def number_inc_gt(typechar, loopvar, stop, step, sgn):
""" Increase number and check if it exceeds a limit. """
if sgn == 0:
return False
if typechar in ('#', '!'):
fp_left = fp.from_bytes(loopvar).iadd(step)
loopvar[:] = fp_left.to_bytes()
return fp_left.gt(stop) if sgn > 0 else stop.gt(fp_left)
else:
int_left = vartypes.sint_to_value(loopvar) + step
loopvar[:] = vartypes.value_to_sint(int_left)
return int_left > stop if sgn > 0 else stop > int_left
def randomize(val):
""" Reseed the random number generator. """
# RANDOMIZE converts to int in a non-standard way - looking at the first two bytes in the internal representation
# on a program line, if a number outside the signed int range (or -32768) is entered,
# the number is stored as a MBF double or float. Randomize then:
# - ignores the first 4 bytes (if it's a double)
# - reads the next two
# - xors them with the final two (most signifant including sign bit, and exponent)
# and interprets them as a signed int
# e.g. 1# = /x00/x00/x00/x00 /x00/x00/x00/x81 gets read as /x00/x00 ^ /x00/x81 = /x00/x81 -> 0x10000-0x8100 = -32512 (sign bit set)
# 0.25# = /x00/x00/x00/x00 /x00/x00/x00/x7f gets read as /x00/x00 ^ /x00/x7f = /x00/x7F -> 0x7F00 = 32512 (sign bit not set)
# /xDE/xAD/xBE/xEF /xFF/x80/x00/x80 gets read as /xFF/x80 ^ /x00/x80 = /xFF/x00 -> 0x00FF = 255
s = val[1]
final_two = s[-2:]
mask = bytearray('\x00\x00')
if len(s) >= 4:
mask = s[-4:-2]
final_two = bytearray(chr(final_two[0]^mask[0]) + chr(final_two[1]^mask[1]))
n = vartypes.sint_to_value(final_two)
state.basic_state.rnd_seed &= 0xff
get_random_int(1) # RND(1)
state.basic_state.rnd_seed += n * rnd_step
state.basic_state.rnd_seed %= rnd_period
def randomize(val):
""" Reseed the random number generator. """
# RANDOMIZE converts to int in a non-standard way - looking at the first two bytes in the internal representation
# on a program line, if a number outside the signed int range (or -32768) is entered,
# the number is stored as a MBF double or float. Randomize then:
# - ignores the first 4 bytes (if it's a double)
# - reads the next two
# - xors them with the final two (most signifant including sign bit, and exponent)
# and interprets them as a signed int
# e.g. 1# = /x00/x00/x00/x00 /x00/x00/x00/x81 gets read as /x00/x00 ^ /x00/x81 = /x00/x81 -> 0x10000-0x8100 = -32512 (sign bit set)
# 0.25# = /x00/x00/x00/x00 /x00/x00/x00/x7f gets read as /x00/x00 ^ /x00/x7f = /x00/x7F -> 0x7F00 = 32512 (sign bit not set)
# /xDE/xAD/xBE/xEF /xFF/x80/x00/x80 gets read as /xFF/x80 ^ /x00/x80 = /xFF/x00 -> 0x00FF = 255
s = val[1]
final_two = s[-2:]
mask = bytearray(2)
if len(s) >= 4:
mask = s[-4:-2]
final_two = bytearray(
chr(final_two[0] ^ mask[0]) + chr(final_two[1] ^ mask[1]))
n = vartypes.sint_to_value(final_two)
state.basic_state.rnd_seed &= 0xff
get_random_int(1) # RND(1)
state.basic_state.rnd_seed += n * rnd_step
state.basic_state.rnd_seed %= rnd_period
def value_cvi(ins):
""" CVI: return the int value of a byte representation. """
cstr = vartypes.pass_string_unpack(parse_bracket(ins))
if len(cstr) < 2:
raise error.RunError(error.IFC)
return vartypes.pack_int(vartypes.sint_to_value(cstr[:2]))
def sint_to_str(s):
""" Convert signed int token to Python string. """
return str(vartypes.sint_to_value(s))
def sint_to_str(s):
""" Convert signed int token to Python string. """
return str(vartypes.sint_to_value(s))
def value_cvi(ins):
""" CVI: return the int value of a byte representation. """
cstr = vartypes.pass_string_unpack(parse_bracket(ins))
if len(cstr) < 2:
raise error.RunError(error.IFC)
return vartypes.pack_int(vartypes.sint_to_value(cstr[:2]))
