CROSS-PLATFORM DEVELOPMENT ON MOBILE DEVICESTakaaki Mizuno

DeNA

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

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

Cross-Platform development environments

Are cross-platform dev denelopment envivonments workable ?

• Not good at least now• It’s ok for simple apps

Business Apps

• Not so badGames

Most important thing is…

To know the characteristics of each environment

Native Layer

Cross-platformEnvironment layer

Your code

Erase the differenceBut limit the capability sometimes

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

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

Difficult to catch up with interface trends.

• Pull to refresh• Side menu

UIWebView based application for iOS

Really Slow

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

Chrome iOS version is SLOW

Facebook Application for iOS

Facebook will return to native

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

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

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

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.

But if you want to use JavaScript still…

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

DeNA’s answer

ngCore• JavaScript based Game development environment.

• Try https://developer.mobage.com/⇛

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!”;}

}

JSX

we are observing 4% to 27% increase in performance

Try it

http://jsx.github.com/

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}

})]);

Try it

http://denadev.github.com/Arctic.js/

ExGame• Converts Flash Lite 1.1 SWF into JavaScript and make it

executable on iOS/Android devices.

How to use ExGame• DeNA provides ExGame to the partner developers.• Please access to our development sites:

http://developer.dena.jp/mbga/en/