Source code for pylib.drawblock

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""Draw with block characters.

:Date: 2019-11-15

.. module:: drawblock
  :platform: *nix, Windows
  :synopsis: Draw with block characters.

.. moduleauthor:: Daniel Weschke <daniel.weschke@directbox.de>
"""

def histogram(f, x=None):
  """Histogram chart with block symbols.

  ::

    dots
     ,_,
     |8|
     |7|
     |6|
     |5|
     |4|
     |3|
     |2|
     |1|
     ```

    ▁▂▃▄▅▆▇█
    12345678
  """
  from collections import defaultdict
  chars = defaultdict(lambda: defaultdict(int))

  # w/o comma no 2d tuple
  pixel_map = ((0x2581,),  # Lower one eighth block, also used for value 0
               (0x2582,),  # Lower one quarter block
               (0x2583,),  # Lower three eighths block
               (0x2584,),  # Lower half block
               (0x2585,),  # Lower five eighths block
               (0x2586,),  # Lower three quarters block
               (0x2587,),  # Lower seven eighths block
               (0x2588,))  # Full block
  #print(pixel_map)
  pixel_rows = 8
  pixel_cols = 1

  def normalize(coord):
    coord_type = type(coord)
    if coord_type == int:
      return coord
    if coord_type == float:
      return int(round(coord))
    raise TypeError("Unsupported coordinate type <{0}>".format(type(coord)))

  def get_pos(x, y):
    """Convert x, y to cols, rows"""
    return x // 1, y // pixel_rows

  def set(x, y):
    """Set a pixel of the :class:`Canvas` object.
    :param x: x coordinate of the pixel
    :param y: y coordinate of the pixel
    """
    x = normalize(x)
    y = normalize(y)
    col, row = get_pos(x, y)

    if type(chars[row][col]) != int:
      return

    chars[row][col] |= pixel_map[y % pixel_rows][x % pixel_cols]

    # fill also below the tip
    if row > 0:
      for i in range(row):
        chars[i][col] |= pixel_map[pixel_rows-1][x % pixel_cols]

  def rows(min_x=None, min_y=None, max_x=None, max_y=None):
    """Returns a list of the current :class:`Canvas` object lines.
    :param min_x: (optional) minimum x coordinate of the canvas
    :param min_y: (optional) minimum y coordinate of the canvas
    :param max_x: (optional) maximum x coordinate of the canvas
    :param max_y: (optional) maximum y coordinate of the canvas
    """
    if not chars.keys():
      return []

    minrow = min_y // pixel_rows if min_y is not None else min(chars.keys())
    maxrow = (max_y - 1) // pixel_rows if max_y is not None else max(chars.keys())
    mincol = min_x // 1 if min_x is not None else min(min(x.keys()) for x in chars.values())
    maxcol = (max_x - 1) // 1 if max_x is not None else max(max(x.keys()) for x in chars.values())
    result = []

    for rownum in range(minrow, maxrow+1):
      if not rownum in chars:
        result.append('')
        continue

      maxcol = (max_x - 1) // 1 if max_x is not None else max(chars[rownum].keys())
      row = []

      for x in range(mincol, maxcol+1):
        char = chars[rownum].get(x)

        if not char:
          row.append(chr(0x20))
          #row.append(chr(0x2588))
        elif type(char) != int:
          row.append(char)
        else:
          row.append(chr(char))
      result.append(''.join(row))

    return result

  def frame(min_x=None, min_y=None, max_x=None, max_y=None):
    """String representation of the current :class:`Canvas` object pixels.
    :param min_x: (optional) minimum x coordinate of the canvas
    :param min_y: (optional) minimum y coordinate of the canvas
    :param max_x: (optional) maximum x coordinate of the canvas
    :param max_y: (optional) maximum y coordinate of the canvas
    """
    import os
    result = os.linesep.join(reversed(rows(min_x, min_y, max_x, max_y)))
    return result  # py2: ret.encode('utf-8')

  if x is None:
    for xi, y in enumerate(f):
      set(xi, y)
  else:
    for xi, y in zip(x, f):
      set(xi, y)
  return frame()