purposeFilteringSceneIndex.h

//
// Copyright 2026 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
#ifndef PXR_IMAGING_HDSI_PURPOSE_FILTERING_SCENE_INDEX_H
#define PXR_IMAGING_HDSI_PURPOSE_FILTERING_SCENE_INDEX_H
 
#include "pxr/pxr.h"
 
#include "pxr/imaging/hd/filteringSceneIndex.h"
#include "pxr/imaging/hdsi/api.h"
 
#include "pxr/base/tf/token.h"
#include "pxr/base/vt/array.h"
 
#include <optional>
 
PXR_NAMESPACE_OPEN_SCOPE
 
#define HDSI_PURPOSE_FILTERING_SCENE_INDEX_TOKENS \
    (purposes)
 
TF_DECLARE_PUBLIC_TOKENS(HdsiPurposeFilteringSceneIndexTokens, HDSI_API,
                         HDSI_PURPOSE_FILTERING_SCENE_INDEX_TOKENS);
 
TF_DECLARE_WEAK_AND_REF_PTRS(HdsiPurposeFilteringSceneIndex);
 
class HdsiPurposeFilteringSceneIndex final
    : public HdSingleInputFilteringSceneIndexBase
{
public:
    HDSI_API
    static HdsiPurposeFilteringSceneIndexRefPtr
    New(HdSceneIndexBaseRefPtr const &inputSceneIndex,
        HdContainerDataSourceHandle const &inputArgs);
 
    HDSI_API
    void SetPurposes(VtArray<TfToken> const &purposes);
 
    HDSI_API
    VtArray<TfToken> const &GetPurposes() const;
 
public: // HdSceneIndex overrides
    HDSI_API
    HdSceneIndexPrim GetPrim(const SdfPath &primPath) const override;
    HDSI_API
    SdfPathVector GetChildPrimPaths(const SdfPath &primPath) const override;
 
protected: // HdSingleInputFilteringSceneIndexBase overrides
    HDSI_API
    void _PrimsAdded(
        const HdSceneIndexBase &sender,
        const HdSceneIndexObserver::AddedPrimEntries &entries) override;
    HDSI_API
    void _PrimsRemoved(
        const HdSceneIndexBase &sender,
        const HdSceneIndexObserver::RemovedPrimEntries &entries) override;
    HDSI_API
    void _PrimsDirtied(
        const HdSceneIndexBase &sender,
        const HdSceneIndexObserver::DirtiedPrimEntries &entries) override;
 
protected:
    HDSI_API
    HdsiPurposeFilteringSceneIndex(
        HdSceneIndexBaseRefPtr const &inputSceneIndex,
        HdContainerDataSourceHandle const &inputArgs);
    HDSI_API
    ~HdsiPurposeFilteringSceneIndex() override;
 
private:
    bool _IsFilteringActive() const;
 
    // Returns true if the prim represented by dataSource should be pruned
    // based on the current state (_purposes or _excludedPurposesHint).
    bool _ShouldPrune(const HdContainerDataSourceHandle &dataSource) const;
 
    // nullopt = hint mode (purposes not provided at c'tor time and SetPurposes
    // has not been called).
    // [] = explicit empty = no filtering.
    // [...] = explicit accepted-purpose filter.
    std::optional<VtArray<TfToken>> _purposes;
 
    // Purposes that should be pruned while in hint mode (nullopt _purposes).
    VtArray<TfToken> _excludedPurposesHint;
};
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif