primFlags.h File Reference

#include "pxr/pxr.h"
#include "pxr/usd/usd/api.h"
#include "pxr/base/arch/hints.h"
#include "pxr/base/tf/bitUtils.h"
#include "pxr/base/tf/hash.h"
#include <bitset>

Include dependency graph for primFlags.h:

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Go to the source code of this file.

Classes
struct	Usd_Term
class	Usd_PrimFlagsPredicate
class	Usd_PrimFlagsConjunction
class	Usd_PrimFlagsDisjunction

Typedefs
typedef std::bitset < Usd_PrimNumFlags >	Usd_PrimFlagBits

Enumerations
enum	Usd_PrimFlags {   Usd_PrimActiveFlag, Usd_PrimLoadedFlag, Usd_PrimModelFlag, Usd_PrimGroupFlag,   Usd_PrimComponentFlag, Usd_PrimAbstractFlag, Usd_PrimDefinedFlag, Usd_PrimHasClassSpecifierFlag,   Usd_PrimHasDefiningSpecifierFlag, Usd_PrimInstanceFlag, Usd_PrimHasPayloadFlag, Usd_PrimClipsFlag,   Usd_PrimDeadFlag, Usd_PrimPrototypeFlag, Usd_PrimInstanceProxyFlag, Usd_PrimPseudoRootFlag,   Usd_PrimNumFlags }

Functions
Usd_Term	operator! (Usd_PrimFlags flag)
Usd_PrimFlagsConjunction	operator&& (Usd_Term lhs, Usd_Term rhs)
Usd_PrimFlagsConjunction	operator&& (const Usd_PrimFlagsConjunction &conjunction, Usd_Term rhs)
Usd_PrimFlagsConjunction	operator&& (Usd_Term lhs, const Usd_PrimFlagsConjunction &conjunction)
Usd_PrimFlagsConjunction	operator&& (Usd_PrimFlags lhs, Usd_PrimFlags rhs)
Usd_PrimFlagsDisjunction	operator|| (Usd_Term lhs, Usd_Term rhs)
Usd_PrimFlagsDisjunction	operator|| (const Usd_PrimFlagsDisjunction &disjunction, Usd_Term rhs)
Usd_PrimFlagsDisjunction	operator|| (Usd_Term lhs, const Usd_PrimFlagsDisjunction &disjunction)
Usd_PrimFlagsDisjunction	operator|| (Usd_PrimFlags lhs, Usd_PrimFlags rhs)
Usd_PrimFlagsPredicate	UsdTraverseInstanceProxies (Usd_PrimFlagsPredicate predicate)
Usd_PrimFlagsPredicate	UsdTraverseInstanceProxies ()

Variables
USD_API const Usd_PrimFlagsConjunction	UsdPrimDefaultPredicate
USD_API const Usd_PrimFlagsPredicate	UsdPrimAllPrimsPredicate

Detailed Description

Provides terms for UsdPrim flags that can be combined to form either a conjunction (via &&) or a disjunction (via ||). The result is a predicate functor object that tests those flags on the passed prim. Currently UsdPrim::GetFilteredChildren(), UsdPrim::GetNextFilteredSibling(), UsdPrim::GetFilteredDescendants(), and UsdPrimRange() accept these predicates to filter out unwanted prims.

For example:

// Get only loaded model children.
prim.GetFilteredChildren(UsdPrimIsModel && UsdPrimIsLoaded)

For performance, these predicates are implemented by a bitwise test, so arbitrary boolean expressions cannot be represented. The set of boolean expressions that can be represented are conjunctions with possibly negated terms (or disjunctions, by De Morgan's law). Here are some examples of valid expressions:

// simple conjunction.
(UsdPrimIsLoaded && UsdPrimIsGroup)
// conjunction with negated term.
(UsdPrimIsDefined && !UsdPrimIsAbstract)
// disjunction with negated term.
(!UsdPrimIsDefined || !UsdPrimIsActive)
// negated conjunction gives a disjunction.
!(UsdPrimIsLoaded && UsdPrimIsModel)
// negated conjunction gives a disjunction, which is further extended.
(!(UsdPrimIsLoaded && UsdPrimIsModel) || UsdPrimIsAbstract)
// equivalent to above.
(!UsdPrimIsLoaded || !UsdPrimIsModel || UsdPrimIsAbstract)

Here are some examples of invalid expressions:

// error: cannot || a term with a conjunction.
(UsdPrimIsLoaded && UsdPrimIsModel) || UsdPrimIsAbstract
// error: cannot && disjunctions.
(!UsdPrimIsDefined || UsdPrimIsAbstract) && (UsdPrimIsModel || !UsdPrimIsActive)

The following variables provide the clauses that can be combined and negated to produce predicates:

Definition in file primFlags.h.

Typedef Documentation

typedef std::bitset<Usd_PrimNumFlags> Usd_PrimFlagBits

Definition at line 95 of file primFlags.h.

Enumeration Type Documentation

enum Usd_PrimFlags

Enumerator
Usd_PrimActiveFlag
Usd_PrimLoadedFlag
Usd_PrimModelFlag
Usd_PrimGroupFlag
Usd_PrimComponentFlag
Usd_PrimAbstractFlag
Usd_PrimDefinedFlag
Usd_PrimHasClassSpecifierFlag
Usd_PrimHasDefiningSpecifierFlag
Usd_PrimInstanceFlag
Usd_PrimHasPayloadFlag
Usd_PrimClipsFlag
Usd_PrimDeadFlag
Usd_PrimPrototypeFlag
Usd_PrimInstanceProxyFlag
Usd_PrimPseudoRootFlag
Usd_PrimNumFlags

Definition at line 71 of file primFlags.h.

Function Documentation

Usd_Term operator! ( Usd_PrimFlags  flag )

inline

Definition at line 115 of file primFlags.h.

Usd_PrimFlagsConjunction operator&& ( Usd_Term  lhs, Usd_Term  rhs  )

inline

Definition at line 353 of file primFlags.h.

Usd_PrimFlagsConjunction operator&& ( const Usd_PrimFlagsConjunction &  conjunction, Usd_Term  rhs  )

inline

Definition at line 361 of file primFlags.h.

Usd_PrimFlagsConjunction operator&& ( Usd_Term  lhs, const Usd_PrimFlagsConjunction &  conjunction  )

inline

Definition at line 366 of file primFlags.h.

Usd_PrimFlagsConjunction operator&& ( Usd_PrimFlags  lhs, Usd_PrimFlags  rhs  )

inline

Definition at line 371 of file primFlags.h.

Usd_PrimFlagsDisjunction operator|| ( Usd_Term  lhs, Usd_Term  rhs  )

inline

Definition at line 456 of file primFlags.h.

Usd_PrimFlagsDisjunction operator|| ( const Usd_PrimFlagsDisjunction &  disjunction, Usd_Term  rhs  )

inline

Definition at line 461 of file primFlags.h.

Usd_PrimFlagsDisjunction operator|| ( Usd_Term  lhs, const Usd_PrimFlagsDisjunction &  disjunction  )

inline

Definition at line 466 of file primFlags.h.

Usd_PrimFlagsDisjunction operator|| ( Usd_PrimFlags  lhs, Usd_PrimFlags  rhs  )

inline

Definition at line 471 of file primFlags.h.

Usd_PrimFlagsPredicate UsdTraverseInstanceProxies ( Usd_PrimFlagsPredicate  predicate )

inline

This function is used to allow the prim traversal functions listed under Prim predicate flags to traverse beneath instance prims and return descendants that pass the specified predicate as instance proxy prims. For example:

// Return all children of the specified prim.  
// If prim is an instance, return all children as instance proxy prims.
prim.GetFilteredChildren(
    UsdTraverseInstanceProxies(UsdPrimAllPrimsPredicate))

// Return children of the specified prim that pass the default predicate.
// If prim is an instance, return the children that pass this predicate
// as instance proxy prims.
prim.GetFilteredChildren(UsdTraverseInstanceProxies());

// Return all model or group children of the specified prim.
// If prim is an instance, return the children that pass this predicate 
// as instance proxy prims.
prim.GetFilteredChildren(UsdTraverseInstanceProxies(UsdPrimIsModel || UsdPrimIsGroup));

Users may also call Usd_PrimFlagsPredicate::TraverseInstanceProxies to enable traversal beneath instance prims. This function is equivalent to:

predicate.TraverseInstanceProxies(true);

However, this function may be more convenient, especially when calling a prim traversal function with a default-constructed tautology predicate.

Definition at line 565 of file primFlags.h.

Usd_PrimFlagsPredicate UsdTraverseInstanceProxies ( )

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Convenience method equivalent to calling UsdTraverseInstanceProxies with the UsdPrimDefaultPredicate that is used by default for prim traversals.

Definition at line 575 of file primFlags.h.

Variable Documentation

USD_API const Usd_PrimFlagsPredicate UsdPrimAllPrimsPredicate

USD_API const Usd_PrimFlagsConjunction UsdPrimDefaultPredicate