grad ( hash v -- gradient )

Vocabulary

noise

Inputs

hash	an object
v	an object

Outputs

gradient

an object

Definition

USING: kernel math sequences ;

IN: noise

:: grad ( hash v -- gradient )
    hash 8 bitand zero? [ v first ] [ v second ] if
    :> u hash 12 bitand zero?
    [ v second ]
    [ hash 13 bitand 12 = [ v first ] [ v third ] if ] if
    :> v hash 1 bitand zero? [ u ] [ u neg ] if hash 2 bitand
    zero? [ v ] [ v neg ] if + ; inline