Path¶
Iterator that describes a Path
This module implements an iterator Path
to be used the
descriptions of the points that form a particular path. There are also
the following classes with specialised paths:
Aswell as the following preimplemented useful paths:
Path¶

class
steering.path.
Path
(path_func, domain_end, domain_start=0, increment=1)[source]¶ Iterator that describes a Path
Provides a flexible interface to describe dynamic paths as an iterator, it uses a Path Function in the form of f(x) = y to describe the path.
Parameters: Example
The way this class is meant to be used is by subclassing it and creating your own class with your own properties, this is a slightly useluess implementation of
CircumferencePath
that only traverses the path once.class OnceCircumferencePath(Path): def __init__(self, center, radius): self.center = center self.radius = radius def circumference_path(self, x): angle = math.radians(x) center = self.center x = center[0] + math.cos(angle)*self.radius y = center[1] + math.sin(angle)*self.radius return x, y super(OnceCircumferencePath, self).__init__(parabola_path, domain_start = 0, domain_end = 360, increment = 15) >>> mypath = OnceCircumferencePath(center = (50, 50), radius = 50) >>> next(mypath) (100.0, 50.0) >>> next(mypath) (98.29629131445341, 62.940952255126035) >>> next(mypath) (93.30127018922194, 75.0)
A good tip is to use lambda functions in order to have dynamically updated paths, this allows to have attributes like ‘center’ update with the position of something in the game, which will alter the points the path will produce
class OnceCircumferencePath(Path): def __init__(self, center, radius): self.center = center self.radius = radius def circumference_path(self, x): angle = math.radians(x) # Notice that we are now calling the attribute 'center' as a function center = self.center() x = center[0] + math.cos(angle)*self.radius y = center[1] + math.sin(angle)*self.radius return x, y super(OnceCircumferencePath, self).__init__(parabola_path, domain_start = 0, domain_end = 360, increment = 15) >>> character = SomeGameObjectWithARect() # The 'center' parameter is now defined as a lambda functions that gets the position of a character >>> mypath = OnceCircumferencePath(center = (lambda: character.rect.center), radius = 50)

as_list
()[source]¶ Returns the path as a list of points
This ignores the infinity of
CyclicPath
andMirroredPath
and returns a finite list. Nevertheless, you should keep in mind that if for your own subclasses this methods does not return the expected results, it’s probabbly the method’s fault (my faul) and you should implement your own since this is used for drawing indicators.Returns: Return type: list(tuple(float, float))

Special Paths¶

class
steering.path.
CyclicPath
(path_func, domain_end, domain_start=0, increment=1)[source]¶ Iterator that implements Cyclic Paths
This is a subclass of
Path
that returns to the path’s starting point once it reaches the end, this produces an infinite iterator.Uses the same parameters as
Path
.

class
steering.path.
MirroredPath
(path_func, domain_end, domain_start=0, increment=1)[source]¶ Iterator that implements Mirrored Paths
This is a subclass of
Path
that Mirrors the path produced by the given function, this produces an infinite iterator that backtracks on the traversed path once it reaches it’s domain_end, and does the same after it reaches domain_start.Uses the same parameters as
Path
.
as_list
()[source]¶ Returns the path as a list of points
This ignores the infinity of
CyclicPath
andMirroredPath
and returns a finite list. Nevertheless, you should keep in mind that if for your own subclasses this methods does not return the expected results, it’s probabbly the method’s fault (my faul) and you should implement your own since this is used for drawing indicators.Returns: Return type: list(tuple(float, float))

Preimplemented Paths¶

class
steering.path.
PathCircumference
(center, radius, start=0)[source]¶ Circumferencelike
CyclicPath
Parameters: