolean I int Lclass; class J long [type> array of type long myMethod(int n, String s, int[] arr) (ILjava/lang/String;[I>)J JNI Cheatsheet / Example
24. #AndroidDevDays JNI is slooooow! Respect 16ms rule
25. #AndroidDevDays Conclusion Use AndroidJavaObject: • Less boilerplate • Less error prone • Faster (caching) But: • JNI is more flexible • AndroidJavaObject has bugs
26. #AndroidDevDays AndroidJavaObject Bugs * var result = javaObject.Call<TResult>(TParam param); C# • we can’t pass string[] as TParam (NoSuchMethodException) • we can’t return null objects from Java (Exception: JNI: Init'd AndroidJavaObject with null ptr!) * Tested on Unity 5.0.1f1
27. #AndroidDevDays C# • AndroidJavaObject • Pure JNI (Java Native Interface) Java → C# • Unity Messaging • AndroidJavaProxy Two Way Communication
28. #AndroidDevDays Unity Messaging
29. #AndroidDevDays UnityPlayer.UnitySendMessage( "GameController", "OnPushMessage", "New gift"); Java Unity Messaging
30. #AndroidDevDays Pros: • Quick to implement Cons: • Always 1 frame late • Only string parameters • Requires GameObject • Requires unity-classes.jar in classpath Unity Messaging
31. #AndroidDevDays AndroidJavaProxy Java public interface IPushMessageListener { void onPushMessage(String message); } • Wrapper around java.lang.Proxy
32. Java public interface IPushMessageListener { void onPushMessage(String message); } C# public class PushMessageListener : AndroidJavaProxy { public PushMessageListener() : base("com.zasadnyy.IPushMessageListener") { … } void onPushMessage(string message) { … } } AndroidJavaProxy
33. #AndroidDevDays Pros: • Immediate result • No type restriction on parameters • No extra dependencies on Java side Cons: • Bug with null string parameter • Local reference table is limited to 512 entries AndroidJavaProxy
34. Devil is in the details
35. #AndroidDevDays Details • Unity is single threaded • Unity main thread != Android main thread • Implement equals() in all AndroidJavaProxy’ies • Differences between GameObject and Activity lifecycle • Keep calm and signal 11
36. #AndroidDevDays Thank you! Presentation will be available at: v.zasadnyy.com/slides/ Vitaliy Zasadnyy @zasadnyy