reflection.h

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//
// Copyright (C) 2013-2016 LunarG, Inc.
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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), offset(pOffset),
        glDefineType(pGLDefineType), size(pSize), index(pIndex), counterIndex(-1), type(pType.clone()) { }

    const TType* const getType() const { return type; }
    int getBinding() const
    {
        if (type == nullptr || !type->getQualifier().hasBinding())
            return -1;
        return type->getQualifier().layoutBinding;
    }
    void dump() const
    {
        printf("%s: offset %d, type %x, size %d, index %d, binding %d",
               name.c_str(), offset, glDefineType, size, index, getBinding() );

        if (counterIndex != -1)
            printf(", counter %d", counterIndex);

        printf("\n");
    }
    static TObjectReflection badReflection() { return TObjectReflection(); }

    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;
    int counterIndex;

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

    const TType* type;
};

// The full reflection database
class TReflection {
public:
    TReflection() : badReflection(TObjectReflection::badReflection())
    { 
        for (int dim=0; dim<3; ++dim)
            localSize[dim] = 0;
    }

    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;
    }

    // see getIndex(const char*)
    int getIndex(const TString& name) const { return getIndex(name.c_str()); }

    // Thread local size
    unsigned getLocalSize(int dim) const { return dim <= 2 ? localSize[dim] : 0; }

    void dump();

protected:
    friend class glslang::TReflectionTraverser;

    void buildCounterIndices(const TIntermediate&);
    void buildAttributeReflection(EShLanguage, const TIntermediate&);

    // 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;

    unsigned int localSize[3];
};

} // end namespace glslang

#endif // _REFLECTION_INCLUDED