1. CROSS-PLATFORM
DEVELOPMENT ON
MOBILE DEVICES
Takaaki Mizuno
DeNA

2. Takaaki Mizuno
• 15 years experience in Engineering.
• Works to DeNA Co., Ltd and Oceans Inc.

3. How to develop the app both for
iOS/Android ?
There are 2 options:
• Develop for both separately with different
languages ( Objective-C / Java )
• Use cross-platform development
environment and develop for both platform
at once

4. Cross-Platform development
environments

5. Are cross-platform dev denelopment
envivonments workable ?
• Not good at least now
• It’s ok for simple apps
Business
Apps
• Not so badGames

6. Most important thing is…
To know the characteristics of each environment
Native Layer
Cross-platform
Environment layer
Your code
Erase the difference
But limit the capability
sometimes

7. Business Apps
• Pros
• Write once, run on both devices
• No need to pass Apple’s review
• Cons
• UI of both environments are totally different
• Really slow

8. UI of both environments are different
• Android have “hardware back key” and “Menu”
• Positions of Tab Bar are different
• Android devices have so many aspect ratios and screen
sizes.
• You have to care about such differences in your code

9. Difficult to catch up with interface trends.
• Pull to refresh
• Side menu

10. UIWebView based application for iOS
Really Slow

11. Why ?
• Apple doesn’t allow to use JIT strategy

12. Chrome iOS version is SLOW

13. Facebook Application for iOS

14. Facebook will return to native

15. Game
• Pros
• Write once, run on both devices
• No need to pass Apple’s review
• Cons
• UI of both environments are totally different
• Really slow
• Use JavaScript

16. User Interface
• You don’t need to use native-like user interface

17. Speed
• Compiling code to native ( Unity )
• Preparing alternative Canvas ( appMobi )
• Use OpenGL directly ( ngCore )

18. JavaScript
• JavaScript for mobile application is totally different from
web app’s one ( such as using jQuery ).
• JavaScript is not suitable for large scale development.
• Because it is difficult to find a bug.

19. But if you want to use JavaScript still…

20. Closure Compiler
• Google’s answer for large scale JavaScript development
• It optimizes the code and finds error in code.

21. DeNA’s answer

22. ngCore
• JavaScript based Game development environment.
• Try ⇛ https://developer.mobage.com/

23. JSX
• a faster, safer, easier alternative to JavaScript
• JSX compilers compiles JSX code into JavaScript
interface Flyable {
abstract function fly() : void;
}
abstract class Animal {
function eat() : void {
log "An animal is eating!”;
}
}
class Bat extends Animal implements Flyable {
override function fly() : void {
log "A bat is flying!”;
}
}

24. JSX
we are observing 4% to 27% increase in performance

25. Try it
http://jsx.github.com/

26. Arctic.js
• Game engine for smartphone web browsers written in
JavaScript with HTML5 Canvas.
• It provides ActionScript3 friendly APIs which Flash
developers are familiar to.
var keyFrame = new arc.anim.KeyFrameAnimation(12, 5, [
new arc.anim.Timeline(this._yellowImg, {
1 : {visible:true},
3 : {visible:false}
}),
new arc.anim.Timeline(this._orangeImg, {
1 : {visible:true},
5 : {visible:false}
}),
new arc.anim.Timeline(this, {
1 :
{scaleX:0.5, scaleY:0.5, transition:arc.anim.Transition.SINE_OUT},
5 : {scaleX:3, scaleY:3}
})
]);

27. Try it
http://denadev.github.com/Arctic.js/

28. ExGame
• Converts Flash Lite 1.1 SWF into JavaScript and make it
executable on iOS/Android devices.

29. How to use ExGame
• DeNA provides ExGame to the partner developers.
• Please access to our development sites:
http://developer.dena.jp/mbga/en/