def GenerateValidDominos(Start = 0, End = 4095):
logging.debug("Checking Domino Values from {} to {}" . format(Start, End))
bPass = 1
Row1 = 0
Row2 = 0
ValidValues = []
for x in range(Start,(End+1),1):
bPass = True
DPips = BitArray('0x000')
DPips.uint = x
Row1 = DPips[:6]
Row2 = DPips[-6:]
logging.debug("Index Value:{} Binary Value:{}" .format(x,DPips.bin))
#Row 1 and 2 Pip Count
R1_PC = len(list(Row1.findall([1])))
R2_PC = len(list(Row2.findall([1])))
#Total pips between rows must be 6.
if (R1_PC + R2_PC) != 6: bPass = False
logging.debug("Row 1 Value:{} Binary Value:{} Pip Count:{}" .format(Row1.uint, Row1.bin, R1_PC))
logging.debug("Row 2 Value:{} Binary Value:{} Pip Count:{}" .format(Row2.uint, Row2.bin, R2_PC))
logging.debug("Pip count validity: {}" . format(bPass))
#Generate the reverse of the bit stream.
DFlip = BitArray('0x000')
DFlip.uint = x
DFlip.reverse()
ReversedValue = DFlip.uint
logging.debug("Flipped Row Value:{} Binary Value:{}" .format(ReversedValue, DFlip.bin))
#The domino is a mirror iamge of itself and is invalid.
if (ReversedValue == x):
logging.debug("Fail: Mirror Domino")
bPass = False
#The rotated domino exists as a prior value.
if (ReversedValue in ValidValues):
logging.debug("Fail: Exists previously (rotated)")
bPass = False
#The specified domino passed all rules and is valid.
if (bPass == True):
ValidValues.append(x)
logging.debug("Passed: Added Value {}({}) to list." . format(x, DPips.bin))
logging.debug("---")
logging.debug(ValidValues)
return ValidValues
def testCreationFromUint(self):
s = BitArray(uint=15, length=6)
self.assertEqual(s.bin, "001111")
s = BitArray(uint=0, length=1)
self.assertEqual(s.bin, "0")
s.uint = 1
self.assertEqual(s.uint, 1)
s = BitArray(length=8)
s.uint = 0
self.assertEqual(s.uint, 0)
s.uint = 255
self.assertEqual(s.uint, 255)
self.assertEqual(s.len, 8)
self.assertRaises(bitstring.CreationError, s._setuint, 256)
def testCreationFromUint(self):
s = BitArray(uint=15, length=6)
self.assertEqual(s.bin, '0b001111')
s = BitArray(uint=0, length=1)
self.assertEqual(s.bin, '0b0')
s.uint = 1
self.assertEqual(s.uint, 1)
s = BitArray(length=8)
s.uint = 0
self.assertEqual(s.uint, 0)
s.uint = 255
self.assertEqual(s.uint, 255)
self.assertEqual(s.len, 8)
self.assertRaises(bitstring.CreationError, s._setuint, 256)
def joshua_saxby_scrambler():
"""
My own implementation of the CD sector scrambler, based partly on commentary
and analysis from Kris Kaspersky's aforementioned book, and also based on
my interpretation of the ECMA-130 Annex B scrambler description
"""
# start value has least significant bit set to 1
register = BitArray(uint=0b0000000000000001, length=16)
# NOTE: BitArray library addresses bits in big-endian order
# Bit clock = XOR least two significant bits
register[0] = register[14] ^ register[15]
yield register.uint
while True:
# XOR the register with a copy of itself shifted one right
copy = register.uint >> 1
register.uint = register.uint ^ copy
# shift the result to the right again
register.uint >>= 1
# Bit clock = XOR least two significant bits
register[0] = register[14] ^ register[15]
# Kris Kaspersky claims that if the first bit (LSB) is set to 1, we
# should toggle the second MSB (bit right of MSB)
# The following if block does this, and it DOES cause the output of
# this implementation to produce sequences identical to other third
# party produced sequences, but it is not clear yet how this relates
# to the reference material, ECMA-130 Annex B
if register[15]:
register[1] = not register[1]
yield register.uint
def __place_domino(self, x, y, value, canvas):
#Paints Domino, X,Y @ Left Corner of Domino
#PYX Library
if (self.RadiusCorners == True):
w = self.Domino_Width
h = self.Domino_Height
r = self.CornerRadius
pyx_circle = pyx.path.circle(x + r, y + r, r)
canvas.fill(pyx_circle, [pyx.color.rgb.black])
pyx_circle = pyx.path.circle((x + w) - r, y + r, r)
canvas.fill(pyx_circle, [pyx.color.rgb.black])
pyx_circle = pyx.path.circle(x + r, (y + h) - r, r)
canvas.fill(pyx_circle, [pyx.color.rgb.black])
pyx_circle = pyx.path.circle((x + w) - r, (y + h) - r, r)
canvas.fill(pyx_circle, [pyx.color.rgb.black])
pyx_rec = pyx.path.rect(x, y + r, w, h - (2 * r))
canvas.fill(pyx_rec, [pyx.color.rgb.black])
pyx_rec = pyx.path.rect(x + r, y, w - (2 * r), h)
canvas.fill(pyx_rec, [pyx.color.rgb.black])
else:
pyx_rec = pyx.path.rect(x, y, self.Domino_Width,
self.Domino_Height)
canvas.fill(pyx_rec, [pyx.color.rgb.black])
px = 0
py = 0
DPips = BitArray('0x000')
DPips.uint = int(value)
#BitArrays are big endian by default
BitRow = [BitArray(6), BitArray(6)]
BitRow[0] = DPips[:6] # First Row
BitRow[1] = DPips[-6:] # Second Row
for py in range(2):
for px in range(8):
#First and list pip are always placed
#Pip 1-6 based on bitrow
if (px == 0) or (px == 7) or (BitRow[py][px - 1] is True):
YCord = y + (self.Pip_Padding + (self.Pip_Radius) +
((py * 2) * (self.Pip_Diameter)))
XCord = x + (self.Pip_Padding + (self.Pip_Radius) +
((px * 2) * (self.Pip_Diameter)))
pyx_circle = pyx.path.circle(XCord, YCord, self.Pip_Radius)
canvas.fill(pyx_circle, [pyx.color.rgb.white])
return ()
def encode(word):
# we build a dictionnary with all possible symbols and associate each of them with a number
symbols ={}
for letter in string.printable:
bits = BitArray(BITS_USED)
bits.uint = len(symbols)
symbols[letter] = bits
# the code we'll return
code = BitStream()
# a sequence of characters
sequence = ""
# for each character in the word we are encoding
for c in word:
# we add it to the sequence we are currently considering
temp = sequence + c
# if we know the result we just keep it and parse the next character
if temp in symbols:
sequence = temp
# otherwise
else:
# we add the previously known sequence to the code
code.append(symbols[sequence])
# and add the new sequence to our dictionnary of known sequences
if len(symbols) < 1<<BITS_USED:
bits = BitArray(BITS_USED)
bits.uint = len(symbols)
symbols[temp] = bits
# the sequence is reset to only the new character
sequence = c
# there is usually a last unincoded sequence to be added
code.append(symbols[sequence])
return code
