TrueVision3D 6.5, XNA and HLSL tips & samples by Zaknafein/Renaud Bédard.
I finally decided to purchase a proper domain name, and I’m currently setuping the new host of The Instruction Limit, located at http://www.theinstructionlimit.com/.
So update your bookmarks, and I’ll translate the links, upload the media and make a couple of fixes in the coming days. When it’ll be all done, I’ll redirect requests directly to my new host.
(Part one is here.)
You know, I was so confident when writing the first post that I was addressing a common problem (which is not entirely untrue considering Google hits) and that it would be a pretty straightforward “here’s the issue, here’s the fix, enjoy” scenario.
Boy, was I wrong.
The common approach when trying to fix a bug is to first reproduce the problem. While I had no difficulty making a fictitious test case that does reproduce the “unreachable hashed entry” issue, I’m having all the trouble in the world finding a proper, real-world, justifiable algorithm that needs a hash table with mutable keys.
It just never seems to me like a reasonable thing to do.
Nevertheless, being the stubborn bastard that I am, I’ll present here a recipe to encounter the problem with as much justifications as I could make up. And if ever you’re ever stuck in a situation where you do need a hash set to react properly with mutable entries, well you’ll have a solution of sorts.
Take a deep breath (this is a looooong one) and hit the jump.
In this little series of posts (probably two three), I’m going to address a problem that has happened to me yesterday and was a real blocker in my algorithm : how to get a hash table (HashSet or Dictionary) to work with keys that change their hash code over time.
Updated! Now supports nVidia’s ShaderPerf tool.
Downloads
EffectCompiler.zip [51.3kb] - XNA Game Studio Express 2.0 (Visual C# 2005 Express), Source + Binaries
Description
Yesterday I took apart my Effect Compiling Tool which took a HLSL shader and converted it to Windows/Xbox360 bytecode, and made it into something more useful outside of XNA.
It’s always been somewhat of a hassle for me to compile and disassemble HLSL shaders. I can edit them pretty well in Visual Studio with code coloring and tabulations/undo’s/whatnot, but to compile them I always had to go with something else. I had read in the book Programming Vertex and Pixel Shaders by W.Engel how to compile them in VC++ 2005 using a Custom Build Step and fxc.exe, but when working in C# I had to have a parallel C++ project just for shaders, which is dumb. Also, fxc.exe has become less and less stable for some reason… So I finally made my own compiler and disassembler using XNA 2.0.
While working on some tangent project you’ll know about pretty soon, I’ve been trying to pack color data that had little visual importance from 24-bit “Truecolor” R8G8B8 to 16-bit “Highcolor” R5G6B5. Intuitively the solution is to take the most significant bits of each component and fit it inside two 8-bit containers by using bitwise operations.
But the problem is, bitshifting and just any bitwise operator are not supported in shaders before SM4.0, and I am still lagging behind with my videocard and OS so I can’t run those yet. And anyway, I assume 95% of the world can’t either.
So the only way to make this is to resort to integer arithmetic (division, multiplication and modulus). And since it took me most of the day to have it working, I thought I’d share my little HLSL snippet with the world.
Update : Now with 232.3% less arithmetic instructions!
Hit the jump for the full HLSL code and some insights on how it works.
There is an ongoing thread on the XNA Creators Club forums about how to create an installer using Inno Setup, a free and very capable installer program.
The script described by Pelle in the first posts of this thread works great for XNA GSE 1.0 and Refresh, but is problematic for XNA GS 2.0 games because of the dependency on .NET 2.0 Service Pack 1. I won’t bring much new information in this post, but will try to summarize everything I read and tried it into a tested & true solution that I’m currently using for the Fez installer.
Please note that this solution does not work if your game requires use of the GamerServicesComponent of live networking using XNA, since you need the whole Game Studio for it to work. (see this post)
Also, it wasn’t made with 64-bit operating systems in mind, so if you’re going to support them you’ll have to modify it. It has been known to work on Vista though.
I’ve been trying out XNA 2.0 recently and sadly, my former method of using the internal WindowsGameForm and play with it to add all the desired controls has seemingly stopped working. :(
Fortunately, Pedro Güida on CodeProject has found a much simpler way to achieve that, and which enables the use of the Windows Forms Designer instead of adding all the controls by hand like I did. I’m currently implementing that in the Fez editor and I encourage you to do the same! It’s the cleanest method I’ve seen yet.
I’m mostly posting this because my article on Windows Forms has been the most popular on my blog since I posted it, and I wouldn’t like people to take the time to implement it and find out it just doesn’t work anymore. I’ll put a note on the original article that says “XNA 1.0 Refresh only!”, if people are still using that.
The aforementioned article also presents how to use XNA with Visual Studio 2008, WPF projects and even Silverlight, so it’s a good read in any case.
** Updated with pictures! **
Alright, here’s a couple of explainations about the rendering technology behind Fez, what we call trixels.
Some people on deviantART and the TIGS blog post have pointed out how these are pretty much just voxels, but with a trendy name. As the lead programmer, I beg to differ… a bit.
I’ve been working (my ass off and compromising my job and social life) on this game called Fez for a couple of months, and 5 hours from the Independent Games Festival entry submission deadline, it’s finally OVER!
Well, the demo. But it’s a full level, with dialogues, collectibles, sound, music and a pretty full demonstration of the game’s concept… which I can’t show too much of right now, especially the concept and what’s original about it, but here’s some in-game material that I can release. It’s a screenshot, taken directly from the game, no mocking-up here.