xy::QuadTree Class Reference

Partition system for entities with QuadTreeItem components. Entities are sorted in a tree hierarchy which can be queried with a given area to return a set of entities which are contained or intersect said area. Generally more useful for scenes with a lot of static entities such as a platform game with fixed scenery. If using a scene with a lot of dynamic objects consider using xy::DynamicTreeSystem instead. More...

#include <QuadTree.hpp>

Inheritance diagram for xy::QuadTree:

Public Member Functions
	QuadTree (xy::MessageBus &, sf::FloatRect rootArea)
	Constructor. More...
void	process (float) override
	Implement this for system specific processing to entities.
std::vector< xy::Entity >	queryArea (sf::FloatRect area, std::uint64_t=std::numeric_limits< std::uint64_t >::max()) const
	Queries the QuadTree with the given area. Returns a vector of entities whose QuadTreeItems are contained in tree nodes which intersect the given area. /param area The area to query /param filterFlags Only entities with QuadTreeItems matching the given bit flags are returns. Defaults to all flags set.
std::vector< xy::Entity >	queryPoint (sf::Vector2f, std::uint64_t=std::numeric_limits< std::uint64_t >::max()) const
	Queries the quad tree with the given position. Returns a vector of entities whose QuadTreeItems are contained in tree nodes which also contain the given point /param area The area to query /param filterFlags Only entities with QuadTreeItems matching the given bit flags are returns. Defaults to all flags set.
sf::FloatRect	getRootArea () const
	Returns the area with which the QuadTree was created.
const std::vector< xy::Entity > &	getOutsideRootEnts () const
	Returns a vector of any entities which fall outside of the root area.
std::vector< xy::Entity > &	getOutsideRootEnts ()
std::size_t	getEntityCount () const
	Returns the total number of entities which fall within the root area.
Public Member Functions inherited from xy::System
	System (MessageBus &mb, UniqueType t)
	Constructor. Pass in a reference to the concrete implementation to generate a unique type ID for this system.
UniqueType	getType () const
	Returns the unique type ID of the system.
const std::vector< Entity > &	getEntities () const
	Returns a list of entities that this system is currently interested in.
void	addEntity (Entity)
	Adds an entity to the list to process.
void	removeEntity (Entity)
	Removes an entity from the list to process.
const ComponentMask &	getComponentMask () const
	Returns the component mask used to mask entities with corresponding components for this system to process.
virtual void	handleMessage (const Message &)
	Used to process any incoming system messages.
bool	isActive () const
	Returns true if the system is currently active. Systems can be activeated and deactivated with Scene::setSystemActive()
template<typename T >
void	requireComponent ()
template<typename T >
T *	postMessage (Message::ID id)

Static Public Attributes
static constexpr sf::Int32	MinNodeEntities = 3
static constexpr std::size_t	MaxNodeEntities = 6u
static constexpr sf::Int32	MaxLevels = 40u

Additional Inherited Members
Public Types inherited from xy::System
using	Ptr = std::unique_ptr< System >
Protected Member Functions inherited from xy::System
template<typename T >
void	requireComponent ()
	Adds a component type to the list of components required by the system for it to be interested in a particular entity. This should only be used in the constructor of the System else types will not be registered.
std::vector< Entity > &	getEntities ()
template<typename T >
T *	postMessage (Message::ID id)
	Posts a message on the system wide message bus.
MessageBus &	getMessageBus ()
	Returns a reference to the MessageBus.
void	setScene (Scene &)
Scene *	getScene ()
	Returns a pointer to the scene to which this system belongs.

Detailed Description

Partition system for entities with QuadTreeItem components. Entities are sorted in a tree hierarchy which can be queried with a given area to return a set of entities which are contained or intersect said area. Generally more useful for scenes with a lot of static entities such as a platform game with fixed scenery. If using a scene with a lot of dynamic objects consider using xy::DynamicTreeSystem instead.

See also

DynamicTreeSystem

Constructor & Destructor Documentation

QuadTree()

xy::QuadTree::QuadTree	(	xy::MessageBus &	,
		sf::FloatRect	rootArea
	)

Constructor.

Parameters

rootArea

Area in world coordinates for the root node of the tree. All subsequent nodes are contained within this area