Does the OpenGL fixed function pipeline compute lighting in view-space?
If the answer is yes, then how does it cope with view transformations with non-uniform scale? Actually, how does it cope with view transformations incorporating any scale at all?
If this is true then scaling the view space will result in different light-to-vertex distances, meaning the lighting intensity for point-lights will change as the view matrix is scaled.
Lighting in world-space would make the computed point-light intensity independent of view space scaling, but would require:
Points awarded for a good answer with any additional background info you can dig up on fixed-function lighting pipelines in general.
I think your question comes from a confusion of "view space" with "post-projection space". They are not the same.
View space, or camera space, is the space of the scene relative to the camera. Thus, the camera is sitting at the origin, looking down the -Z axis, with +Y being up. In terms of OpenGL fixed-function, camera space is the space after multiplying positions and normals by the GL_MODELVIEW matrix.
Post-projection space is what you get after multiplying camera space values by the GL_PROJECTION matrix. This is in fact why there are two separate matrices. You do lighting in camera space, and you send the post-projection positions off for rasterization.
OpenGL does not do lighting in post-projection space. So the aspect ratio, camera zoom, and so forth does not affect lighting. Nor does the perspective divide.
Does the OpenGL fixed function pipeline compute lighting in view-space?
Yes, and so should you.
If the answer is yes, then how does it cope with view transformations with non-uniform scale? Actually, how does it cope with view transformations incorporating any scale at all?
The exact same way that it copes with the model-to-world transform incorporating scale.
It's just a matrix. The math neither knows nor cares where a particular scale transform happens to be, whether it is in the model-to-world part or the world-to-camera part. All that matters is that a scale is present. Or a skew or any other form of transform.
And remember: it is far more likely that the model-to-world transform uses scales than the world-to-camera transform does. You are more likely to need to rescale geometry to fit into the world than you are to need to rescale geometry for the camera matrix. The scaling for camera zooms, aspect ratio, and the like is a part of the perspective matrix, not the camera matrix.
It "copes" with this in the usual way: normals are transformed by the inverse-transpose of the model-to-view matrix. This alters the normals (full disclosure: that's my eBook tutorial) so that they still fit the model after the scaling. This is necessary regardless of what space you're in.
If this is true then scaling the view space will result in different light-to-vertex distances, meaning the lighting intensity for point-lights will change as the view matrix is scaled.
... and? Since all of the objects are transformed by the same camera matrix (within a single scene), all of the objects will have the same scale applied. Therefore, if they were all in the same scale in world-space, they will all be in the same scale in camera-space.
So what's the problem? Yes, the attenuation changes, but it changes equally for all objects. Thus, there isn't a problem, so long as your attenuation factors are designed for this camera space.