HdCollectionExpressionEvaluator Class Reference

#include <collectionExpressionEvaluator.h>

Public Types
enum	MatchKind { MatchAll, ShallowestMatches, ShallowestMatchesAndAllDescendants }

Public Member Functions
	HdCollectionExpressionEvaluator ()=default
	Default c'tor. Constructs an empty evaluator. More...
HD_API	HdCollectionExpressionEvaluator (const HdSceneIndexBaseRefPtr &sceneIndex, const SdfPathExpression &expr)
HD_API	HdCollectionExpressionEvaluator (const HdSceneIndexBaseRefPtr &sceneIndex, const SdfPathExpression &expr, const HdCollectionPredicateLibrary &predicateLib)
bool	IsEmpty () const
HdSceneIndexBaseRefPtr	GetSceneIndex () const
HD_API SdfPredicateFunctionResult	Match (const SdfPath &path) const
HD_API void	PopulateAllMatches (const SdfPath &rootPath, SdfPathVector *const result) const
HD_API void	PopulateMatches (const SdfPath &rootPath, MatchKind matchKind, SdfPathVector *const result) const

Detailed Description

Evaluates SdfPathExpressions with prims from a given HdSceneIndex.

Definition at line 40 of file collectionExpressionEvaluator.h.

Member Enumeration Documentation

enum HdCollectionExpressionEvaluator::MatchKind

Option to configure the paths returned by PopulateMatches.

• MatchAll: Return the paths of all prims that match the expression.

• ShallowestMatches: Return the paths of just the top level prims that match, in a level-order or BFS sense.

• ShallowestMatchesAndAllDescendants: Returns the paths of the top level prims that match the expression, as well as all their descendants.

Enumerator
MatchAll
ShallowestMatches
ShallowestMatchesAndAllDescendants

Definition at line 111 of file collectionExpressionEvaluator.h.

Constructor & Destructor Documentation

HdCollectionExpressionEvaluator::HdCollectionExpressionEvaluator ( )

default

Default c'tor. Constructs an empty evaluator.

HD_API HdCollectionExpressionEvaluator::HdCollectionExpressionEvaluator	(	const HdSceneIndexBaseRefPtr &	sceneIndex,
		const SdfPathExpression &	expr
	)

Constructs an evaluator that evaluates expr on prims from sceneIndex using the predicates in HdGetCollectionPredicateLibrary().

HD_API HdCollectionExpressionEvaluator::HdCollectionExpressionEvaluator	(	const HdSceneIndexBaseRefPtr &	sceneIndex,
		const SdfPathExpression &	expr,
		const HdCollectionPredicateLibrary &	predicateLib
	)

Constructs an evaluator that evaluates expr on prims from sceneIndex using the predicates in predicateLib.

Member Function Documentation

HdSceneIndexBaseRefPtr HdCollectionExpressionEvaluator::GetSceneIndex ( ) const

inline

Returns the scene index provided during construction, or nullptr if it was default constructed.

Definition at line 72 of file collectionExpressionEvaluator.h.

bool HdCollectionExpressionEvaluator::IsEmpty ( ) const

inline

Returns true if the evaluator has an invalid scene index or an empty underlying SdfPathExpressionEval object.

Definition at line 65 of file collectionExpressionEvaluator.h.

HD_API SdfPredicateFunctionResult HdCollectionExpressionEvaluator::Match

(

const SdfPath &

path

)

const

Returns the result of evaluating the expression (provided on construction) against the scene index prim at path.

HD_API void HdCollectionExpressionEvaluator::PopulateAllMatches	(	const SdfPath &	rootPath,
		SdfPathVector *const	result
	)		const

Updates result with the paths of all prims in the subtree at rootPath (including rootPath) that match the expression (provided on construction).

An empty evaluator would leave result unaffected.

Note

: result is guaranteed to have unique paths because a scene index prim is traversed at most once.

HD_API void HdCollectionExpressionEvaluator::PopulateMatches	(	const SdfPath &	rootPath,
		MatchKind	matchKind,
		SdfPathVector *const	result
	)		const

Utility that uses matchKind to configure the paths returned by result when evaluating the expression for the subtree at rootPath (including rootPath).

If matchKind is MatchAll, the result is identical to that returned by PopulateAllMatches.

Example: Consider a scene index with prims: {"/a", "/a/foobar", "/a/foobar/b", "/a/foobar/bar", "/a/foobar/baz"}

PopulateMatches would return different results for the expression "/a/*bar" depending on matchKind as follows:

MatchAll : {"/a/foobar", "/a/foobar/bar"}

ShallowestMatches : {"/a/foobar"}

ShallowestMatchesAndAllDescendants: {"/a/foobar", "/a/foobar/b", "/a/foobar/bar", "/a/foobar/baz"}

Note

: result is guaranteed to have unique paths because a scene index prim is traversed at most once.

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

• pxr/imaging/hd/collectionExpressionEvaluator.h