1  # SPDX-FileCopyrightText: 2020 Kattni Rembor for Adafruit Industries
  2  #
  3  # SPDX-License-Identifier: MIT
  4  
  5  """
  6  `adafruit_led_animation.animation.chase`
  7  ================================================================================
  8  
  9  Theatre chase animation for CircuitPython helper library for LED animations.
 10  
 11  * Author(s): Kattni Rembor
 12  
 13  Implementation Notes
 14  --------------------
 15  
 16  **Hardware:**
 17  
 18  * `Adafruit NeoPixels <https://www.adafruit.com/category/168>`_
 19  * `Adafruit DotStars <https://www.adafruit.com/category/885>`_
 20  
 21  **Software and Dependencies:**
 22  
 23  * Adafruit CircuitPython firmware for the supported boards:
 24    https://circuitpython.org/downloads
 25  
 26  
 27  """
 28  
 29  from math import ceil
 30  
 31  from adafruit_led_animation.animation import Animation
 32  
 33  
 34  class Chase(Animation):
 35      """
 36      Chase pixels in one direction in a single color, like a theater marquee sign.
 37  
 38      :param pixel_object: The initialised LED object.
 39      :param float speed: Animation speed rate in seconds, e.g. ``0.1``.
 40      :param color: Animation color in ``(r, g, b)`` tuple, or ``0x000000`` hex format.
 41      :param size: Number of pixels to turn on in a row.
 42      :param spacing: Number of pixels to turn off in a row.
 43      :param reverse: Reverse direction of movement.
 44      """
 45  
 46      # pylint: disable=too-many-arguments
 47      def __init__(
 48          self, pixel_object, speed, color, size=2, spacing=3, reverse=False, name=None
 49      ):
 50          self._size = size
 51          self._spacing = spacing
 52          self._repeat_width = size + spacing
 53          self._num_repeats = ceil(len(pixel_object) / self._repeat_width)
 54          self._overflow = len(pixel_object) % self._repeat_width
 55          self._direction = 1 if not reverse else -1
 56          self._reverse = reverse
 57          self._offset = 0
 58  
 59          def _resetter():
 60              self._offset = 0
 61              self._reverse = reverse
 62              self._direction = 1 if not reverse else -1
 63  
 64          self._reset = _resetter
 65  
 66          super().__init__(pixel_object, speed, color, name=name)
 67  
 68      on_cycle_complete_supported = True
 69  
 70      @property
 71      def reverse(self):
 72          """
 73          Whether the animation is reversed
 74          """
 75          return self._reverse
 76  
 77      @reverse.setter
 78      def reverse(self, value):
 79          self._reverse = value
 80          self._direction = -1 if self._reverse else 1
 81  
 82      def draw(self):
 83          def bar_colors():
 84              bar_no = 0
 85              for i in range(self._offset, 0, -1):
 86                  if i > self._spacing:
 87                      yield self.bar_color(bar_no, i)
 88                  else:
 89                      yield self.space_color(bar_no, i)
 90                      bar_no = 1
 91              while True:
 92                  for bar_pixel in range(self._size):
 93                      yield self.bar_color(bar_no, bar_pixel)
 94                  for space_pixel in range(self._spacing):
 95                      yield self.space_color(bar_no, space_pixel)
 96                  bar_no += 1
 97  
 98          colorgen = bar_colors()
 99          self.pixel_object[:] = [next(colorgen) for _ in self.pixel_object]
100  
101          if self.draw_count % len(self.pixel_object) == 0:
102              self.cycle_complete = True
103          self._offset = (self._offset + self._direction) % self._repeat_width
104  
105      def bar_color(self, n, pixel_no=0):  # pylint: disable=unused-argument
106          """
107          Generate the color for the n'th bar_color in the Chase
108  
109          :param n: The pixel group to get the color for
110          :param pixel_no: Which pixel in the group to get the color for
111          """
112          return self.color
113  
114      def space_color(self, n, pixel_no=0):  # pylint: disable=unused-argument,no-self-use
115          """
116          Generate the spacing color for the n'th bar_color in the Chase
117  
118          :param n: The pixel group to get the spacing color for
119          :param pixel_no: Which pixel in the group to get the spacing color for
120          """
121          return 0
122  
123      def reset(self):
124          """
125          Reset the animation.
126          """
127          self._reset()