[Development] QtCS: OpenGL session notes

[marius.storm-olsen at nokia.com]

On 27/06/2012 12:14, ext Sean Harmer wrote:
> On Wednesday 27 June 2012 16:30:50 marius.storm-olsen at nokia.com
> wrote:
>> On 25/06/2012 13:44, ext Girish Ramakrishnan wrote:
>>> Future plans - Desktop OpenGL 3+ support, ES 3 support
>>
>> We've just added ANGLE support in Qt (-angle <dir>), to enable
>> DirectX usage instead of OpenGL ES 2 on Windows, due to many buggy
>> drivers.
>
> You mean for embedded flavours of Windows right? OpenGL 3+ works fine
> on desktop windows - although getting hold of a Core Profile context
> on Windows via Qt was broken last time I tried it (but that was some
> months ago).

No, I don't mean for embedded alone. Desktop OpenGL drivers are also of 
quite varying quality, and the DirectX drivers are usually better.

Not to mention that with Windows 8 you might have a hard time getting 
access to the OpenGL APIs, depending on which system you are on and how 
integrated you want to be.

No WGL/EGL support for Metro applications afaik, see 
http://msdn.microsoft.com/en-us/library/windows/apps/br205756.aspx and
http://social.msdn.microsoft.com/Forums/en-US/winappswithnativecode/thread/c77de65a-1fbb-491f-9f6b-0c4a7b452ec2 
and
http://social.msdn.microsoft.com/Forums/en-US/winappswithcsharp/thread/a861db02-dce8-4f61-9969-b8a7a7cd55c7

(Yes, non-Metro apps can use OpenGL just fine, although reports have 
come back that currently the OpenGL drivers are lagging behind the 
DirectX ones.)

No OpenGL for Windows 8 RT (ARM) version either, which should also be a 
target.


>> How will this effort affect this usage?
>
> The same way it will affect those platforms that only support OpenGL
> ES2 I guess - they just won't use the new features/capabilities.

Ok, so ifdef out the extensions completely when we compile with the 
ANGLE library?


>> Will we actively contribute to the ANGLE project, to ensure it's
>> usable when we extend our use of OpenGL?
>>
>> It would be bad for end users if they rely on ANGLE and we change
>> the OpenGL backend to use functionality not covered by ANGLE in the
>> next version, making migration to the next version of Qt
>> impossible.
>>
>> What is the timeline for OpenGL 3+ support, and when is OpenGL ES
>> 3 scheduled for release?
>
> It is possible to use OpenGL 3 (or even 4) on the desktop right now
> just that Qt does not yet wrap the new features.
>
> OpenGL ES 3 is scheduled for release "soon" which translates to
> probably sometime this year. It is supposed to reduce the delta
> between desktop OpenGL and OpenGL ES.

Good to know, thanks.


-- 
.marius