redTOAST Studios' World Project.
Interestingly, in Perl and Python it IS 1. C and C++ seem to agree with your finding though. I'm guessing your discovery is in C#, yes?
That would be correct. Basically, using x % 2 == 1 is a poor check of oddness. I had some terrain mip chain code that was incorrect on negative regions. x % 2 != 0 works fine.