Pillow/src/PIL/FontFile.py
2024-02-05 17:18:52 +00:00

135 lines
3.5 KiB
Python

#
# The Python Imaging Library
# $Id$
#
# base class for raster font file parsers
#
# history:
# 1997-06-05 fl created
# 1997-08-19 fl restrict image width
#
# Copyright (c) 1997-1998 by Secret Labs AB
# Copyright (c) 1997-1998 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#
from __future__ import annotations
import os
from typing import BinaryIO
from . import Image, _binary
WIDTH = 800
def puti16(
fp: BinaryIO, values: tuple[int, int, int, int, int, int, int, int, int, int]
) -> None:
"""Write network order (big-endian) 16-bit sequence"""
for v in values:
if v < 0:
v += 65536
fp.write(_binary.o16be(v))
class FontFile:
"""Base class for raster font file handlers."""
bitmap: Image.Image | None = None
def __init__(self) -> None:
self.info: dict[bytes, bytes | int] = {}
self.glyph: list[
tuple[
tuple[int, int],
tuple[int, int, int, int],
tuple[int, int, int, int],
Image.Image,
]
| None
] = [None] * 256
def __getitem__(self, ix: int) -> (
tuple[
tuple[int, int],
tuple[int, int, int, int],
tuple[int, int, int, int],
Image.Image,
]
| None
):
return self.glyph[ix]
def compile(self) -> None:
"""Create metrics and bitmap"""
if self.bitmap:
return
# create bitmap large enough to hold all data
h = w = maxwidth = 0
lines = 1
for glyph in self.glyph:
if glyph:
d, dst, src, im = glyph
h = max(h, src[3] - src[1])
w = w + (src[2] - src[0])
if w > WIDTH:
lines += 1
w = src[2] - src[0]
maxwidth = max(maxwidth, w)
xsize = maxwidth
ysize = lines * h
if xsize == 0 and ysize == 0:
return
self.ysize = h
# paste glyphs into bitmap
self.bitmap = Image.new("1", (xsize, ysize))
self.metrics: list[
tuple[tuple[int, int], tuple[int, int, int, int], tuple[int, int, int, int]]
| None
] = [None] * 256
x = y = 0
for i in range(256):
glyph = self[i]
if glyph:
d, dst, src, im = glyph
xx = src[2] - src[0]
x0, y0 = x, y
x = x + xx
if x > WIDTH:
x, y = 0, y + h
x0, y0 = x, y
x = xx
s = src[0] + x0, src[1] + y0, src[2] + x0, src[3] + y0
self.bitmap.paste(im.crop(src), s)
self.metrics[i] = d, dst, s
def save(self, filename: str) -> None:
"""Save font"""
self.compile()
# font data
if not self.bitmap:
msg = "No bitmap created"
raise ValueError(msg)
self.bitmap.save(os.path.splitext(filename)[0] + ".pbm", "PNG")
# font metrics
with open(os.path.splitext(filename)[0] + ".pil", "wb") as fp:
fp.write(b"PILfont\n")
fp.write(f";;;;;;{self.ysize};\n".encode("ascii")) # HACK!!!
fp.write(b"DATA\n")
for id in range(256):
m = self.metrics[id]
if not m:
puti16(fp, (0,) * 10)
else:
puti16(fp, m[0] + m[1] + m[2])