Re: [Openexr-devel] Shade me confused

[Nafees Bin Zafar]

Are there plans for a GL_HALF_NV type?  I would thing it would be at 
least equally natural for the main program to do the conversion to half, 
and explicitly specify that it's sending in half format data.  Also it 
is plausible to imagine that an application's internal format is half, 
in which case there would have to be a convert to float, only for a 
convert back to half to occur right away in the driver.

Or am I missing something?  Is comptime's internal format half, or 
float?  Nuke uses floats.

-n

Drew Hess wrote:

> It is float data that gets uploaded to the card, due to a bug in the 
> current (as of 4290) Nvidia drivers.  Once the bug is fixed, we'll be able 
> to send half data to the card instead.  It may be fixed in today's 4390 
> drivers on Windows, but I'm waiting for the equivalent Linux drivers to 
> find out.
>
> The magic conversion happens in the glTexImage2D call (the GL_FLOAT 
> parameter specifies the input pixel type).
>
>
> -dwh-
>
>
> On Thu, 27 Mar 2003, Nafees Bin Zafar wrote:
>
>  
>
> > Hi Drew.  Looking through the ImageViewFragShader class, I see that the 
> > texel data passed into glTexImage2D() is just regular float data.  The 
> > internal format spec is set to GL_FLOAT_RGBA16_NV.  So where does the 
> > magic conversion to half type occur?
> >
> > I am hoping that float data doesn't get transferred to the graphics card 
> > because that would transfer 16 unnecessary bits.
> >
> > -n
> >
> >
> >    
>
>
>
>
>  


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