AyStar search algorithm struct. More...

#include <aystar.h>

Public Member Functions
void	AddStartNode (AyStarNode *start_node, int g)
	Adds a node from where to start an algorithm. More...

int	Main ()
	This is the function you call to run AyStar. More...

int	Loop ()
	This function is the core of AyStar. More...

void	CheckTile (AyStarNode current, PathNode parent)
	Checks one tile and calculate its f-value.

Data Fields
AyStar_CalculateG *	CalculateG

AyStar_CalculateH *	CalculateH

AyStar_GetNeighbours *	GetNeighbours

AyStar_EndNodeCheck *	EndNodeCheck

AyStar_FoundEndNode *	FoundEndNode

void *	user_target

void *	user_data

uint8_t	loops_per_tick
	How many loops are there called before Main() gives control back to the caller. 0 = until done.

int	max_path_cost
	If the g-value goes over this number, it stops searching, 0 = infinite.

int	max_search_nodes = AYSTAR_DEF_MAX_SEARCH_NODES
	The maximum number of nodes that will be expanded, 0 = infinite.

std::vector< AyStarNode >	neighbours

Protected Member Functions
void	OpenListAdd (PathNode parent, const AyStarNode node, int f, int g)
	Adds a node to the open list. More...

Protected Attributes
CNodeList_HashTableT< PathNode, 8, 10 >	nodes

Detailed Description

AyStar search algorithm struct.

Before calling #Init(), fill #CalculateG, #CalculateH, #GetNeighbours, #EndNodeCheck, and #FoundEndNode. If you want to change them after calling #Init(), first call #Free() !

The #user_path, #user_target, and #user_data[10] are intended to be used by the user routines. The data not accessed by the AyStar code itself. The user routines can change any moment they like.

Definition at line 103 of file aystar.h.

Member Function Documentation

◆ AddStartNode()

void AyStar::AddStartNode	(	AyStarNode *	start_node,
		int	g
	)

Adds a node from where to start an algorithm.

Multiple nodes can be added if wanted. You should make sure that #Clear() is called before adding nodes if the AyStar has been used before (though the normal main loop calls #Clear() automatically when the algorithm finishes.

Parameters

start_node	Node to start with.
g	the cost for starting with this node.

Definition at line 168 of file aystar.cpp.

References Debug, OpenListAdd(), TileX(), and TileY().

◆ Loop()

int AyStar::Loop ( )

This function is the core of AyStar.

It handles one item and checks its neighbour items. If they are valid, they are added to be checked too.

Returns

Possible values:

AYSTAR_EMPTY_OPENLIST : indicates all items are tested, and no path has been found.
AYSTAR_LIMIT_REACHED : Indicates that the max_search_nodes limit has been reached.
AYSTAR_FOUND_END_NODE : indicates we found the end. Path_found now is true, and in path is the path found.
AYSTAR_STILL_BUSY : indicates we have done this tile, did not found the path yet, and have items left to try.

Definition at line 92 of file aystar.cpp.

References AYSTAR_EMPTY_OPENLIST, AYSTAR_FOUND_END_NODE, AYSTAR_LIMIT_REACHED, AYSTAR_STILL_BUSY, CheckTile(), CNodeList_HashTableT< Titem_, Thash_bits_open_, Thash_bits_closed_ >::ClosedCount(), CNodeList_HashTableT< Titem_, Thash_bits_open_, Thash_bits_closed_ >::InsertClosedNode(), max_search_nodes, and CNodeList_HashTableT< Titem_, Thash_bits_open_, Thash_bits_closed_ >::PopBestOpenNode().

Referenced by Main().

◆ Main()

int AyStar::Main ( )

This is the function you call to run AyStar.

Returns

Possible values:

AYSTAR_FOUND_END_NODE : indicates we found an end node.
AYSTAR_NO_PATH : indicates that there was no path found.
AYSTAR_STILL_BUSY : indicates we have done some checked, that we did not found the path yet, and that we still have items left to try.

Note: When the algorithm is done (when the return value is not AYSTAR_STILL_BUSY) #Clear() is called automatically. When you stop the algorithm halfway, you should call #Clear() yourself!

Definition at line 137 of file aystar.cpp.

References AYSTAR_EMPTY_OPENLIST, AYSTAR_FOUND_END_NODE, AYSTAR_LIMIT_REACHED, AYSTAR_NO_PATH, AYSTAR_STILL_BUSY, Debug, Loop(), and loops_per_tick.

◆ OpenListAdd()

void AyStar::OpenListAdd	(	PathNode *	parent,
		const AyStarNode *	node,
		int	f,
		int	g
	)

protected

Adds a node to the open list.

It makes a copy of node, and puts the pointer of parent in the struct.

Definition at line 25 of file aystar.cpp.

References CNodeList_HashTableT< Titem_, Thash_bits_open_, Thash_bits_closed_ >::CreateNewNode(), and CNodeList_HashTableT< Titem_, Thash_bits_open_, Thash_bits_closed_ >::InsertOpenNode().

Referenced by AddStartNode(), and CheckTile().

The documentation for this struct was generated from the following files:

src/pathfinder/aystar.h
src/pathfinder/aystar.cpp

Public Member Functions

Data Fields