OpenGL to be crippled on Vista?

"Microsoft's current plan for OpenGL on Windows Vista is to layer OpenGL over Direct3D in order to use OpenGL with a composited desktop to obtain the Aeroglass experience. This means that OpenGL performance will be significantly reduced - perhaps as much as 50%. It would be technically straightforward to provide an OpenGL ICD within the full Aeroglass experience without compromising the stability or the security of the operating system. Layering OpenGL over Direct3D is a policy more than a technical decision."

Source: http://www.osnews.com/story.php?news_id=11489


Is this another anti-competitive attempt by Microsoft to impose DirectX on developers by crippling OpenGL, which is the standard on MacOS and Linux? Sure DirectX has been the preferred API for Windows and Xbox, but still... this makes me quite angry. I hope lawsuits can arise from this!

Xaero_Vincent wrote:

Is this another anti-competitive attempt by Microsoft to impose DirectX on developers by crippling OpenGL, which is the standard on MacOS and Linux? Sure DirectX has been the preferred API for Windows and Xbox, but still... this makes me quite angry. I hope lawsuits can arise from this!

Great first post.

You'll rise among the ranks of Orbit86 and Beer28 soon, young Padawan.

Orbit86 wrote:

lol Jeremy, he writes a whole paragraph and you answer with 3 words..lmfaooo

Dammit! An architect on the appropriate team - who presented at WinHEC - promised me that they would put out official clarification this week. Unfortunately I promised I wouldn't post the content of his email so I can't really say too much more.

Except to say, read the second sentence of the original post carefully:

"If an OpenGL ICD is run - the desktop compositor will switch off - significantly degrading the user experience."

I'm not sure on what basis the OP claims that there will be 'significant degradation' nor that "OpenGL performance will be significantly reduced - perhaps as much as 50%" when using the OpenGL to Direct3D translator that will be used when no ICD is available or the ICD does not support the selected pixel format. For 3D accelerated games like Doom 3, which is all that most people here probably care about, I anticipate that if an ICD is provided, it will be used - no translation to Direct3D.

The translator is still an improvement over Windows XP - if no ICD is installed, software rendering occurs on XP. On Vista it will use the OGL/D3D translator. The translator should be faster than software rendering.

this is FUD.

All video card vendors need to do to provide first class OpenGL support for Vista is to provide a driver written to the new Vista driver model (LDDM).


This is the same thing they do for XP (WDM).

Jorgie

Mike Dimmick wrote:

Dammit! An architect on the appropriate team - who presented at WinHEC - promised me that they would put out official clarification this week. Unfortunately I promised I wouldn't post the content of his email so I can't really say too much more.

Except to say, read the second sentence of the original post carefully:

"If an OpenGL ICD is run - the desktop compositor will switch off - significantly degrading the user experience."

I'm not sure on what basis the OP claims that there will be 'significant degradation' nor that "OpenGL performance will be significantly reduced - perhaps as much as 50%" when using the OpenGL to Direct3D translator that will be used when no ICD is available or the ICD does not support the selected pixel format. For 3D accelerated games like Doom 3, which is all that most people here probably care about, I anticipate that if an ICD is provided, it will be used - no translation to Direct3D.

The translator is still an improvement over Windows XP - if no ICD is installed, software rendering occurs on XP. On Vista it will use the OGL/D3D translator. The translator should be faster than software rendering.

If  it turns that Vista won't support OpenGL without either altering the user experiance (which is what will happen if they turn off desktop compositer when you use the drivers from Nvidia or ATI) or a decreasing performance I will be incredibly pissed off. I am working on an Indie game and it will need to run on Mac (which means I will use OpenGL) because Mac users are more open to Indie games and while it will probally ship before Vista I plan to make Indie games for awhile.

Why did I know this would happen?

The current OpenGL to Direct3D translator is fixed at version 1.4, but ICDs can support a higher version of the standard if they want to, since additional functions can be looked up with wglGetProcAddress. nVidia already ships an OpenGL 2.0 ICD with their XP drivers. Games will be able to use the ICD and all the features it supplies, including any manufacturer-specific features.

To make this absolutely clear: the desktop compositor will only be disabled - current plan - when the ICD is actually in use. Just having one installed, but not running an accelerated OpenGL app using the ICD, will make no difference - if your hardware supports the desktop compositor, it will be used. There are other circumstances where the compositor will be switched off: when a DirectX app locks the primary display surface (i.e. writes directly to the active video memory buffer), and when hardware overlays are used (e.g. for certain accelerated video playback).

Microsoft is focused on trying to get Windows Vista out. Supporting the additional features of 1.5 and 2.0 are presumably out in order to reduce scope, for the release version. There's nothing stopping them opting to upgrade the feature set of the translator over time, although I admit that the software rendering in Windows XP has not been upgraded (AFAIK).

Awsome, if the compositor is only disabled when the app is running then it won't matter because most games and modelers are fullscreen applications.

Beer28 wrote:

I don't plan to use windows again seriously, and I'm not even targeting my game for it, so I guess it's too bad for windows users.

I guess we'll have to put up with F.E.A.R. and Battlefield 2 then...*sigh*

Beer28 wrote:

Mike Dimmick wrote: Why did I know this would happen? The current OpenGL to Direct3D translator is fixed at version 1.4, but ICDs can support a higher version of the standard if they want to, since additional functions can be looked up with wglGetProcAddress. nVidia already ships an OpenGL 2.0 ICD with their XP drivers. Games will be able to use the ICD and all the features it supplies, including any manufacturer-specific features.

If they lock it at 1.4 that would be horribly unfair, because all the new features exposed in newer cards are in the 2.0 specification.

gizmo_ wrote:

I guess we'll have to put up with F.E.A.R. and Battlefield 2 then...*sigh*

Beer28 wrote:

I also don't expect you to know this because you don't use the platform, but I can have compositing on and use all the openGL features in windowed mode, while I retain my transparent and effects enabled desktop with X.