# vim: set et sw=4 sts=4 fileencoding=utf-8:
#
# The colorzero color library
# Copyright (c) 2016-2018 Dave Jones <dave@waveform.org.uk>
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"Defines various easing functions for :meth:`Color.gradient`."
from __future__ import (
unicode_literals,
print_function,
division,
absolute_import,
)
from collections import namedtuple
[docs]def linear(steps):
"Linear easing function; yields *steps* values between 0.0 and 1.0"
for t in range(steps):
yield t / (steps - 1)
[docs]def ease_in(steps):
"Quadratic ease-in function; yields *steps* values between 0.0 and 1.0"
for t in linear(steps):
yield t ** 2
[docs]def ease_out(steps):
"Quadratic ease-out function; yields *steps* values between 0.0 and 1.0"
for t in linear(steps):
yield t * (2 - t)
[docs]def ease_in_out(steps):
"Quadratic ease-in-out function; yields *steps* values between 0.0 and 1.0"
for t in linear(steps):
yield 2 * t * t if t < 0.5 else (4 - 2 * t) * t - 1