[4.1.3] WallSprites crash in software renderer

[Rachael]

What happens if you copy the entirety of the RenderSprite::Project function and dump it into RenderWallSprite::Project (and replace everything that's there)? Does it still crash?

[drfrag]

They look very different. Wall of errors.

[drfrag]

I've checked today's devbuild and as expected it crashes. The feature must have worked sometime as it was added in 2014 in "Q&D port of decal code to draw generic wall sprites". May be it was screwed after the floatification.

[drfrag]

Seems it's fixed for real this time, just made a PR. https://github.com/coelckers/gzdoom/pull/947
It was again introduced in the refactoring started with "move visibility calculation to LightVisibility", this commit: "move more of the light calculation code to the drawerargs".

[Rachael]

Why'd you revert the previous commit? That was still passing information to the drawers, that is now ignored.

[drfrag]

Sorry, the description said it fixed the crash and it still crashed. Now it doesn't crash so i thought it was not needed.
First i reverted it to investigate the issue with a different approach.

[Rachael]

We don't revert commits just because they say the wrong thing. Only if they actually cause major problems.

Needless to say, all that information was missing, and while you might say it didn't actually fix the crash, for me and Sanya it did, so obviously it did put in some necessary information, and did help to some extent.

[drfrag]

I know but for me it was not obvious that that information was needed else i wouldn't have reverted it. Your post came too late else i'd have changed the PR.
The fact is now it doesn't crash and that was the objective, i looked at the original commit and found that information was missing so somewhow i recreated that part.

[Rachael]

Thank you for that fix.

[drfrag]

You're welcome.