fontio.py

   1 # SPDX-FileCopyrightText: 2020 Melissa LeBlanc-Williams for Adafruit Industries
   2 #
   3 # SPDX-License-Identifier: MIT
   4
   5 """
   6 `fontio`
   7 ================================================================================
   8
   9 fontio for Blinka
  10
  11 **Software and Dependencies:**
  12
  13 * Adafruit Blinka:
  14   https://github.com/adafruit/Adafruit_Blinka/releases
  15
  16 * Author(s): Melissa LeBlanc-Williams
  17
  18 """
  19
  20 from PIL import ImageFont
  21 from displayio import Bitmap
  22
  23 __version__ = "0.0.0-auto.0"
  24 __repo__ = "https://github.com/adafruit/Adafruit_Blinka_displayio.git"
  25
  26
  27 class BuiltinFont:
  28     """Simulate a font built into CircuitPython"""
  29
  30     def __init__(self):
  31         self._font = ImageFont.load_default()
  32         self._generate_bitmap(0x20, 0x7E)
  33
  34     def _generate_bitmap(self, start_range, end_range):
  35         char_width, char_height = self.get_bounding_box()
  36         self._bitmap = Bitmap(
  37             char_width * (end_range - start_range + 1), char_height, 2
  38         )
  39         for character in range(start_range, end_range + 1):
  40             ascii_char = chr(character)
  41             ascii_mask = self._font.getmask(ascii_char, mode="1")
  42             for y in range(char_height):
  43                 for x in range(char_width):
  44                     color = ascii_mask.getpixel((x, y))
  45                     character_position = character - start_range
  46                     self._bitmap[character_position * char_width + x, y] = (
  47                         1 if color else 0
  48                     )
  49
  50     def get_bounding_box(self):
  51         """Returns the maximum bounds of all glyphs in the font in
  52         a tuple of two values: width, height.
  53         """
  54         return self._font.getsize("M")
  55
  56     def get_glyph(self, codepoint):
  57         """Returns a `fontio.Glyph` for the given codepoint or None if no glyph is available."""
  58         if 0x20 <= codepoint <= 0x7E:
  59             glyph_index = codepoint - 0x20
  60         else:
  61             return None
  62
  63         bounding_box = self._font.getsize(chr(codepoint))
  64         width, height = bounding_box
  65         return Glyph(
  66             bitmap=self._bitmap,
  67             tile_index=glyph_index,
  68             width=width,
  69             height=height,
  70             dx=0,
  71             dy=0,
  72             shift_x=width,
  73             shift_y=0,
  74         )
  75
  76     @property
  77     def bitmap(self):
  78         """Bitmap containing all font glyphs starting with ASCII and followed by unicode. Use
  79         `get_glyph` in most cases. This is useful for use with `displayio.TileGrid` and
  80         `terminalio.Terminal`.
  81         """
  82         return self._bitmap
  83
  84
  85 # pylint: disable=too-few-public-methods, invalid-name, too-many-arguments
  86 class Glyph:
  87     """Storage of glyph info"""
  88
  89     def __init__(self, bitmap, tile_index, width, height, dx, dy, shift_x, shift_y):
  90         self.bitmap = bitmap
  91         self.width = width
  92         self.height = height
  93         self.dx = dx
  94         self.dy = dy
  95         self.shift_x = shift_x
  96         self.shift_y = shift_y
  97         self.tile_index = tile_index
  98
  99
 100 # pylint: enable=too-few-public-methods, invalid-name, too-many-arguments