vboSimpleMemoryManager.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_ST_VBO_SIMPLE_MEMORY_MANAGER_H
#define PXR_IMAGING_HD_ST_VBO_SIMPLE_MEMORY_MANAGER_H
 
#include "pxr/pxr.h"
#include "pxr/imaging/hdSt/api.h"
#include "pxr/imaging/hdSt/bufferArrayRange.h"
#include "pxr/imaging/hdSt/resourceRegistry.h"
#include "pxr/imaging/hdSt/strategyBase.h"
 
#include "pxr/imaging/hd/bufferArray.h"
#include "pxr/imaging/hd/bufferSpec.h"
#include "pxr/imaging/hd/bufferSource.h"
 
PXR_NAMESPACE_OPEN_SCOPE
 
class HdStResourceRegistry;
 
class HdStVBOSimpleMemoryManager : public HdStAggregationStrategy
{
public:
    HdStVBOSimpleMemoryManager(HdStResourceRegistry* resourceRegistry)
        : _resourceRegistry(resourceRegistry) {}
    
    HDST_API
    virtual HdBufferArraySharedPtr CreateBufferArray(
        TfToken const &role,
        HdBufferSpecVector const &bufferSpecs,
        HdBufferArrayUsageHint usageHint);
 
    HDST_API
    virtual HdBufferArrayRangeSharedPtr CreateBufferArrayRange();
 
    HDST_API
    virtual HdStAggregationStrategy::AggregationId ComputeAggregationId(
        HdBufferSpecVector const &bufferSpecs,
        HdBufferArrayUsageHint usageHint) const;
 
    virtual HdBufferSpecVector GetBufferSpecs(
        HdBufferArraySharedPtr const &bufferArray) const;
 
    virtual size_t GetResourceAllocation(
        HdBufferArraySharedPtr const &bufferArray, 
        VtDictionary &result) const;
 
protected:
    class _SimpleBufferArray;
 
    class _SimpleBufferArrayRange final : public HdStBufferArrayRange
    {
    public:
        _SimpleBufferArrayRange(HdStResourceRegistry* resourceRegistry)
            : HdStBufferArrayRange(resourceRegistry)
            , _bufferArray(nullptr)
            , _numElements(0) {
        }
 
        bool IsValid() const override {
            return (bool)_bufferArray;
        }
 
        HDST_API
        bool IsAssigned() const override;
 
        bool IsImmutable() const override;
 
        bool RequiresStaging() const override;
    
        bool Resize(int numElements) override {
            _numElements = numElements;
            return _bufferArray->Resize(numElements);
        }
 
        HDST_API
        void CopyData(HdBufferSourceSharedPtr const &bufferSource) override;
 
        HDST_API
        VtValue ReadData(TfToken const &name) const override;
 
        int GetElementOffset() const override {
            return 0;
        }
 
        int GetByteOffset(TfToken const& resourceName) const override {
            TF_UNUSED(resourceName);
            return 0;
        }
 
        size_t GetNumElements() const override {
            return _numElements;
        }
 
        int GetCapacity() const {
            return _bufferArray->GetCapacity();
        }
 
        size_t GetVersion() const override {
            return _bufferArray->GetVersion();
        }
 
        void IncrementVersion() override {
            _bufferArray->IncrementVersion();
        }
 
        HDST_API
        size_t GetMaxNumElements() const override;
 
        HDST_API
        HdBufferArrayUsageHint GetUsageHint() const override;
 
        HDST_API
        HdStBufferResourceSharedPtr GetResource() const override;
 
        HDST_API
        HdStBufferResourceSharedPtr GetResource(TfToken const& name) override;
 
        HDST_API
        HdStBufferResourceNamedList const& GetResources() const override;
 
        HDST_API
        void SetBufferArray(HdBufferArray *bufferArray) override;
 
        HDST_API
        void DebugDump(std::ostream &out) const override;
 
        void Invalidate() {
            _bufferArray = NULL;
        }
 
    protected:
        HDST_API
        const void *_GetAggregation() const override;
 
        HDST_API
        HdStBufferResourceSharedPtr _AddResource(TfToken const& name,
                                                   HdTupleType tupleType,
                                                   int offset,
                                                   int stride);
 
    private:
        _SimpleBufferArray * _bufferArray;
        size_t _numElements;
    };
 
    using _SimpleBufferArraySharedPtr =
        std::shared_ptr<_SimpleBufferArray>;
    using _SimpleBufferArrayRangeSharedPtr =
        std::shared_ptr<_SimpleBufferArrayRange>;
    using _SimpleBufferArrayRangePtr =
        std::weak_ptr<_SimpleBufferArrayRange>;
 
    class _SimpleBufferArray final : public HdBufferArray
    {
    public:
        HDST_API
        _SimpleBufferArray(HdStResourceRegistry* resourceRegistry,
                           TfToken const &role,
                           HdBufferSpecVector const &bufferSpecs,
                           HdBufferArrayUsageHint usageHint);
 
        HDST_API
        ~_SimpleBufferArray() override;
 
        HDST_API
        bool GarbageCollect() override;
 
        HDST_API
        void DebugDump(std::ostream &out) const override;
 
        HDST_API
        bool Resize(int numElements);
 
        HDST_API
        void Reallocate(
                std::vector<HdBufferArrayRangeSharedPtr> const &ranges,
                HdBufferArraySharedPtr const &curRangeOwner) override;
 
        HDST_API
        size_t GetMaxNumElements() const override;
 
        int GetCapacity() const {
            return _capacity;
        }
 
        HDST_API
        HdStBufferResourceSharedPtr GetResource() const;
 
        HDST_API
        HdStBufferResourceSharedPtr GetResource(TfToken const& name);
 
        HdStBufferResourceNamedList const& GetResources() const {return _resourceList;}
 
        HDST_API
        HdBufferSpecVector GetBufferSpecs() const;
 
    protected:
        HDST_API
        void _DeallocateResources();
 
        HDST_API
        HdStBufferResourceSharedPtr _AddResource(TfToken const& name,
                                                   HdTupleType tupleType,
                                                   int offset,
                                                   int stride);
    private:
        HdStResourceRegistry* const _resourceRegistry;
        int _capacity;
        size_t _maxBytesPerElement;
        HgiBufferUsage _bufferUsage;
 
        HdStBufferResourceNamedList _resourceList;
 
        _SimpleBufferArrayRangeSharedPtr _GetRangeSharedPtr() const {
            return GetRangeCount() > 0
                ? std::static_pointer_cast<_SimpleBufferArrayRange>(GetRange(0).lock())
                : _SimpleBufferArrayRangeSharedPtr();
        }
    };
    
    HdStResourceRegistry* const _resourceRegistry;
};
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif  // PXR_IMAGING_HD_ST_VBO_SIMPLE_MEMORY_MANAGER_H