vectorSchema.h

//
// Copyright 2022 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
 
#ifndef PXR_IMAGING_HD_VECTOR_SCHEMA_H
#define PXR_IMAGING_HD_VECTOR_SCHEMA_H
 
#include "pxr/imaging/hd/api.h"
 
#include "pxr/imaging/hd/dataSource.h"
 
PXR_NAMESPACE_OPEN_SCOPE
 
// ----------------------------------------------------------------------------
 
class HdVectorSchema
{
public:
    HdVectorSchema(HdVectorDataSourceHandle const &vector)
      : _vector(vector) {}
 
    HD_API
    static HdVectorDataSourceHandle
    BuildRetained(
        size_t count,
        const HdDataSourceBaseHandle *values);
 
    HD_API
    HdVectorDataSourceHandle GetVector();
    HD_API
    bool IsDefined() const;
 
    explicit operator bool() const { return IsDefined(); }
 
    HD_API
    size_t GetNumElements() const;
 
    using UnderlyingDataSource = HdVectorDataSource;
 
protected:
    template<typename T>
    typename T::Handle _GetTyped(const size_t element) const {
        return
            _vector
            ? T::Cast(_vector->GetElement(element))
            : nullptr;
    }
 
    HdVectorDataSourceHandle _vector;
};
 
template<typename T>
class HdVectorOfTypedSampledDataSourcesSchema : public HdVectorSchema
{
public:
    HdVectorOfTypedSampledDataSourcesSchema(HdVectorDataSourceHandle const &vector)
      : HdVectorSchema(vector) {}
 
    typename T::Handle GetElement(const size_t element) const {
        return _GetTyped<T>(element);
    }
};
 
template<typename T>
using HdTypedVectorSchema = HdVectorOfTypedSampledDataSourcesSchema<T>;
 
template<typename Schema>
class HdVectorOfSchemasSchema : public HdVectorSchema
{
public:
    HdVectorOfSchemasSchema(HdVectorDataSourceHandle const &vector)
      : HdVectorSchema(vector) {}
    
    Schema GetElement(const size_t element) const {
        using DataSource = typename Schema::UnderlyingDataSource;
        return Schema(_GetTyped<DataSource>(element));
    }
};
 
template<typename T>
using HdSchemaBasedVectorSchema = HdVectorOfSchemasSchema<T>;
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif