Sergey Sharybin
fcc2ca0089
The root of the issue comes to the way how we sample the gaussian filter in RE_filter_value(). We need to scale x to -3*sigma..3*sigma segment in order to get the whole bell. The old code tried to do it, but failed dramatically, plus it used some weird gaussian sampling formula. Replaced it with much more clear one, which gives proper blur now. There's no visible different in AA sampling in BI render tho. Other filters like Mitchell still tends to give wrong square shaped blurs, but they're much more difficult to resolve because they're just wrong in the code -- for some reason smaller kernel size means more blur. Let's solve this later.