Acts::INavigationPolicy Class Reference

Base class for all navigation policies. More...

#include <Acts/Navigation/INavigationPolicy.hpp>

Inheritance diagram for Acts::INavigationPolicy:

Classes
struct	EmptyState

Public Member Functions
virtual	~INavigationPolicy ()=default
	Virtual destructor so policies can be held through this base class.
virtual void	connect (NavigationDelegate &delegate) const =0
	Connect a policy with a delegate (usually a member of a volume).
virtual void	createState (const GeometryContext &gctx, const NavigationArguments &args, NavigationPolicyStateManager &stateManager, const Logger &logger) const
	Create and initialize the state for this policy.
void	initializeStatelessCache (const GeometryContext &gctx, const Logger &logger=getDummyLogger())
	One-time initialization step that probes whether this policy pushes only default (empty) states and caches the result (mutating internal state), allowing the navigator to skip the per-volume-entry state creation and the matching pop entirely for volumes with such policies.
bool	isStateless () const
	Whether this policy is known to push only default (empty) states, see initializeStatelessCache.
virtual bool	isValid (const GeometryContext &gctx, const NavigationArguments &args, NavigationPolicyState &state, const Logger &logger) const
	Check if the policy is in a valid state for navigation.
virtual void	popState (NavigationPolicyStateManager &stateManager, const Logger &logger) const
	Remove the state for this policy from the state manager.
virtual void	visit (const std::function< void(const INavigationPolicy &)> &visitor) const
	Convenience function to walk over all navigation policies.

Static Public Member Functions
static void	noopInitializeCandidates (const GeometryContext &, const NavigationArguments &, NavigationPolicyState &, const AppendOnlyNavigationStream &, const Logger &)
	Noop update function that is suitable as a default for default navigation delegates.

Protected Member Functions
template<NavigationPolicyConcept T>
void	connectDefault (NavigationDelegate &delegate) const
	Internal helper function for derived classes that conform to the concept and have a conventional updateState method.

Detailed Description

Base class for all navigation policies.

The policy needs to be connected to a delegate via a virtual method for it to become active. The update method is not part of the class interface. The conventional updateState method is only required for use with the navigation policy factory, otherwise connect is free to connect any function.

Member Function Documentation

connect()

virtual void Acts::INavigationPolicy::connect ( NavigationDelegate & delegate ) const

pure virtual

Connect a policy with a delegate (usually a member of a volume).

This method exists to allow a policy to ensure a non-virtual function is registered with the delegate.

Parameters

delegate

The delegate to connect to

Implemented in Acts::CylinderNavigationPolicy, Acts::Experimental::MultiLayerNavigationPolicy, Acts::IndexGridNavigationPolicy< GridType >, Acts::IndexGridNavigationPolicy< RegularCylinderIndexGrid >, Acts::IndexGridNavigationPolicy< RegularDiscIndexGrid >, Acts::IndexGridNavigationPolicy< RegularPlaneIndexGrid >, Acts::IndexGridNavigationPolicy< RegularRingIndexGrid >, Acts::MultiLayerNavigationPolicy, Acts::MultiNavigationPolicy, Acts::SurfaceArrayNavigationPolicy, and Acts::TryAllNavigationPolicy.

connectDefault()

template<NavigationPolicyConcept T>

void Acts::INavigationPolicy::connectDefault ( NavigationDelegate & delegate ) const

protected

Internal helper function for derived classes that conform to the concept and have a conventional updateState method.

Mainly used to save some boilerplate.

Template Parameters

T	The type of the navigation policy

Parameters

delegate

The delegate to connect to

createState()

virtual void Acts::INavigationPolicy::createState ( const GeometryContext & gctx, const NavigationArguments & args, NavigationPolicyStateManager & stateManager, const Logger & logger ) const

virtual

Create and initialize the state for this policy.

Parameters

gctx	The geometry context
args	The navigation arguments
stateManager	The state manager to push the new state onto
logger	Logger for debug output

Reimplemented in Acts::MultiNavigationPolicy.

initializeStatelessCache()

void Acts::INavigationPolicy::initializeStatelessCache	(	const GeometryContext &	gctx,
		const Logger &	logger = getDummyLogger() )

One-time initialization step that probes whether this policy pushes only default (empty) states and caches the result (mutating internal state), allowing the navigator to skip the per-volume-entry state creation and the matching pop entirely for volumes with such policies.

This is an eager initialization (deliberately not a lazy first-call latch): it is called for all attached policies at the end of Gen3 geometry construction, once every policy is in place. It must be called again should a policy be attached after that point; an uninitialized policy conservatively reports stateful via isStateless, so skipping this step is always safe.

Note

This relies on the contract that the defaultness of the state a navigation policy pushes does not depend on the geometry context or the navigation arguments: a policy either always pushes a real state (it has something to validate) or always pushes the default empty state.

Parameters

gctx	The current geometry context object, e.g. alignment
logger	Logger for debug output

isStateless()

bool Acts::INavigationPolicy::isStateless

(

)

const

Whether this policy is known to push only default (empty) states, see initializeStatelessCache.

Returns

true if the policy was probed and found stateless

isValid()

virtual bool Acts::INavigationPolicy::isValid ( const GeometryContext & gctx, const NavigationArguments & args, NavigationPolicyState & state, const Logger & logger ) const

virtual

Check if the policy is in a valid state for navigation.

Parameters

gctx	The geometry context
args	The navigation arguments
state	The navigation policy state to check
logger	Logger for debug output

Returns

True if the policy state is valid, false otherwise

Reimplemented in Acts::MultiNavigationPolicy.

popState()

virtual void Acts::INavigationPolicy::popState ( NavigationPolicyStateManager & stateManager, const Logger & logger ) const

virtual

Remove the state for this policy from the state manager.

Parameters

stateManager	The state manager to pop the state from
logger	Logger for debug output

Reimplemented in Acts::MultiNavigationPolicy.

visit()

virtual void Acts::INavigationPolicy::visit ( const std::function< void(const INavigationPolicy &)> & visitor ) const

virtual

Convenience function to walk over all navigation policies.

The default implementation just calls this on itself, while the MultiNavigationPolicy will call it on all it's children.

Parameters

visitor

The visitor function to call for each policy

Reimplemented in Acts::MultiNavigationPolicy.