def _do_fuzzy(self):
from random import seed, randint
seed(0)
rgb = tuple(randint(0, 255) for i in range(3))
hls = rgb_to_hls(*rgb)
hls2rgb = hls_to_rgb(*hls)
self.assertEqual(rgb, hls2rgb)
rgb2hls = rgb_to_hls(*hls2rgb)
self.assertEqual(rgb2hls, hls)
def _do_fuzzy(self):
from random import seed, randint
seed(0)
rgb = tuple(randint(0, 255) for i in range(3))
hls = rgb_to_hls(*rgb)
hls2rgb = hls_to_rgb(*hls)
self.assertEqual(rgb, hls2rgb)
rgb2hls = rgb_to_hls(*hls2rgb)
self.assertEqual(rgb2hls, hls)
def darken(self, context, amount=None):
if amount is None:
amount = Value(10.0, '%')
hue, lightness, saturation = utils.rgb_to_hls(*self.value)
if isinstance(amount, Value):
if amount.unit == '%':
if not amount.value:
return self
lightness *= amount.value / 100.0
else:
raise errors.EvalException(self.lineno, 'invalid unit %s '
'for color calculations.' % amount.unit)
elif isinstance(amount, Number):
lightness -= (amount.value / 100.0)
if lightness < 0:
lightness = 0.0
return Color(utils.hls_to_rgb(hue, lightness, saturation))
def darken(self, context, amount=None):
if amount is None:
amount = Value(10.0, '%')
hue, lightness, saturation = utils.rgb_to_hls(*self.value)
if isinstance(amount, Value):
if amount.unit == '%':
if not amount.value:
return self
lightness *= amount.value / 100.0
else:
raise errors.EvalException(
self.lineno, 'invalid unit %s for color '
'calculations.' % amount.unit)
elif isinstance(amount, Number):
lightness -= (amount.value / 100.0)
if lightness < 0:
lightness = 0.0
return Color(utils.hls_to_rgb(hue, lightness, saturation))
def tint(self, context, lighten=None):
"""Specifies a relative value by which to lighten the color (e.g. toward
white). This works in the opposite manner to the brighten function; a
value of 0% produces white (no ink); a value of 50% produces a color
halfway between the original and white (e.g. 50% halftone). Less
ink also means colour saturation decreases linearly with the amount of
ink used. Only positive values between 0-100 for tints are allowed; if you
wish to darken an existing color use the darken method or shade_color.
N.B. real printing presses -- and therefore some software -- may produce
slightly different saturations at different tone curves. If you're really,
REALLY anal about the colour that gets reproduced, you should probably
trust your design software. For most intents and purposes, though, this
is going to be more than sufficient.
Valueless tints will be returned unmodified.
"""
if lighten is None:
return self
elif isinstance(lighten, (Value, Number)):
lighten = lighten.value
lighten = abs(lighten) # Positive values only!
hue, lit, sat = utils.rgb_to_hls(*self.value)
# Calculate relative lightness
lavail = 1.0 - lit
lused = lavail - (lavail * (lighten / 100))
lnew = lused + (1.0 - lavail)
# Corresponding relative (de-)saturation
if lit == 0:
lit = 1
snew = sat * (1 / (lnew/lit))
return Color(utils.hls_to_rgb(hue, lnew, snew))
def tint(self, context, lighten=None):
"""Specifies a relative value by which to lighten the color (e.g. toward
white). This works in the opposite manner to the brighten function; a
value of 0% produces white (no ink); a value of 50% produces a color
halfway between the original and white (e.g. 50% halftone). Less
ink also means colour saturation decreases linearly with the amount of
ink used. Only positive values between 0-100 for tints are allowed; if you
wish to darken an existing color use the darken method or shade_color.
N.B. real printing presses -- and therefore some software -- may produce
slightly different saturations at different tone curves. If you're really,
REALLY anal about the colour that gets reproduced, you should probably
trust your design software. For most intents and purposes, though, this
is going to be more than sufficient.
Valueless tints will be returned unmodified.
"""
if lighten is None:
return self
elif isinstance(lighten, (Value, Number)):
lighten = lighten.value
lighten = abs(lighten) # Positive values only!
hue, lit, sat = utils.rgb_to_hls(*self.value)
# Calculate relative lightness
lavail = 1.0 - lit
lused = lavail - (lavail * (lighten / 100))
lnew = lused + (1.0 - lavail)
# Corresponding relative (de-)saturation
if lit == 0:
lit = 1
snew = sat * (1 / (lnew / lit))
return Color(utils.hls_to_rgb(hue, lnew, snew))
def rgb_to_hls_overflow(self):
self._assertEqualHLS(rgb_to_hls(10, 300, 250),
[0.4713, 0.6078, 1.4500])
def rgb_to_hls_underflow(self):
self._assertEqualHLS(rgb_to_hls(-10, 100, 250),
[0.5962, 0.4706, 1.0833])
def rgb_to_hls(self):
self._assertEqualHLS(rgb_to_hls(10, 100, 250),
[0.6042, 0.5098, 0.9600])
def rgb_to_hls_overflow(self):
self._assertEqualHLS(rgb_to_hls(10, 300, 250),
[0.4713, 0.6078, 1.4500])
def rgb_to_hls_underflow(self):
self._assertEqualHLS(rgb_to_hls(-10, 100, 250),
[0.5962, 0.4706, 1.0833])
def rgb_to_hls(self):
self._assertEqualHLS(rgb_to_hls(10, 100, 250),
[0.6042, 0.5098, 0.9600])
