Official feedback on OpenGL 4.0 thread

[kRogue]

On DSA and why it is more than just a convenience, see slide 67 of http://www.slideshare.net/Mark_Kilga...gl-32-and-more

But in all honesty, that the state is not shadowed is kind of screwy... we are not talking alot of data really... if we think about it, most objects just have a few bytes of state (here for example for textures I am not talking about the texture data itself but all the glTexParameters) so even if one had one million GL objects running around, it is not a lot of data...the only object that may have a fair amount of state is GLSL programs (as they save the values of uniforms) but one does not query those values anyways..

[Groovounet]

New topic, precision qualifiers: highp mediump lowp.

How does it works with "double"? I expect
lowp vec4 Color; to actually be a vec4 of half-float.
What about:
highp vec4 Color; would is be a vec4 of double-float?
And finally:
lowp dvec4 Color; ???
mediump dvec4 Color; ???
highp dvec4 Color; ???

I have found any detail about that...

[Pierre Boudier]

lowp/mediump/highp are currently ignored on desktop implementations (at least on amd). they are supported to ease porting of ES apps.

[Groovounet]

My own little OpenGL 3.3 review:
http://www.g-truc.net/post-0267.html

[Dark Photon]

On DSA and why it is more than just a convenience, see slide 67 of http://www.slideshare.net/Mark_Kilga...gl-32-and-more

Wow. Amazed at all the DSA dittos with nobody asking for bindless.

What I'd really like to see in 4.1 is the huge perf benefit of NV bindless batches in the core (namely just NV_vertex_buffer_unified_memory), or at least EXT/ARB extension. Convenience (DSA) is good, but performance sells.

But to add my voice, great job to the ARB on the 3.2/4.0 specs! An amazing amount of excellent work! Been said before, but this is like unwrapping Christmas presents.

[Ilian Dinev]

I second bindless, and really hope for shader_buffer_load .

[Stephen A]

On DSA and why it is more than just a convenience, see slide 67 of http://www.slideshare.net/Mark_Kilga...gl-32-and-more

Wow. Amazed at all the DSA dittos with nobody asking for bindless.

I guess this has something to do with how fragile bindless graphics are (or seem to be).

[Groovounet]

This post give a clue on how AMD will emulate double on Radeon 57XX <

http://oscarbg.blogspot.com/2009/10/...rt-in-gpu.html

I quite expect GeForce GTS 450 or so to do the same ... as everyone else actually.

Is anyone as ever had a need of double for something on the GPU?

The only need I ever had of double was back when I was student and I did some kind of physic simulation based on dynamics and probably not the most clever implementation. Double help to maintain computation stability.

[Dark Photon]

I guess this has something to do with how fragile bindless graphics are (or seem to be).

Could you clarify that? I don't find it "fragile" at all.

And the API mod for mere bindless batch support is so very, very simple, non-intrusive, and "intuitive". I'd take that alone! (i.e. vertex_buffer_unified_memory). shader_buffer_load is cool but could follow later IMO.

[Alfonse Reinheart]

Is anyone as ever had a need of double for something on the GPU?

Scientists do. I imagine the guys working on Folding@home are frothing at the mouth to get more bits of precision and IEEE-754-2008 support into more people's houses.

But scientists care more about this getting into OpenCL than OpenGL.