Shaders must die
It came in as a simple thought, and now I can’t shake it off. So I say:

Ok, now that the controversial bits are done, let’s continue.
Archive for 'rant'Shaders must dieIt came in as a simple thought, and now I can’t shake it off. So I say: Ok, now that the controversial bits are done, let’s continue. Another Vista review (after 6 months of usage)Ok, I don’t exactly like Windows Vista. But I just spent 6 months using Vista as my primary OS at work… because everyone else was using XP, and someone had to make sure everything works on Vista as well. So it was me. In summary, Vista is not that bad. Once you get used to changes in Explorer, different skin and so on – it’s actually usable. I think they have made some real improvements in the underlying technology, too bad they managed to “compensate” for all of that by inconsistencies and lack of polish in user interface. At this point it’s minor quirks in UI that annoy me, but apart from that, Vista is okay. Look:
So yeah. It’s not stellar, it has tons of small annoyances (and some large ones – try developing web plugins with UAC on…), but it’s usable. I might have gotten used to it by now, actually. How view on C++ changes over timeIt’s funny how one’s view on things change over time. Back in 2002, I wrote something that would be roughly translated like “C++ amazes me more and more”. In a positive sense! And I was talking about what is Boost.Spirit now. A reply on local game development forums I wrote today (again, rough translation): “C++ is very hard and quite a horrible language, maybe you should not use it unless there are no alternatives”. That’s quite a change in attitude we have here! I feel like much of C++ horrors are a consequence of “it just somehow happened” (the whole template metaprogramming thing) or as a backwards compatibility with C requirement. Or maybe not, but I do agree with what ryg says here. Let’s play the internet memes: Achievement of the week: MakeVistaDWMHappyDanceThis was the function that I added:
I know. Reading from screen when Aero is on is slow, bad and wrong. But then, what do you do? It’s better than users staring an all-white window just because Vista decided to draw it white, no matter what you think you’re drawing into it. …still,
that Nicholas added a while ago. Cool tech vs. boring detailsSome of the stuff I’ve been working on last week:
Boring tiny little details. This probably best summarizes where lion’s share of time goes when developing anything. I’m not working on some cool spherical harmonics lightmap compression. Or on cunning ways to encode shadow map information for better filtering. Or on using CUDA to compute something interesting. In other words, I’m not working on cool technology. Instead I’m adding missing menu items. Fixing obscure corner cases. Fighting inconsistencies in operating system APIs. Spotting misplaced pixels. Adding missing keyboard shortcuts. Nothing interesting to blog about! But still, methinks the difference between software that is merely “good” and software that is “great” is in the details. And only in the details. I’ll just take care of tons of more details. Maybe it will result in something good. Crunchtime!A few weeks ago it was all calm in the source control. Now it’s crunchtime! I’m the master of svn deception. I do tons of useless commits just so that the stats look good. Yeah! …ok, back to work. The awesome support we doYesterday’s experience catching up with Unity forums, as I remember it: Take a quick look at zillions of new posts. Answer about five questions with “what’s the value of your camera’s near plane?”. There should be some way to automate all of this. For every 20th question, reply with “increase your near plane!”, or something. Implicit to-pointer operators must die!
Seriously. Suppose there is some class, let’s say
Probably because it’s easier to pass color to OpenGL this way, or something like that. This is evil. Like, really evil. Especially if that class did not have comparison operators defined, and some totally unrelated code four years later does:
Ouch! Sounds like someone will spend four hours debugging something that looks like an event routing issue that only happens on Windows and only with optimizations on (yes, I just did that…). What happens here? The compiler takes pointers to two colors and compares the pointers. If for some reason both colors are temporary objects, then it can even happen that both get folded into the same variable/register/whatnot. The pointers are the same. Ouch! Implicit “nice” operators are just disguised evil. Remove that operator, add something like OpenGL 3: a big step in no direction at all?Well, the post title pretty much summarizes my take on it, doesn’t it? I guess I could just stop typing now… but I won’t! So after some promises, delays and a period of deadly silence, OpenGL 3.0 was released. Response to it was “interesting“, to say at least. Some part of that response is related to seriously mishandled communication on Khronos part. Some part is because GL 3.0 is not what it was promised to be. Let’s just ignore the communication issue, it does not affect OpenGL itself in a direct way (it affects the developer community though). By the way, I borrowed part of the post title from a blog post linked from opengl.org. In general, I do not agree with that blog post, but it’s a valid point of view. Unlike some other blog posts linked from opengl.org that are just pure garbage… I am not sure what are the goals of OpenGL at this point. OpenGL’s current position, as far as games are concerned, seems to be roughly this:
Why? Because Windows has got D3D, which is far more stable, comes with useful tools, more often updated and actually works for variety of users (I’ll get to this point in a second). Mobile platforms have OpenGL ES, which is decent. All consoles have their own APIs (some of them similar to D3D, none of them similar to GL). So that leaves OpenGL as the choice on OS X, Linux and such. Not because it’s better. Because it’s the only choice. “Oh, but look, id uses OpenGL! Two other games use OpenGL as well!” Well, good for them. But they are in a different league than “the rest of us”. For some games, driver writers will do whatever it takes to get those games running correct & fast. Surprise surprise, id games fall into this category. For the rest of us – no such luxury. Hey, try talking to your friendly IHV, the most likely answer is “yeah, but are really busy with some high profile games right now, ping us back in two months”. After two months, repeat. So the rest comes from somone who is not working on the high-profile games that IHVs specially tune drivers to. If OpenGL’s goals are to stay in this current position, then GL 3.0 is okay. It adds some new features, brings some extensions into core, hey, it even says “it’s quite likely that maybe perhaps someday some of the old cruft in the API will be removed, if we feel like it”. No problem with that. However, OpenGL is advertised as something different, as if it wants to:
Which is quite different from it’s current position. I’m not sure if that’s the goal of OpenGL. Myself, I don’t care about the mythical cross-platform API that would actually work on those different platforms. API is a tool to do stuff; if different platforms have different APIs – no problem with that. However, if OpenGL wants to achieve this advertised goal, it has to do several things. First and foremost: Actually work Stable drivers and runtime. In it’s current state, GL is too complex to implement good quality drivers/runtime. Complexity can be reduced in several ways:
GL 3.0 could have done both of the above, instead it did none. It could have cleaned up the API, and provide one platform independent GL 1.x/2.x library that calls into actual 3.0 runtime. All the fixed function, immediate mode, display lists, whatever would be in one nice library. Even existing apps could continue to function transparently this way (with the benefit of actually simpler = more stable drivers). Support platforms/hardware/features user needs This is of course dependent on the user in question. For someone like us, we still have to support 10 year old hardware. D3D9 does a fine job for that (provided you have drivers installed, and DX9 runtime installed – which comes included in XP SP2 and upwards). OpenGL 2.1 and earlier would do a fine job for that, provided it would “actually work” (see above). If GL 3.0 would be as was originally promised – almost new API, shader model 2.0+ hardware, it would be sort of fine. In our case, that would mean writing and supporting two renderers – “old GL” and “new GL”, where old one would be used on old hardware or old platforms where “new GL” is not available. If the new runtime were much leaner, much more stable and generally nicer, this would not be a big problem. With actual GL 3.0, in theory one does not have to write two renderers. Minimum hardware level for GL 3.0 is shader model 4+ though. So to support both old hardware/platforms and new hardware/platforms, quite a lot of duplication has to be done. Especially if you intend to go towards proposed “future GL path”, i.e. start dropping deprecated functionality from the codebase. At which point you’ll probably write two separate renderers already. So we’re back to where original GL 3.0 would have been, just without any extra niceness/stability/leanness right now. Oh, and look at vendor announcements from 2008 OpenGL BOF. NVIDIA: we have almost full drivers now. AMD: we’re committed to having drivers. Intel: look for GL 3.0 on future platforms. In other words, looks like current Intel’s cards won’t ever have GL 3.0 drivers. And in our target market, Intel has the majority of cards. That sounds very much like “just ignore whole GL 3.0 thing” plan to me. Be nice This is a point of far lesser importance than “actually work” and “support what is needed” ones. Having good tools (PIX, …), documentation, code examples etc. is nice. But not much more; being nicest API in the world does not do much if it does not actually work or does not support what you need. Even in this area, actual GL 3.0 is not nice – it’s full of redundancies and crap that goes 15 years back in history. Summing it up To me, GL 3.0 looks like a blunder. Instead of fixing the core problems, they just postponed that. Well, Keep up the good work! Invincible shutdown buttons!I booted into Vista yesterday to test something. It offered a bunch of updates to install. After they were installed, I got this: I am not sure what shutdown buttons do when they look like this. I guess they are invincible, or something. Ha, I’m your log off button! You can’t kill me! Yes, one of the updates installed was the ATI driver update, so I guess there’s some glitch somewhere in the driver update that makes some buttons be displayed like this… But hey, this is not some random driver that I found on the net, it’s the one that is officially suggested by Vista’s update! |