95 Patches Ready The Intel Mesa Driver For OpenGL 4 On Haswell

[Ancurio]

In case you own a Haswell system I propose the following experiment: Keep the extension announcement in place but error out whenever some code really tries to use fp64. Report back in a year because at least I am curious whether your statement will still be true then.

This feature is six years old; suddenly having support in a FOSS driver isn't going to magically inspire developers to use double precision in their shaders. I feel like fp64 is one of those things that are exposed in GL not because developers asked for it, but because the hardware can do it.

[skies]

95 patches for a feature nobody uses, just so a string somewhere changes from "3.3" to "4.0"..

OpenGL is used a lot outside games you know? Movie & special effects creation, 3D animation, Oil & Gas exploration, Scientific imaging, medical equipment, chemical engineering, weapons systems and maybe even nuclear power plants use OpenGL for instrument visualisation.

You never know what extensions are used in professional applications, so you have to support all of them.

[Kraut]

I wonder if some future developer love for Haswell IGPU will help to get my multi monitor setup running where I have one monitor connected to my 290 and the second one on the iGPU. Works like a charm on windows and I don't have my 290 go in high voltage mode just because of a second monitor being connected to it.

[starshipeleven]

This feature is six years old; suddenly having support in a FOSS driver

This is not just "a FOSS driver". It is the only linux driver for Intel iGPUs.

And no, adding support for it was required to allow sanctioned/safe use of other OpenGL 4.x features as Intel cannot really go and say "well I lack only this feature but your program should theoretically work fine too, so do that manual GL version override and stfu"

[caligula]

Then what are you complaining at? Intel GPUs worked fine for office work, it's not like libreoffice needs OpenGL 4.x

Obviously Intel should have shipped (MIT) free OpenGL 4.5 / OpenCL 2.0 / H.265 / Vulkan drivers for Hurd, BSD, and Linux already 3 years ago like RPi foundation did with RPi, all the chinese PowerVR/Mali powered boards did out of the box. They even hand you free money if you buy their GPU. Intel is the devil.

[Ancurio]

And no, adding support for it was required to allow sanctioned/safe use of other OpenGL 4.x features as Intel cannot really go and say "well I lack only this feature but your program should theoretically work fine too, so do that manual GL version override and stfu"

I'm sorry, this is not how OpenGL works. Most extensions are stand-alone and don't have inter-dependencies; I can't thing of a single extension that depends on doubles for that matter.

It's just that some games are unfortunately written so that they check for waay more features than they really use (ie. by hard depending on a GL version, instead of saying "core prof + these extensions"). I guess it's because the proprietary drivers have never really hinged behind in GL versions, and when they did, there were no ARB extensions being incrementally implemented (it was all or nothing). So game developers never had to care.

[starshipeleven]

I'm sorry, this is not how OpenGL works.

Quit being an idiot already. You cannot claim the device supports OpenGL 4.x unless the device supports ALL OpenGL 4.x extensions. End of story. You cannot say "oh it supports OpenGL 3.3 and <list of extensions>".

So quite a few useful OpenGL 4.x extensions CANNOT BE UFFICIALLY SUPPORTED by the driver (even if they actually work fine) unless this one gets done. Sure you can force a GL version override easily and everything will work fine, but that's not how OpenGL was meant to be used and it you are doing it at your own risk, so cannot be the official solution.

It's just that some games are unfortunately written so that they check for waay more features than they really use

Because this is how it was meant to be.

OpenGL version was supposed to tell a customer with an easy number what stuff could run on what hardware, because each number means "all features in this longish list are supported".
If you let everyone add features at random or not add some that they think are not useful or whatever, then the whole castle falls down.

[Ancurio]

Quit being an idiot already. You cannot claim the device supports OpenGL 4.x unless the device supports ALL OpenGL 4.x extensions. End of story. You cannot say "oh it supports OpenGL 3.3 and <list of extensions>".

So quite a few useful OpenGL 4.x extensions CANNOT BE UFFICIALLY SUPPORTED by the driver (even if they actually work fine) unless this one gets done. Sure you can force a GL version override easily and everything will work fine, but that's not how OpenGL was meant to be used and it you are doing it at your own risk, so cannot be the official solution.

Because this is how it was meant to be.

OpenGL version was supposed to tell a customer with an easy number what stuff could run on what hardware, because each number means "all features in this longish list are supported".
If you let everyone add features at random or not add some that they think are not useful or whatever, then the whole castle falls down.

Yes, you have indeed no idea how ARB extensions work I see no point in furthering this discussion.

[starshipeleven]

Yes, you have indeed no idea how ARB extensions work I see no point in furthering this discussion.

Nice retreat. What about you link me some part of the spec that allows vendors to claim they support OpenGL X even if they don't support the ARB extensions introduced by that OpenGL?

[W.Irrkopf]

I'm sorry, this is not how OpenGL works. Most extensions are stand-alone and don't have inter-dependencies; I can't thing of a single extension that depends on doubles for that matter.

While that may be correct, some extensions do not just depend on specific other extensions to be present but require a minimum GL level. E.g. ARB_ES3_1_compatibility has the following in the "Dependencies" section:
OpenGL 4.4, ARB_ES2_compatibility, ARB_ES3_compatibility are required. That was just the topmost extension in imirkin's glxinfo list.

So while in theory most games and applications should be able to work without fp64, they would not because in reality commercial software usually doesn't check for each extension individually but just for some minimum GL level plus a few optional extensions.

And before anyone asks: No, I'm not going to create a dependency graph that lists all the extensions that directly or indirectly require fp64 - and that would be the most reliably way to see whether moderns games/applications really do not require fp64 either directly or indirectly.