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superoptimo

OpenGL Why OpenGL 3.0 is so badly?

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superoptimo    129
The real question is Why the maintenance of a mutable object system in OpenGL 3.0 is so badly? How it affects its performance? Which disadvantages it presents on Geometry shaders?

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superoptimo    129
I don't get it.

is it so bad enough for throwing it away?

Of course, OpenGL doesn't reflect the real architecture of Graphics processors. But it works!

At least on my computer, OGL beats DX9c. But I didn't experiment with DX10 yet, may the situation would be far different. (core 2 duo with NVidia 8400)

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Numsgil    501
Back in the day OpenGL was ahead of the curve, and hardware was racing to catch up. Most games let you switch between the software rasterizer and hardware acceleration. Now it's the other way around, and the hardware guys are setting the curve and the API people are racing to keep up. OpenGL is way behind, or forces the hardware guys to jump through hoops, while DirectX is mostly on par with what the hardware is doing, so basically if you're game needs to use the latest hardware features (which most AAA titles do), then you're pretty much stuck with DirectX.

If you don't care about the latest features, and you don't mind a little obtuseness here and there (and lack of support on most integrated chipsets), then OpenGL is fine.

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Cromulent    398
Quote:
Original post by Numsgil
Back in the day OpenGL was ahead of the curve, and hardware was racing to catch up. Most games let you switch between the software rasterizer and hardware acceleration. Now it's the other way around, and the hardware guys are setting the curve and the API people are racing to keep up. OpenGL is way behind, or forces the hardware guys to jump through hoops, while DirectX is mostly on par with what the hardware is doing, so basically if you're game needs to use the latest hardware features (which most AAA titles do), then you're pretty much stuck with DirectX.


Which features is OpenGL lacking that DirectX has then?

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Yann L    1802
Quote:
Original post by Numsgil
OpenGL is way behind, or forces the hardware guys to jump through hoops, while DirectX is mostly on par with what the hardware is doing,

This is incorrect. OpenGL offers essentially everything DX10 offers (and very shortly also D3D10.1, and possibly even more). It's not about functionality, it's about driver support and about facilitating both driver development and application development. Essentially, D3D costs both IHVs and application developers less money to maintain than OpenGL. That's the whole deal with OpenGL 3.0, not functionality.

Quote:
Original post by Numsgil
so basically if you're game needs to use the latest hardware features (which most AAA titles do), then you're pretty much stuck with DirectX.

Also incorrect. You can access the latest features with OpenGL, but you have to rely on driver support. Which can be very variable depending on IHV. And very few (probably no) current AAA games use the latest DX10 features. Heck, most AAA games don't even use the latest DX9 features.

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Ignifex    520
As posted above, OpenGL does not lack any features. It is just not a good representation of today's hardware, making it difficult to implement in the drivers. Current OpenGL also makes programming more difficult than it should, with a larger specification (causing a longer learning curve) and unclean code (using extensions and redundant calls).

OpenGL 3.0 should have been a new clean API, featuring an object model that would make learning and working with OpenGL easier. It would also make driver development a lot easier, without the functionality the hardware is not made for. Also, the object model would make code look a lot cleaner.

The reason for not writing a new API is presumably because it would force application developers to write new code to continue using the latest hardware. This in itself is a contradiction, because the latest hardware should require change to use after 10 years, no matter the API that uses it. OpenGL's answer so far was to use extensions. The new answer is probably deprecation.

Right now we can only hope OpenGL 3.1 will be what we have hoped to see now.

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MARS_999    1627
OpenGL 3 is a step in the right direction, a lot of old crud is going to be cleared away with each revision. GL3 and GL2.1 with extensions is DX10 compliant. So no need to worry about being left behind as long as you are on Nvidia hardware, and soon ATI will be up to speed also. Intel who knows their GPUs blow, and so do there drivers. I hope this isn't the case with Larrabee, or it will be the fastest death of a GPU since i740!!!! :)

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soconne    105
Its good to see more evidence that the gamedev forums are no longer open to free discussion, as my last post was deleted from this thread. Keep up the good work gamedev staff!

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superoptimo    129
Quote:

Its good to see more evidence that the gamedev forums are no longer open to free discussion, as my last post was deleted from this thread. Keep up the good work gamedev staff!


hmmm!... it feels like somebody is twisting the public opinion about cross platform development. There is a silent power behind of this forum.

So, the message is clear. The advice is to keep Micro$oft untouched. Don't blame against the M$ empire or against of its nice Windows OS... or the contrary you'll be silenced.

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_the_phantom_    11250
In fact his post had nothing todo with MS (that's an S btw, not a $, please refrain from trolling) and wasn't remotely useful in the slightest thus it was removed (and not by myself either).

There was no twisting at all, only the removal of a dumb post; lets just say there is a reason his rating is 0.

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Yann L    1802
Not to fuel the conspiracy theories, I removed his post. It was a troll post that had absolutely nothing to do with Microsoft.

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V-man    813
Quote:
Original post by Ignifex
As posted above, OpenGL does not lack any features.


Geometry shaders has not been included in GL 3.0
I'm not sure why because the spec touches some DX10 features.
You can of course continue to use GL 2.1 and GL_EXT_geomtry_shader4
Instancing is not present but one could argue that GL doesn't need it.

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_the_phantom_    11250
Yes, but the point was it wasn't in the core.

If you are going to take the 'you can do it via this extension' route then GL3.0 is basically redundant as basically everything you can do it with it could be done via extensions already.

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soconne    105
Quote:
Original post by Yann L
Not to fuel the conspiracy theories, I removed his post. It was a troll post that had absolutely nothing to do with Microsoft.


When did this post become solely about Microsoft? I was simply pointing out the ridiculous wants and needs of cleaner API by some developers. Its called a pun. Look it up.

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_the_phantom_    11250
Quote:
Original post by soconne
Quote:
Original post by Yann L
Not to fuel the conspiracy theories, I removed his post. It was a troll post that had absolutely nothing to do with Microsoft.


When did this post become solely about Microsoft? I was simply pointing out the ridiculous wants and needs of cleaner API by some developers. Its called a pun. Look it up.


He was responding to superoptimo's post following your own.

And no, it wasn't a pun, a pun is a play on words (maybe you should look it up before telling others to) what you posted was nothing short of idiotic troll bait and this is a formal statement telling you to drop it now.

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superoptimo    129
Well, I wouldn't like to discuss about Microsoft on this forum.

The problem raises when we start comparing OpenGL against DirectX, because each API has its own way to do the same thing. F.E. OpenGL doesn't require Instancing at all.

Instead of thinking about how much likes/dislikes OpenGL from DX10, just think about programmers and applications.

It's true that OpenGL evolution goes too slow and OGL3 is a little disappointing, but who cares? sometimes it's more convenient when you hate the idea of rewriting the whole engine every year. Take in consideration how different becomes each DirectX version, see how they always broke the entire API, and who knows how different from DX10 would be the upcoming DX11. When DX would reach its maturity? never.

Also think about the users that are developing for non-windows platforms, They're important people too! and there is more life outside of Windows Vista.

However, in this topic the real question is how much performance we're loosing with the current OGL3.0 specification. At this moment, it's no clear at all.

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_the_phantom_    11250
Quote:
Original post by superoptimo
Take in consideration how different becomes each DirectX version, see how they always broke the entire API, and who knows how different from DX10 would be the upcoming DX11. When DX would reach its maturity? never.


DX9 was around for about 5 years before DX10 came along and will continue to be around for the forseeable future. DX10 did break compatibility but in a good way because at a certain point your abstraction no longer abstracts well enough and a rethink is required. DX11 is DX10 with some concepts changed and brings added flexibility which would be well worth the [short] amount of time those changes will require in current code based which work on DX10 hardware.

There is a difference between 'mature', indeed I would argue that DX9 is mature now as it is stable and well known, and 'stagnant'; OpenGL has become the later.

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Yann L    1802
Quote:
Original post by superoptimo
F.E. OpenGL doesn't require Instancing at all.

Of course it does. The idea that OpenGL doesn't need instancing is a common misconception. It needed it less than DX, due to its nature of being a state machine and having less drawcall overhead. But this doesn't mean that native instancing wouldn't be tremendously beneficial to OpenGL as well. That's why NVidia created the EXT_draw_instanced extension some time ago, and the concept is now part of GL3.0 (exhibit A, exhibit B...)

Quote:
Original post by superoptimo
Instead of thinking about how much likes/dislikes OpenGL from DX10, just think about programmers and applications.

Instead of thinking about programmers and applications, think about driver support. Because that is the one most important aspect of any hardware abstraction API out there.

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Demirug    884
Quote:
Original post by superoptimoTake in consideration how different becomes each DirectX version, see how they always broke the entire API, and who knows how different from DX10 would be the upcoming DX11. When DX would reach its maturity? never.


I am not sure how many Direct3D transitions you have done. As I use DirectX since it was called “Game SDK” I had take any one of them. So far there were only two larger breaks. The first one was the move from the execute buffers to a draw primitive concept and the second one the big cut for Direct3D 10. All other versions changes were quite easy and mostly doable with some search replace. The move to Direct3D 11 will be an easy one. I can port our current Direct3D 10 backend in less than one day and then start using the new stuff.

I agree that it would be nice if Direct3D stops changing but how should this happens when the hardware that is controlled still changes? OpenGLs answer to this challenge are extensions. I would not call this maturity either especial if I see the sections about interaction with other calls in the documentation.


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