I have just moved the as3corelib library over to GitHub (at the urging of Darron Schall). This should make the project a little easier to manage, and in particular, make it easier for developers to contribute patches, and for me to review and accept them. All files, issues, source, and wiki pages have been moved from the old site to the new one. The old site is still up, but directs people to the new site, and will no longer be updated.

I have finally released the source code for my PewPew game. PewPew is a game I started working on over a year ago to help me understand what optimizations would be required to convert a web based Flash game to run on the iPhone. I had planned to release the code earlier, but a little hiccup around iPhone support delayed that. Now that Adobe AIR for Android is in public pre-release, and I have had time to comment all of the code, it is ready to be released.

I have just posted a new release (.93) of as3corelib. The corelib project is an ActionScript 3 Library that contains a number of classes and utilities for working with ActionScript? 3. You can view a complete list of changes in the change list (items 75 - 106). You can download the updated SWC and source from the project’s download page. Thanks to Christian Cantrell for helping build the release.

Prompted by some of the work from Grant Skinner (in particular his FOTB 2009 session) and Thibault Imbert, I have been doing a lot of research lately into optimizing ActionScript 3 content. Not just how to make it run faster, but how to approach the process of optimization. I am also starting to work on a small project which works with pixel data from images, and on which I anticipate performance might be an issue when working with larger images.

I don’t have a formal computer science training / education, so I never got the chance to learn about working with low level data structures (bits and bytes). I have wanted to learn this for some time, but had difficulty finding resources for it which didn’t assume I had a computer science degree. Well, yesterday, FITC posted all of the video sessions from FITC Toronto, and I spent some time watching Lee Brimelow’s presentation on working with ByteArrays.

For the past month or two, I have been spending time building a game (something I haven’t done since my Flash 4 days). This has really been a lot of fun, as it has allowed me to use some of the Flash Player APIs which I really haven’t had a chance or need to use before. One thing which I have been (slowly) learning about are using Matrix transformations on DisplayObjects.

If you have read my blog any this week, you have probably noticed that I have been doing some basic research on collision detection within the Flash Player. As part of this, I have put together a simple test suite, showing the performance of a couple of different techniques for checking for collision. This is by no means meant to be exhaustive (and currently tilts towards boundary collision). However, I wanted to post the results as the current information is useful (if nothing more than to confirm existing assumptions), and perhaps generate more tests an ideas around collision detection.

Yesterday I blogged about how you can use the BitmapData.hitTest API to do collision detection between the visible parts of multiple DisplayObject instances. This works very well, but as some of the BitmapData apis can be cpu intensive (particularly new BitmapData and BitmapData.draw) you have to take care to make sure that performance does not get out of hand. This post will discuss a number of approaches for optimizing collision detection when using BitmapData.

The Flash Player contains a number of APIs for handling collision detection within Flash content. The DisplayObject class contains hitTest and hitTestPoint which can be useful if you need to detect bounding box collisions, or detect collisions between an individual point and bounding boxes or shapes. However, BitmapData also contains a hitTest API, which can check collisions on BitmapData. Where the API really shines, is when you need to detect collisions between the visible areas of DisplayObjects (and not just of their bounding boxes).

I have just uploaded a new class to the as3corelib library that makes it easy to monitor files for changes. The class is called FileMonitor, and is in the com.adobe.air.filesystem package. Here is a simple example of it in use: import com.adobe.air.filesystem.FileMonitor; import flash.filesystem.File; import flash.events.Event; import com.adobe.air.filesystem.events.FileMonitorEvent; private var monitor:FileMonitor; private function onSelectButtonClick():void { var f:File = File.desktopDirectory; f.addEventListener(Event.SELECT, onFileSelect); f.browseForOpen("Select a File to Watch."); } private function onFileSelect(e:Event):void { var file:File = File(e.