import ipywidgets as wd
from vpython import *
# This version uses Jupyter notebook slider
# See Color-RGB-HSV2 for a version that uses VPython slider
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