[Bf-committers] OpenGL Profiles Project?

[Michael Matthews]

Thank you very much guys, this is very good information.  Keep it coming if
anyone else has anything they think is obvious, but which might not be clear
yet.

On Tue, Oct 5, 2010 at 2:28 PM, Mathew Burrack <mburrack at yahoo.com> wrote:

> I actually had to write similar code back in the day for realMYST/URU for
> handling the peculiarities of various graphics cards (and back then, there
> were a TON more of them!). Having the user select a profile still doesn't
> make sense; instead, all it really takes is a bitfield of what capabilities
> you want to run with, which the OGL code checks (are GL_POINTS supported? If
> that bit is set, go that path, else go the fallback path, etc).
>
> In an ideal world, all you have to do is populate that bitfield with what
> you can detect from GL_EXTENSIONS, etc. Obviously, though, that never really
> works. So instead, you have a list of "exceptions", keyed off of the
> reported device name, vendor name, and driver version, that says "force this
> bit off" or "force this bit on". The startup code populates the bitfield
> based on what it detects, then checks the list of exceptions for bits to
> "fix" based on the card detected.
>
> That way, the user never has to select anything, and the code automatically
> does what it's supposed to, and enabling/disabling certain functionality
> based on a graphics card misbehaving is a simple matter of adding a line or
> two to the exception file (which can easily be tweaked based on bug reports
> from various users based on their gfx card; what's more, testing the fix
> with that user is dead simple, since all you have to do is send them a new
> exceptions list).
>
> ...worked on realMYST/URU just fine, at least :)
>
> -Mathew
>
> --- On Tue, 10/5/10, Tom M <letterrip at gmail.com> wrote:
>
> > From: Tom M <letterrip at gmail.com>
> > Subject: Re: [Bf-committers] OpenGL Profiles Project?
> > To: "bf-blender developers" <bf-committers at blender.org>
> > Date: Tuesday, October 5, 2010, 11:00 AM
> > It might be worth looking at how Ogre
> > and possibly CrystalSpace handle this.
> >
> > LetterRip
> >
> > On Tue, Oct 5, 2010 at 9:29 AM, Ton Roosendaal <ton at blender.org>
> > wrote:
> > > Hi,
> > >
> > > The sad truth is that the implementation of Opengl,
> > driver versions,
> > > bugs in drivers, all make Opengl not work as smooth as
> > it could be.
> > >
> > > The idea of a Profile is that you can setup per-system
> > settings that
> > > match the used hardware. These could be topics like:
> > > - FSA
> > > - Buffer swap methods
> > > - Bitmap support
> > > - mipmap settomgs
> > > - GLSL support levels
> > > - VBO (I guess)
> > > - dual graphics cards (?)
> > > - multi monitor setups, or stereo
> > > - ....
> > >
> > > This should not to be automatically checked on,
> > because most cards
> > > support it more or less. The profile is to ensure you
> > can get maximum
> > > performance and best quality user experience.
> > >
> > > What is also possible it to extend our bgl calls
> > (like
> > > bglBegin(GL_POINTS)), which wraps specific problematic
> > calls in Opengl
> > > to match what we expect. The choosen profile can work
> > that way without
> > > polluting the code with checks, making it all local in
> > a single C file
> > > or so.
> > >
> > > If you check in our code, the places where opengl
> > extension or vendor
> > > strings are being checked is probably a good
> > indication where we have
> > > issues.
> > >
> > > Hope this info helps. Be warned it's not the best
> > beginner code
> > > project, good understanding of opengl on various
> > systems, and on how
> > > Blender uses opengl is required. And don't forget
> > Mesa!
> > >
> > > Thanks,
> > >
> > > -Ton-
> > >
> > >
> > ------------------------------------------------------------------------
> > > Ton Roosendaal  Blender Foundation   ton at blender.org
> >  www.blender.org
> > > Blender Institute   Entrepotdok 57A  1018AD
> > Amsterdam   The Netherlands
> > >
> > > On 5 Oct, 2010, at 8:50, Mathew Burrack wrote:
> > >
> > >> Not to butt in here, but what exactly is the point
> > of the OpenGL
> > >> profiles? To simplify setting up OpenGL display
> > settings? What's
> > >> wrong with auto-detecting what the card is capable
> > of and just using
> > >> that? Is the goal to avoid settings that are buggy
> > on certain cards?
> > >>
> > >> It just seems to me like the end users would want
> > it to Just Work
> > >> and not care (or even necessarily know about) the
> > difference between
> > >> the profiles, and would just end up picking the
> > first one that
> > >> worked, not necessarily the best one.
> > >>
> > >> (Just trying to understand the goal here :)
> > >>
> > >> --mcn
> > >>
> > >>
> > >> --- On Mon, 10/4/10, Knapp <magick.crow at gmail.com>
> > wrote:
> > >>
> > >>> From: Knapp <magick.crow at gmail.com>
> > >>> Subject: Re: [Bf-committers] OpenGL Profiles
> > Project?
> > >>> To: "bf-blender developers" <bf-committers at blender.org>
> > >>> Date: Monday, October 4, 2010, 11:12 PM
> > >>> Might start by doing a hardware poll
> > >>> among the users. Perhaps on the
> > >>> Blender.org site and also a few of the other
> > bigger blender
> > >>> sites. I
> > >>> would bet that you could find a much narrower
> > design goal
> > >>> that way.
> > >>>
> > >>> I will start out here. Nvidia Gforce 7600 GS.
> > A nice card
> > >>> for blender
> > >>> but I am hoping to update soon.
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
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>
>
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