This week I ran into a Subversion switch problem. If you don’t know about Subversion and switch, skip this post:).

My situation: i ran Subversion on a windows machine for testing and was fiddling with the switch statement:

svn switch file:///c:/myrep/mybranch

Subversion gave me an error:
svn: ‘file:///c:/myrep/mybranch/
is not the same repository as
‘file:///C:/myrep’

If I set an environment variable %REP% = file:///c:/myrep/ and use svn switch %REP%/mybranch, everything works fine. I don’t have a clue how or why, but this does seem to fix it.

In this post we will be looking at the creation of a distorted panorama using a displacement map. The two examples below show the difference between a panorama without and with distortion (notice how in the distorted version the grid bends):

Some simple tricks to note up front:

• detecting the mouse outside of the panorama is done through an empty movieclip with a stage-sized hitarea and an onpress=null
• in order to displace the whole stage at once, you can set the displacement map on the root but you need to mask the stage through code (ie setMask)

We will be looking at a visual way to generate the required displacement maps using a 3D program and an imaging program. Ofcourse you can generate the required maps through code as well, but I like the visual way of doing stuff like this. It has its limitations of course. I have summed up the whole process in a slide show below. The different resources that are required can be downloaded below as well. Note that I’m still experimenting with this stuff:). Some of the slides refer back to previous posts.

The slides refer to some resources. The base map and difference calculation resources can be found here. The displacement maps can be retrieved from the downloaded source file, but now you know how to create them yourself as well. Let’s conclude with what happens if you tinker with the rendered image and force overflows etc:

I already blogged about this, but I saw that some items could use some more explanation. Please read “Getting the displacement you need” first for the basic idea.

In short the principle is:

• you have a reference map, say A
• you apply a distortion effect to the reference map created a distorted version of A say A’
• you calculate the displacement map that could transform A into A’ by calculating the difference in pixel value between A and A’

Some important points before we start:

Use a lossless image format (eg bmp). If you use lossy compression anywhere in the pipeline, you are throwing information away. This missing information results in artifacts in the displacement map. So, save all images as BMP for example. Import them into flash and set the properties to lossless.

We will now describe some steps in my previous post in some more detail. (more…)

Happy new year all! The first post in this new year is something I see a lot of beginners run into. They create a flash movie which has to load some resources and they simply go like:

   obj.loadSomething("mycontent.swf");

Running the sample locally works fine ofcourse since everything is where you expect it to be.
However, after deployment your swf might be loaded into another swf, or loaded from a html page at another location and your content suddenly breaks. Why? Since “mycontent.swf” was a relative location.

So how do you fix it? Well there are several solutions:

1. use a complete path
2. use a resource file to define a content path
3. use _url to determine where your swf actually is and thus where your content is

Option 1 isn’t very good, if your content is moved to another folder on the webserver, it breaks again. Option 2 does not actually solve the problem, since now you have to find the resource file :). Let’s go with option 3.

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To follow up on the first bitmap post, I’m posting some code I wrote a few weeks ago to print a movieclip. The Flash Print API is pretty mind-boggling at times I think. Although this code is in no way a general print-problemsolving formula, it does show how to use the bitmap and the print API’s combined to print a movieclip (for example a screen) sized to fit on whatever paper you are providing.

It is not a utility class, and it can certainly be improved, nevertheless it provides a good starting point. It will probably be refactored and become part of our framework. Note that it does not provide page-breaking and other formatting, its purpose is to implement a PrintScreen kind of mechanism.

I think one of the things that slows some of us down most now and then, is the drive to improve on the way things are done. That’s probably why starting something new is tiresome, since there is so much to improve upon, in turn slowing progress itself. If you do not carefully state priorities, this kind of backtrack improvement can quickly lead you off track, and you’ll be improving things you never knew needed improvement in the first place, and you probably can’t remember why you are doing what you are doing anyway. Luckily “look for things to improve” is not our only mantra :), “don’t do things yourself, others can do better” is another one of my favourites, and not only because I liked the Dragon Prince series.

But look here, I’m getting side-tracked myself, the point is that looking at my earlier post, I could see straight away that I was going to need to improve on source code postings. I wanted a few things from my source-code-post-mechanism:

1. provide source code in a readable format (keep the pretty printing)
2. provide linenumbers that will disappear when you copy & paste the code
3. not necessarily break formatting (wrap lines etc)
4. provide long listings inline, with scrollbars if needed
5. allow sources to be downloaded

Armed with my checklist I set out in the World of Wordpress plugins (it’s a pun only understood by Warcraft players). Which reminds me, if you see me reverting back to some kind of awfull shorthand, such as kk hf m8, cu l8r (okay have fun mate, see you later) it is because I play too much online games :).

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