! Copyright (C) 2008 Eduardo Cavazos.
! See http://factorcode.org/license.txt for BSD license.
-USING: colors kernel combinators math math.functions accessors ;
+USING: accessors arrays colors combinators kernel locals math
+math.functions sequences sorting ;
IN: colors.hsv
! h [0,360)
! s [0,1]
! v [0,1]
-TUPLE: hsva < color { hue read-only } { saturation read-only } { value read-only } { alpha read-only } ;
+TUPLE: hsva < color
+{ hue read-only }
+{ saturation read-only }
+{ value read-only }
+{ alpha read-only } ;
C: <hsva> hsva
{ 5 [ [ value>> ] [ p ] [ q ] tri ] }
} case
] [ alpha>> ] bi <rgba> ;
+
+:: rgba>hsva ( rgba -- hsva )
+ rgba >rgba-components :> ( r g b a )
+ r g b 3array natural-sort first3 :> ( 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 ;