import threading
try:
import Queue as queue
except ImportError:
import queue
from collections import deque
from time import sleep, clock
from xmlreader import XMLReader
import helpers
from helpers import Struct
import math
import sys
import pose
import simobject
import supervisor
from quadtree import QuadTree, Rect
PAUSE = 0
RUN = 1
RUN_ONCE = 2
DRAW_ONCE = 3
[docs]class Simulator(threading.Thread):
"""The simulator manages simobjects and their collisions, commands supervisors
and draws the world using the supplied *renderer*.
The simulator runs in a separate thread. None of its functions are thread-safe,
and should never be called directly from other objects (except for the functions
inherited from `threading.Thread`). The communication with the simulator
should be done through its *in_queue* and *out_queue*. See :ref:`ui-sim-queue`.
:param renderer: The renderer that will be used to draw the world.
The simulator will assume control of the renderer.
The renderer functions also have to be considered thread-unsafe.
:type renderer: :class:`~renderer.Renderer`
:param in_queue: The queue that is used to send events to the simulator.
:type in_queue: :class:`Queue.Queue`
"""
__nice_colors = (0x55AAEE, 0x66BB22, 0xFFBB22, 0xCC66AA,
0x77CCAA, 0xFF7711, 0xFF5555, 0x55CC88)
def __init__(self, renderer, in_queue):
"""Create a simulator with *renderer* and *in_queue*
"""
super(Simulator, self).__init__()
#Attributes
self.__stop = False
self.__state = PAUSE
self.__renderer = renderer
self.__center_on_robot = False
self.__orient_on_robot = False
self.__show_sensors = True
self.__draw_supervisors = False
self.__show_tracks = True
self.__in_queue = in_queue
self._out_queue = queue.Queue()
# Zoom on scene - Move to read_config later
self.__time_multiplier = 1.0
self.__time = 0.0
# Plots
self.plot_expressions = []
# World objects
self.__robots = []
self.__trackers = []
self.__obstacles = []
self.__supervisors = []
self.__background = []
self.__zoom_default = 1
self.__world = None
self.__log_queue = deque()
# Internal objects
self.__qtree = None
[docs] def read_config(self, filename):
'''Load in the objects from the world XML file '''
self.log('Loading new world')
try:
world = XMLReader(filename, 'simulation').read()
except Exception as e:
raise Exception('[Simulator.read_config] Failed to parse ' + filename \
+ ': ' + str(e))
else:
self.load_world(world)
[docs] def load_world(self, world):
'''Load the objects from an already parsed world'''
self.__world = world
self.__supervisor_param_cache = None
self.__center_on_robot = False
self.__construct_world()
def __construct_world(self):
"""Creates objects previously loaded from the world xml file.
This function uses the world in ``self.__world``.
All the objects will be created anew, including robots and supervisors.
All of the user's code is reloaded.
"""
if self.__world is None:
return
helpers.unload_user_modules()
self.__state = DRAW_ONCE
self.__robots = []
self.__obstacles = []
self.__supervisors = []
self.__background = []
self.__trackers = []
self.__qtree = None
for thing in self.__world:
if thing.type == 'robot':
try:
# Create robot
robot_class = helpers.load_by_name(thing.robot.type,'robots')
if thing.robot.options is not None:
robot = robot_class(thing.robot.pose, options = Struct(thing.robot.options))
else:
robot = robot_class(thing.robot.pose)
robot.set_logqueue(self.__log_queue)
if thing.robot.color is not None:
robot.set_color(thing.robot.color)
elif len(self.__robots) < 8:
robot.set_color(self.__nice_colors[len(self.__robots)])
# Create supervisor
sup_class = helpers.load_by_name(thing.supervisor.type,'supervisors')
info = robot.get_info()
info.color = robot.get_color()
if thing.supervisor.options is not None:
supervisor = sup_class(thing.robot.pose, info, options = Struct(thing.supervisor.options))
else:
supervisor = sup_class(thing.robot.pose, info)
supervisor.set_logqueue(self.__log_queue)
name = "Robot {}: {}".format(len(self.__robots)+1, sup_class.__name__)
if self.__supervisor_param_cache is not None and \
len(self.__supervisor_param_cache) > len(self.__supervisors):
supervisor.set_parameters(self.__supervisor_param_cache[len(self.__supervisors)])
self._out_queue.put(("make_param_window",
(robot, name,
supervisor.get_ui_description())))
self.__supervisors.append(supervisor)
# append robot after supervisor for the case of exceptions
self.__robots.append(robot)
# Create trackers
self.__trackers.append(simobject.Path(thing.robot.pose,robot.get_color()))
except:
self.log("[Simulator.construct_world] Robot creation failed!")
raise
#raise Exception('[Simulator.construct_world] Unknown robot type!')
elif thing.type == 'obstacle':
if thing.polygon.color is None:
thing.polygon.color = 0xFF0000
self.__obstacles.append(
simobject.Polygon(thing.polygon.pose,
thing.polygon.points,
thing.polygon.color))
elif thing.type == 'marker':
if thing.polygon.color is None:
thing.polygon.color = 0x00FF00
self.__background.append(
simobject.Polygon(thing.polygon.pose,
thing.polygon.points,
thing.polygon.color))
else:
raise Exception('[Simulator.construct_world] Unknown object: '
+ str(thing.type))
self.__time = 0.0
if not self.__robots:
raise Exception('[Simulator.construct_world] No robot specified!')
else:
self.__recalculate_default_zoom()
if not self.__center_on_robot:
self.focus_on_world()
self.__supervisor_param_cache = None
self.step_simulation()
self._out_queue.put(('reset',()))
def __recalculate_default_zoom(self):
"""Calculate the zoom level that will show the robot at about 10% its size
"""
maxsize = 0
for robot in self.__robots:
xmin, ymin, xmax, ymax = robot.get_bounds()
maxsize = max(maxsize,math.sqrt(float(xmax-xmin)**2 + float(ymax-ymin)**2))
if maxsize == 0:
self.__zoom_default = 1
else:
self.__zoom_default = max(self.__renderer.size)/maxsize/10
def __reset_world(self):
"""Resets the world and objects to starting position.
All the user's code will be reloaded.
"""
if self.__world is None:
return
self.__supervisor_param_cache = [sv.get_parameters() for sv in self.__supervisors ]
self.__construct_world()
[docs] def run(self):
"""Start the thread. In the beginning there's no world, no obstacles
and no robots.
The simulator will try to draw the world undependently of the
simulation status, so that the commands from the UI get processed.
"""
self.log('starting simulator thread')
time_constant = 0.02 # 20 milliseconds
self.__renderer.clear_screen() #create a white screen
self.__update_view()
while not self.__stop:
try:
sleep(time_constant/self.__time_multiplier)
self.__process_queue()
if self.__state == RUN or \
self.__state == RUN_ONCE:
self.__time += time_constant
# First, move robots
for i, robot in enumerate(self.__robots):
robot.move(time_constant)
self.__trackers[i].add_point(robot.get_pose())
self.fwd_logqueue()
# Second, check for collisions and update sensors
if self.__check_collisions():
#print("Collision detected!")
self.__state = DRAW_ONCE
self.fwd_logqueue()
# Now calculate supervisor outputs for the new position
for i, supervisor in enumerate(self.__supervisors):
info = self.__robots[i].get_info()
inputs = supervisor.execute( info, time_constant)
self.__robots[i].set_inputs(inputs)
self.fwd_logqueue()
if self.plot_expressions:
self.announce_plotables()
# Draw to buffer-bitmap
# Note that if the robot moves immediately after calculation,
# the supervisor would draw the previous state.
if self.__state != PAUSE:
self.__draw()
if self.__state == DRAW_ONCE or \
self.__state == RUN_ONCE:
self.pause_simulation()
self.fwd_logqueue()
except Exception as e:
self._out_queue.put(("exception",sys.exc_info()))
self.pause_simulation()
self.fwd_logqueue()
def __draw(self):
"""Draws the world and items in it.
This will draw the markers, the obstacles,
the robots, their tracks and their sensors
"""
if self.__robots and self.__center_on_robot:
# Temporary fix - center onto first robot
robot = self.__robots[0]
if self.__orient_on_robot:
self.__renderer.set_screen_center_pose(robot.get_pose())
else:
self.__renderer.set_screen_center_pose(pose.Pose(robot.get_pose().x, robot.get_pose().y, 0.0))
self.__renderer.clear_screen()
if self.__draw_supervisors:
for supervisor in self.__supervisors:
supervisor.draw_background(self.__renderer)
for bg_object in self.__background:
bg_object.draw(self.__renderer)
for obstacle in self.__obstacles:
obstacle.draw(self.__renderer)
# Draw the robots, trackers and sensors after obstacles
if self.__show_tracks:
for tracker in self.__trackers:
tracker.draw(self.__renderer)
for robot in self.__robots:
robot.draw(self.__renderer)
if self.__show_sensors:
robot.draw_sensors(self.__renderer)
if self.__draw_supervisors:
for supervisor in self.__supervisors:
supervisor.draw_foreground(self.__renderer)
# update view
self.__update_view()
def __update_view(self):
"""Signal the UI that the drawing process is finished,
and it is safe to access the renderer.
"""
self._out_queue.put(('update_view',()))
self._out_queue.join() # wait until drawn
def __draw_once(self):
if self.__state == PAUSE:
self.__state = DRAW_ONCE
def refresh(self):
self.__draw_once()
[docs] def focus_on_world(self):
"""Scale the view to include all of the world (including robots)"""
def include_bounds(bounds, o_bounds):
xl, yb, xr, yt = bounds
xlo, ybo, xro, yto = o_bounds
if xlo < xl: xl = xlo
if xro > xr: xr = xro
if ybo < yb: yb = ybo
if yto > yt: yt = yto
return xl, yb, xr, yt
def bloat_bounds(bounds, factor):
xl, yb, xr, yt = bounds
w = xr-xl
h = yt-yb
factor = (factor-1)/2.0
return xl - w*factor, yb - h*factor, xr + w*factor, yt + h*factor
self.__center_on_robot = False
bounds = self.__robots[0].get_bounds()
for robot in self.__robots:
bounds = include_bounds(bounds, bloat_bounds(robot.get_bounds(),4))
for obstacle in self.__obstacles:
bounds = include_bounds(bounds, obstacle.get_bounds())
xl, yb, xr, yt = bounds
self.__renderer.set_view_rect(xl,yb,xr-xl,yt-yb)
self.__draw_once()
[docs] def focus_on_robot(self, rotate = True):
"""Center the view on the (first) robot and follow it.
If *rotate* is true, also follow the robot's orientation.
"""
self.__center_on_robot = True
self.__orient_on_robot = rotate
self.__draw_once()
[docs] def show_sensors(self, show = True):
"""Show or hide the robots' sensors on the simulation view
"""
self.__show_sensors = show
self.__draw_once()
[docs] def show_tracks(self, show = True):
"""Show/hide tracks for every robot on simulator view"""
self.__show_tracks = show
self.__draw_once()
[docs] def show_supervisors(self, show = True):
"""Show/hide the information from the supervisors"""
self.__draw_supervisors = show
self.__draw_once()
[docs] def show_grid(self, show=True):
"""Show/hide gridlines on simulator view"""
self.__renderer.show_grid(show)
self.__draw_once()
[docs] def adjust_zoom(self,factor):
"""Zoom the view by *factor*"""
self.__renderer.set_zoom_level(self.__zoom_default*factor)
self.__draw_once()
[docs] def apply_parameters(self,robot,parameters):
"""Apply *parameters* to the supervisor of *robot*.
The parameters have to correspond to the requirements of the supervisor,
as specified in :meth:`supervisor.Supervisor.get_ui_description`
"""
index = self.__robots.index(robot)
if index < 0:
self.log("Robot not found")
else:
self.__supervisors[index].set_parameters(parameters)
self.__draw_once()
[docs] def add_plotable(self,expression):
"""A plotable is an expression that yields a numerical
value. It is evaluated every cycle and the values are announced by the
simulator in the ``plot_update`` signal.
The expression has access to the following variables:
``robot`` - the first robot in the scene
``supervisor`` - the supervisor of this robot
``math`` - the math module
"""
if expression is not None and expression not in self.plot_expressions:
self.plot_expressions.append(expression)
def announce_plotables(self):
plots = {'time':self.__time}
for expr in self.plot_expressions:
try:
plots[expr] = \
eval(expr,{},
{'robot':self.__robots[0],
'supervisor':self.__supervisors[0],
'math':math})
except Exception as e:
self.log(str(e))
plots[expr] = 0
self._out_queue.put(('plot_update',(plots,)))
[docs] def plotables(self):
""" Returns a list with some examples of plotables"""
return {
"Robot's X coordinate":"robot.get_pose().x",
"Robot's Y coordinate":"robot.get_pose().y",
"Robot's orientation":"robot.get_pose().theta",
"Robot's orientation (degrees)":"robot.get_pose().theta*57.29578",
"Estimated X coordinate":"supervisor.pose_est.x",
"Estimated Y coordinate":"supervisor.pose_est.y",
"Estimated orientation":"supervisor.pose_est.theta",
"Estimated orientation (degrees)":"supervisor.pose_est.theta*57.29578",
"Left wheel speed":"robot.ang_velocity[0]",
"Right wheel speed":"robot.ang_velocity[1]",
"Linear velocity":"robot.diff2uni(robot.ang_velocity)[0]",
"Angular velocity":"robot.diff2uni(robot.ang_velocity)[1]"
# The possibilities are infinite
#"":"",
}
# Stops the thread
[docs] def stop(self):
"""Stop the simulator thread when the entire program is closed"""
self.log('stopping simulator thread')
self.__stop = True
self._out_queue.put(('stopped',()))
[docs] def start_simulation(self):
"""Start/continue the simulation"""
if self.__robots:
self.__state = RUN
self._out_queue.put(('running',()))
[docs] def pause_simulation(self):
"""Pause the simulation"""
self.__state = PAUSE
self._out_queue.put(('paused',()))
[docs] def step_simulation(self):
"""Do one step"""
if self.__state != RUN:
self.__state = RUN_ONCE
#self._out_queue.put(('paused',()))
[docs] def reset_simulation(self):
"""Reset the simulation to the start position"""
self.__state = DRAW_ONCE
self.__reset_world()
[docs] def set_time_multiplier(self,multiplier):
"""Shorten the interval between evaluation cycles by *multiplier*,
speeding up the simulation"""
self.__time_multiplier = multiplier
### FIXME Those two functions are not thread-safe
[docs] def get_time(self):
"""Get the internal simulator time."""
return self.__time
[docs] def is_running(self):
"""Get the simulation state as a `bool`"""
return self.__state == RUN
###------------------
def __check_collisions(self):
"""Update proximity sensors and detect collisions between objects"""
collisions = []
checked_robots = []
if self.__qtree is None:
self.__qtree = QuadTree(self.__obstacles)
if len(self.__robots) > 1:
rqtree = QuadTree(self.__robots)
else: rqtree = None
# check each robot
for robot in self.__robots:
# update proximity sensors
for sensor in robot.get_external_sensors():
sensor.get_world_envelope(True)
rect = Rect(sensor.get_bounding_rect())
sensor.update_distance()
# distance to obstacles
for obstacle in self.__qtree.find_items(rect):
sensor.update_distance(obstacle)
# distance to other robots
if rqtree is None: continue
for other in rqtree.find_items(rect):
if other is not robot:
sensor.update_distance(other)
rect = Rect(robot.get_bounding_rect())
# against nearest obstacles
for obstacle in self.__qtree.find_items(rect):
if robot.has_collision(obstacle):
collisions.append((robot, obstacle))
# against other robots
if rqtree is not None:
for other in rqtree.find_items(rect):
if other is robot: continue
if other in checked_robots: continue
if robot.has_collision(other):
collisions.append((robot, other))
checked_robots.append(robot)
if len(collisions) > 0:
# Test code - print out collisions
for (robot, obstacle) in collisions:
self.log("Collision with {}".format(obstacle), obj = robot, color=robot.get_color())
# end of test code
return True
return False
def __process_queue(self):
"""Process external calls
"""
while not self.__in_queue.empty():
tpl = self.__in_queue.get()
if isinstance(tpl,tuple) and len(tpl) == 2:
name, args = tpl
if name in self.__class__.__dict__:
try:
self.__class__.__dict__[name](self,*args)
except TypeError:
self.log("Wrong simulator event parameters {}{}".format(name,args))
self._out_queue.put(("exception",sys.exc_info()))
except Exception as e:
self._out_queue.put(("exception",sys.exc_info()))
else:
self.log("Unknown simulator event '{}'".format(name))
else:
self.log("Wrong simulator event format '{}'".format(tpl))
self.__in_queue.task_done()
def log(self, message, obj=None, color=None):
if obj is None:
obj = self
print("{}: {}".format(obj.__class__.__name__,message))
self._out_queue.put(("log",(message,obj.__class__.__name__,color)))
def fwd_logqueue(self):
while self.__log_queue:
obj, message = self.__log_queue.popleft()
color = None
# Get the color
if isinstance(obj,simobject.SimObject):
color = obj.get_color()
elif isinstance(obj,supervisor.Supervisor):
color = obj.robot_color
self._out_queue.put(("log",(message,obj.__class__.__name__,color)))
#end class Simulator
