UE::Geometry::FIndexPriorityQueue Class Reference

#include <IndexPriorityQueue.h>

Classes
struct	FQueueNode

Public Member Functions
	FIndexPriorityQueue ()
	FIndexPriorityQueue (int maxID)
void	Initialize (int MaxNodeID)
void	Clear (bool bFreeMemory=true)
int	GetCount () const
int	GetFirstNodeID () const
float	GetFirstNodePriority () const
bool	Contains (int NodeID) const
void	Insert (int NodeID, float priority)
int	Dequeue ()
void	Remove (int NodeID)
void	Update (int NodeID, float Priority)
float	GetPriority (int id)
bool	IsValidQueue () const
bool	CheckIds ()

Public Attributes
bool	EnableDebugChecks = false
TDynamicVector< FQueueNode >	nodes
int	num_nodes
TArray< int >	id_to_index

Detailed Description

This is a min-heap priority queue class that does not use an object for each queue node. Integer IDs must be provided by the user to identify unique nodes. Internally an array is used to keep track of the mapping from ids to internal indices, so the max ID must also be provided.

Constructor & Destructor Documentation

FIndexPriorityQueue() [1/2]

UE::Geometry::FIndexPriorityQueue::FIndexPriorityQueue ( )

inline

This constructor is provided for convenience, you must call Initialize()

FIndexPriorityQueue() [2/2]

UE::Geometry::FIndexPriorityQueue::FIndexPriorityQueue ( int  maxID )

inline

Calls Initialize()

Parameters

maxID

maximum external ID that will be passed to any public functions

Member Function Documentation

CheckIds()

bool UE::Geometry::FIndexPriorityQueue::CheckIds ( )

inline

Check if node ordering is correct (for debugging/testing)

Clear()

void UE::Geometry::FIndexPriorityQueue::Clear ( bool  bFreeMemory = true )

inline

Reset the queue to empty state. if bFreeMemory is false, we don't discard internal data structures, so there will be less allocation next time

Contains()

bool UE::Geometry::FIndexPriorityQueue::Contains ( int  NodeID ) const

inline

Returns

true if id is already in queue

Dequeue()

int UE::Geometry::FIndexPriorityQueue::Dequeue ( )

inline

Remove node at head of queue, update queue, and return id for that node

Returns

ID of node at head of queue

GetCount()

int UE::Geometry::FIndexPriorityQueue::GetCount ( ) const

inline

Returns

current size of queue

GetFirstNodeID()

int UE::Geometry::FIndexPriorityQueue::GetFirstNodeID ( ) const

inline

Returns

id of node at head of queue

GetFirstNodePriority()

float UE::Geometry::FIndexPriorityQueue::GetFirstNodePriority ( ) const

inline

Returns

id of node at head of queue

GetPriority()

float UE::Geometry::FIndexPriorityQueue::GetPriority ( int  id )

inline

Query the priority at node id, assuming it exists in queue. Behavior is undefined if you call w/ id that is not in queue

Returns

priority for node

Initialize()

void UE::Geometry::FIndexPriorityQueue::Initialize ( int  MaxNodeID )

inline

Initialize internal data structures. Internally a fixed-size array is used to track mapping from IDs to internal node indices, so maxID must be provided up-front. If this seems problematic or inefficient, this is not the Priority Queue for you.

Parameters

MaxNodeID

maximum external ID that will be passed to any public functions

Insert()

void UE::Geometry::FIndexPriorityQueue::Insert ( int  NodeID, float  priority  )

inline

Add id to list w/ given priority. Do not call with same id twice!

IsValidQueue()

bool UE::Geometry::FIndexPriorityQueue::IsValidQueue ( ) const

inline

Check if node ordering is correct (for debugging/testing)

Remove()

void UE::Geometry::FIndexPriorityQueue::Remove ( int  NodeID )

inline

Remove node associated with given ID from queue. Behavior is undefined if you call w/ id that is not in queue

Update()

void UE::Geometry::FIndexPriorityQueue::Update ( int  NodeID, float  Priority  )

inline

Update priority at node id, and then move it to correct position in queue. Behavior is undefined if you call w/ id that is not in queue

Member Data Documentation

EnableDebugChecks

bool UE::Geometry::FIndexPriorityQueue::EnableDebugChecks = false

set this to true during development to catch issues

id_to_index

TArray<int> UE::Geometry::FIndexPriorityQueue::id_to_index

mapping from external ids to internal node indices

nodes

TDynamicVector<FQueueNode> UE::Geometry::FIndexPriorityQueue::nodes

tree of allocated nodes, stored linearly. active up to num_nodes (allocated may be larger)

num_nodes

int UE::Geometry::FIndexPriorityQueue::num_nodes

count of active nodes

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The documentation for this class was generated from the following file:

• Engine/Source/Runtime/GeometryCore/Public/Util/IndexPriorityQueue.h