Nov 3
Thanks to Tronster for today’s guest article! If you’re interested in writing a guest article, e-mail Jackson about your idea.
Natively, Flash does not offer a two-dimensional array type. But, Flash’s one-dimensional Array and various other container types (i.e., Object, Dictionary, and Vector) allow for user-created 2D array solutions. Today’s article explores the performance of various ways to make a 2D array.
Jul 18
Today’s article is about an unintuitive-yet-simple optimization you can use to hugely increase the speed of reading from Array, Vector, Dictionary, Object, and dynamic classes. Need I say more? Read on for this amazing speedup!
During some recent memory profiling I was reacquainted with just how many ways there are to unknowingly allocate an object in AS3. The problem is seldom the allocation itself, but rather the later garbage collection (GC) to delete those objects. Ever used a Flash profiler only to see a huge chunk of your CPU time going to [reap], [mark], or [sweep]? Yeah, that’s the GC at work. Today’s article talks about some of the ways you end up allocating objects in AS3 without using the new keyword. These subtle errors can end up costing you!
Jun 27
The Vector3D class debuted in Flash Player 10.0 as Adobe’s official implementation of, well, a 3D mathematical vector (not the pseudo-Array class Vector). Weirdly, it has a w component and is therefore technically a 4D vector, but its API inconsistently make use of the fourth dimension. There are also strange oversights, inefficiencies, and functionality it really should have always had. Read on for my custom Vector3D derivative—Vector3DExt—that fixes all of these problems by extending and improving on the original.
Jun 20
AS3 has two integer types: int and uint. In my experience, most AS3 programmers just use int everywhere and ignore uint. This is usually acceptable as the need for unsigned integers is rare compared to their signed counterparts. However, there are significant performance differences between the two. Read on for the impact of uint on your loops. The original version of this article’s performance test contained a small-but-critical error that led to a lot of incorrect analysis and results. This version of the article has been corrected.
When you construct an Array or a Vector, you can specify an initial size. Why would you do this?There are various reasons you may want to reserve initially-unused slots for logic reasons, but are there any performance gains to be had by pre-allocating this space for an Array or Vector you intend to completely fill right away? Today I’ll take a look to see just how much performance can be gained by pre-allocating Arrays and Vectors.
Oct 25
I recently received an e-mail from asking which is faster: a DisplayObjectContainer or a Vector of DisplayObject. To ask this is to question whether or not we can do better than the Flash Player’s native container of DisplayObjects using AS3. It turns out that we can. Read on for several ways to improve on DisplayObjectContainer‘s speed.
Oct 18
There are three main ways to access the contents of objects in AS3: the dot (.) operator, the index ([]) operator, and the in operator. The first two are well known and functionally-equivalent because obj.property evaluates to the same value as obj["property"]. The in operator is different as I’ve described before: it returns a Boolean indicating whether or not the object has the given property. There are a lot of cases—error checking, for example—where we only care if an object has a property and not what that property is. So, can we improve performance by using the is operator rather than the index or dot operators? (UPDATE: hasOwnProperty results added)
Apr 30
It struck me recently that there are a lot of ways to convert variables of many types to a the String type. The ease of doing this is one of AS3′s strengths over languages where it’s error-prone, possibly insecure, and just plain difficult. The C language is the most obvious example of this and, since then, seemingly every language has enshrined string conversion in ways ranging from global String() functions (AS3) that take any variable to adding toString() to the base Object type (Java, AS3, others). AS3 seems to have chosen “all of the above” and there are now many ways to convert to a string. Below I’ll look at them from a performance standpoint and see if the everyday, run-of-the-mill boring string conversion can be improved by choosing one option over another.
Apr 20
I was reminded about the flash.sampler API by Grant Skinner’s recent post about it. While only available in the debug player, it can still tell us some valuable information about what goes on in the release player. Today I’m using the getSize function to find out how much memory overhead various classes impose, even when they are empty.
