glslang/glslang/MachineIndependent/reflection.h

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#ifndef _REFLECTION_INCLUDED
#define _REFLECTION_INCLUDED

#include "../Public/ShaderLang.h"
#include "../Include/Types.h"

#include <list>
#include <set>

//
// A reflection database and its interface, consistent with the OpenGL API reflection queries.
//

namespace glslang {

class TIntermediate;
class TIntermAggregate;
class TReflectionTraverser;

// Data needed for just a single object at the granularity exchanged by the reflection API
class TObjectReflection {
public:
    TObjectReflection(const TString& pName, const TType& pType, int pOffset, int pGLDefineType, int pSize, int pIndex) : 
        name(pName), type(pType.clone()),
        offset(pOffset), glDefineType(pGLDefineType), size(pSize), index(pIndex) { }

    void dump() const {
        printf("%s: offset %d, type %x, size %d, index %d, binding %d\n",
               name.c_str(), offset, glDefineType, size, index, getBinding() );
    }

    const TType* const getType() const { return type; }

    TString name;
    int offset;
    int glDefineType;
    int size;         // data size in bytes for a block, array size for a (non-block) object that's an array
    int index;

    static TObjectReflection badReflection() { return TObjectReflection(); }

protected:
    int getBinding() const {
        if (type == nullptr || type->getQualifier().layoutBinding == TQualifier::layoutBindingEnd)
            return -1;
        return type->getQualifier().layoutBinding;
    }

    TObjectReflection() : type(nullptr), offset(-1), glDefineType(-1), size(-1), index(-1) { }

    const TType* type;
};

// The full reflection database
class TReflection {
public:
    TReflection() : badReflection(TObjectReflection::badReflection()) { }
    virtual ~TReflection() {}

    // grow the reflection stage by stage
    bool addStage(EShLanguage, const TIntermediate&);

    // for mapping a uniform index to a uniform object's description
    int getNumUniforms() { return (int)indexToUniform.size(); }
    const TObjectReflection& getUniform(int i) const
    {
        if (i >= 0 && i < (int)indexToUniform.size())
            return indexToUniform[i];
        else
            return badReflection;
    }

    // for mapping a block index to the block's description
    int getNumUniformBlocks() const { return (int)indexToUniformBlock.size(); }
    const TObjectReflection& getUniformBlock(int i) const 
    {
        if (i >= 0 && i < (int)indexToUniformBlock.size())
            return indexToUniformBlock[i];
        else
            return badReflection;
    }

    // for mapping an attribute index to the attribute's description
    int getNumAttributes() { return (int)indexToAttribute.size(); }
    const TObjectReflection& getAttribute(int i) const
    {
        if (i >= 0 && i < (int)indexToAttribute.size())
            return indexToAttribute[i];
        else
            return badReflection;
    }

    // for mapping any name to its index (block names, uniform names and attribute names)
    int getIndex(const char* name) const 
    {
        TNameToIndex::const_iterator it = nameToIndex.find(name);
        if (it == nameToIndex.end())
            return -1;
        else
            return it->second;
    }

    void dump();

protected:
    friend class glslang::TReflectionTraverser;

    // Need a TString hash: typedef std::unordered_map<TString, int> TNameToIndex;
    typedef std::map<TString, int> TNameToIndex;
    typedef std::vector<TObjectReflection> TMapIndexToReflection;

    TObjectReflection badReflection; // return for queries of -1 or generally out of range; has expected descriptions with in it for this
    TNameToIndex nameToIndex;        // maps names to indexes; can hold all types of data: uniform/buffer and which function names have been processed
    TMapIndexToReflection indexToUniform;
    TMapIndexToReflection indexToUniformBlock;
    TMapIndexToReflection indexToAttribute;
};

} // end namespace glslang

#endif // _REFLECTION_INCLUDED