Sign in to follow this  
Followers 0
TheChubu

OpenGL
OpenGL 4.4 spec is published

20 posts in this topic

I'm excited about ARB_Sparse_Texture, though I'm a little confused as to why they don't support any of the 3-component texture formats.

1

Share this post


Link to post
Share on other sites

Not a very interesting revision, but the new extensions (sparse texture, bindless texture) are intriguing...

2

Share this post


Link to post
Share on other sites

Well, since I didn't saw any thread about it, here it is:

 

OpenGL 4.4 released.

 

OpenGL registry where you can see the pdfs of the spec.

 

And nVidia's drivers for it (Linux/Windows/x86/x86_64/yaddayadda). There are a few new extensions also available for OpenGL 3 hardware.

 

Thanks for the heads up.  I'll have to check it out.

Edited by MarekKnows.com
0

Share this post


Link to post
Share on other sites

I think the biggest improvement is the conformace test. From what i head from who prefer DX over GL is that the drivers sometimes have different behaviours for different cards (with openGL). With this change, all the driver will(?should?) have the same behaviour, making it easier to develop openGL programs.

1

Share this post


Link to post
Share on other sites

So, OpenGL 4.4 specs have been published, and AMD still doesn't have a [i]working[/i] implementation of OpenGL 4.3. This is wonderful. rolleyes.gif

0

Share this post


Link to post
Share on other sites

I'm excited about ARB_Sparse_Texture, though I'm a little confused as to why they don't support any of the 3-component texture formats.

GPU hardware hasn't supported 3-component texture formats for a long time (aside from packed formats like DXT1).

If you ask GL to give you an RGB texture, on the GPU it will allocate an RGBA texture and pretend that the alpha channel doesn't exit...

I think the biggest improvement is the conformace test. From what i head from who prefer DX over GL is that the drivers sometimes have different behaviours for different cards (with openGL). With this change, all the driver will(?should?) have the same behaviour, making it easier to develop openGL programs.

Yeah that's something that I always have a whinge about, so this makes me very happy biggrin.png

[the ARB] has created the first set of formal OpenGL conformance tests since OpenGL 2.0 [and] full certification is mandatory for OpenGL 4.4 and onwards

Edited by Hodgman
2

Share this post


Link to post
Share on other sites

Not gonna comment on the features since I'm still trying to play catch up (this is what happens when you live in a place where any upgrade to a PC ends up costing an entire salary, let alone getting a new computer that isn't already outdated).

 

I'm curious about the certification part, though. Yeah, sure, having a guarantee that drivers always work the same is nice, but how do they plan to enforce it? Does this mean it'll be outright illegal to release an OpenGL driver that isn't certified? I can see that being a massive issue for FOSS drivers (which does matter on Linux). Does anybody have exact details on what certification allows?

 

EDIT: should have checked more carefully

http://www.khronos.org/conformance/

 

OK, it's mostly a trademark issue (so e.g. Mesa probably still would be safe since it doesn't call itself OpenGL). It seems that FOSS implementations still would be able to go through the implementers program if they want to use the name (not the adopters one due to the fee).

Edited by Sik_the_hedgehog
0

Share this post


Link to post
Share on other sites

So, OpenGL 4.4 specs have been published, and AMD still doesn't have a working implementation of OpenGL 4.3. This is wonderful. rolleyes.gif

Well, AMD is much less of an issue than Intel, they (AMD) are actually pretty good nowadays. Intel is the real problem. They not only do not have a working implementation of OpenGL 4.0, but they also do not have a working implementation of OpenGL 3.0.

 

Which makes me wonder what this entire certification thing will be good for at all.

 

Intel will not pull functional 3.0 (let's not even imagine 4.4) drivers out of their magic hat, but Intel integrated GPUs are the main GPU in every El Cheapo computer, and in the major share of non-tablet computers anyway, too. And, outside the world of Android, they're pretty much omni-present in tablets as well.

 

Which will probably mean no more and no less than OpenGL will simply not be supported (or supported even worse as it is now) on a considerable share of hardware. Sorry for being pessimistic, but I just can't see Intel producing a quality 4.x driver and undergo certification any time soon. They'll just show everyone the middle finger, knowing their CPUs are sold anyway.

0

Share this post


Link to post
Share on other sites

 

So, OpenGL 4.4 specs have been published, and AMD still doesn't have a working implementation of OpenGL 4.3. This is wonderful. rolleyes.gif

Well, AMD is much less of an issue than Intel, they (AMD) are actually pretty good nowadays. Intel is the real problem. They not only do not have a working implementation of OpenGL 4.0, but they also do not have a working implementation of OpenGL 3.0.

 

Which makes me wonder what this entire certification thing will be good for at all.

 

Intel will not pull functional 3.0 (let's not even imagine 4.4) drivers out of their magic hat, but Intel integrated GPUs are the main GPU in every El Cheapo computer, and in the major share of non-tablet computers anyway, too. And, outside the world of Android, they're pretty much omni-present in tablets as well.

 

Which will probably mean no more and no less than OpenGL will simply not be supported (or supported even worse as it is now) on a considerable share of hardware. Sorry for being pessimistic, but I just can't see Intel producing a quality 4.x driver and undergo certification any time soon. They'll just show everyone the middle finger, knowing their CPUs are sold anyway.

 

 

 I really don't consider Intel to be that big of any issue. Their integrated graphics are in a completely different class compared to AMD and Nvidia's dedicated GPUs. I mean whats the real advantage to being able to enable the latest OpenGL 4 / DX11 level features in a game if its going to run at 5fps?

Edited by Chris_F
0

Share this post


Link to post
Share on other sites

 

Intel will not pull functional 3.0 (let's not even imagine 4.4) drivers out of their magic hat, but Intel integrated GPUs are the main GPU in every El Cheapo computer, and in the major share of non-tablet computers anyway, too. And, outside the world of Android, they're pretty much omni-present in tablets as well.

 

Which will probably mean no more and no less than OpenGL will simply not be supported (or supported even worse as it is now) on a considerable share of hardware. Sorry for being pessimistic, but I just can't see Intel producing a quality 4.x driver and undergo certification any time soon. They'll just show everyone the middle finger, knowing their CPUs are sold anyway.

 

 

I would be surprised if they added this certification if Intel haven't already said yes to it. What would be the point if it's still just AMD/Nvidia?

 

 

 

 I really don't consider Intel to be that big of any issue. Their integrated graphics are in a completely different class compared to AMD and Nvidia's dedicated GPUs. I mean whats the real advantage to being able to enable the latest OpenGL 4 / DX11 level features in a game if its going to run at 5fps?

 

 

That seems rather irrelevant in the context of conformance, where the point is that any features should behave the same, which is just as important if one only uses 2.0 functionality. AMD/Nvidia are already close enough, and the real advantage of the conformance tests would be when writing an application that doesn't require the beefiest hardware and being able to rely on it working the intended way on any device.

0

Share this post


Link to post
Share on other sites

Certification is just required for GL4.4+, so all that Intel (or AMD for that matter, should they be so inclined) have to do is freeze their implementation at a pre-4.4 level and hey-presto!  No need for certification and they can continue to ship driver bugs.

 

I wouldn't underestimate Intel, by the way.  Haswell is looking pretty good, is beating comparable parts from AMD, and in a couple more generations we may well see them emerging as a third serious player in the market.

0

Share this post


Link to post
Share on other sites

I wouldn't underestimate Intel, by the way.  Haswell is looking pretty good, is beating comparable parts from AMD, and in a couple more generations we may well see them emerging as a third serious player in the market.


Yeah, this.

Both in desktop and mobile the Intel machine has woken up and starting to push serious resources into the development; with AMD's CPU division sucking away the profits from graphics if Intel can keep up investment they could move into second place.

As for GL4.4; there isn't really a great deal to it.
From the headline features;

- Buffer Storage has mostly provoked arguements as to how useful it'll be (more so when the notes on the extension say that at least one of the bits might be ignored) - I'm pretty sure this also basically mimics D3D11's buffer controls

- Async Queries could be useful if you are doing anything which requires GPU output which would normally bounce thru a CPU buffer

- Shader Variable Layout, while intresting from a 'yay!' point of view is again basically a HLSL parity feature

- Multi-bind is a good addition but nothing earth shattering (and it's bizzare it wasn't about before... see D3D10)

- The 10-11-11 vertex format support is just... well, sane.. again, surprising it wasn't there before.

There are some intresting extensions about (sparse, bindless, draw parameters, variable group size(!), indirect parameters) but the core feels like a 'tidying up missing features vs D3D11' really.

Maybe GL4.5 will bring something new to the table in the core, we'll see, as D3D is basically stuck at D3D11 due to the enforcement of Win8.1 for D3D11.2 - OGL has basically a 3rd chance to try and become a viable option again.
2

Share this post


Link to post
Share on other sites

GPU hardware hasn't supported 3-component texture formats for a long time (aside from packed formats like DXT1).


If you ask GL to give you an RGB texture, on the GPU it will allocate an RGBA texture and pretend that the alpha channel doesn't exit...
 

 

Learn something new every day! Good to know this.. 

0

Share this post


Link to post
Share on other sites

Don't be like that, its getting there! tongue.png

 

"Getting there" isn't good enough.  GL4.3 has been specified for the past year, AMD are a member of the standards body that specified it, they should have had a full GL4.3 driver long ago.

0

Share this post


Link to post
Share on other sites

They should put more effort into streamlining the API again, and I'm not sure why we don't have a single state vector yet, neither why samplers are not solely shader side for example.

It would also be nice to be able to generate and submit a command buffer sequence easily. (Create it once, resubmit it as many times as you want, sorta like a copy/paste operation.)

 

How many ways do we need to specify a typed multi-dimensional array ?

BufferData, BufferStorage, TextureImage*, TexStorage*... That's way too many...

 

The API is at last giving us access to hardware features that have been available for years now, but the API isn't making the jump I'd like to see and change once and for all into OpenGL Lean & Mean, a promise from 2002 for OpenGL 2.0... (Long before 3.0/Long Peaks)

Edited by Ingenu
0

Share this post


Link to post
Share on other sites

What I don't get about query buffers is that for most query objects (including occlusion and timer, the most interesting ones) it says that at most one query can be active at a time.

 

In other words, you can now read many queries into a buffer object to avoid stalls and to avoid a round-trip to the CPU, but you can still only run one query at a time. Which, frankly, isn't so much different.

 

The only useful application is really transform feedback and/or geometry shader (where more than one query at a time can be active).

0

Share this post


Link to post
Share on other sites

Has anyone tried to implement the sparse textures? I've placed glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SPARSE_ARB, GL_TRUE) into my code and it compiles fine but there does not seem to be anything shader specific written in the specs (similar to the AMD versions where you use sparseTexture(sampler, coord)).

0

Share this post


Link to post
Share on other sites
Ah, yes, that omission... it took me a while to spot it as well (mostly because I couldn't believe it WAS missing); but yes, as it stands ARB_sparse_texture lacks the GLSL extension for shader -> cpu feedback loops.

While annoying this doesn't render the extension useless it just means you have to manage things via corser CPU side controls rather than using a shader feedback loop (which, to be honest, for a streaming solution you'll want anyway so no foul there really).

Part of me wonders if this omission is due to an NV or Intel GPU weakness where their current hardware can do the virtual texturing bit just fine but can't do the feedback loop; probably because it pretty much requires a writable buffer to be bound to any pipeline stage to be completely viable for all situations something AMD can do but it seems NV can't/won't expose on some/all of their hardware (see D3D11.1 'uav on all pipeline stages' issue for NV)... and god knows about Intel.

Truth be told however this extension, and the more powerful AMD varient get more intresting once the tiled resource extension comes into play; I don't have a link to the pdf handy but basically you'll be able to reserve a buffer (say 128meg) and then allocate out of that tile sized resources to your sparse textures rather than relying on the driver's best guess as it currently stands. (edit: and now I have the link to hand! Hardware Virtual Textures has the details.)

Combine sparse, memory controls and bindless and you've got one hell of a powerful set of features going forward. Edited by phantom
1

Share this post


Link to post
Share on other sites

Part of me wonders if this omission is due to an NV or Intel GPU weakness where their current hardware can do the virtual texturing bit just fine but can't do the feedback loop;

Indeed, Nvidia supports the general virtual memory framework but not the shader feedback. Hence DX11.2 having two tiers for tiled resources, with the second tier having the shader extensions.

Edited by MJP
1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0