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import ipywidgets as wd
from vpython import *

# Jupyter version of GlowScript demo program Color-RGB-HSV

scene.userzoom = False
scene.userspin = False
scene.width = 400
scene.height = 200
scene.range = 1
box(pos=vector(10,0,0)) # Force creation of canvas; box is not seen because it is outside the canvas
scene.caption = 'You can Ctrl-C copy the RGB and HSV values shown above.'

C = ['Red', 'Green', 'Blue', 'Hue', 'Saturation', 'Value']
sliders = []
lastvalues = []
adjusting = False

def set_background(change):
    global adjusting
    if adjusting: return # in the process of resetting various slider values
    s = []
    N = -1
    for i in range(6): # Get values for all 6 sliders
        val = sliders[i].value
        s.append(val)
        if val != lastvalues[i]:
            N = i
            lastvalues[i] = val
    adjusting = True # prevent circular updating of slider values
    if N < 3:
        rgb = vector(s[0],s[1],s[2])
        hsv = color.rgb_to_hsv(rgb)
        sliders[3].value = lastvalues[3] = int(1000*hsv.x)/1000 # reset HSV slider positions; display 3 figures
        sliders[4].value = lastvalues[4] = int(1000*hsv.y)/1000
        sliders[5].value = lastvalues[5] = int(1000*hsv.z)/1000
    else:
        hsv = vector(s[3],s[4],s[5])
        rgb = color.hsv_to_rgb(hsv)
        sliders[0].value = lastvalues[0] = int(1000*rgb.x)/1000 # reset RGB slider positions; display 3 figures
        sliders[1].value = lastvalues[1] = int(1000*rgb.y)/1000
        sliders[2].value = lastvalues[2] = int(1000*rgb.z)/1000
    scene.background = rgb
    # For readability, limit precision of display of quantities to 3 figures
    f = "RGB = <{:1.3f}, {:1.3f}, {:1.3f}>, HSV = <{:1.3f}, {:1.3f}, {:1.3f}>"
    scene.title = f.format(rgb.x, rgb.y, rgb.z, hsv.x, hsv.y, hsv.z)
    adjusting = False

for i in range(6):
    sliders.append(wd.FloatSlider(description=C[i], min=0, max=1, step=0.001, value=0))
    lastvalues.append(0)
    sliders[i].observe(set_background, names='value') # watch for changes in slider.value
display(wd.VBox(children=sliders)) # stack (default horizontal) sliders vertically
sliders[0].value = 1 # make the background red


    

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