9/Feb 2013
By admin
4 min. read
This week I had one of the most interesting debugging sessions in a while. Here’s the minimal code snippet exhibiting the problem. It doesn’t really make much sense in itself, but I tried to remove everything not related to the bug itself (the actual case was much more convoluted):
1struct SVar
2{
3 SVar() : m_v(23000) {}
4 void operator=(unsigned short t)
5 {
6 if(_rotr16(m_v, 1) != t)
7 {
8 m_v += t * 100;
9 }
10 }
11 unsigned short m_v;
12};
13static const int MAX_T = 1000;
14struct Lol
15{
16 __declspec(noinline) void Cat(int t)
17 {
18 unsigned short newT = static_cast<unsigned short>(t < MAX_T ?
26/Jan 2013
By admin
2 min. read
Recently I had to write a tiny MSVC plugin to help visualizing one of our structures. It’s been a while since I’ve done it last time, so I started Googling for help. The good news is – it’s now much easier to find information/articles (mostly unofficial). The bad news – there are still many dark corners & I ran into a problem that took me a while to figure out.
16/Jan 2013
By admin
1 min. read
Today I was contacted by Syama Pedersen and asked about participation in an indie game project called Junkers. I don’t really have too much spare time these days, so it’s not possible, but I thought I’d at least help spreading the word, perhaps someone would be interested in joining their team. Demo reel can be found here, contact Syama if you’d like to help.
Old comments Pawel W 2013-01-16 08:29:21 Pretty cool anims for ones done “by hand”.
29/Oct 2012
By admin
8 min. read
Recently, I spent some time debugging all kinds of crazy, once-in-a-blue-moon type of bugs, usually MP related and often happening in final/release builds only. The annoying problem with these is they tend to “hide” when you try to repro them and then pop up 5 minutes later when you’re investigating something else. That’s why it’s often crucial to catch every chance you get and try to extract as much information as possible out of every case.
18/Oct 2012
By admin
4 min. read
I’ve been optimizing RDE’s vector class a little bit recently. In all honesty, it’s probably the least interesting container, there are only so many ways to do things, so it all boils down to working at the instruction level, trying to eliminate everything that’s not needed. Those few cycles don’t even matter in the grand scheme of things, but it can be an interesting learning experience at times. One of the functions I was interested in was erase.
9/Sep 2012
By admin
4 min. read
Pointers to member functions is one of those aspects of C++ that I use every 2 years or so. I know how they work, but I usually need some refreshing on the details (especially the syntax kills me every time, although I might actually remember it now). One of the gotchas with them is - you’re not supposed to cast it to void* (see this question for example). That’s one of those guidelines that I read long time ago, absorbed and never gave a second thought.
4/Sep 2012
By admin
4 min. read
Had an interesting little debugging adventure recently. Few weeks ago we started getting QA reports about some of the visual effects looking all weird. I tested it locally, it all seemed fine. QA dug deeper and they discovered it only occured with disc builds (not necessarily running from a DVD, just after installing fully preprocessed build), P4 version was good. The problem with installed builds is they are very close to final, fully optimized, all assets in final version with no debug info etc, so it’s pain in the ass to debug.
23/Jul 2012
By admin
4 min. read
I’ve not been reading too many C++ books recently, but I have a foggy memory of a recommendation they include: do not pass arguments by value, unless it is a built-in type. Justification is given, probably, but it does not seem to stick and people tend to only remember the “pass by value - bad” part. There is plenty of programmers out there, who do it automatically - built-in by value, anything else - by reference.
11/Jun 2012
By admin
3 min. read
Recently I got fed up with manually attaching to game process every time. I knew there were some macros that would search for given executable and attach automatically, I even found some of them. Sadly, it seems like API changes slightly with every release, so couldn’t get any of them to work with MSVC2010. In the end, I just hacked my own one, attaching it below (MSVC2010, probably won’t work with any other version).
10/May 2012
By admin
6 min. read
I can’t remember the exact date, but I know it was early May or the end of April, 2002. I’ve just realized I had started my gamedev adventure almost exactly 10 years ago. It seemed like a logical step, never really considered any other career choice, it was my dream job and quite natural progression after few years of demo coding. I responded to a job advertisement at the gbadev mailing list (wow, I love the Internet, I actually found this post), flew to Palermo for a weekend, survived my first job interview (even though I was still slightly hung over from the party 7th Sense guys took me the day before…) and before I knew it - I was flying to Italy again, this time for good.
6/Apr 2012
By admin
1 min. read
My recent article turned out to be quite popular, however it seems that people focus on the problem of undefined behavior rather than optimization itself. Quick clarification then, so that we’re all on the same page. I do not advocate relying on undefined behaviors. They are… undefined (duh). I merely noticed in practice you can have ‘null references’, just as you can have null pointers. I also would be very surprised if there was any compiler that actually generates code testing against null pointer dereference.
2/Apr 2012
By admin
6 min. read
Programming games is an uphill battle. We always try to fight for more, but our resources are limited. There’s never enough RAM, the CPUs are never too powerful and obviously same thing applies to bandwidth - we could always use some more. The eternal problem of mutiplayer game is trying to send as much information as possible using as little memory as possible. One of the weapons in our arsenal is compression.
25/Mar 2012
By admin
3 min. read
One of the most popular questions that fresh C++ programmers ask is about differences between pointers and references and which one to use. One of the differences people cite is “references can never be NULL”. That’s true in theory and according to the standard, but in practice, especially when mixing pointers and references there’s nothing preventing you from doing this:
13/Mar 2012
By admin
2 min. read
Usually, around this time, I publish my collection of links to GDC presentations. This year however haven’t been really paying too much attention, took a week off and went to Mexico. I’ve only started to catch up… Do not despair, though, Jare has done a great job and you can find links at his blog.
The trip itself was fun, although very different from our previous adventures as it was the first time we took our 10 months old daughter with us.
12/Feb 2012
By admin
4 min. read
Few days ago, we released Darkness 2, the game I’ve been working on for the past 18 months. I won’t write too much about the game itself, if you’re interested, you probably know about it already, if not - check out the demo. Usually, once the game is on the market, devs will keep on stressing how they were killing themselves in order to make the best product possible.
29/Oct 2011
By admin
1 min. read
Hopefully, your engine includes a crash handler. If it does not, stop reading, add one (here’s simple example) and then continue. In most cases, when something goes wrong, log files contains fully resolved callstack. However, sometimes, especially at the last stage and (semi) final builds, crash reporter might be disabled and now all we have is a list of addresses. Luckily, it’s still possible to resolve those, using Sony’s tools (that’s also what I use in PS3 version of MemTracer).
2/Oct 2011
By admin
6 min. read
The broken windows theory is a criminological theory first introduced in 1982 article by James Q. Wilson and George L. Kelling. The gist of it is given in this example: “Consider a building with a few broken windows. If the windows are not repaired, the tendency is for vandals to break a few more windows. Eventually, they may even break into the building, and if it’s unoccupied, perhaps become squatters or light fires inside.
30/Sep 2011
By admin
2 min. read
Two trailers released recently. Starbreeze showed first footage of their Syndicate remake:
I mostly worked on cancelled Bourne project when I was there, but lots of friends still at SBZ, so I’m glad to see their hard work is coming to fruition.
Few days before, 2K released trailer for the game I’ve been working on for the last 15 months - Darkness 2:
I really like it, mostly because it explains the setting/first game events a little bit.
21/Aug 2011
By admin
4 min. read
As you can probably tell from this blog, I spent fair chunk of my time optimizing code/thinking about optimizations. One of the main problems with optimizing code is making sure we didn’t break anything in the process. It might be tricky, especially when modifying algorithms with many edge cases, but even simple changes are dangerous, probably because people don’t test them so thoroughly. I still feel a little bit nervous upon seeing “Little optimization in XXX” in P4 changelist description (heck, I’ll be the first one to admit, I broke code as recently as last week…).
24/Jul 2011
By admin
5 min. read
As you are probably aware, game developers have mixed feelings about STL. Sure, it has advantages, it’s already there, doesn’t have to be coded from scratch, it’s standard. On the other hand, the guidelines are very broad, implementations can vary wildly. Performance/memory guarantees seems to be hard to enforce. Even if the interface is always the same, there’s enough wiggle room underneath to seriously break some applications. Take clear() method for example.