shaderSection.h

//
// Copyright 2020 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
 
#ifndef PXR_IMAGING_HGI_SHADERSECTION_H
#define PXR_IMAGING_HGI_SHADERSECTION_H
 
#include "pxr/pxr.h"
#include "pxr/imaging/hgi/api.h"
#include <memory>
#include <ostream>
#include <string>
#include <vector>
 
PXR_NAMESPACE_OPEN_SCOPE
 
//struct to hold attribute definitions
struct HgiShaderSectionAttribute
{
    std::string identifier;
    std::string index;
};
 
using HgiShaderSectionAttributeVector =
    std::vector<HgiShaderSectionAttribute>;
 
class HgiShaderSection
{
public:
    HGI_API
    virtual ~HgiShaderSection();
 
    HGI_API
    virtual void WriteType(std::ostream& ss) const;
 
    HGI_API
    virtual void WriteIdentifier(std::ostream& ss) const;
 
    HGI_API
    virtual void WriteDeclaration(std::ostream& ss) const;
 
    HGI_API
    virtual void WriteParameter(std::ostream& ss) const;
 
    HGI_API
    virtual void WriteArraySize(std::ostream& ss) const;
 
    HGI_API
    virtual void WriteBlockInstanceIdentifier(std::ostream& ss) const;
 
    const std::string& GetIdentifier() const {
        return _identifierVar;
    }
 
    HGI_API
    const HgiShaderSectionAttributeVector& GetAttributes() const;
    
    const std::string& GetArraySize() const {
        return _arraySize;
    }
 
    bool HasBlockInstanceIdentifier() const {
        return !_blockInstanceIdentifier.empty();
    }
 
protected:
    HGI_API
    explicit HgiShaderSection(
            const std::string &identifier,
            const HgiShaderSectionAttributeVector& attributes = {},
            const std::string &defaultValue = std::string(),
            const std::string &arraySize = std::string(),
            const std::string &blockInstanceIdentifier = std::string());
 
    HGI_API
    const std::string& _GetDefaultValue() const;
 
private:
    const std::string _identifierVar;
    const HgiShaderSectionAttributeVector _attributes;
    const std::string _defaultValue;
    const std::string _arraySize;
    const std::string _blockInstanceIdentifier;
};
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif