Re: [WINED3D 3/3] Add support for R32F and R16F texture formats

[Frank Richter]

On 04.09.2006 07:33, Ivan Gyurdiev wrote:
> ... using:
> GL_ARB_texture_float
> GL_ARB_half_float_pixel
>
> The internal format is RGB16/32F, which is wasteful (2 unused colors),
> but there's no way around that.

What about INTENSITY or LUMINANCE textures?

-f.r.

[WINED3D 3/3] Add support for R32F and R16F texture formats

[Ivan Gyurdiev]

Frank Richter wrote:
> On 04.09.2006 07:33, Ivan Gyurdiev wrote:
> > ... using:
> > GL_ARB_texture_float
> > GL_ARB_half_float_pixel
> >
> > The internal format is RGB16/32F, which is wasteful (2 unused colors),
> > but there's no way around that.
>
> What about INTENSITY or LUMINANCE textures

It seems they store things to luminance and intensity bits internally.
Then at pixel processing time, luminance is replicated to r,g,b with 
alpha 1, and intensity is replicated to all channels.

So, it makes sense to me that those would work, but they don't.
I tried LUMINANCE32F_ARB, and INTENSITY32F_ARB.
3Dc demo with FBOs refuses to work with both.
It works perfectly with RGB32F_ARB.

Since I haven't read the spec inside and out, and am not very familiar 
with how luminance and intensity values are processed internally, it 
seems more cautious to me to stick to RGB(A) formats. Also, I'm reading 
comments like these:

GL_EXT_framebuffer_object:

* An internal format is "color-renderable" if it is one of the  
          formats from table 3.16 whose base internal format is RGB or  
          RGBA.  No other formats, including compressed internal  
          formats, are color-renderable.