renderIndex.h

//
// Copyright 2016 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_IMAGING_HD_RENDER_INDEX_H
#define PXR_IMAGING_HD_RENDER_INDEX_H

#include "pxr/pxr.h"
#include "pxr/imaging/hd/api.h"
#include "pxr/imaging/hd/version.h"
#include "pxr/imaging/hd/changeTracker.h"
#include "pxr/imaging/hd/dirtyList.h"
#include "pxr/imaging/hd/perfLog.h"
#include "pxr/imaging/hd/primTypeIndex.h"
#include "pxr/imaging/hd/resourceRegistry.h"
#include "pxr/imaging/hd/sortedIds.h"
#include "pxr/imaging/hd/tokens.h"

#include "pxr/imaging/hd/sceneIndex.h"
#include "pxr/imaging/hd/mergingSceneIndex.h"
#include "pxr/imaging/hd/legacyPrimSceneIndex.h"
#include "pxr/imaging/hd/legacyTaskFactory.h"
#include "pxr/imaging/hd/noticeBatchingSceneIndex.h"

#include "pxr/imaging/hf/perfLog.h"

#include "pxr/usd/sdf/path.h"

#include "pxr/base/gf/vec4i.h"
#include "pxr/base/tf/hashmap.h"

#include <tbb/enumerable_thread_specific.h>

#include <vector>
#include <unordered_map>
#include <memory>
#include <optional>

PXR_NAMESPACE_OPEN_SCOPE

class HdRprim;
class HdSprim;
class HdBprim;
class HdDrawItem;
class HdRprimCollection;
class HdSceneDelegate;
class HdRenderDelegate;
class HdExtComputation;
class VtValue;
class HdInstancer;
class HdDriver;

using HdDriverVector = std::vector<HdDriver*>;
using HdRprimCollectionVector = std::vector<HdRprimCollection>;
using HdTaskSharedPtr = std::shared_ptr<class HdTask>;
using HdResourceRegistrySharedPtr = std::shared_ptr<class HdResourceRegistry>;
using HdTaskSharedPtrVector = std::vector<HdTaskSharedPtr>;
using HdTaskContext = std::unordered_map<TfToken,
                           VtValue,
                           TfToken::HashFunctor>;

class HdRenderIndex final 
{
public:
    typedef std::vector<HdDrawItem const*> HdDrawItemPtrVector;

    //    hgi = Hgi::CreatePlatformDefaultHgi()
    //    hgiDriver = new HdDriver<Hgi*>(HgiTokens→renderDriver, hgi)
    //    HdRenderIndex::New(_renderDelegate, {_hgiDriver})
    // 
    HD_API
    static HdRenderIndex* New(
        HdRenderDelegate *renderDelegate,
        HdDriverVector const& drivers,
        const std::string &instanceName=std::string(),
        const std::string &appName=std::string());

    static HdRenderIndex *NewForBackendEmulation(
        HdRenderDelegate *renderDelegate, 
        HdDriverVector const& drivers,
        HdSceneIndexBaseRefPtr const &terminalSceneIndex);

    static HdRenderIndex *
    NewForFrontendEmulation(HdRenderDelegate *nullRenderDelegate);

    HD_API
    ~HdRenderIndex();

    HD_API
    void Clear();

    HD_API
    void RemoveSubtree(const SdfPath &root, HdSceneDelegate* sceneDelegate);

    // ---------------------------------------------------------------------- //
    HD_API
    SdfPath GetRprimPathFromPrimId(int primId) const;
 
    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    HD_API
    void EnqueueCollectionToSync(HdRprimCollection const &collection);

    HD_API
    void SyncAll(HdTaskSharedPtrVector *tasks, HdTaskContext *taskContext);

    HD_API bool IsSyncAllInProgress() const;

    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    //  by renderTags and collection.
    HD_API
    HdDrawItemPtrVector GetDrawItems(HdRprimCollection const& collection,
                                     TfTokenVector const& renderTags);

    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    HdChangeTracker& GetChangeTracker() { return _tracker; }
    HdChangeTracker const& GetChangeTracker() const { return _tracker; }

    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    HD_API
    bool IsRprimTypeSupported(TfToken const& typeId) const;

    HD_API
    void InsertRprim(TfToken const& typeId,
                     HdSceneDelegate* sceneDelegate,
                     SdfPath const& rprimId);

    HD_API
    void RemoveRprim(SdfPath const& id);

    bool HasRprim(SdfPath const& id) { 
        return _rprimMap.find(id) != _rprimMap.end();
    }

    HD_API
    HdRprim const *GetRprim(SdfPath const &id) const;

    HD_API
    HdSceneDelegate *GetSceneDelegateForRprim(SdfPath const &id) const;

    HD_API
    bool GetSceneDelegateAndInstancerIds(SdfPath const &id,
                                         SdfPath* sceneDelegateId,
                                         SdfPath* instancerId) const;

    HD_API
    TfToken GetRenderTag(SdfPath const& id) const;

    TfToken UpdateRenderTag(SdfPath const& id,
                            HdDirtyBits bits);

    HD_API
    const SdfPathVector &GetRprimIds() { return _rprimIds.GetIds(); }


    HD_API
    SdfPathVector GetRprimSubtree(SdfPath const& root);


    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    HD_API
    void InsertInstancer(HdSceneDelegate* delegate,
                         SdfPath const &id);

    HD_API
    void RemoveInstancer(SdfPath const& id);

    bool HasInstancer(SdfPath const& id) {
        return _instancerMap.find(id) != _instancerMap.end();
    }

    HD_API
    HdInstancer *GetInstancer(SdfPath const &id) const;

    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    template <typename T>
    void InsertTask(HdSceneDelegate* delegate, SdfPath const& id);

    HD_API
    void RemoveTask(SdfPath const& id);

    bool HasTask(SdfPath const& id) {
        return _taskMap.find(id) != _taskMap.end();
    }

    HD_API
    HdTaskSharedPtr const& GetTask(SdfPath const& id) const;

    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    HD_API
    bool IsSprimTypeSupported(TfToken const& typeId) const;

    HD_API
    void InsertSprim(TfToken const& typeId,
                     HdSceneDelegate* delegate,
                     SdfPath const& sprimId);

    HD_API
    void RemoveSprim(TfToken const& typeId, SdfPath const &id);

    HD_API
    HdSprim *GetSprim(TfToken const& typeId, SdfPath const &id) const;

    HD_API
    SdfPathVector GetSprimSubtree(TfToken const& typeId,
                                  SdfPath const& root);

    HD_API
    HdSprim *GetFallbackSprim(TfToken const& typeId) const;


    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //

    HD_API
    bool IsBprimTypeSupported(TfToken const& typeId) const;

    HD_API
    void InsertBprim(TfToken const& typeId,
                     HdSceneDelegate* delegate,
                     SdfPath const& bprimId);

    HD_API
    void RemoveBprim(TfToken const& typeId, SdfPath const &id);

    HD_API
    HdBprim *GetBprim(TfToken const& typeId, SdfPath const &id) const;

    HD_API
    SdfPathVector GetBprimSubtree(TfToken const& typeId,
                                  SdfPath const& root);

    HD_API
    HdBprim *GetFallbackBprim(TfToken const& typeId) const;

    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //
    HD_API
    void InsertSceneIndex(
            const HdSceneIndexBaseRefPtr &inputScene,
            SdfPath const& scenePathPrefix,
            bool needsPrefixing = true);

    HD_API
    void RemoveSceneIndex(
            const HdSceneIndexBaseRefPtr &inputScene);

    HD_API
    HdSceneIndexBaseRefPtr GetTerminalSceneIndex() const;

    HD_API
    HdSceneIndexBaseRefPtr GetEmulationSceneIndex() const;
    
    // ---------------------------------------------------------------------- //
    // ---------------------------------------------------------------------- //
    HD_API
    HdRenderDelegate *GetRenderDelegate() const;

    // The render delegate may require access to a render context / device 
    // that is provided by the application.
    HD_API
    HdDriverVector const& GetDrivers() const;

    HD_API
    HdResourceRegistrySharedPtr GetResourceRegistry() const;

    HD_API
    void SceneIndexEmulationNoticeBatchBegin();

    HD_API
    void SceneIndexEmulationNoticeBatchEnd();

    HD_API
    void MergingSceneIndexNoticeBatchBegin();

    HD_API
    void MergingSceneIndexNoticeBatchEnd();

    HD_API
    std::string GetInstanceName() const;

private:
    // The render index constructor is private so we can check
    // renderDelegate before construction: see HdRenderIndex::New(...).
    HdRenderIndex(
        HdRenderDelegate *renderDelegate, 
        HdDriverVector const& drivers,
        const std::string &instanceName,
        const std::string &appName,
        HdSceneIndexBaseRefPtr const &terminalSceneIndex = nullptr,
        bool createFrontendEmulationOnly = false);

    // ---------------------------------------------------------------------- //
    // Private Helper methods 
    // ---------------------------------------------------------------------- //

    // Go through all RPrims and reallocate their instance ids
    // This is called once we have exhausted all 24bit instance ids.
    void _CompactPrimIds();

    // Allocate the next available instance id to the prim
    void _AllocatePrimId(HdRprim* prim);

    using HdTaskCreateFnc =
            std::function<HdTaskSharedPtr(HdSceneDelegate*, SdfPath const&)>;

    // Implements InsertTask<T>.
    // Inserts task going through emulation if enabled.
    HD_API
    void _InsertSceneDelegateTask(
        HdSceneDelegate* delegate, 
        SdfPath const& taskId,
        HdLegacyTaskFactorySharedPtr factory);

    template <typename T>
    static inline const TfToken & _GetTypeId();


    // Private versions of equivalent public methods which insert and remove
    // from this render index.
    // 
    // The public versions check to see if scene delegate emulation is active.
    // If not, they call through to these. Otherwise, they forward to the
    // the HdLegacyPrimSceneIndex member. If a legacy render delegate is also
    // in use, the scene index chain will terminate with a
    // HdSceneIndexAdapterSceneDelegate. That will call the private versions
    // directly so that the internal render index tables are updated.
    // 
    // This prevents cyclic insertion/removals while allowing a single 
    // HdRenderIndex to be used for both front and back-end emulation.
    //
    // Note: all render index users should call the public APIs; only
    // sceneIndexAdapterSceneDelegate.cpp should call these versions, to keep
    // state synchronized.  Note, for example, that _RemoveSubtree and _Clear
    // don't affect the task map, since tasks aren't part of emulation, whereas
    // RemoveSubtree and Clear do affect the task map...
    friend class HdSceneIndexAdapterSceneDelegate;
    void _InsertRprim(TfToken const& typeId,
                      HdSceneDelegate* sceneDelegate,
                      SdfPath const& rprimId);
    void _InsertSprim(TfToken const& typeId,
                      HdSceneDelegate* delegate,
                      SdfPath const& sprimId);
    void _InsertBprim(TfToken const& typeId,
                      HdSceneDelegate* delegate,
                      SdfPath const& bprimId);
    void _InsertInstancer(HdSceneDelegate* delegate,
                          SdfPath const &id);
    void _InsertTask(HdSceneDelegate* delegate,
                     SdfPath const &id,
                     HdTaskSharedPtr const &task);

    void _RemoveRprim(SdfPath const& id);
    void _RemoveSprim(TfToken const& typeId, SdfPath const& id);
    void _RemoveBprim(TfToken const& typeId, SdfPath const& id);
    void _RemoveInstancer(SdfPath const& id);
    void _RemoveSubtree(SdfPath const& id, HdSceneDelegate* sceneDelegate);
    void _RemoveRprimSubtree(const SdfPath &root,
                             HdSceneDelegate* sceneDelegate);
    void _RemoveInstancerSubtree(const SdfPath &root,
                                 HdSceneDelegate* sceneDelegate);
    void _RemoveExtComputationSubtree(const SdfPath &root,
                                      HdSceneDelegate* sceneDelegate);
    void _RemoveTaskSubtree(const SdfPath &root,
                            HdSceneDelegate* sceneDelegate);
    void _RemoveTask(SdfPath const &id);
    void _Clear();

    // ---------------------------------------------------------------------- //
    // Index State
    // ---------------------------------------------------------------------- //
    struct _RprimInfo {
        HdSceneDelegate *sceneDelegate;
        HdRprim *rprim;
    };

    class _NoticeBatchingContext;

    HdLegacyPrimSceneIndexRefPtr _emulationSceneIndex;
    std::unique_ptr<_NoticeBatchingContext> _emulationBatchingCtx;

    std::unique_ptr<class HdSceneIndexAdapterSceneDelegate> _siSd;

    HdMergingSceneIndexRefPtr _mergingSceneIndex;
    std::unique_ptr<_NoticeBatchingContext> _mergingBatchingCtx;

    HdSceneIndexBaseRefPtr _terminalSceneIndex;

    struct _TaskInfo {
        HdSceneDelegate *sceneDelegate;
        HdTaskSharedPtr task;
    };

    typedef std::unordered_map<SdfPath, _TaskInfo, SdfPath::Hash> _TaskMap;
    typedef TfHashMap<SdfPath, _RprimInfo, SdfPath::Hash> _RprimMap;
    typedef std::vector<SdfPath> _RprimPrimIDVector;

    typedef Hd_PrimTypeIndex<HdSprim> _SprimIndex;
    typedef Hd_PrimTypeIndex<HdBprim> _BprimIndex;

    _RprimMap _rprimMap;
    Hd_SortedIds _rprimIds;

    // Prim id -> rprim path table. Only maintained (and non-empty optional)
    // if the prim id is not coming from the given terminal scene index.
    //
    std::optional<_RprimPrimIDVector> _rprimPrimIdMap;

    _TaskMap _taskMap;

    _SprimIndex _sprimIndex;
    _BprimIndex _bprimIndex;

    HdChangeTracker _tracker;

    typedef TfHashMap<SdfPath, HdInstancer*, SdfPath::Hash> _InstancerMap;
    _InstancerMap _instancerMap;

    HdRenderDelegate *_renderDelegate;
    HdDriverVector _drivers;

    HdSceneIndexBaseRefPtr _finalEmulationSceneIndex;

    std::string _instanceName;

    // ---------------------------------------------------------------------- //
    // Sync State
    // ---------------------------------------------------------------------- //
    HdRprimCollectionVector _collectionsToSync;
    HdDirtyList _rprimDirtyList;

    // Call depth to SyncAll().  Should only ever be 0 or 1.
    std::atomic<int> _syncAllDepth;

    // ---------------------------------------------------------------------- //

    void _InitPrimTypes();

    bool _CreateFallbackPrims();

    void _DestroyFallbackPrims();

    typedef tbb::enumerable_thread_specific<HdDrawItemPtrVector>
        _ConcurrentDrawItems;

    void _AppendDrawItems(const SdfPathVector &rprimIds,
                          size_t begin,
                          size_t end,
                          HdRprimCollection const& collection,
                          _ConcurrentDrawItems* result);

    static void _ConfigureReprs();

    // Remove default constructor
    HdRenderIndex() = delete;

    // Don't allow copies
    HdRenderIndex(const HdRenderIndex &) = delete;
    HdRenderIndex &operator=(const HdRenderIndex &) = delete; 

};

template <typename T>
void
HdRenderIndex::InsertTask(HdSceneDelegate* delegate, SdfPath const& id)
{
    _InsertSceneDelegateTask(
        delegate, id, HdMakeLegacyTaskFactory<T>());
}

PXR_NAMESPACE_CLOSE_SCOPE

#endif //PXR_IMAGING_HD_RENDER_INDEX_H