luva
CIE 1976 LUV colors

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<luva> ( l u v alpha -- luva )

Vocabulary
colors.luv

Class description
The class of CIE 1976 LUV (commonly called CIELUV) colors with an alpha channel.

Definition

IN: colors.luv

TUPLE: luva l u v alpha ;

Methods

USING: accessors colors.lch colors.luv kernel locals.backend
math math.functions math.libm ;

M: luva >LCHuv
    [
        [ l>> ] [ u>> ] [ v>> ] tri 3 load-locals
        0 get-local -1 get-local fatan2 rad>deg
        [ dup 360 > ] [ 360 - ] while
        [ dup 0 < ] [ 360 + ] while load-local
        -3 get-local -2 get-local sq -1 get-local sq +
        sqrt 0 get-local 4 drop-locals
    ] [ alpha>> ] bi <LCHuv> ;


USING: colors.luv ;

M: luva >luva ; inline


USING: colors colors.luv colors.xyz ;

M: luva >rgba >xyza >rgba ;


USING: accessors colors.luv colors.luv.private colors.xyz
colors.xyz.private kernel locals.backend math math.functions ;

M: luva >xyza
    [
        wp_x wp_y wp_z xyz-to-uv 2 load-locals
        [ l>> ] [ u>> ] [ v>> ] tri 3 load-locals
        52 -2 get-local * 13 -2 get-local * -4 get-local *
        -1 get-local + / 1 - 3 / load-local
        -3 get-local xyz_kappa xyz_epsilon * > -3 get-local [
            load-local 0 get-local 16 + 116 / 3 ^ wp_y *
            1 drop-locals
        ] curry -3 get-local [
            load-local 0 get-local xyz_kappa / wp_y *
            1 drop-locals
        ] curry if load-local 0 get-local -5 * load-local
        39 -5 get-local * 13 -5 get-local * -6 get-local *
        -3 get-local + / 5 - -1 get-local * load-local
        0 get-local -1 get-local - -3 get-local 1/3 + /
        load-local -4 get-local 0 get-local * -2 get-local +
        load-local -1 get-local -4 get-local 0 ~3 more~
    ] [ alpha>> ] bi <xyza> ;