[HOpenGL] MacOSX accumulation buffer.

[Sebastiaan Visser]

That sad, because the document is from `Mar 26 2001'...

On Jan 27, 2009, at 7:34 PM, Corey O'Connor wrote:
> Not I.:-\ Last time I tried I used some hefty desktop graphics cards
> too. That was several years ago when this technote definitely applied:
> http://developer.apple.com/technotes/tn/tn2014.html#Section10
>
> "Mac OS X also supports AUX (auxiliary) buffers and an 8-bit stencil
> buffer. Accumulation buffers are not supported in hardware on Mac OS
> X."
>
> Cheers,
> Corey O'Connor
>
> On Tue, Jan 27, 2009 at 10:21 AM, Sebastiaan Visser  
> <sfvisser at cs.uu.nl> wrote:
>> Hello,
>>
>> Maybe my question is not really related to the HOpenGL library in
>> particular, but more general a MacOSX+OpenGL problem. I hope some  
>> of you
>> guys recognize this issue.
>>
>> It seems there is no way to get the accumulation buffer to work  
>> efficiently
>> on MacOSX. Using this buffer to implement a neat motion blur slows  
>> down the
>> framerate to less than 8 fps on my machine. A brand new Macbook  
>> with the
>> newest NVIDIA GeForce 9400M running a very simple demo with just  
>> one 3D
>> torus.
>>
>> I am using this initialization code:
>>
>>> initialDisplayMode $= [
>>>    ...
>>>  , WithAccumBuffer
>>>  ]
>>>
>>> initialDisplayCapabilities $= [
>>>    ...
>>>  , Where DisplayAccA IsEqualTo 8 -- Also tried 1, 16, 24, 32...
>>>  ]
>>
>> And use the buffer like this:
>>
>>> withMotionBlur comp = do
>>>  accum Mult 0.95
>>>  comp
>>>  accum Accum 0.05
>>>  accum Return 1.2
>>
>> The result looks verry pretty but is terribly slow.
>>
>> Is there someone how has ever used the accumulation buffer on  
>> MacOSX without
>> experiencing slowdowns?
>>
>> Thanks,
>>
>> --
>> sebastiaan