! Copyright (C) 2008 Eduardo Cavazos.
! See http://factorcode.org/license.txt for BSD license.
-USING: colors kernel combinators math math.functions accessors ;
+USING: accessors colors combinators kernel math math.functions
+random sequences sorting ;
IN: colors.hsv
! h [0,360)
! s [0,1]
! v [0,1]
-TUPLE: hsva < color hue saturation value alpha ;
+TUPLE: hsva
+{ hue read-only }
+{ saturation read-only }
+{ value read-only }
+{ alpha read-only } ;
C: <hsva> hsva
+INSTANCE: hsva color
+
<PRIVATE
-: Hi ( hsv -- Hi ) hue>> 60 / floor 6 mod ; inline
+: Hi ( hsv -- Hi ) hue>> 60 / floor 6 mod >integer ; inline
: f ( hsv -- f ) [ hue>> 60 / ] [ Hi ] bi - ; inline
PRIVATE>
-M: hsva >rgba ( hsva -- rgba )
+M: hsva >rgba
[
dup Hi
{
{ 4 [ [ t ] [ p ] [ value>> ] tri ] }
{ 5 [ [ value>> ] [ p ] [ q ] tri ] }
} case
- ] [ alpha>> ] bi <rgba> ;
+ ] [ alpha>> ] bi <rgba> ; inline
+
+<PRIVATE
+
+: sort-triple ( a b c -- d e f )
+ sort-pair [ sort-pair ] dip sort-pair ;
+
+PRIVATE>
+
+GENERIC: >hsva ( color -- hsva )
+
+M: object >hsva >rgba >hsva ;
+
+M: hsva >hsva ; inline
+
+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 ;
+
+: complimentary-color ( color -- color' )
+ >hsva {
+ [ hue>> 180 + 360 mod ]
+ [ saturation>> ]
+ [ value>> ]
+ [ alpha>> ]
+ } cleave <hsva> ;
+
+: golden-rainbow ( num-colors saturation luminance -- colors )
+ [ random-unit ] 3dip '[
+ 0.618033988749895 + 1.0 mod dup _ _ 1.0 <hsva>
+ ] replicate nip ;