May 20, 2008 by Mark.

Alright, I ended my zealous trek through the inner workings of SIMD just because I wasn’t using it enough in my project. Don’t get me wrong, its a really nice piece of technology to dabble in, especially when doing math on a large scale (say, Matrices). But for the day-to-day programmer in me, I really don’t get to use it as much as you might think.

But, I’ve done some detective work and most compilers nowadays optimize the code in such a way that SIMD gets incorporated automatically. Therefore, learning SIMD should be put in the same category as learning Assembly. Its nice to have but in reality it will be rarely used, if ever. I have a feeling that I’ll run into a situation where SIMD is required and its the only thing that can save the world from total destruction. Well, until then, I’ll just shelve it.

On the bright side, I finally gave my game/rendering engine a real name: ‘Radiant.’ I don’t know why I named it that, and for some reason, I never second guessed it. It was one of those spur of the moments that I hit F2 and started typing. Don’t ask me what or why, I’m still in the wilderness on that one. Anyway, progress on the engine is a bit slow just because the only time I get to work on is during bus trips to and from Hamilton, or other places. If there were more hours in the day, I could actually get something done.

I should also say that I’ve re-worked the way the engine is laid out because all my singletons were not working well with DLLs (I think I wrote about that, somewhere). This quickly because a mess. SVN likes things to be done in order and in small chunks, else it starts bugging you about cleaning up the repository. I like to do things in big chunks, literally taking a +1 Battle Axe to the tree and then rebuilding it from scratch. Bad tactic, I know. Lets just say, SVN was in pain. Poor thing.

As a side note, I found out something interesting today about the MSVC build system; It supports multi-core compilation! Its like your own distributed build but on your own machine, Hooray. More on this later.

Posted in GEL, Open Source, 3D Stuff, C/C++ | No Comments »

March 26, 2008 by Mark.

I’ve been scouring the internet for some decent resources on math, collision detection, and physics, so here are some:

• Essential Math
• Game Physics Resources
• Real-Time Collision Detection
• Advanced Character Physics
• Simple Math Primer
• Flipcode’s Articles
• Harvey Cartel’s Collision Detection Site (Thanks Miksago)
  

More to come, later.

Posted in GEL, 3D Stuff, C/C++, Stuff, Uncategorized | 1 Comment »

March 24, 2008 by Mark.

With all the craziness that last weekend brought, one of which was a book I ordered from Amazon. Just like the title says its a book about collision detection within 2D and 3D environments. It’s a bit on the expensive side, about $50, but its worth every penny. I had a chance to read the first 5 chapters on Sunday. It started off with a quick math primer and then dove head first into how collision detection works. It has a few chapters on bounding volumes and space partitioning; the two topics I have been obsessing over for the last few weeks.

Possibly the best thing about this book when compared to my other math books is that it explains the concepts with code, more then with math. For most programmers, this is a godsend. Reading a few lines of code is much easier (at least, for myself) then trying to comprehend or remember mathematical symbols.

Regardless, If you’re building an engine of some sort (Graphical, Physics, etc), this book is definitely an asset. Collision detection is not only used in physics engines, it is the core functionality of Octrees and Scene Management. Ergo, it is an integral part of an engine. Although, I don’t recommend this book to novices, or people that do not have any 3D engine building knowledge under their belt. It is Math and Algorithm heavy and requires substantial engine design theory.

EDIT: Looking through some of the supplementary books from the Morgan Kaufmann series, they all seem very interesting. If those books are of the same quality as the Real-Time Collision Detection book, then this entires series of books will end up on my bookshelf very soon. It’s something to be desired.

Posted in 3D Stuff, C/C++, Stuff | No Comments »

March 17, 2008 by Mark.

I have been working on my game engine (Which still does not have a name; Suggestions are appreciated) for a while now. It has seen its share of refactors ever since I started on it back in 2006. But recently, I have come to a fork in the road. I am overwhelmed with the amount of things that I need to keep track of which makes me second guess some of my design decisions that I have made. One of which, is weather or not to write my own scenegraph or to use a stock one, say, OpenSceneGraph.

From experience, I can tell you that the amount of time that it would require to learn, implement, and test OSG’s implementation would be comparable to the amount of time it would take me to write one from scratch. I have been plagued with these sorts of decisions ever since I started the rewrite of my code. The benefits of using a library over writing your own can only be determined by the ease of use of the library. For example, if its easy to build, incorporate and debug then it probably is better to choose it then to write one from scratch. In the case of OSG, the library is big. No, its Massive!

I am still not convinced that OSG would be worth using over my own implementation, simply because of the learning curve and the work required to properly incorporate it into my engine. I would literally have to wrap my engine around OSG, rather then have it work symbiotically. That just does not sit well with me. Regardless, I will still poke around inside OSG and learn how their scenegraph implementation works.

Where is my trusty Bearded Axe, its time for some hacking!

Posted in GEL, Open Source, 3D Stuff, C/C++, Stuff | No Comments »

February 12, 2008 by Mark.

Seems that my favorite pattern is also the bane of my current Game Engine development. Turns out that a singleton pattern doesn’t like to play nice with Dynamically Linked Libraries. The whole notion of being dynamic is counter productive to static members inside functions or classes. Looks like the only way to actually fix this is to wrap it all up in a big handler of some sort and have the calling code manage it. Either that or create a section of shared memory in the DLL and allow it to manage the singletons. Seems like a bit of a pain in the butt just to avoid a global variable. Hmm, unless I can wrap it in another creational pattern, possibly Builder or Abstract Factory…

More research is required. And research requires Tea. Therefore more Tea is required.

Posted in GEL, Open Source, 3D Stuff, C/C++ | No Comments »

February 11, 2008 by Mark.

On my spare time (if there is such a thing), I have been slowly putting together my Game Engine. The foundational stuff is pretty much written and tested and I am just about to start writing the heart of this engine, the renderer. But as I’m thinking about the code structure, I am also debating if I should stick it out on the web as an Open Source project. I read up on a bunch of licenses but none of them were exactly what I needed. The type of license I’m looking for is one that would credit my name whenever it is used or redistributed. Also, it would force people who wants to use it for commercial use to cough up some coin. In other words: free for personal use, not free for commercial use, and my name to be always credited. Anyone know of a license like this?

One of the licenses I found useful was the MAME license. I might ask its author for a copy. On another note, I just set up an SVN server to host my engine. Also, I am slowly putting together a webpage for this project so people can easily find it. I’ll post the link soon.

EDIT: Dave advised me against using some of the lesser known licenses and advocated LGPL. I’m going to give LGPL a thorough read.

Posted in GEL, Open Source, 3D Stuff, C/C++, win32 | 1 Comment »