#! /usr/bin/env python

#------------------------------------------------------------------------------
#  Visualizzatore colori HSV
#  colorHSV.py - by C.Fin - Python2&3
#------------------------------------------------------------------------------

try:
    import tkinter             # Python 3.x
except ImportError:
    import Tkinter as tkinter  # Python 2.x

#------------------------------------------------------------------------------

class GUI:

    def __init__(self):
        self.form = tkinter.Tk()
        self.form.resizable(False, False)
        self.canvas = tkinter.Canvas(
            self.form, highlightthickness=0, width=480, height=300)
        self.canvas.pack(side="left", fill="both", expand=1, padx=4, pady=4)
        self.frame1 = tkinter.Frame()
        self.frame1.pack(side="left", fill="both", expand=1)
        self.scaleH = tkinter.Scale(self.frame1, to=0, from_=360, showvalue=0)
        self.scaleH.pack(side="left", fill="y", expand=1, pady=4, padx=4)
        self.scaleS = tkinter.Scale(
            self.frame1, to=0.0, from_=1.0, showvalue=0, resolution=0.005)
        self.scaleS.pack(side="left", fill="y", expand=1, pady=4)
        self.scaleV = tkinter.Scale(
            self.frame1, to=0.0, from_=1.0, showvalue=0, resolution=0.005)
        self.scaleV.pack(side="left", fill="y", expand=1, pady=4, padx=4)

#------------------------------------------------------------------------------
# IN:  H 0-360     S 0.0-1.0   V 0.0-1.0
# OUT: R 0.0-1.0   G 0.0-1.0   B 0.0-1.0
#------------------------------------------------------------------------------

def hsv_to_rgb(h, s, v):
    if h == 360: h = 0
    i = int(h / 60)       # settore 0..5
    f = (h % 60) / 60.0   # offset 0.0..1.0 nel settore
    pv = v * ( 1 - s )
    qv = v * ( 1 - s*f )
    tv = v * ( 1 - s * (1 - f) )
    return {        
               0: (v,  tv, pv),
               1: (qv, v,  pv),  
               2: (pv, v,  tv),
               3: (pv, qv, v),   
               4: (tv, pv, v),   
               5: (v,  pv, qv)
           }[i]

#------------------------------------------------------------------------------

class ColorHSV:

    def __init__(self):
        self.gui = GUI()
        self.gui.scaleH.configure(command=self.disegna)
        self.gui.scaleS.configure(command=self.disegna)
        self.gui.scaleV.configure(command=self.disegna)


    def disegna(self, _=None):
        h = self.gui.scaleH.get()
        s = self.gui.scaleS.get()
        v = self.gui.scaleV.get()
        r, g, b = [ int(x * 255) for x in hsv_to_rgb(h, s, v) ]
        self.gui.canvas.configure(bg="#%02x%02x%02x" % (r, g, b))
        self.gui.form.title(
            "HSV: %3d  %1.2f  %1.2f    RGB: %3d %3d %3d - %02X%02X%02X" %
            (h, s, v, r, g ,b, r, g, b) )


    def start(self):
        self.gui.form.mainloop()

#------------------------------------------------------------------------------

app = ColorHSV()
app.start()