[Mesa3d-dev] GL_INTENSITY as a base format for texture images?

[Gareth H. <ga...@va...>]

Brian, this is in relation to the demo program I sent you earlier.

I've adapted one of the old GLUT demos to test all the different texture
environment modes for all texture formats.  The problem I'm seeing is
textures with GL_INTENSITY as a base or internal format.  It appears
that GL_INTENSITY is an illegal base format for an image (as it's not
valid for glDrawPixels) and thus is rejected in the format/type test in
Mesa (can't remember where that test is).  Perhaps I'm just missing
something, but my quick reading of the spec and the Red Book seem to
indicate that this is in fact true, but it really doesn't make sense to
me.  

The GL_INTENSITY texture combine functionality will surely never be
invoked if you can't make a GL_INTENSITY texture image, right?  From
looking at the implementation of the apply_texture (or whatever)
function, we need to be able to assign the base format to GL_INTENSITY
to get the correct texturing functionality inside the software
rasterizer, which is what I would have expected.  This is causing an
error at the moment.

Caveat: I'm kinda working really hard at the moment and haven't slept
much lately.  Don't be too cruel if I'm an idiot :-)

-- Gareth