244 lines
7.5 KiB
Python
244 lines
7.5 KiB
Python
#!/usr/bin/env python2
|
|
"""
|
|
Miscellaneous Routines.
|
|
"""
|
|
from sys import maxint as INF
|
|
from struct import pack, unpack
|
|
|
|
|
|
## Matrix operations
|
|
##
|
|
MATRIX_IDENTITY = (1, 0, 0, 1, 0, 0)
|
|
|
|
def mult_matrix((a1,b1,c1,d1,e1,f1), (a0,b0,c0,d0,e0,f0)):
|
|
'''Returns the multiplication of two matrices.'''
|
|
return (a0*a1+c0*b1, b0*a1+d0*b1,
|
|
a0*c1+c0*d1, b0*c1+d0*d1,
|
|
a0*e1+c0*f1+e0, b0*e1+d0*f1+f0)
|
|
|
|
def translate_matrix((a,b,c,d,e,f), (x,y)):
|
|
'''Translates a matrix by (x,y).'''
|
|
return (a,b,c,d,x*a+y*c+e,x*b+y*d+f)
|
|
|
|
def apply_matrix_pt((a,b,c,d,e,f), (x,y)):
|
|
'''Applies a matrix to a point.'''
|
|
return (a*x+c*y+e, b*x+d*y+f)
|
|
|
|
def apply_matrix_norm((a,b,c,d,e,f), (p,q)):
|
|
'''Equivalent to apply_matrix_pt(M, (p,q)) - apply_matrix_pt(M, (0,0))'''
|
|
return (a*p+c*q, b*p+d*q)
|
|
|
|
|
|
## Utility functions
|
|
##
|
|
|
|
# uniq
|
|
def uniq(objs):
|
|
'''Eliminates duplicated elements.'''
|
|
done = set()
|
|
for obj in objs:
|
|
if obj in done: continue
|
|
done.add(obj)
|
|
yield obj
|
|
return
|
|
|
|
# csort
|
|
def csort(objs, key):
|
|
'''Order-preserving sorting function.'''
|
|
idxs = dict( (obj,i) for (i,obj) in enumerate(objs) )
|
|
return sorted(objs, key=lambda obj:(key(obj), idxs[obj]))
|
|
|
|
# drange
|
|
def drange(v0, v1, d):
|
|
'''Returns a discrete range.'''
|
|
assert v0 < v1
|
|
return xrange(int(v0)/d, int(v1+d-1)/d)
|
|
|
|
# get_bound
|
|
def get_bound(pts):
|
|
'''Compute a minimal rectangle that covers all the points.'''
|
|
(x0, y0, x1, y1) = (INF, INF, -INF, -INF)
|
|
for (x,y) in pts:
|
|
x0 = min(x0, x)
|
|
y0 = min(y0, y)
|
|
x1 = max(x1, x)
|
|
y1 = max(y1, y)
|
|
return (x0,y0,x1,y1)
|
|
|
|
# pick
|
|
def pick(seq, func, maxobj=None):
|
|
'''Picks the object obj where func(obj) has the highest value.'''
|
|
maxscore = None
|
|
for obj in seq:
|
|
score = func(obj)
|
|
if maxscore is None or maxscore < score:
|
|
(maxscore,maxobj) = (score,obj)
|
|
return maxobj
|
|
|
|
# choplist
|
|
def choplist(n, seq):
|
|
'''Groups every n elements of the list.'''
|
|
r = []
|
|
for x in seq:
|
|
r.append(x)
|
|
if len(r) == n:
|
|
yield tuple(r)
|
|
r = []
|
|
return
|
|
|
|
# nunpack
|
|
def nunpack(s, default=0):
|
|
'''Unpacks 1 to 4 byte integers (big endian).'''
|
|
l = len(s)
|
|
if not l:
|
|
return default
|
|
elif l == 1:
|
|
return ord(s)
|
|
elif l == 2:
|
|
return unpack('>H', s)[0]
|
|
elif l == 3:
|
|
return unpack('>L', '\x00'+s)[0]
|
|
elif l == 4:
|
|
return unpack('>L', s)[0]
|
|
else:
|
|
raise TypeError('invalid length: %d' % l)
|
|
|
|
# decode_text
|
|
PDFDocEncoding = ''.join( unichr(x) for x in (
|
|
0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
|
|
0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
|
|
0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0017, 0x0017,
|
|
0x02d8, 0x02c7, 0x02c6, 0x02d9, 0x02dd, 0x02db, 0x02da, 0x02dc,
|
|
0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
|
|
0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
|
|
0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
|
|
0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
|
|
0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
|
|
0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
|
|
0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
|
|
0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
|
|
0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
|
|
0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
|
|
0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
|
|
0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x0000,
|
|
0x2022, 0x2020, 0x2021, 0x2026, 0x2014, 0x2013, 0x0192, 0x2044,
|
|
0x2039, 0x203a, 0x2212, 0x2030, 0x201e, 0x201c, 0x201d, 0x2018,
|
|
0x2019, 0x201a, 0x2122, 0xfb01, 0xfb02, 0x0141, 0x0152, 0x0160,
|
|
0x0178, 0x017d, 0x0131, 0x0142, 0x0153, 0x0161, 0x017e, 0x0000,
|
|
0x20ac, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
|
|
0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x0000, 0x00ae, 0x00af,
|
|
0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
|
|
0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
|
|
0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
|
|
0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
|
|
0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
|
|
0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
|
|
0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
|
|
0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
|
|
0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
|
|
0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff,
|
|
))
|
|
def decode_text(s):
|
|
'''Decodes a PDFDocEncoding string to Unicode.'''
|
|
if s.startswith('\xfe\xff'):
|
|
return unicode(s[2:], 'utf-16be', 'ignore')
|
|
else:
|
|
return ''.join( PDFDocEncoding[ord(c)] for c in s )
|
|
|
|
# enc
|
|
def enc(x, codec='ascii'):
|
|
'''Encodes a string for SGML/XML/HTML'''
|
|
x = x.replace('&','&').replace('>','>').replace('<','<').replace('"','"')
|
|
return x.encode(codec, 'xmlcharrefreplace')
|
|
|
|
def bbox2str((x0,y0,x1,y1)):
|
|
return '%.3f,%.3f,%.3f,%.3f' % (x0, y0, x1, y1)
|
|
|
|
def matrix2str((a,b,c,d,e,f)):
|
|
return '[%.2f,%.2f,%.2f,%.2f, (%.2f,%.2f)]' % (a,b,c,d,e,f)
|
|
|
|
|
|
## ObjIdRange
|
|
##
|
|
class ObjIdRange(object):
|
|
|
|
"A utility class to represent a range of object IDs."
|
|
|
|
def __init__(self, start, nobjs):
|
|
self.start = start
|
|
self.nobjs = nobjs
|
|
return
|
|
|
|
def __repr__(self):
|
|
return '<ObjIdRange: %d-%d>' % (self.get_start_id(), self.get_end_id())
|
|
|
|
def get_start_id(self):
|
|
return self.start
|
|
|
|
def get_end_id(self):
|
|
return self.start + self.nobjs - 1
|
|
|
|
def get_nobjs(self):
|
|
return self.nobjs
|
|
|
|
|
|
## Plane
|
|
##
|
|
## A data structure for objects placed on a plane.
|
|
## Can efficiently find objects in a certain rectangular area.
|
|
## It maintains two parallel lists of objects, each of
|
|
## which is sorted by its x or y coordinate.
|
|
##
|
|
class Plane(object):
|
|
|
|
def __init__(self, objs=None, gridsize=50):
|
|
self._objs = {}
|
|
self.gridsize = gridsize
|
|
if objs is not None:
|
|
for obj in objs:
|
|
self.add(obj)
|
|
return
|
|
|
|
def __repr__(self):
|
|
return ('<Plane objs=%r>' % list(self))
|
|
|
|
def _getrange(self, (x0,y0,x1,y1)):
|
|
for y in drange(y0, y1, self.gridsize):
|
|
for x in drange(x0, x1, self.gridsize):
|
|
yield (x,y)
|
|
return
|
|
|
|
# add(obj): place an object in a certain area.
|
|
def add(self, obj):
|
|
for k in self._getrange((obj.x0, obj.y0, obj.x1, obj.y1)):
|
|
if k not in self._objs:
|
|
r = []
|
|
self._objs[k] = r
|
|
else:
|
|
r = self._objs[k]
|
|
r.append(obj)
|
|
return
|
|
|
|
# find(): finds objects that are in a certain area.
|
|
def find(self, (x0,y0,x1,y1)):
|
|
r = set()
|
|
for k in self._getrange((x0,y0,x1,y1)):
|
|
if k not in self._objs: continue
|
|
for obj in self._objs[k]:
|
|
if obj in r: continue
|
|
r.add(obj)
|
|
if (obj.x1 <= x0 or x1 <= obj.x0 or
|
|
obj.y1 <= y0 or y1 <= obj.y0): continue
|
|
yield obj
|
|
return
|
|
|
|
|
|
# create_bmp
|
|
def create_bmp(data, bits, width, height):
|
|
info = pack('<IiiHHIIIIII', 40, width, height, 1, bits, 0, len(data), 0, 0, 0, 0)
|
|
assert len(info) == 40, len(info)
|
|
header = pack('<ccIHHI', 'B', 'M', 14+40+len(data), 0, 0, 14+40)
|
|
assert len(header) == 14, len(header)
|
|
# XXX re-rasterize every line
|
|
return header+info+data
|