def _jitter_clamp(self, x, lb, ub, lane):
s = conf.TILE_SIZE[1]
lb = s * lb + 1
ub = s * (ub + 1) - 1
inv_mean = 1. / conf.CRASH_POS_JITTER
x = min(max(ir(x + randsgn() * expo(inv_mean)), lb), ub)
tile_x = ((x - 1) if lane < 2 else x) / s
return (tile_x, x)
def _jitter_clamp (self, x, lb, ub, lane):
s = conf.TILE_SIZE[1]
lb = s * lb + 1
ub = s * (ub + 1) - 1
inv_mean = 1. / conf.CRASH_POS_JITTER
x = min(max(ir(x + randsgn() * expo(inv_mean)), lb), ub)
tile_x = ((x - 1) if lane < 2 else x) / s
return (tile_x, x)
def generate( self ):
'''Utilizes the Python standard library function for sampling from an
exponential distribution.
Returns:
A random value governed by the exponential distribution with the user
supplied rate.
'''
return expo( self.rate )
def update(self):
fps = self.level.game.scheduler.timer.fps
speed = ir(float(conf.CAR_SPEED) / fps)
speed_jitter = float(conf.CAR_SPEED_JITTER) / fps
for lane, (lane_mode, stopping, (dirn, cars)) in \
enumerate(zip(self._modes, self._stopping, self.cars)):
# remove OoB cars
if cars and self.oob(dirn, cars[0].rect):
cars.pop(0)
# add cars if needed
if not cars or self.needs_car(dirn, cars[-1].rect):
self.add_car(lane)
# move cars
prev = None
new_mode = current_mode = 'moving'
for car in cars:
if lane_mode == 'moving':
car.start()
if car.mode == 'moving':
r = car.rect
front = car.front(dirn)
v = speed + max(1 - speed,
randsgn() * ir(expo(1 / speed_jitter)))
stop = front + dirn * v
# stop before stop marker
if lane_mode != 'moving' and current_mode == 'moving':
if dirn * front <= dirn * stopping:
stop = stopping
new_mode = lane_mode
# stop before next car
if prev is not None:
this_stop = prev.back(dirn) - \
dirn * conf.CAR_GAP[current_mode]
stop = dirn * min(dirn * stop, dirn * this_stop)
new_v = dirn * (stop - front)
if new_v < v:
# velocity reduced
v = max(0, new_v)
if v == 0 and \
(current_mode == 'moving' or prev.mode != 'moving'):
# to make sure we only stop if every car in front
# has stopped - in case this car is faster than the
# one in front
car.set_mode(new_mode)
current_mode = new_mode
r.move_ip(v * dirn, 0)
else:
new_mode = current_mode = car.mode
prev = car
def update (self):
fps = self.level.game.scheduler.timer.fps
speed = ir(float(conf.CAR_SPEED) / fps)
speed_jitter = float(conf.CAR_SPEED_JITTER) / fps
for lane, (lane_mode, stopping, (dirn, cars)) in \
enumerate(zip(self._modes, self._stopping, self.cars)):
# remove OoB cars
if cars and self.oob(dirn, cars[0].rect):
cars.pop(0)
# add cars if needed
if not cars or self.needs_car(dirn, cars[-1].rect):
self.add_car(lane)
# move cars
prev = None
new_mode = current_mode = 'moving'
for car in cars:
if lane_mode == 'moving':
car.start()
if car.mode == 'moving':
r = car.rect
front = car.front(dirn)
v = speed + max(1 - speed,
randsgn() * ir(expo(1 / speed_jitter)))
stop = front + dirn * v
# stop before stop marker
if lane_mode != 'moving' and current_mode == 'moving':
if dirn * front <= dirn * stopping:
stop = stopping
new_mode = lane_mode
# stop before next car
if prev is not None:
this_stop = prev.back(dirn) - \
dirn * conf.CAR_GAP[current_mode]
stop = dirn * min(dirn * stop, dirn * this_stop)
new_v = dirn * (stop - front)
if new_v < v:
# velocity reduced
v = max(0, new_v)
if v == 0 and \
(current_mode == 'moving' or prev.mode != 'moving'):
# to make sure we only stop if every car in front
# has stopped - in case this car is faster than the
# one in front
car.set_mode(new_mode)
current_mode = new_mode
r.move_ip(v * dirn, 0)
else:
new_mode = current_mode = car.mode
prev = car
