FontFile.py 3.5 KB

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  1. #
  2. # The Python Imaging Library
  3. # $Id$
  4. #
  5. # base class for raster font file parsers
  6. #
  7. # history:
  8. # 1997-06-05 fl created
  9. # 1997-08-19 fl restrict image width
  10. #
  11. # Copyright (c) 1997-1998 by Secret Labs AB
  12. # Copyright (c) 1997-1998 by Fredrik Lundh
  13. #
  14. # See the README file for information on usage and redistribution.
  15. #
  16. from __future__ import annotations
  17. import os
  18. from typing import BinaryIO
  19. from . import Image, _binary
  20. WIDTH = 800
  21. def puti16(
  22. fp: BinaryIO, values: tuple[int, int, int, int, int, int, int, int, int, int]
  23. ) -> None:
  24. """Write network order (big-endian) 16-bit sequence"""
  25. for v in values:
  26. if v < 0:
  27. v += 65536
  28. fp.write(_binary.o16be(v))
  29. class FontFile:
  30. """Base class for raster font file handlers."""
  31. bitmap: Image.Image | None = None
  32. def __init__(self) -> None:
  33. self.info: dict[bytes, bytes | int] = {}
  34. self.glyph: list[
  35. tuple[
  36. tuple[int, int],
  37. tuple[int, int, int, int],
  38. tuple[int, int, int, int],
  39. Image.Image,
  40. ]
  41. | None
  42. ] = [None] * 256
  43. def __getitem__(self, ix: int) -> (
  44. tuple[
  45. tuple[int, int],
  46. tuple[int, int, int, int],
  47. tuple[int, int, int, int],
  48. Image.Image,
  49. ]
  50. | None
  51. ):
  52. return self.glyph[ix]
  53. def compile(self) -> None:
  54. """Create metrics and bitmap"""
  55. if self.bitmap:
  56. return
  57. # create bitmap large enough to hold all data
  58. h = w = maxwidth = 0
  59. lines = 1
  60. for glyph in self.glyph:
  61. if glyph:
  62. d, dst, src, im = glyph
  63. h = max(h, src[3] - src[1])
  64. w = w + (src[2] - src[0])
  65. if w > WIDTH:
  66. lines += 1
  67. w = src[2] - src[0]
  68. maxwidth = max(maxwidth, w)
  69. xsize = maxwidth
  70. ysize = lines * h
  71. if xsize == 0 and ysize == 0:
  72. return
  73. self.ysize = h
  74. # paste glyphs into bitmap
  75. self.bitmap = Image.new("1", (xsize, ysize))
  76. self.metrics: list[
  77. tuple[tuple[int, int], tuple[int, int, int, int], tuple[int, int, int, int]]
  78. | None
  79. ] = [None] * 256
  80. x = y = 0
  81. for i in range(256):
  82. glyph = self[i]
  83. if glyph:
  84. d, dst, src, im = glyph
  85. xx = src[2] - src[0]
  86. x0, y0 = x, y
  87. x = x + xx
  88. if x > WIDTH:
  89. x, y = 0, y + h
  90. x0, y0 = x, y
  91. x = xx
  92. s = src[0] + x0, src[1] + y0, src[2] + x0, src[3] + y0
  93. self.bitmap.paste(im.crop(src), s)
  94. self.metrics[i] = d, dst, s
  95. def save(self, filename: str) -> None:
  96. """Save font"""
  97. self.compile()
  98. # font data
  99. if not self.bitmap:
  100. msg = "No bitmap created"
  101. raise ValueError(msg)
  102. self.bitmap.save(os.path.splitext(filename)[0] + ".pbm", "PNG")
  103. # font metrics
  104. with open(os.path.splitext(filename)[0] + ".pil", "wb") as fp:
  105. fp.write(b"PILfont\n")
  106. fp.write(f";;;;;;{self.ysize};\n".encode("ascii")) # HACK!!!
  107. fp.write(b"DATA\n")
  108. for id in range(256):
  109. m = self.metrics[id]
  110. if not m:
  111. puti16(fp, (0,) * 10)
  112. else:
  113. puti16(fp, m[0] + m[1] + m[2])