125 lines
4.1 KiB
Python
125 lines
4.1 KiB
Python
# SPDX-FileCopyrightText: 2020 Kattni Rembor for Adafruit Industries
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#
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# SPDX-License-Identifier: MIT
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"""
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`adafruit_led_animation.animation.rainbow`
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================================================================================
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Rainbow animation for CircuitPython helper library for LED animations.
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* Author(s): Kattni Rembor
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Implementation Notes
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--------------------
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**Hardware:**
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* `Adafruit NeoPixels <https://www.adafruit.com/category/168>`_
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* `Adafruit DotStars <https://www.adafruit.com/category/885>`_
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**Software and Dependencies:**
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* Adafruit CircuitPython firmware for the supported boards:
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https://circuitpython.org/downloads
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"""
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from adafruit_led_animation.animation import Animation
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from adafruit_led_animation.color import BLACK, colorwheel
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from adafruit_led_animation import MS_PER_SECOND, monotonic_ms
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__version__ = "0.0.0+auto.0"
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__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_LED_Animation.git"
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class Rainbow(Animation):
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"""
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The classic rainbow color wheel.
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:param pixel_object: The initialised LED object.
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:param float speed: Animation refresh rate in seconds, e.g. ``0.1``.
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:param float period: Period to cycle the rainbow over in seconds. Default 5.
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:param float step: Color wheel step. Default 1.
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:param str name: Name of animation (optional, useful for sequences and debugging).
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:param bool precompute_rainbow: Whether to precompute the rainbow. Uses more memory.
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(default True).
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"""
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# pylint: disable=too-many-arguments
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def __init__(
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self, pixel_object, speed, period=5, step=1, name=None, precompute_rainbow=True
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):
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super().__init__(pixel_object, speed, BLACK, name=name)
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self._period = period
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self._step = step
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self._wheel_index = 0
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self.colors = None
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self._generator = self._color_wheel_generator()
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if precompute_rainbow:
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self.generate_rainbow()
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def generate_rainbow(self):
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"""Generates the rainbow."""
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self.colors = []
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i = 0
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while i < 256:
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self.colors.append(colorwheel(int(i)))
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i += self._step
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on_cycle_complete_supported = True
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def _color_wheel_generator(self):
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period = int(self._period * MS_PER_SECOND)
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num_pixels = len(self.pixel_object)
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last_update = monotonic_ms()
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cycle_position = 0
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last_pos = 0
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while True:
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cycle_completed = False
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now = monotonic_ms()
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time_since_last_draw = now - last_update
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last_update = now
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pos = cycle_position = (cycle_position + time_since_last_draw) % period
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if pos < last_pos:
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cycle_completed = True
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last_pos = pos
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wheel_index = int((pos / period) * len(self.colors))
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if self.colors:
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self._draw_precomputed(num_pixels, wheel_index)
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else:
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wheel_index = int((pos / period) * 256)
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self.pixel_object[:] = [
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colorwheel((i + wheel_index) % 255) for i in range(num_pixels)
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]
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self._wheel_index = wheel_index
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if cycle_completed:
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self.cycle_complete = True
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yield
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def _draw_precomputed(self, num_pixels, wheel_index):
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for i in range(0, num_pixels, len(self.colors)):
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num = len(self.colors)
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if i + len(self.colors) > num_pixels:
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num = num_pixels - i
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if wheel_index + num > len(self.colors):
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colors_left = len(self.colors) - wheel_index
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self.pixel_object[i : i + colors_left] = self.colors[wheel_index:]
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self.pixel_object[i + colors_left : i + num] = self.colors[
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: num - colors_left
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]
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else:
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self.pixel_object[i : i + num] = self.colors[
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wheel_index : wheel_index + num
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]
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def draw(self):
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next(self._generator)
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def reset(self):
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"""
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Resets the animation.
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"""
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self._generator = self._color_wheel_generator()
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