rgba
Colors

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<rgba> ( red green blue alpha -- rgba )

Vocabulary
colors

Class description
The class of colors with red, green, blue and alpha channel components. The slots store color components, which are real numbers in the range 0 to 1, inclusive.

Definition

IN: colors

TUPLE: rgba
    { red read-only } { green read-only } { blue read-only }
    { alpha read-only } ;

Methods

USING: colors colors.cmyk kernel math math.order ;

M: rgba >cmyka
    >rgba-components [
        [ 1 swap - ] tri@ 3dup min min
        [ [ - 0.0 1.0 clamp ] curry tri@ ] keep
    ] dip <cmyka> ;


USING: colors colors.gray kernel math ;

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


USING: colors colors.hsl combinators kernel locals.backend math
math.order ;

M: rgba >hsla
    >rgba-components [
        3 load-locals -2 get-local -1 get-local 0 get-local min
        min load-local
        -3 get-local -2 get-local -1 get-local max max
        load-local -1 get-local 0 get-local + 2 / load-local
        -1 get-local -2 get-local - load-local 0 get-local zero?
        [ 0.0 0.0 ] -2 get-local -6 get-local -5 get-local -4
        get-local 0 get-local -1 get-local -3 get-local [
            7 load-locals -6 get-local dup -5 get-local =
            -4 get-local -3 get-local -2 get-local [
                3 load-locals drop -2 get-local -1 get-local -
                0 get-local / -2 get-local -1 get-local <
                6.0 0.0 ? + 3 drop-locals
            ] curry curry curry
            -4 get-local -3 get-local -5 get-local -2 get-local 
            [
                4 load-locals dup -3 get-local =
                -2 get-local -1 get-local 0 get-local [
                    3 load-locals drop
                    -2 get-local -1 get-local - 0 get-local /
                    2.0 + 3 drop-locals
                ] curry curry curry
                -2 get-local -1 get-local -3 get-local 0
                get-local [
                    4 load-locals dup -3 get-local =
                    -2 get-local -1 get-local 0 get-local [
                        3 load-locals drop
                        -2 get-local -1 get-local -
                        0 get-local / 4.0 + 3 drop-locals
                    ] curry curry curry [ no-case ] if
                    4 drop-locals
                ] curry curry curry curry if 4 drop-locals
            ] curry curry curry curry if 6.0 /
            -1 get-local 0.5 >
            -2 get-local -6 get-local 0 get-local [
                3 load-locals -2 get-local 2 -1 get-local -
                0 get-local - / 3 drop-locals
            ] curry curry curry
            -2 get-local -6 get-local 0 get-local [
                3 load-locals
                -2 get-local -1 get-local 0 get-local + /
                3 drop-locals
            ] curry curry curry if 7 drop-locals
        ] curry curry curry curry curry curry curry if
        -1 get-local 7 drop-locals
    ] dip <hsla> ;


USING: colors colors.hsv colors.hsv.private combinators kernel
math ;

M:: rgba >hsva ( rgba -- hsva )
    rgba >rgba-components :> ( r g b a ) r g b sort-triple
    :> ( z y x ) x z = x zero? or
    [ 0 0 x a <hsva> ] [
        {
            { [ r x = g z = and ] [ 5 x b - x z - / + ] }
            { [ r x = g z > and ] [ 1 x g - x z - / - ] }
            { [ g x = b z = and ] [ 1 x r - x z - / + ] }
            { [ g x = b z > and ] [ 3 x b - x z - / - ] }
            { [ b x = r z = and ] [ 3 x g - x z - / + ] }
            { [ b x = r z > and ] [ 5 x r - x z - / - ] }
        } cond 6 / 360 * x z - x / x a <hsva>
    ] if ;


USING: accessors colors colors.hsl colors.hwb kernel
locals.backend math math.order ;

M: rgba >hwba
    >hsla [ hue>> ] [ >rgba-components ] bi 5 load-locals
    -3 get-local -2 get-local -1 get-local min min load-local
    -4 get-local -3 get-local -2 get-local max max 1 swap -
    load-local
    -6 get-local -1 get-local 0 get-local -2 get-local <hwba>
    7 drop-locals ;


USING: colors colors.lab colors.xyz ;

M: rgba >laba >xyza >laba ;


USING: colors colors.luv colors.xyz ;

M: rgba >luva >xyza >luva ;


USING: colors ;

M: rgba >rgba ; inline


USING: colors colors.ryb colors.ryb.private kernel ;

M: rgba >ryba
    >rgba-components [ [ rgb>ryb ] normalized ] [ <ryba> ] bi* ;


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

M: rgba >xyza
    [
        [ red>> ] [ green>> ] [ blue>> ] tri
        [ invert-rgb-compand ] tri@ 3 load-locals
        -2 get-local 0.4124564 * -1 get-local 0.3575761 *
        0 get-local 0.1804375 * + + -2 get-local 0.2126729 *
        -1 get-local 0.7151522 * 0 get-local 0.072175 * + +
        -2 get-local 0.0193339 * -1 get-local 0.119192 *
        0 get-local 0.9503041 * + + 3 drop-locals
    ] [ alpha>> ] bi <xyza> ;


USING: colors colors.yiq math ;

M:: rgba >yiqa ( rgba -- yiqa )
    rgba >rgba-components :> ( r g b a ) 0.3 r * 0.59 g *
    0.11 b * + + :> y r y - :> r-y b y - :> b-y 0.74 r-y *
    0.27 b-y * - :> i 0.48 r-y * 0.41 b-y * +
    :> q y i q a <yiqa> ;


USING: colors colors.yuv colors.yuv.private math ;

M:: rgba >yuva ( rgba -- yuva )
    rgba >rgba-components :> ( r g b a ) Wr r * Wg g * Wb b * +
    + :> y Umax 1 Wb - / b y - * :> u Vmax 1 Wr - / r y - *
    :> v y u v a <yuva> ;