grad8() [1/3]

static fl::i8 grad8 ( fl::u8 hash, fl::i8 x )

inlinestatic

Definition at line 249 of file noise.cpp.hpp.

{
    // since the tests below can be done bit-wise on the bottom
    // four bits, there's no need to mask off the higher bits
    //  hash = hash & 15;
 
    fl::i8 u,v;
    if(hash & 8) {
        u=x; v=x;
    } else {
    if(hash & 4) {
        u=1; v=x;
    } else {
        u=x; v=1;
    }
    }
 
    if(hash&1) { u = -u; }
    if(hash&2) { v = -v; }
 
    return fl::avg7(u,v);
}

References FL_NO_EXCEPT, and x.