h+ ( a b -- c )

Vocabulary

math.vectors.homogeneous

Inputs

a	an object
b	an object

Outputs

c

an object

Definition

USING: kernel math math.vectors sequences ;

IN: math.vectors.homogeneous

: h+ ( a b -- c )
    2dup [ (homogeneous-w) ] bi@ over =
    [ [ [ (homogeneous-xyz) ] bi@ v+ ] dip suffix ] [
        drop
        [ [ (homogeneous-xyz) ] [ (homogeneous-w) ] bi* v*n ]
        [ [ (homogeneous-w) ] [ (homogeneous-xyz) ] bi* n*v v+ ]
        [ [ (homogeneous-w) ] [ (homogeneous-w) ] bi* * suffix ]
        2tri
    ] if ;