Tag: Flash Page 6 of 8

Flash AS3: How to get useful error statements from Flash

On August 20, 2010

One of my main frustrations with Flash is the lack of useful error statements when I am testing a program. The compiler errors are okay – they catch my syntax mistakes and point out the location of the problem in my code (usually). Runtime errors , on the other hand, are an exercise in frustration. Flash usually provides cryptic runtime errors like “null object reference” and then gives me a vague hint about where the problem is in my code. Then, I spend lots of time adding trace statements to try to figure out where the code is failing. Once I know where the code fails, I can figure out why. I have constantly wondered why Flash can’t simply give me the exact location where the program crashed.

Flash runtime error

Well, one of my coworkers figured out how to get useful error statements from Flash the other day and I’m ashamed to admit that I didn’t know this (neither did he, and we’ve both been developing in Flash for over 5 years). In Flash CS3 or higher, simply open the Publish Settings and go to the Flash tab. One of the checkboxes on this tab says “Permit Debugging.” Enable this and Flash will tell you exactly where your program failed, so you can quickly track down why it happened.

As always, I’ve attached a quick example. The sample Flash file has a problem that will cause Flash to throw a runtime error. Compile it and note how it only tells you that the problem is in the actionscript on frame 1 (no duh). Now, change the publish settings to permit debugging and try again. This time, at the end of the error message, it will actually tell you the exact line of code where the program crashed.

Once you are finished testing your applications, you should probably turn debugging off before publishing your final SWF.

Download the sample file here.

Why HTML5 is not going to kill Flash anytime soon.

By Andy

On June 22, 2010

In Flash, HTML/CSS, Uncategorized

html5_vs_flash Ever since Steve Jobs announced that Flash will NEVER be allowed on the iPhone or iPad, there has been a lot of talk about HTML5 – how it is going to kill Flash once and for all. Let’s just ignore the fact that Apple, Adobe, Microsoft, and Google all have a large financial stake in the outcome of this argument. What about the technical feasibility of replacing Flash with HTML5? Well, HTML5 has some pretty cool features, but it is not going to kill Flash anytime soon. Here’s why:

Reason #1: The browser support isn’t there yet.
There is a lot of talk about how “all the modern browsers already support HTML5.” Well, that may be true, if you ignore Internet Explorer in your list of modern browsers. Somewhere between 30% and 50% of people on the web use Internet Explorer. At least 8% of people are still using IE6, which is a decade old and doesn’t even fully support HTML4! And what about all of the people using outdated versions of Firefox? The modern browsers may already support HTML5, but modern browser market penetration is probably somewhere around 50% and it will be years before it reaches a level necessary for most people to adopt it as the standard. As a developer, I can tell you that most developers will be stuck programming in HTML4 for the next 5 years or more, because it’s hard to explain to clients why their mother can’t look at their fancy new website. Flash has a 98% market penetration. HTML5 won’t be able to compete with that for a long time.

Reason #2: There is still no video standard for HTML5.
This is a related issue to Reason #1. There are currently at least 3 video standards competing for dominance in HTML5. Most browsers support only one of the 3 formats. It’s a bit like the recent Blu-ray vs. HD DVD war. Eventually, one will be the winner, but in the meantime, no standard means hassles for developers. It is simply easier for developers (and clients) to build things to a standard that most people can view, so most of them will probably stick with Flash video for now (remember the 98% market penetration from reason #1).

Reason#3: No DRM on HTML5 video.
HTML can deliver video directly through your browser with no plug-in. That’s great. The other great thing about HTML5 video is that you can right-click the video and save it to your desktop. Well, it’s great for consumers, but the idea of putting video on the web with no DRM (Digital Rights Management) makes studio execs panic. There is NO WAY that movie and TV studios are going to put all of their content out there to be downloaded and stored on your hard drive. Many large video sites like hulu.com have already said that they will not be switching over to HTML5 until the DRM issue is resolved.

Reason #4: Developers can’t protect their intellectual property.
As a developer, I can tell you that programming games and rich web applications isn’t easy. It takes hundreds of hours to program a cool Flash game. Even if I could do it in HTML5 and Javascript, I’m not going to to do it. The reason is simple: HTML5 code is visible to anyone who visits my web page. If I’ve spent all that time creating a cool game, I don’t want to expose all of my code to everyone in the world. If I did that, there would be crappy clones of my game popping up all over the web within a week or two. Flash allows me to protect my intellectual property in a way that HTML5 doesn’t.

Reason #5: Coding for multiple browsers is easier in Flash.
Not only does Flash protect my code from prying eyes, it provides me with a single set of rules to follow for coding across multiple platforms (Windows, Mac) and multiple browsers (IE, Firefox, Safari, Chrome, etc). To create something cool in HTML5, I would need to use Javascript. The simple fact is: Javascript sucks. It behaves differently in different browsers and you spend more time tracking down weird, browser-specific bugs than you do actually creating awesome web apps. Flash just makes development easier (and ultimately cheaper for clients).

Reason #5: HTML5 simply can’t compete with Flash in providing a rich media experience.
HTML5 has some animation capabilities built in to it, but Flash is way ahead of it in this regard. Flash provides a Graphical interface that a designer can use to create incredible animations and graphics. HTML5 requires a programmer to create cool animations. Flash is more powerful and easier for people to work with. I’m not saying that HTML5 and Javascript won’t catch up to Flash, but it won’t happen for a long time.

Reason #6: HTML5 is slower than Flash.
Ever since Apple’s announcement, people have assumed that what Steve Jobs said was true – Flash is too slow for the iPhone. Well, a number of clever people have actually run speed comparisons between Flash and HTML and have found that HTML5 is generally SLOWER and MORE RESOURCE INTENSIVE than Flash. Ouch. That doesn’t sound like progress to me.

Reason #7: Nobody really cares.
Frankly, most people don’t care how they get their content, as long as they get it. Despite what Steve Jobs thinks, no one really cares what technology is used to allow them to watch videos on YouTube. Even the Apple fankids who are applauding the decision not to put Flash on the iPhone probably don’t really care – most of them had never heard of HTML5 before this announcement and most of them still don’t really know what Jobs is talking about . It’s all about delivering the content. If Apple can’t give people the content they want, then people will use a different technology.

Obviously, I make my living as a Flash developer, so you may be inclined to think that I’m biased towards Flash. That may be true, but I am really just a developer – I will use whatever tools are best for the job. Right now, Flash is the best tool for creating a rich web experience . It has the best combination of capabilities and market penetration. HTML5 simply can’t compete with it right now.

Need more info? Here are some links I’ve found that are great resources for HTML5 development:

A video discussing the HTML5 vs Flash debate from a developer’s perspective

A good explanation of HTML5 video and how to properly implement it for best cross-browser support

Latest news and articles about HTML5 video

Flash AS3: A quick test of Five3D

By Andy

On May 21, 2010

In Actionscript/AS3, Flash, Flash 3D (Papervision, Five3D), Flash drawing API

Five3D is a compact Actionscript library that allows you to create 3D views quickly and easily. Much like Papervision3D, Away3D or Sandy, it allows you to create basic 3D graphics with Actionscript. Why would you use Five3D instead of one of these other libraries? Here’s a quick rundown of the advantages and shortcomings of Five3D that I have found:

Five3D has a stripped-down feature set. If you need to do something simple like move a large number of planes in 3D space, Five3D will be easier to set up than the other 3D packages. The drawback is that it doesn’t do many of the things that the other engines do, like providing built-in primitives or Collada imports.
Five3D handles vector objects without first turning them into bitmaps. You can actually use Flash’s native drawing API to create vector shapes and move them in 3D while still retaining the vectors. This creates smoother renders than the other 3D engines, especially when scaling and rotating objects. The other 3D engines create bitmaps of textures and then map them onto the surfaces of objects.
Five3D handles 3D text really well. You can convert fonts into vectors and then use them as 3D objects. This makes 3D text effects really simple.
The default handling of bitmap textures is cleaner than Papervision. With Five3D, bitmap textures on planes map much more smoothly than with Papervision’s defaults. You can map textures just as well in Papervision, but it’s a little bit of a hassle to set up.
The Five3D library is written to extend the native flash classes in a way that is really intuitive. For example, a MovieClip3D is just like a MovieClip, but it has additional features like a z-coordinate. Half the time, you can guess what properties each object will have without even looking them up in the docs.
Five3D doesn’t use a camera object. Depending on your needs, this could be an advantage or a disadvantage. You can handle this by simply creating a Sprite3D container to hold all of your objects. Then, move the container to simulate camera movement. I often do this in Papervision projects anyway because of various issues I have had with the camera.

I have built a simple “Hello World” test of Five3D, which you can see below. It’s not very exciting, but it isn’t supposed to be. When I started playing with Five3D, I had a hard time finding a simple, stripped-down example that could get me started, so that is what I’ve built here. You can download the source files here. I have also added links to some more advanced tutorials and samples at the bottom of this post.

I did run into some weird Five3D quirks when I built this. First, when I created a MovieClip3D object and added it to the scene, it wasn't appearing on stage. I traced all of the properties and everything indicated that it was on the stage, but it was not displaying. I Googled around a bit and found this website with the answer: you have to call the activate() function for MovieClip3D objects to get them to render on the stage. I don't understand why you need to do this, but it fixed my problem.

The other quirk that you need to know about is that you have to turn on z-sorting. By default, it z-sorts according to your addChild() calls, just like regular MovieClips. If you don't need z-sorting, just add the 3D items in the correct sequence. I'm guessing that this helps to optimize the code. If you need your objects to spin in 3D space, you can turn on z-sorting with the childrenSorted property (check out the example source code for usage).

Thanks to Mathieu Badimon for this amazing Actionscript package.

Links:

Download the source files for the example above

A 3D text sample with source code

A simple example of Five3D with source code

A fun Five3D experiment

A tutorial on building a 3D photo album with Five3D

Info on integrating Five3D with Jiglib physics

Essential AS3 classes: getURL and PixelPerfectCollision Detection

By Andy

On May 11, 2010

In Actionscript/AS3, Flash

As I have made the transition to AS3 class-based programming, I have built a package of useful classes that handle functionality I need all the time. For example, I have a class that handles the basic rollover functionality for a button. Rather than write this code over and over, I made a class that takes care of it. That’s the main benefit of working in classes – things become more modular and you (theoretically) spend less time building repetitive code. I am always looking for good code to add to my core package of classes and the following two classes definitely fit the bill. I use them all the time and I thought I’d help more people locate them:

getURL:
One of the biggest hassles in AS3 is writing 10 lines of code to accomplish the same thing that you can do with one line in AS2. The getURL() function was killed in AS3. Now you need to set up a URLRequest… it’s a hassle. Well, Actionscript guru Senocular has created a getURL() class that mimics the behavior of the AS2 function. simply add the class to your import statements and then use it just like you did in AS2. Grab it here.

Pixel Perfect Collision:
One of the more annoying problems with Flash is that collision-detection has never lived up to its promise. In AS2, the hitTest() function only allowed you to check if the bounding boxes of 2 objects were touching. This worked great if all of your graphics were rectangular, but it often registered a collision between objects that, visually, looked like they were still pretty far apart. Grant Skinner was the first person to solve this problem with his AS2 collision-detection code. His original code was then ported to as3 by Boulevart. I had been using that code for projects, but it had a few shortcomings – it didn’t work for rotated or scaled objects and both objects had to share the same parent. I was just recently contemplating an update to the AS3 Collision class to fix some of these issues when I found an updated version by Troy Gilbert. It not only handles rotated and scaled objects, but he has optimized the code and removed the constructor (which was really unnecessary anyway). You will definitely want to get his PixelPerfectCollision class.

That’s all for now. If you’ve found any other classes that you use all the time, leave a comment and let me know.