def get_values(self):
b = [float(x) for x in self.begin.split(',')]
e = [float(x) for x in self.end.split(',')]
b_hsv = rgb2hsv(b)
e_hsv = rgb2hsv(e)
size_fact = 1.0 / (float(self.size) - 1.0)
# Ignore the undefined hues
if b_hsv[0] is None:
b_hsv[0] = e_hsv[0]
elif e_hsv[0] is None:
e_hsv[0] = b_hsv[0]
if b_hsv[0] is None:
# There is no hue at all!
b_hsv[0] = e_hsv[0] = 0.0 # unused value
hue_step = 0.0
else:
# Compute hue
# Because the hue is an angle, there is two ways to interpolate it;
# choose the shorter path
diff1 = e_hsv[0] - b_hsv[0]
diff2 = e_hsv[0] - b_hsv[0] + 360.0
if diff2 >= 360.0:
diff2 -= 360.0
assert 0.0 <= diff2 < 360.0
if abs(diff1) < abs(diff2):
hue_step = diff1
else:
hue_step = diff2
colors = []
for i in xrange(self.size):
u = i * size_fact
hue = b_hsv[0] + u * hue_step
if hue < 0.0:
hue += 360.0
elif hue > 360.0:
hue -= 360.0
colors.append(Color.to_string(*hsv2rgb((
hue,
b_hsv[1] + u * (e_hsv[1] - b_hsv[1]),
b_hsv[2] + u * (e_hsv[2] - b_hsv[2])
))))
return colors
def test_hsv_interpolation(self):
tests = [((120.0, 0.8, 0.2), (170.0, 0.5, 0.2), [(120.0, 0.8, 0.2),
(130.0, 0.74, 0.2),
(140.0, 0.68, 0.2),
(150.0, 0.62, 0.2),
(160.0, 0.56, 0.2),
(170.0, 0.5, 0.2)]),
((260.0, 0.2, 0.7), (40.0, 0.8, 0.1), [(260.0, 0.2, 0.7),
(288.0, 0.32, 0.58),
(316.0, 0.44, 0.46),
(344.0, 0.56, 0.34),
(12.0, 0.68, 0.22),
(40.0, 0.8, 0.1)])]
for b, e, expected in tests:
b = hsv2rgb(b)
e = hsv2rgb(e)
interp = HSVColorInterpolator(','.join(str(c) for c in b),
','.join(str(c) for c in e), 6)
for i, color in enumerate(interp.get_values()):
color = [float(e) for e in color.split(',')]
color = rgb2hsv(color)
self.assertAlmostEqual(color[0], expected[i][0], delta=0.2)
self.assertAlmostEqual(color[1], expected[i][1], delta=0.005)
self.assertAlmostEqual(color[2], expected[i][2], delta=0.005)
def test_hsv_interpolation(self):
tests = [((120.0, 0.8, 0.2), (170.0, 0.5, 0.2),
[(120.0, 0.8, 0.2), (130.0, 0.74, 0.2), (140.0, 0.68, 0.2),
(150.0, 0.62, 0.2), (160.0, 0.56, 0.2), (170.0, 0.5, 0.2)]),
((260.0, 0.2, 0.7), (40.0, 0.8, 0.1),
[(260.0, 0.2, 0.7), (288.0, 0.32, 0.58), (316.0, 0.44, 0.46),
(344.0, 0.56, 0.34), (12.0, 0.68, 0.22), (40.0, 0.8, 0.1)])]
for b, e, expected in tests:
b = hsv2rgb(b)
e = hsv2rgb(e)
interp = HSVColorInterpolator(','.join(str(c) for c in b),
','.join(str(c) for c in e),
6)
for i, color in enumerate(interp.get_values()):
color = [float(e) for e in color.split(',')]
color = rgb2hsv(color)
self.assertAlmostEqual(color[0], expected[i][0], delta=0.2)
self.assertAlmostEqual(color[1], expected[i][1], delta=0.005)
self.assertAlmostEqual(color[2], expected[i][2], delta=0.005)
