AdvancedActuators¶

This module contains the more advanced actuators. AdvancedActuators allow for more actions and not only movement. It can also be more advanced movement classes.

class gamelib.Actuators.AdvancedActuators.PathFinder(game=None, actuated_object=None, circle_waypoints=True)¶

Important

This module assume a one step movement. If you need more than one step, you will need to sub-class this module and re-implement next_waypoint().

This actuator is a bit different than the simple actuators (SimpleActuators) as it requires the knowledge of both the game object and the actuated object.

The constructor takes the following parameters:

Parameters:	game (gamelib.Game.Game) – A reference to the instanciated game engine. actuated_object (gamelib.BoardItem.BoardItem) – The object to actuate. circle_waypoints (bool) – If True the next_waypoint() method is going to circle between the waypoints (when the last is visited, go back to the first)

add_waypoint(row, column)¶

Add a waypoint to the list of waypoints.

Waypoints are used one after the other on a FIFO basis (First In, First Out).

Parameters:	row (int) – The “row” part of the waypoint’s coordinate. column – The “column” part of the waypoint’s coordinate.
Raises:	HacInvalidTypeException – If any of the parameters is not an int.

Example:

pf = PathFinder(game=mygame, actuated_object=npc1)
pf.add_waypoint(3,5)
pf.add_waypoint(12,15)

clear_waypoints()¶

Empty the waypoints stack.

Example:

pf.clear_waypoints()

current_path()¶

This method simply return a copy of the current path of the actuator.

The current path is to be understood as: the list of positions still remaining. All positions that have already been gone through are removed from the stack.

Important

A copy of the path is returned for every call to that function so be wary of the performances impact.

Example:

mykillernpc.actuator = PathFinder(
                        game=mygame,
                        actuated_object=mykillernpc
                    )
mykillernpc.actuator.set_destination(
                        mygame.player.pos[0],
                        mygame.player.pos[1]
                    )
mykillernpc.actuator.find_path()
for i in mykillernpc.actuator.current_path():
    print(i)

current_waypoint()¶

Return the currently active waypoint.

If no waypoint have been added, this function return None.

Returns:	Either a None tuple or the current waypoint.
Return type:	A None tuple or a tuple of integer.

Example:

(row,column) = pf.current_waypoint()
pf.set_destination(row,column)

find_path()¶

Find a path to the destination.

Destination (PathFinder.destination) has to be set beforehand. This method implements a Breadth First Search algorithm (Wikipedia) to find the shortest path to destination.

Example:

mykillernpc.actuator = PathFinder(
        game=mygame, actuated_object=mykillernpc
    )
mykillernpc.actuator.set_destination(
        mygame.player.pos[0], mygame.player.pos[1]
    )
mykillernpc.actuator.find_path()

Warning

PathFinder.destination is a tuple! Please use PathFinder.set_destination(x,y) to avoid problems.

next_action()¶

That method needs to be implemented by all behavioral actuators or a NotImplementedError exception will be raised.

Raises:	NotImplementedError

next_move()¶

This method return the next move calculated by this actuator.

In the case of this PathFinder actuator, next move does the following:

If the destination is not set return NO_DIR (see Constants) - If the destination is set, but the path is empty and actuated object’s position is different from destination: call find_path()

Look at the current waypoint, if the actuated object is not at that position return a direction from the Constants module. The direction is calculated from the difference betwen actuated object’s position and waypoint’s position.

If the actuated object is at the waypoint position, then call next_waypoint(), set the destination and return a direction. In this case, also call find_path().

In any case, if there is no more waypoints in the path this method returns NO_DIR (see Constants)

Example:

seeker = NPC(model=Sprites.SKULL)
seeker.actuator = PathFinder(game=mygame,actuated_object=seeker)
while True:
    seeker.actuator.set_destination(mygame.player.pos[0],mygame.player.pos[1])
    # next_move() will call find_path() for us.
    next_move = seeker.actuator.next_move()
    if next_move == Constants.NO_DIR:
        seeker.actuator.set_destination(mygame.player.pos[0],mygame.player.pos[1])
    else:
        mygame.current_board().move(seeker,next_move,1)

next_waypoint()¶

Return the next active waypoint.

If no waypoint have been added, this function return None. If there is no more waypoint in the stack:

if PathFinder.circle_waypoints is True this function reset the waypoints stack and return the first one.
else, return None.

Returns:	Either a None tuple or the next waypoint.
Return type:	A None tuple or a tuple of integer.

Example:

pf.circle_waypoints = True
(row,column) = pf.next_waypoint()
pf.set_destination(row,column)

pause()¶

Set the actuator state to PAUSED.

Example:

mygame.pause()

remove_waypoint(row, column)¶

Remove a waypoint from the stack.

This method removes the first occurrence of a waypoint in the stack.

If the waypoint cannot be found, it raises a ValueError exception. If the row and column parameters are not int, an HacInvalidTypeException is raised.

Parameters:	row (int) – The “row” part of the waypoint’s coordinate. column – The “column” part of the waypoint’s coordinate.
Raises:	HacInvalidTypeException – If any of the parameters is not an int. ValueError – If the waypoint is not found in the stack.

Example:

method()

set_destination(row=0, column=0)¶

Set the targeted destination.

Parameters:	row (int) – “row” coordinate on the board grid column (int) – “column” coordinate on the board grid
Raises:	HacInvalidTypeException – if row or column are not int.

Example:

mykillernpc.actuator.set_destination(
    mygame.player.pos[0], mygame.player.pos[1]
)

start()¶

Set the actuator state to RUNNING.

If the actuator state is not RUNNING, actuators’ next_move() function (and all derivatives) should not return anything.

Example:

mygame.start()

stop()¶

Set the actuator state to STOPPED.

Example:

mygame.stop()