[osg-users] [osg-submissions] GL3 Mac OS X needs VertexArrayObject

[Mathieu MARACHE]

I've finally made my mods against master branch on my clone for the
OpenSceneGraph repo.

https://github.com/openscenegraph/OpenSceneGraph/compare/master...mathieu:feature/CoreProfileMacOSX?expand=1

I use the example osgsimplegl3 to display files, I've added the
osgUtil::Optimizer to retessellate since CoreProfile doesn't do QUADS or
POLYGONS.

I've hacked into Geometry only to create a VAO and bind it. If I unbind it
I don't get anything displayed with the osgsimplegl3 example.

However this doesn't look good since only the first geometry gets
displayed...

WIP


--
nǝıɥʇɐƜ

On 9 June 2016 at 11:57, Mathieu MARACHE <mathieu.marache at gmail.com> wrote:

> Hi Robert,
>
> Indeed VAO support is needed (in obligatory sense) for Macosx Core Profile
> targets but would be useful to other platforms also since it would make the
> system more efficient.
>
> I'm putting osg-users's mailing list in copy to see if someone has more
> insight into VAO.
>
> I've tried to setup VAO inside Geometry and make appropriate calls when
> needed but fail to show more than one geometry...
>
> I was on OpenSceneGraph-3.4 branch, I will try to setup a working branch
> from master to show what I came up with. We can discuss on what would the
> appropriate route should be to implement this. As you mentioned it would
> imply osg::Geometry and maybe also osg::State modifications...
>
> Regards
>
> --
> nǝıɥʇɐƜ
>
> On 9 June 2016 at 09:19, Robert Osfield <robert.osfield at gmail.com> wrote:
>
>> Hi Mathieu,
>>
>> On 9 June 2016 at 07:44, Mathieu MARACHE <mathieu.marache at gmail.com>
>> wrote:
>> > I'm struggling to understand what to do. I merely put up a solution
>> that was
>> > explained in a staled thread from 2012 (!), subject was : OpenGL 3.2
>> support
>> > in OS X 10.7 (Lion)
>>
>> This was clearly just a hack to get things "working" not an actual
>> solution.
>>
>>
>> > I see your points, you are right this is not a general solution.
>> >
>> > I'll be reading a bit more on VAO and try to add VAO support directly in
>> > Geometry is possible...
>>
>> I would be worth just moving the discussion about VAO support to
>> osg-users so we can all discuss the what solution.  I'm happy to pitch
>> in some time to getting this resolved for 3.6.
>>
>> Right now from what I've learnt that natural place for binding the VAO
>> would be in osg::Geometry.  It may be that osg::State would be the
>> part of the OSG that does the binding as it already manages the vertex
>> arrays and associated buffer objects.    The VAO essentially wraps up
>> all the vertex array settings in one place so that once it's set up
>> one just binds a single VAO object rather than a VBO and then specify
>> the individual vertex arrays within this.  In theory this should mean
>> the system is more efficient - as long as we get the design and
>> implementation right.
>>
>> Robert.
>> _______________________________________________
>> osg-submissions mailing list
>> osg-submissions at lists.openscenegraph.org
>>
>> http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
>>
>
>
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