pdziepak@quarnos.org
FreeSpace is a 10-year-old game and despite the fact SCP developers have been doing great work since 2002 there are still many parts of code that were left unchanged. That means there is a great variety of antipatterns. Some of them are being solved while the others are so complex that their refactorization will require large amount of work. One of these antipatterns, easily found in FSO, is The Blob.
When I finished adding support of subtractive shaders to FSO engine (described in my previous post) I decided to implement post-processing. It usually doesn't require many changes in existing code. That was good since I wasn't familiar with the majority of FSO source code at that time. The other reason was that it is easy to achieve satisfactory results adding a few very simple post-processing effects. However, most of them will be used only in cutscenes rendered by the engine.
It has been a long time since my last post here. Many things have changed, most notably the language in which this devlog is written. I considered switching to English a few months ago, when my blog was still active, but I didn't found enough reasons for that.
Now, the situation is different. In September I joined FreeSpace Source Code Project. The main goal of this project is to keep FreeSpace, almost 10-year-old game, up to date, by improving every aspect of the game. It wouldn't be possible if Volition, Inc., the studio that created FreeSpace, hadn't given fans the whole source code in 2002. Since then, it is an open source project, not completely free (it can't be sold or used commercially in any other way), though. The website of SCP is a bit outdated, but you may find many interesting things on one of the biggest FreeSpace forum: HardLight.net or on the Polish FreeSpace website: FreeSpace.pl.
I've started contributing to SCP by improving the way in which shaders source code was stored and managed. There were dozens of *.sdr files containing shaders with different features implemented. The ones with normal mapping, the ones with environment mapping, the ones with glow maps, etc. Each possible combination of feature had to be in a separate file, that's why SCP developers ended up with over 60 (if I recognize correctly) shaders, which shared very much with each other.
I decided to introduce subtractive shader. This technique consists in creating one shader (one vertex shader and one fragment shader to be exact) with all the features implemented. Then according to the current needs parts of the code can be enabled or disabled using GLSL preprocessor instructions #define and #ifdef.
. It was easy to implement in the rendering engine and only a bit harder to create one unified shader. I don't want to describe here in details how shaders are managed in FSO, because it is also improved by my next patch which I will describe soon in my next post.
Po długim okresie prac nad Quarnem (niestety nie obyło się bez przerw), w końcu zdecydowałem się na wydanie wersji 0.0.90. Warto zaznaczyć, że nie jest to wersja nadająca się do użytkowania. Jej głównym zadaniem jest wyznaczenie osiągniętego milestone.
Zainteresowani mogą ściągnąć Quarna tutaj lub bezpośrednio tutaj. Możliwe jest także ściągnięcie gotowego obrazu dyskietki w tym miejscu. Uprzedzam, że w wielu częściach kod jest jeszcze niedopracowany i czasami wręcz razi błędami, jednak głównym celem tego wydania było ustabilizowanie pewnej podstawy na bazie której będą prowadzone dalsze prace. W najbliższej przyszłości planuję po kolei zająć się poszczególnymi elementami systemu znacząco je dopracowując. Obecnie, są one jedynie zalążkami, których głównym zadaniem jest wykorzystanie możliwości podsystemu Manes.