Flash Haxe Gaming SDK, their tools, our tools

So Adobe released a few weeks ago its Gaming SDK for flash. The package includes Starling, Away3D and Feathers, three well know quality open source ActionScript3 libraries. You can easily find some externs for most of them on http://lib.haxe.org, which is great! However, during the development of my last game (which used Starling and Haxe) I found out that using haxelibs wasn't enough. A lot of good stuff is happening in the AS3 side, Starling is improving day after day on Github, users create really useful extensions for it. Time is precious and we don't want to write externs for everything or rewrite everything in haxe do we? Thanks to the great haxe/flash support, we can easily use all the good stuff in a matter of seconds, we can hack AS3 code and use the result from Haxe too. In this post I will try to teach beginners how to fish AS3 :)

• how to compile a bunch of .as files into a .swf using the Flex SDK.
• how to use those .swf files in haxe (with no extra work)
• how to patch things when haxe is not happy with the .swf

We'll end up with the entire Adobe Gaming SDK, and more, for Haxe. But the journey is more important than the destination. NOTE: If you are not interested in the process and just want the SDK, I created a bunch of github repositories to host the results. See the test repository to learn how to play with it https://github.com/labe-me/haxe-gaming-sdk-test NOTE: I do not intend to write any extern for these libraries (I am too lazy for that), hence I won't submit them to haxelib. Feel free to use my work in any way you want to create nice haxelib packages. As far as I am concerned I really enjoy the haxelib git support :) Start. We are going to compile .as files, you'll need to install the Flex SDK. Let's learn how it works with Starling. (1) get the library sources:
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Drawing API with Starling

This week a very cool contribution was added to Starling by Robert Silverton, the Graphics API Extension! So what is it? From github: This extension adds Jon Pace's 'Fill' and 'Stroke' display objects, with support for adding arbitrary vertices that are then triangulated for rendering on the GPU. The aim is to reproduce Flash's graphics API as closely as possible via simplified lineTo, moveTo etc calls within Shape.graphics and Sprite.graphics. Once the basics have been reproduced, the API can be augmented with more powerful features. An ear-clipping algorithm is currently used for triangulating the simple polygons generated by the moveTo, lineTo methods. Supports both simple and non-simple (self-intersecting) polygons. For those of you who always felt that not having a drawing API was limiting, there you go. We are already thinking about some new APIs we could add to Flash Player and AIR to make this extension even more powerful. Graphics query, anyone? Feel free to contribute and enhance it. Lee Thomason from our team has already sent some optimizations for curveTo. See you there! [...]

Read more: Drawing API with Starling

Epic Flash memory leak track down

Have you ever had a memory instantiation problem that was impossible to track down? Here is a post that might help you with that kind of thing!

Beware! This post is very long… but VERY instructive! If you want to learn some internal mechanism of Flash, I strongly suggest you read it from top to bottom without skipping parts!:)

The Context

Yesterday I was helping Luca (creator of Nape physic engine, made with haXe) to find what seemed to be a big memory leak. There was a couple framework used so it could be directly from Nape… or from Starling… or from debug tool running… or from a port error from haXe…

So I though it was going to be simple

I got TheMiner running and started profiling. It was pretty easy to find a LOT of memory allocation coming from Starling. The SWC version available is over 4 months old and back then there was a lot of useless instantiation coming from TouchProcessor.as
If you use Starling, I suggest you build from sources as these instantiation are gone now.
There are a couple left but no big deal.

We also saw that Nape was using a LOT of anonymous function call and some try catch. This create what’s called activation-object. And there was a lot of these. So by removing anon-calls and try catch we were able to remove a lot of instanciation.

And After removing the debugging tools, It was clear it was coming from haXe or Nape.

But even when recording all samples allocated by the VM I could not find the damn allocation. (we are talking of more than 1Mo per sec)

Then I wrote a Scala script to try to identify samples that could have been missed, but that didn’t help me much since that was only an override of constructor and constructorProp avm opcodes.

Simplifying the context

So I decided to look a bit further into the bytecode and found something very interesting.

After simplifying the problem multiple time, I got this very simple code to demonstrate the bug.
Because Nape has that very nice abstraction layer, it can support both standard DisplayObject as well as Starling 3D DisplayObject.

The leak happens when Nape try to set the DisplayObject properties like .x, .y, .rotation, etc.
Let’s create a fake DisplayObject class and name it DO [...]

Read more: Epic Flash memory leak track down

Nape and Starling together? It’s possible!

Hey, friends!

Somebody of you already tried fastest 2D flash physics engine Nape with a GPU 2D rendering framework Starling together and noticed that Body.graphic property is class of flash.display.DisplayObject and it can’t be assigned to the starling.display.DisplayObject instance.

So, some of you just used Box2D, some of you controlled Starling DisplayObjects manually, maybe some did what I did, but keep it away from public, but I like Body.graphic property – it’s really useful and I wish all as3 developers can easily use fastest 2d physics engine with 2D GPU rendering engine.

Today I’m glad to present you modified Nape FP 10+ swcs (release and debug) of the Milestone 7.2 “r3″ (maybe not fully) compatible with the Starling.

I just replaced Body.graphic flash.display.DisplayObject class by the Dynamic class (* in as3) and removed Body.graphic.rotation radians to degrees conversion to make it compatible with Starling in my case.
Now I can use Nape as usual, with usual DisplayObjects, it’s really cool!
Yes, there are possible some more compatibility issues, but this changes was enough in my case and Nape worked with the Starling DisplayObjects fine.

Feel free to download and use this swcs with Starling Framework!
debug swc
release swc

I like a challenge with caxe and flib compiling on Windows in the MinGW I faced while recompiling swc, it was fun!
To get the working swcs on Windows, you should

Read more: Nape and Starling together? It’s possible!