rgbtohsv

// Returns given RGB color as an HSV color in 23bit INT format
// usage: /rgbtohsv R G B [ action ]
rgbtohsv = [
    local r g b mn d h s v
    r = (divf $arg1 0xFF)
    g = (divf $arg2 0xFF)
    b = (divf $arg3 0xFF)
    v = (maxf $r $g $b)
    mn = (minf $r $g $b)

    if (=f $mn $v) [
        d = 0
        h = 0
        s = 0
    ] [
        d = (-f $v $mn)
        s = (divf $d $v)
        h = (casef $v $r [
            floor (*f 60 (modf (divf (-f $g $b) $d) 6))
        ] $g [
            *f 60 (+f (divf (-f $b $r) $d) 2)
        ] $b [
            *f 60 (+f (divf (-f $r $g) $d) 4)
        ])
    ]
    if (>= $numargs 4) [ doargs $arg4 ] [
        | $v (<< $s 7) (<< $h 16)
    ]
]