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Diffstat (limited to 'PIL/PcfFontFile.py')
| -rw-r--r-- | PIL/PcfFontFile.py | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/PIL/PcfFontFile.py b/PIL/PcfFontFile.py new file mode 100644 index 0000000..9a689b2 --- /dev/null +++ b/PIL/PcfFontFile.py @@ -0,0 +1,256 @@ +# +# THIS IS WORK IN PROGRESS +# +# The Python Imaging Library +# $Id: PcfFontFile.py 2134 2004-10-06 08:55:20Z fredrik $ +# +# 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 + +import string + +# -------------------------------------------------------------------- +# 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:string.index(s, "\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 |