cz.cuni.amis.pathfinding.map

Interface IPFMapView<NODE>

All Known Subinterfaces:

IPFKnownMapView<NODE>

All Known Implementing Classes:

IPFKnownMapView.DefaultView, IPFMapView.DefaultView

public interface IPFMapView<NODE>

This interface provides additional information about the map algorithms are going to work with. In its implementation you may provide custom view on the map as needed for your search (for instance you need to forbid some nodes / edges or change the general cost of nodes / edges in order to change how your agent is going to plan the path).

Generally, you will use IPFMap interface to define the map in general and then use this IPFMapView interface to specify a specific needs you need to impose over the map as is "forbidding" some nodes or "imposing additional costs onto the nodes".

Author:

Jimmy

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	IPFMapView.DefaultView<NODE> Default view does not impose any specific view on the map... all nodes/arcs are opened, no extra cost/nodes defined.

Method Summary

Modifier and Type	Method and Description
int	getArcExtraCost(NODE nodeFrom, NODE nodeTo, int mapCost) Method defining extra-arc cost, that is a cost that is added to IPFMap.getArcCost(Object, Object).
Collection<NODE>	getExtraNeighbors(NODE node, Collection<NODE> mapNeighbors) This method may return new nodes which are not present in 'mapNeighbors' (as returned by IPFMap.getNeighbors(Object)).
int	getNodeExtraCost(NODE node, int mapCost) Method defining extra-node cost, that is a cost that is added to IPFMap.getNodeCost(Object).
boolean	isArcOpened(NODE nodeFrom, NODE nodeTo) Arcs filter.
boolean	isNodeOpened(NODE node) Nodes filter.

Method Detail

getExtraNeighbors

Collection<NODE> getExtraNeighbors(NODE node,
                                   Collection<NODE> mapNeighbors)

This method may return new nodes which are not present in 'mapNeighbors' (as returned by IPFMap.getNeighbors(Object)). Such nodes are then exclusively accessible to your particular agent, that is, this methods is adding nodes that can be accessed by the agent but are not part of your general map description.

"node" MUST NOT BE ADDED TO "mapNeighbors"!

Returned collection must not contain multiple references to a single neighbor (multi-graph is forbidden).

Returned collection must not contain any node from "mapNeighbors".

Parameters:

node -

mapNeighbors - neighbors of the "node" as returned by IPFMap.getNeighbors(Object), may return null

getNodeExtraCost

int getNodeExtraCost(NODE node,
                     int mapCost)

Method defining extra-node cost, that is a cost that is added to IPFMap.getNodeCost(Object).

This allows you to provide "customization" to the graph nodes, simply, it is a way of telling "this node is cool to have in path" (negative cost) or "this node is bad to have in path" (positive cost).

Parameters:

node -

mapCost - cost of the node as returned by underlying IPFMap.getNodeCost(Object)

Returns:

getArcExtraCost

int getArcExtraCost(NODE nodeFrom,
                    NODE nodeTo,
                    int mapCost)

Method defining extra-arc cost, that is a cost that is added to IPFMap.getArcCost(Object, Object).

This allows you to provide "customization" to the graph arc costs. It allows you to say "this is a cool arc to use for travel" (negative extra cost) or "this edge is hard to cross" (positive extra cost).

NOTE THAT YOU MUST AVOID HAVING NEGATIVELY-VALUED ARCs (IPFMap.getArcCost(Object, Object) + getArcExtraCost(Object, Object, int) < 0)!

Such arcs might lead to negative-valued circles which will make exploratory algorithms to endlessly walk in circles.

Parameters:

nodeFrom -

nodeTo -

mapCost - cost of the arc as returned by underlying IPFMap.getArcCost(Object, Object)

Returns:

isNodeOpened

boolean isNodeOpened(NODE node)

Nodes filter. Method defining which nodes are allowed to be explored / used by path finding algorithms, i.e., algorithm will never return path leading to such nodes. May be used to define "forbidden" nodes.

Parameters:

node -

Returns:

isArcOpened

boolean isArcOpened(NODE nodeFrom,
                    NODE nodeTo)

Arcs filter. Method defining which "arc" (oriented links between nodes) can be used for the purpose of path-planning. It can be used to "forbid" usage of some arc, that is you can rule out some arc you do not want your agent to be able to travel.

Parameters:

nodeFrom -

nodeTo -

Returns: