I have been quite away from Android development.
I have been coding a game for iOS: Shaman Doctor and now I am testing Unity3d.
This blog describes my wish to port that coroutines to other platforms.
Introduction
In Unity3d I am coding in C# and I learned about coroutines.
To give you an idea of how they work, check this blog posts:
Unity3d implementation for coroutines is somehow different.
To understand what I am saying, read the first link.
It gives an explanation of how it should be working inside Unity3d.
Usage
In the code where I use Unity3d coroutines is where I need to do a state machine code.
A super simple example would be:
Imagine you need to add a button but you can only click it once every two seconds.
I can imagine two possible implementations. Bare in mind that I didn't test this code.
Using time. objective-c code:
#define SECONDS_TO_ENABLE 2@synthesize lastTimeUsed;@implementation PotionController- (id)init {self = [super init];if (self) {self.lastTimeUsed = 0;}return self;}- (void)click {NSTimeInterval now = [[NSDate date] timeIntervalSince1970];NSTimeInterval difference = fabs(self.lastTimeUsed - now);// if two seconds haven't pass, return.if ( difference < SECONDS_TO_ENABLE ) {return;}self.lastTimeUsed = now;// Click logic here.}
Disabling and sending an enable msg to be run after 2 seconds. Android code.
In this case it's a done with the View's postDelayed() method. It could be done
with a Handler as well.
public void click(final View view) {view.setEnabled(false);// Send a postDelayed to turn it on again.view.postDelayed(new Runnable() {@Overridepublic void run() {view.setEnabled(True);}}, 2000L);// Click logic here.}
The same thing done with C# inside Unity3d would be:
void OnMouseDown() {StartCoroutine(this.ClickLogic());}private IEnumerator ClickLogic() {// Click Logicyield return new WaitForSeconds(2.0f);}
What happens when you click more than once in a two seconds time frame?
Honestly, I am not sure what happens when you call StartCoroutine() when
a previous coroutine was started, but it works.
I hope that someone can clarify this.
Now try to port this code from Unity3d to android or iOS.
IEnumerator TellMeASecret(){PlayAnimation("LeanInConspiratorially");while(playingAnimation)yield return null;Say("I stole the cookie from the cookie jar!");while(speaking)yield return null;PlayAnimation("LeanOutRelieved");while(playingAnimation)yield return null;}
How can this be used in Android/iOS
Ordinary coroutines
Although Unity3d's coroutines are different from the ordinary, I wanted to know if it was possible to implement them in Android/iOS.
Android
My first google search about this was "java coroutines" and I learned that ordinary coroutines would need one of this options:
- Modified JVMs (Can't be used in Android)
- Modified Bytecode (Can't be used in Android)
- Platform-specific JNI mechanisms (Not sure if it would work in Android)
- Thread abstractions (Not sure how performant would work inside Android)
I feel this is a dead end for Android.
iOS
I didn't research a lot about iOS.
Here is a list of links that look interesting:
Unity3d implementation alike
After reading Richard Fine's blog post I thought it would be interesting to achieve something similar to that in the different platforms.
My big doubt is finding a way to implement something similar to an IEnumerator.
Using scala
Inside cocos2d-iphone
I am not sure if cocos2d's internal would support something like this.
Inside cocos2d-x
This is the real challenge.
Finding a way to implement Unity3d's coroutines but keeping it multiplatform.
Perhaps finding a way of doing it in C++.
What do you guys think?
