Pillow/PIL/PcfFontFile.py
Brian Crowell 37f22ebfcd py3k: Use string methods instead of string module
First, we go for the obvious stuff. The string module methods are gone in
3.0, so we translate them to the appropriate methods on the string class.
2013-01-10 08:42:49 -06:00

255 lines
6.2 KiB
Python

#
# THIS IS WORK IN PROGRESS
#
# The Python Imaging Library
# $Id$
#
# portable compiled font file parser
#
# history:
# 1997-08-19 fl created
# 2003-09-13 fl fixed loading of unicode fonts
#
# Copyright (c) 1997-2003 by Secret Labs AB.
# Copyright (c) 1997-2003 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
import Image
import FontFile
# --------------------------------------------------------------------
# declarations
PCF_MAGIC = 0x70636601 # "\x01fcp"
PCF_PROPERTIES = (1<<0)
PCF_ACCELERATORS = (1<<1)
PCF_METRICS = (1<<2)
PCF_BITMAPS = (1<<3)
PCF_INK_METRICS = (1<<4)
PCF_BDF_ENCODINGS = (1<<5)
PCF_SWIDTHS = (1<<6)
PCF_GLYPH_NAMES = (1<<7)
PCF_BDF_ACCELERATORS = (1<<8)
BYTES_PER_ROW = [
lambda bits: ((bits+7) >> 3),
lambda bits: ((bits+15) >> 3) & ~1,
lambda bits: ((bits+31) >> 3) & ~3,
lambda bits: ((bits+63) >> 3) & ~7,
]
def l16(c):
return ord(c[0]) + (ord(c[1])<<8)
def l32(c):
return ord(c[0]) + (ord(c[1])<<8) + (ord(c[2])<<16) + (ord(c[3])<<24)
def b16(c):
return ord(c[1]) + (ord(c[0])<<8)
def b32(c):
return ord(c[3]) + (ord(c[2])<<8) + (ord(c[1])<<16) + (ord(c[0])<<24)
def sz(s, o):
return s[o:s.index("\0", o)]
##
# Font file plugin for the X11 PCF format.
class PcfFontFile(FontFile.FontFile):
name = "name"
def __init__(self, fp):
magic = l32(fp.read(4))
if magic != PCF_MAGIC:
raise SyntaxError, "not a PCF file"
FontFile.FontFile.__init__(self)
count = l32(fp.read(4))
self.toc = {}
for i in range(count):
type = l32(fp.read(4))
self.toc[type] = l32(fp.read(4)), l32(fp.read(4)), l32(fp.read(4))
self.fp = fp
self.info = self._load_properties()
metrics = self._load_metrics()
bitmaps = self._load_bitmaps(metrics)
encoding = self._load_encoding()
#
# create glyph structure
for ch in range(256):
ix = encoding[ch]
if ix is not None:
x, y, l, r, w, a, d, f = metrics[ix]
glyph = (w, 0), (l, d-y, x+l, d), (0, 0, x, y), bitmaps[ix]
self.glyph[ch] = glyph
def _getformat(self, tag):
format, size, offset = self.toc[tag]
fp = self.fp
fp.seek(offset)
format = l32(fp.read(4))
if format & 4:
i16, i32 = b16, b32
else:
i16, i32 = l16, l32
return fp, format, i16, i32
def _load_properties(self):
#
# font properties
properties = {}
fp, format, i16, i32 = self._getformat(PCF_PROPERTIES)
nprops = i32(fp.read(4))
# read property description
p = []
for i in range(nprops):
p.append((i32(fp.read(4)), ord(fp.read(1)), i32(fp.read(4))))
if nprops & 3:
fp.seek(4 - (nprops & 3), 1) # pad
data = fp.read(i32(fp.read(4)))
for k, s, v in p:
k = sz(data, k)
if s:
v = sz(data, v)
properties[k] = v
return properties
def _load_metrics(self):
#
# font metrics
metrics = []
fp, format, i16, i32 = self._getformat(PCF_METRICS)
append = metrics.append
if (format & 0xff00) == 0x100:
# "compressed" metrics
for i in range(i16(fp.read(2))):
left = ord(fp.read(1)) - 128
right = ord(fp.read(1)) - 128
width = ord(fp.read(1)) - 128
ascent = ord(fp.read(1)) - 128
descent = ord(fp.read(1)) - 128
xsize = right - left
ysize = ascent + descent
append(
(xsize, ysize, left, right, width,
ascent, descent, 0)
)
else:
# "jumbo" metrics
for i in range(i32(fp.read(4))):
left = i16(fp.read(2))
right = i16(fp.read(2))
width = i16(fp.read(2))
ascent = i16(fp.read(2))
descent = i16(fp.read(2))
attributes = i16(fp.read(2))
xsize = right - left
ysize = ascent + descent
append(
(xsize, ysize, left, right, width,
ascent, descent, attributes)
)
return metrics
def _load_bitmaps(self, metrics):
#
# bitmap data
bitmaps = []
fp, format, i16, i32 = self._getformat(PCF_BITMAPS)
nbitmaps = i32(fp.read(4))
if nbitmaps != len(metrics):
raise IOError, "Wrong number of bitmaps"
offsets = []
for i in range(nbitmaps):
offsets.append(i32(fp.read(4)))
bitmapSizes = []
for i in range(4):
bitmapSizes.append(i32(fp.read(4)))
byteorder = format & 4 # non-zero => MSB
bitorder = format & 8 # non-zero => MSB
padindex = format & 3
bitmapsize = bitmapSizes[padindex]
offsets.append(bitmapsize)
data = fp.read(bitmapsize)
pad = BYTES_PER_ROW[padindex]
mode = "1;R"
if bitorder:
mode = "1"
for i in range(nbitmaps):
x, y, l, r, w, a, d, f = metrics[i]
b, e = offsets[i], offsets[i+1]
bitmaps.append(
Image.fromstring("1", (x, y), data[b:e], "raw", mode, pad(x))
)
return bitmaps
def _load_encoding(self):
# map character code to bitmap index
encoding = [None] * 256
fp, format, i16, i32 = self._getformat(PCF_BDF_ENCODINGS)
firstCol, lastCol = i16(fp.read(2)), i16(fp.read(2))
firstRow, lastRow = i16(fp.read(2)), i16(fp.read(2))
default = i16(fp.read(2))
nencoding = (lastCol - firstCol + 1) * (lastRow - firstRow + 1)
for i in range(nencoding):
encodingOffset = i16(fp.read(2))
if encodingOffset != 0xFFFF:
try:
encoding[i+firstCol] = encodingOffset
except IndexError:
break # only load ISO-8859-1 glyphs
return encoding