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__(
  44. self, ix: int
  45. ) -> (
  46. tuple[
  47. tuple[int, int],
  48. tuple[int, int, int, int],
  49. tuple[int, int, int, int],
  50. Image.Image,
  51. ]
  52. | None
  53. ):
  54. return self.glyph[ix]
  55. def compile(self) -> None:
  56. """Create metrics and bitmap"""
  57. if self.bitmap:
  58. return
  59. # create bitmap large enough to hold all data
  60. h = w = maxwidth = 0
  61. lines = 1
  62. for glyph in self.glyph:
  63. if glyph:
  64. d, dst, src, im = glyph
  65. h = max(h, src[3] - src[1])
  66. w = w + (src[2] - src[0])
  67. if w > WIDTH:
  68. lines += 1
  69. w = src[2] - src[0]
  70. maxwidth = max(maxwidth, w)
  71. xsize = maxwidth
  72. ysize = lines * h
  73. if xsize == 0 and ysize == 0:
  74. return
  75. self.ysize = h
  76. # paste glyphs into bitmap
  77. self.bitmap = Image.new("1", (xsize, ysize))
  78. self.metrics: list[
  79. tuple[tuple[int, int], tuple[int, int, int, int], tuple[int, int, int, int]]
  80. | None
  81. ] = [None] * 256
  82. x = y = 0
  83. for i in range(256):
  84. glyph = self[i]
  85. if glyph:
  86. d, dst, src, im = glyph
  87. xx = src[2] - src[0]
  88. x0, y0 = x, y
  89. x = x + xx
  90. if x > WIDTH:
  91. x, y = 0, y + h
  92. x0, y0 = x, y
  93. x = xx
  94. s = src[0] + x0, src[1] + y0, src[2] + x0, src[3] + y0
  95. self.bitmap.paste(im.crop(src), s)
  96. self.metrics[i] = d, dst, s
  97. def save(self, filename: str) -> None:
  98. """Save font"""
  99. self.compile()
  100. # font data
  101. if not self.bitmap:
  102. msg = "No bitmap created"
  103. raise ValueError(msg)
  104. self.bitmap.save(os.path.splitext(filename)[0] + ".pbm", "PNG")
  105. # font metrics
  106. with open(os.path.splitext(filename)[0] + ".pil", "wb") as fp:
  107. fp.write(b"PILfont\n")
  108. fp.write(f";;;;;;{self.ysize};\n".encode("ascii")) # HACK!!!
  109. fp.write(b"DATA\n")
  110. for id in range(256):
  111. m = self.metrics[id]
  112. if not m:
  113. puti16(fp, (0,) * 10)
  114. else:
  115. puti16(fp, m[0] + m[1] + m[2])