findShortestPath_MultipleStartPositions

next: iMesh::findShortestPath_WithQueryCallBack()

Contents, API Reference, Interfaces, iMesh, findShortestPath_MultipleStartPositions

iMesh::findShortestPath_MultipleStartPositions()

Description

Finds the shortest path from a given set of start positions to a given end position for agents with a specified collision shape.

Syntax

iPath* findShortestPath_MultipleStartPositions(const iShape* shape, const iCollisionContext* context, const cPosition* positionBuffer, tUnsigned32 positionBufferSize, const cPosition& goal, iQueryCallBack* queryCallBack) const;

Parameters

	shape		The collision shape to use for this query.
	context		The state of dynamic collision that will apply for this query. An empty context can be specified by passing a value of zero for this argument.
	positionBuffer		Pointer to an array of ground positions. This buffer is not retained after the call and can subsequently be safely deleted.
	positionBufferSize		The size of the array pointed to by positionBuffer.
	goal		The target point for pathfinding. This position must be a valid position on this mesh.
	queryCallBack		A pointer to a valid implementation of the iQueryCallBack interface, or else null.

Requirements

Requires that pathfinding preprocess has been generated on this mesh for the collision shape specified.

Return Value

A newly created Interface iPath object, if a path can be found.
Otherwise a zero pointer is returned.

Remarks

This pathfinding query searches for the shortest path to the specified end position from any of the the array of positions passed in.

This may be used, for example, to find the shortest path from a group of agents to a specified target.

In certain situations where pathfinding constraints are symmetrical (e.g. no directional costs to traverse or one-way off mesh connections) this can then also be used for 'reverse' pathfinding to find the shortest path from a single agent to a set of potential target positions (see iMesh::constructPath_Reversed()).

Queries for which the target position is obstructed can be alot more expensive, so if the target position is potentially obstructed then it is a good idea to call iMesh::testPointCollision() for the target position first.
If the target position is obstructed then you know that the query will fail.
This check is not performed internally to avoid adding overhead in cases where the target position is known in advance to be unobstructed.

Refer to Aborting Pathfinding Early for details about using the query callback mechanism.
Note that if the search is aborted by the query callback then the path returned will not reach the goal.