ZDoom

Call me blind/dumb but I can't tell what's so different about the two screens.

To be honest either can I, when I heard smooth lighting I thought it would be a smooth gradient between different light levels so that there arn't any sharp bright area/dark area lines, this is something I would like

Ditto.

*strains eyes* Nope I just can't see it

Look at how the curved wall behind the crosshair is lit. The two pics are quite different.

I see what you mean but the one in shot 2 just looks like there's no lightning difference full stop. I guess this is one thing better to see in game rather than in screenshots.

Cutmanmike wrote:Call me blind/dumb but I can't tell what's so different about the two screens.

The Heretic ones? Look at the brightness of the cliff walls on that curved part.
Doom fakes contrast by changing wall brightness. With flat lightning, all walls are at sector brightness. With normal lightning, that's still true except for walls that are perfectly aligned on the X or Y axis: ones are a bit brighter than sector, the other are a bit darker. This increases the contrast and helps them look more 3D and less flat picture. With smoothlightning, the brightness depends on the angle, it's not a ternary "angle 0 -> brighter, angle 90 -> darker, anything else: same" behavior. So it allows to have non-orthogonal walls that contrast with each others.

So?

Is someone willing to do the remaining work here?

What is the remaining work, exactly? Just making it into an option, or something else as well? (And if so, what?)

Integrating it properly. The code just hacks the feature in and disables what was there before.

I took a shot at doing it, but I don't know if any thing has changed since the result doesn't look that great (at least I think the screen shots looked better). I also took care of my feature request while I was at it.

Please do me a favor in the future and keep such patches separate. It would make it much easier to undo them if one doesn't work well.

And you are correct: The formula was wrong. The '2*' has become obsolete in the mean time.