>gray ( color -- gray )

Vocabulary

colors.gray

Inputs

color

an object

Outputs

gray

an object

Definition

IN: colors.gray

GENERIC: >gray ( color -- gray )

Methods

USING: accessors colors.cmyk colors.gray combinators kernel math
math.order ;

M: cmyka >gray
    [
        {
            [ cyan>> 0.3 * ]
            [ magenta>> 0.59 * ]
            [ yellow>> 0.11 * ]
            [ black>> ]
        } cleave + + + 1.0 min 1.0 swap -
    ] [ alpha>> ] bi <gray> ;


USING: colors colors.gray kernel ;

M: object >gray >rgba >gray ;


USING: colors colors.gray kernel math ;

M: rgba >gray
    >rgba-components
    [ [ 0.3 * ] [ 0.59 * ] [ 0.11 * ] tri* + + ] dip <gray> ;