hsla
HSL colors

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<hsla> ( hue saturation lightness alpha -- hsla )

Vocabulary
colors.hsl

Class description
The class of HSL (Hue, Saturation, Lightness) colors with an alpha channel. All slots store values in the interval [0,1].

Definition

IN: colors.hsl

TUPLE: hsla
    { hue read-only } { saturation read-only }
    { lightness read-only } { alpha read-only } ;

Methods

USING: colors.hsl ;

M: hsla >hsla ; inline


USING: accessors colors colors.hsl colors.hsl.private
combinators kernel locals.backend math ;

M: hsla >rgba
    { [ hue>> ] [ saturation>> ] [ lightness>> ] [ alpha>> ] }
    cleave [
        3 load-locals -1 get-local zero? 0 get-local [
            load-local
            0 get-local 0 get-local 0 get-local 1 drop-locals
        ] curry 0 get-local -1 get-local -2 get-local [
            3 load-locals -2 get-local 0.5 <
            -2 get-local -1 get-local [
                2 load-locals -1 get-local 0 get-local 1 + *
                2 drop-locals
            ] curry curry -2 get-local -1 get-local [
                2 load-locals -1 get-local 0 get-local +
                -1 get-local 0 get-local * - 2 drop-locals
            ] curry curry if load-local -3 get-local 2 *
            0 get-local - load-local
            0 get-local -1 get-local -2 get-local 1/3 + value
            0 get-local -1 get-local -2 get-local value
            0 get-local -1 get-local -2 get-local 1/3 - value
            5 drop-locals
        ] curry curry curry if 3 drop-locals
    ] dip <rgba> ; inline