xSGE Path
*********


Contents
^^^^^^^^

* xSGE Path

  * xsge_path Classes

    * xsge_path.Path

      * xsge_path.Path Methods

      * xsge_path.Path Event Methods

    * xsge_path.PathLink

      * xsge_path.PathLink Methods

xSGE is a collection of higher-level extensions for the SGE which
enhance the core functionality in an implementation-independent way.
Like the SGE itself, they are distribted under the terms of the GNU
Lesser General Public License.

This extension provides paths for the SGE.  Paths are used to make
objects move in a certain way.


xsge_path Classes
=================


xsge_path.Path
--------------

class xsge_path.Path(x, y, points=(), z=0, visible=False, tangible=False, **kwargs)

   Class for paths: objects which define movement patterns for other
   objects.  Paths are defined as a series of points for an object to
   follow.

   This class is derived from "sge.dsp.Object" and inherits all of
   that class's attributes and methods.

   Note:

     "event_step()" is used to implement path-following behavior. Keep
     this in mind if you derive a class from this one.

   points

      A list of the points that make up the path relative to the
      position of the path in the room, excluding the first point.
      Each point should be a tuple in the form "(x, y)", where x is
      the horizontal location and y is the vertical location.  The
      first point is always "(0, 0)", which is why it is not included
      in this list.


xsge_path.Path Methods
~~~~~~~~~~~~~~~~~~~~~~

Path.__init__(x, y, points=(), z=0, visible=False, tangible=False, **kwargs)

   Arguments set the respective initial attributes of the object. See
   the documentation for "Path" for more information.

   "x", "y", "z", "visible", "tangible", and all arguments passed to
   "kwargs" are passed as the corresponding arguments to the
   constructor method of the parent class.

Path.follow_start(obj, speed, accel=None, decel=None, loop=0)

   Cause "obj" to start following this path at the speed indicated by
   "speed".

   While path objects have a location within the room, this location
   has no bearing on how objects following the path move. Movement is
   determined relative to the location of the object following the
   path when it started, not the location of the path.

   By default, the object follows the path at a constant speed. If
   "accel" or "decel" is set to a value other than "None", the object
   will instead accelerate or decelerate, respectively, by that amount
   each frame on each segment of the path.

   "loop" indicates the number of times the object should follow the
   path after it does so the first time.  For example, if set to "2",
   the object will follow the path a total of 3 times. Set to "None"
   to loop indefinitely.

Path.follow_stop(obj)

   Cause "obj" to stop following this path.


xsge_path.Path Event Methods
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Path.event_follow_end(obj)

   Called when an object, indicated by "obj", finishes following the
   path.


xsge_path.PathLink
------------------

class xsge_path.PathLink(x, y, points=(), next_path=None, next_speed=None, next_accel=None, next_decel=None, next_loop=0, z=0, visible=False, tangible=False, **kwargs)

   Class for path links.  Path links are just like normal paths, but
   can be linked to other path links or paths to form chains.

   By using a chain of path links, you can cause an object to move in
   different ways at different points of the path.  For example, you
   can cause the object to change its speed, or you can cause it to
   accelerate and decelerate only at particular points.

   Note:

     "event_follow_end()" is used to implement path linking.  Keep
     this in mind if you derive a class from this one.

   next_path

      The next "xsge_path.Path" object to be followed after this one.
      If set to "None", no additional paths will be followed.

   next_speed

      The value to pass on to the "speed" argument of the next path's
      "xsge_path.Path.follow_start()" call.  If set to "None", the
      next path will not be followed.

   next_accel

      The value to pass on to the "accel" argument of the next path's
      "xsge_path.Path.follow_start()" call.

   next_decel

      The value to pass on to the "decel" argument of the next path's
      "xsge_path.Path.follow_start()" call.

   next_loop

      The value to pass on to the "loop" argument of the next path's
      "xsge_path.Path.follow_start()" call.


xsge_path.PathLink Methods
~~~~~~~~~~~~~~~~~~~~~~~~~~

PathLink.__init__(x, y, points=(), next_path=None, next_speed=None, next_accel=None, next_decel=None, next_loop=0, z=0, visible=False, tangible=False, **kwargs)

   Arguments set the respective initial attributes of the object. See
   the documentation for "Path" for more information.

   "x", "y", "points", "z", "visible", "tangible", and all arguments
   passed to "kwargs" are passed as the corresponding arguments to the
   constructor method of the parent class.
