assimp/code/AssetLib/Ply/PlyLoader.cpp

/*
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/** @file  PlyLoader.cpp
 *  @brief Implementation of the PLY importer class
 */

#ifndef ASSIMP_BUILD_NO_PLY_IMPORTER

// internal headers
#include "PlyLoader.h"
#include <assimp/IOStreamBuffer.h>
#include <assimp/importerdesc.h>
#include <assimp/scene.h>
#include <assimp/IOSystem.hpp>
#include <memory>

namespace Assimp {

static constexpr aiImporterDesc desc = {
    "Stanford Polygon Library (PLY) Importer",
    "",
    "",
    "",
    aiImporterFlags_SupportBinaryFlavour | aiImporterFlags_SupportTextFlavour,
    0,
    0,
    0,
    0,
    "ply"
};

// ------------------------------------------------------------------------------------------------
// Internal stuff
namespace {
    // ------------------------------------------------------------------------------------------------
    // Checks that property index is within range
    template <class T>
    inline const T &GetProperty(const std::vector<T> &props, int idx) {
        if (static_cast<size_t>(idx) >= props.size()) {
            throw DeadlyImportError("Invalid .ply file: Property index is out of range.");
        }

        return props[idx];
    }

    // ------------------------------------------------------------------------------------------------
    static bool isBigEndian(const char *szMe) {
        ai_assert(nullptr != szMe);

        // binary_little_endian
        // binary_big_endian
        bool isBigEndian{ false };
#if (defined AI_BUILD_BIG_ENDIAN)
        if ('l' == *szMe || 'L' == *szMe) {
            isBigEndian = true;
        }
#else
        if ('b' == *szMe || 'B' == *szMe) {
            isBigEndian = true;
        }
#endif // ! AI_BUILD_BIG_ENDIAN

        return isBigEndian;
    }

} // namespace

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
PLYImporter::PLYImporter() :
        mBuffer(nullptr),
        pcDOM(nullptr),
        mGeneratedMesh(nullptr) {
    // empty
}

// ------------------------------------------------------------------------------------------------
PLYImporter::~PLYImporter() {
    delete mGeneratedMesh;
}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file.
bool PLYImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool /*checkSig*/) const {
    static const char *tokens[] = { "ply" };
    return SearchFileHeaderForToken(pIOHandler, pFile, tokens, AI_COUNT_OF(tokens));
}

// ------------------------------------------------------------------------------------------------
const aiImporterDesc *PLYImporter::GetInfo() const {
    return &desc;
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure.
void PLYImporter::InternReadFile(const std::string &pFile, aiScene *pScene, IOSystem *pIOHandler) {
    const std::string mode = "rb";
    std::unique_ptr<IOStream> fileStream(pIOHandler->Open(pFile, mode));
    if (!fileStream) {
        throw DeadlyImportError("Failed to open file ", pFile, ".");
    }

    // Get the file-size
    const size_t fileSize = fileStream->FileSize();
    if (0 == fileSize) {
        throw DeadlyImportError("File ", pFile, " is empty.");
    }

    IOStreamBuffer<char> streamedBuffer(1024 * 1024);
    streamedBuffer.open(fileStream.get());

    // the beginning of the file must be PLY - magic, magic
    std::vector<char> headerCheck;
    streamedBuffer.getNextLine(headerCheck);

    if ((headerCheck.size() < 3) ||
            (headerCheck[0] != 'P' && headerCheck[0] != 'p') ||
            (headerCheck[1] != 'L' && headerCheck[1] != 'l') ||
            (headerCheck[2] != 'Y' && headerCheck[2] != 'y')) {
        streamedBuffer.close();
        throw DeadlyImportError("Invalid .ply file: Incorrect magic number (expected 'ply' or 'PLY').");
    }

    std::vector<char> mBuffer2;
    streamedBuffer.getNextLine(mBuffer2);
    mBuffer = (unsigned char *)&mBuffer2[0];

    char *szMe = (char *)&this->mBuffer[0];
    const char *end = &mBuffer2[0] + mBuffer2.size();
    SkipSpacesAndLineEnd(szMe, (const char **)&szMe, end);

    // determine the format of the file data and construct the aiMesh
    PLY::DOM sPlyDom;
    this->pcDOM = &sPlyDom;

    if (TokenMatch(szMe, "format", 6)) {
        if (TokenMatch(szMe, "ascii", 5)) {
            SkipLine(szMe, (const char **)&szMe, end);
            if (!PLY::DOM::ParseInstance(streamedBuffer, &sPlyDom, this)) {
                if (mGeneratedMesh != nullptr) {
                    delete (mGeneratedMesh);
                    mGeneratedMesh = nullptr;
                }

                streamedBuffer.close();
                throw DeadlyImportError("Invalid .ply file: Unable to build DOM (#1)");
            }
        } else if (!::strncmp(szMe, "binary_", 7)) {
            szMe += 7;
            const bool bIsBE = isBigEndian(szMe);

            // skip the line, parse the rest of the header and build the DOM
            if (!PLY::DOM::ParseInstanceBinary(streamedBuffer, &sPlyDom, this, bIsBE)) {
                if (mGeneratedMesh != nullptr) {
                    delete (mGeneratedMesh);
                    mGeneratedMesh = nullptr;
                }

                streamedBuffer.close();
                throw DeadlyImportError("Invalid .ply file: Unable to build DOM (#2)");
            }
        } else {
            if (mGeneratedMesh != nullptr) {
                delete (mGeneratedMesh);
                mGeneratedMesh = nullptr;
            }

            streamedBuffer.close();
            throw DeadlyImportError("Invalid .ply file: Unknown file format");
        }
    } else {
        AI_DEBUG_INVALIDATE_PTR(this->mBuffer);
        if (mGeneratedMesh != nullptr) {
            delete (mGeneratedMesh);
            mGeneratedMesh = nullptr;
        }

        streamedBuffer.close();
        throw DeadlyImportError("Invalid .ply file: Missing format specification");
    }

    // free the file buffer
    streamedBuffer.close();

    if (mGeneratedMesh == nullptr) {
        throw DeadlyImportError("Invalid .ply file: Unable to extract mesh data ");
    }

    // if no face list is existing we assume that the vertex
    // list is containing a list of points
    bool pointsOnly = mGeneratedMesh->mFaces == nullptr ? true : false;
    if (pointsOnly) {
        mGeneratedMesh->mPrimitiveTypes = aiPrimitiveType::aiPrimitiveType_POINT;
    }

    // now load a list of all materials
    std::vector<aiMaterial *> avMaterials;
    std::string defaultTexture;
    LoadMaterial(&avMaterials, defaultTexture, pointsOnly);

    // now generate the output scene object. Fill the material list
    pScene->mNumMaterials = (unsigned int)avMaterials.size();
    pScene->mMaterials = new aiMaterial *[pScene->mNumMaterials];
    for (unsigned int i = 0; i < pScene->mNumMaterials; ++i) {
        pScene->mMaterials[i] = avMaterials[i];
    }

    // fill the mesh list
    pScene->mNumMeshes = 1;
    pScene->mMeshes = new aiMesh *[pScene->mNumMeshes];
    pScene->mMeshes[0] = mGeneratedMesh;    

    // Move the mesh ownership into the scene instance
    mGeneratedMesh = nullptr;

    // generate a simple node structure
    pScene->mRootNode = new aiNode();
    pScene->mRootNode->mNumMeshes = pScene->mNumMeshes;
    pScene->mRootNode->mMeshes = new unsigned int[pScene->mNumMeshes];

    for (unsigned int i = 0; i < pScene->mRootNode->mNumMeshes; ++i) {
        pScene->mRootNode->mMeshes[i] = i;
    }
}

static constexpr ai_uint NotSet = 0xFFFFFFFF;

void PLYImporter::LoadVertex(const PLY::Element *pcElement, const PLY::ElementInstance *instElement, unsigned int pos) {
    ai_assert(nullptr != pcElement);
    ai_assert(nullptr != instElement);

    ai_uint aiPositions[3] = { NotSet, NotSet, NotSet };
    PLY::EDataType aiTypes[3] = { EDT_Char, EDT_Char, EDT_Char };

    ai_uint aiNormal[3] = { NotSet, NotSet, NotSet };
    PLY::EDataType aiNormalTypes[3] = { EDT_Char, EDT_Char, EDT_Char };

    unsigned int aiColors[4] = { NotSet, NotSet, NotSet, NotSet };
    PLY::EDataType aiColorsTypes[4] = { EDT_Char, EDT_Char, EDT_Char, EDT_Char };

    unsigned int aiTexcoord[2] = { NotSet, NotSet };
    PLY::EDataType aiTexcoordTypes[2] = { EDT_Char, EDT_Char };

    // now check whether which normal components are available
    unsigned int _a(0), cnt(0);
    for (std::vector<PLY::Property>::const_iterator a = pcElement->alProperties.begin();
            a != pcElement->alProperties.end(); ++a, ++_a) {
        if ((*a).bIsList) {
            continue;
        }

        // Positions
        if (PLY::EST_XCoord == (*a).Semantic) {
            ++cnt;
            aiPositions[0] = _a;
            aiTypes[0] = (*a).eType;
        } else if (PLY::EST_YCoord == (*a).Semantic) {
            ++cnt;
            aiPositions[1] = _a;
            aiTypes[1] = (*a).eType;
        } else if (PLY::EST_ZCoord == (*a).Semantic) {
            ++cnt;
            aiPositions[2] = _a;
            aiTypes[2] = (*a).eType;
        } else if (PLY::EST_XNormal == (*a).Semantic) {
            // Normals
            ++cnt;
            aiNormal[0] = _a;
            aiNormalTypes[0] = (*a).eType;
        } else if (PLY::EST_YNormal == (*a).Semantic) {
            ++cnt;
            aiNormal[1] = _a;
            aiNormalTypes[1] = (*a).eType;
        } else if (PLY::EST_ZNormal == (*a).Semantic) {
            ++cnt;
            aiNormal[2] = _a;
            aiNormalTypes[2] = (*a).eType;
        } else if (PLY::EST_Red == (*a).Semantic) {
            // Colors
            ++cnt;
            aiColors[0] = _a;
            aiColorsTypes[0] = (*a).eType;
        } else if (PLY::EST_Green == (*a).Semantic) {
            ++cnt;
            aiColors[1] = _a;
            aiColorsTypes[1] = (*a).eType;
        } else if (PLY::EST_Blue == (*a).Semantic) {
            ++cnt;
            aiColors[2] = _a;
            aiColorsTypes[2] = (*a).eType;
        } else if (PLY::EST_Alpha == (*a).Semantic) {
            ++cnt;
            aiColors[3] = _a;
            aiColorsTypes[3] = (*a).eType;
        } else if (PLY::EST_UTextureCoord == (*a).Semantic) {
            // Texture coordinates
            ++cnt;
            aiTexcoord[0] = _a;
            aiTexcoordTypes[0] = (*a).eType;
        } else if (PLY::EST_VTextureCoord == (*a).Semantic) {
            ++cnt;
            aiTexcoord[1] = _a;
            aiTexcoordTypes[1] = (*a).eType;
        }
    }

    // check whether we have a valid source for the vertex data
    if (0 != cnt) {
        // Position
        aiVector3D vOut;
        if (NotSet != aiPositions[0]) {
            vOut.x = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiPositions[0]).avList.front(), aiTypes[0]);
        }

        if (NotSet != aiPositions[1]) {
            vOut.y = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiPositions[1]).avList.front(), aiTypes[1]);
        }

        if (NotSet != aiPositions[2]) {
            vOut.z = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiPositions[2]).avList.front(), aiTypes[2]);
        }

        // Normals
        aiVector3D nOut;
        bool haveNormal = false;
        if (NotSet != aiNormal[0]) {
            nOut.x = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiNormal[0]).avList.front(), aiNormalTypes[0]);
            haveNormal = true;
        }

        if (NotSet != aiNormal[1]) {
            nOut.y = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiNormal[1]).avList.front(), aiNormalTypes[1]);
            haveNormal = true;
        }

        if (NotSet != aiNormal[2]) {
            nOut.z = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiNormal[2]).avList.front(), aiNormalTypes[2]);
            haveNormal = true;
        }

        // Colors
        aiColor4D cOut;
        bool haveColor = false;
        if (NotSet != aiColors[0]) {
            cOut.r = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                 aiColors[0])
                                                 .avList.front(),
                    aiColorsTypes[0]);
            haveColor = true;
        }

        if (NotSet != aiColors[1]) {
            cOut.g = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                 aiColors[1])
                                                 .avList.front(),
                    aiColorsTypes[1]);
            haveColor = true;
        }

        if (NotSet != aiColors[2]) {
            cOut.b = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                 aiColors[2])
                                                 .avList.front(),
                    aiColorsTypes[2]);
            haveColor = true;
        }

        // assume 1.0 for the alpha channel if it is not set
        if (NotSet == aiColors[3]) {
            cOut.a = 1.0;
        } else {
            cOut.a = NormalizeColorValue(GetProperty(instElement->alProperties,
                                                 aiColors[3])
                                                 .avList.front(),
                    aiColorsTypes[3]);

            haveColor = true;
        }

        // Texture coordinates
        aiVector3D tOut;
        tOut.z = 0;
        bool haveTextureCoords = false;
        if (NotSet != aiTexcoord[0]) {
            tOut.x = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiTexcoord[0]).avList.front(), aiTexcoordTypes[0]);
            haveTextureCoords = true;
        }

        if (NotSet != aiTexcoord[1]) {
            tOut.y = PLY::PropertyInstance::ConvertTo<ai_real>(
                    GetProperty(instElement->alProperties, aiTexcoord[1]).avList.front(), aiTexcoordTypes[1]);
            haveTextureCoords = true;
        }

        // create aiMesh if needed
        if (nullptr == mGeneratedMesh) {
            mGeneratedMesh = new aiMesh();
            mGeneratedMesh->mMaterialIndex = 0;
        }

        if (nullptr == mGeneratedMesh->mVertices) {
            mGeneratedMesh->mNumVertices = pcElement->NumOccur;
            mGeneratedMesh->mVertices = new aiVector3D[mGeneratedMesh->mNumVertices];
        }
        if (pos >= mGeneratedMesh->mNumVertices) {
            throw DeadlyImportError("Invalid .ply file: Too many vertices");
        }

        mGeneratedMesh->mVertices[pos] = vOut;

        if (haveNormal) {
            if (nullptr == mGeneratedMesh->mNormals)
                mGeneratedMesh->mNormals = new aiVector3D[mGeneratedMesh->mNumVertices];
            mGeneratedMesh->mNormals[pos] = nOut;
        }

        if (haveColor) {
            if (nullptr == mGeneratedMesh->mColors[0])
                mGeneratedMesh->mColors[0] = new aiColor4D[mGeneratedMesh->mNumVertices];
            mGeneratedMesh->mColors[0][pos] = cOut;
        }

        if (haveTextureCoords) {
            if (nullptr == mGeneratedMesh->mTextureCoords[0]) {
                mGeneratedMesh->mNumUVComponents[0] = 2;
                mGeneratedMesh->mTextureCoords[0] = new aiVector3D[mGeneratedMesh->mNumVertices];
            }
            mGeneratedMesh->mTextureCoords[0][pos] = tOut;
        }
    }
}

// ------------------------------------------------------------------------------------------------
// Convert a color component to [0...1]
ai_real PLYImporter::NormalizeColorValue(PLY::PropertyInstance::ValueUnion val, PLY::EDataType eType) {
    switch (eType) {
    case EDT_Float:
        return val.fFloat;
    case EDT_Double:
        return (ai_real)val.fDouble;
    case EDT_UChar:
        return (ai_real)val.iUInt / (ai_real)0xFF;
    case EDT_Char:
        return (ai_real)(val.iInt + (0xFF / 2)) / (ai_real)0xFF;
    case EDT_UShort:
        return (ai_real)val.iUInt / (ai_real)0xFFFF;
    case EDT_Short:
        return (ai_real)(val.iInt + (0xFFFF / 2)) / (ai_real)0xFFFF;
    case EDT_UInt:
        return (ai_real)val.iUInt / (ai_real)0xFFFF;
    case EDT_Int:
        return ((ai_real)val.iInt / (ai_real)0xFF) + 0.5f;
    default:
        break;
    }

    return 0.0f;
}

// ------------------------------------------------------------------------------------------------
// Try to extract proper faces from the PLY DOM
void PLYImporter::LoadFace(const PLY::Element *pcElement, const PLY::ElementInstance *instElement,
        unsigned int pos) {
    ai_assert(nullptr != pcElement);
    ai_assert(nullptr != instElement);

    if (mGeneratedMesh == nullptr) {
        throw DeadlyImportError("Invalid .ply file: Vertices should be declared before faces");
    }

    bool bOne = false;

    // index of the vertex index list
    unsigned int iProperty = NotSet;
    PLY::EDataType eType = EDT_Char;
    bool bIsTriStrip = false;

    // texture coordinates
    unsigned int iTextureCoord = NotSet;
    PLY::EDataType eType3 = EDT_Char;

    // face = unique number of vertex indices
    if (PLY::EEST_Face == pcElement->eSemantic) {
        unsigned int _a = 0;
        for (std::vector<PLY::Property>::const_iterator a = pcElement->alProperties.begin();
                a != pcElement->alProperties.end(); ++a, ++_a) {
            if (PLY::EST_VertexIndex == (*a).Semantic) {
                // must be a dynamic list!
                if (!(*a).bIsList) {
                    continue;
                }

                iProperty = _a;
                bOne = true;
                eType = (*a).eType;
            } else if (PLY::EST_TextureCoordinates == (*a).Semantic) {
                // must be a dynamic list!
                if (!(*a).bIsList) {
                    continue;
                }
                iTextureCoord = _a;
                bOne = true;
                eType3 = (*a).eType;
            }
        }
    }
    // triangle strip
    // TODO: triangle strip and material index support???
    else if (PLY::EEST_TriStrip == pcElement->eSemantic) {
        unsigned int _a = 0;
        for (std::vector<PLY::Property>::const_iterator a = pcElement->alProperties.begin();
                a != pcElement->alProperties.end(); ++a, ++_a) {
            // must be a dynamic list!
            if (!(*a).bIsList) {
                continue;
            }
            iProperty = _a;
            bOne = true;
            bIsTriStrip = true;
            eType = (*a).eType;
            break;
        }
    }

    // check whether we have at least one per-face information set
    if (bOne) {
        if (mGeneratedMesh->mFaces == nullptr) {
            mGeneratedMesh->mNumFaces = pcElement->NumOccur;
            mGeneratedMesh->mFaces = new aiFace[mGeneratedMesh->mNumFaces];
        } else {
            if (mGeneratedMesh->mNumFaces < pcElement->NumOccur) {
                throw DeadlyImportError("Invalid .ply file: Too many faces");
            }
        }

        if (!bIsTriStrip) {
            // parse the list of vertex indices
            if (NotSet != iProperty) {
                const unsigned int iNum = (unsigned int)GetProperty(instElement->alProperties, iProperty).avList.size();
                mGeneratedMesh->mFaces[pos].mNumIndices = iNum;
                mGeneratedMesh->mFaces[pos].mIndices = new unsigned int[iNum];

                std::vector<PLY::PropertyInstance::ValueUnion>::const_iterator p =
                        GetProperty(instElement->alProperties, iProperty).avList.begin();

                for (unsigned int a = 0; a < iNum; ++a, ++p) {
                    mGeneratedMesh->mFaces[pos].mIndices[a] = PLY::PropertyInstance::ConvertTo<unsigned int>(*p, eType);
                }
            }

            if (NotSet != iTextureCoord) {
                const unsigned int iNum = (unsigned int)GetProperty(instElement->alProperties, iTextureCoord).avList.size();

                // should be 6 coords
                std::vector<PLY::PropertyInstance::ValueUnion>::const_iterator p =
                        GetProperty(instElement->alProperties, iTextureCoord).avList.begin();

                if ((iNum / 3) == 2) // X Y coord
                {
                    for (unsigned int a = 0; a < iNum; ++a, ++p) {
                        unsigned int vindex = mGeneratedMesh->mFaces[pos].mIndices[a / 2];
                        if (vindex < mGeneratedMesh->mNumVertices) {
                            if (mGeneratedMesh->mTextureCoords[0] == nullptr) {
                                mGeneratedMesh->mNumUVComponents[0] = 2;
                                mGeneratedMesh->mTextureCoords[0] = new aiVector3D[mGeneratedMesh->mNumVertices];
                            }

                            if (a % 2 == 0) {
                                mGeneratedMesh->mTextureCoords[0][vindex].x = PLY::PropertyInstance::ConvertTo<ai_real>(*p, eType3);
                            } else {
                                mGeneratedMesh->mTextureCoords[0][vindex].y = PLY::PropertyInstance::ConvertTo<ai_real>(*p, eType3);
                            }

                            mGeneratedMesh->mTextureCoords[0][vindex].z = 0;
                        }
                    }
                }
            }
        } else { // triangle strips
            // normally we have only one triangle strip instance where
            // a value of -1 indicates a restart of the strip
            bool flip = false;
            const std::vector<PLY::PropertyInstance::ValueUnion> &quak = GetProperty(instElement->alProperties, iProperty).avList;
            // pvOut->reserve(pvOut->size() + quak.size() + (quak.size()>>2u)); //Limits memory consumption

            int aiTable[2] = { -1, -1 };
            for (std::vector<PLY::PropertyInstance::ValueUnion>::const_iterator a = quak.begin(); a != quak.end(); ++a) {
                const int p = PLY::PropertyInstance::ConvertTo<int>(*a, eType);

                if (-1 == p) {
                    // restart the strip ...
                    aiTable[0] = aiTable[1] = -1;
                    flip = false;
                    continue;
                }
                if (-1 == aiTable[0]) {
                    aiTable[0] = p;
                    continue;
                }
                if (-1 == aiTable[1]) {
                    aiTable[1] = p;
                    continue;
                }

                if (mGeneratedMesh->mFaces == nullptr) {
                    mGeneratedMesh->mNumFaces = pcElement->NumOccur;
                    mGeneratedMesh->mFaces = new aiFace[mGeneratedMesh->mNumFaces];
                }

                mGeneratedMesh->mFaces[pos].mNumIndices = 3;
                mGeneratedMesh->mFaces[pos].mIndices = new unsigned int[3];
                mGeneratedMesh->mFaces[pos].mIndices[0] = aiTable[0];
                mGeneratedMesh->mFaces[pos].mIndices[1] = aiTable[1];
                mGeneratedMesh->mFaces[pos].mIndices[2] = p;

                // every second pass swap the indices.
                flip = !flip;
                if (flip) {
                    std::swap(mGeneratedMesh->mFaces[pos].mIndices[0], mGeneratedMesh->mFaces[pos].mIndices[1]);
                }

                aiTable[0] = aiTable[1];
                aiTable[1] = p;
            }
        }
    }
}

// ------------------------------------------------------------------------------------------------
// Get a RGBA color in [0...1] range
void PLYImporter::GetMaterialColor(const std::vector<PLY::PropertyInstance> &avList,
        unsigned int aiPositions[4],
        PLY::EDataType aiTypes[4],
        aiColor4D *clrOut) {
    ai_assert(nullptr != clrOut);

    if (NotSet == aiPositions[0]) {
        clrOut->r = 0.0f;
    } else {
        clrOut->r = NormalizeColorValue(GetProperty(avList, aiPositions[0]).avList.front(), aiTypes[0]);
    }

    if (NotSet == aiPositions[1]) {
        clrOut->g = 0.0f;
    } else {
        clrOut->g = NormalizeColorValue(GetProperty(avList, aiPositions[1]).avList.front(), aiTypes[1]);
    }

    if (NotSet == aiPositions[2])
        clrOut->b = 0.0f;
    else {
        clrOut->b = NormalizeColorValue(GetProperty(avList, aiPositions[2]).avList.front(), aiTypes[2]);
    }

    // assume 1.0 for the alpha channel ifit is not set
    if (NotSet == aiPositions[3])
        clrOut->a = 1.0f;
    else {
        clrOut->a = NormalizeColorValue(GetProperty(avList, aiPositions[3]).avList.front(), aiTypes[3]);
    }
}

// ------------------------------------------------------------------------------------------------
// Extract a material from the PLY DOM
void PLYImporter::LoadMaterial(std::vector<aiMaterial *> *pvOut, std::string &defaultTexture, const bool pointsOnly) {
    ai_assert(nullptr != pvOut);

    // diffuse[4], specular[4], ambient[4]
    // rgba order
    unsigned int aaiPositions[3][4] = {

        { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF },
        { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF },
        { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF },
    };

    PLY::EDataType aaiTypes[3][4] = {
        { EDT_Char, EDT_Char, EDT_Char, EDT_Char },
        { EDT_Char, EDT_Char, EDT_Char, EDT_Char },
        { EDT_Char, EDT_Char, EDT_Char, EDT_Char }
    };
    PLY::ElementInstanceList *pcList = nullptr;

    unsigned int iPhong = 0xFFFFFFFF;
    PLY::EDataType ePhong = EDT_Char;

    unsigned int iOpacity = 0xFFFFFFFF;
    PLY::EDataType eOpacity = EDT_Char;

    // search in the DOM for a vertex entry
    unsigned int _i = 0;
    for (std::vector<PLY::Element>::const_iterator i = this->pcDOM->alElements.begin();
            i != this->pcDOM->alElements.end(); ++i, ++_i) {
        if (PLY::EEST_Material == (*i).eSemantic) {
            pcList = &this->pcDOM->alElementData[_i];

            // now check whether which coordinate sets are available
            unsigned int _a = 0;
            for (std::vector<PLY::Property>::const_iterator
                            a = (*i).alProperties.begin();
                    a != (*i).alProperties.end(); ++a, ++_a) {
                if ((*a).bIsList) continue;

                // pohng specularity      -----------------------------------
                if (PLY::EST_PhongPower == (*a).Semantic) {
                    iPhong = _a;
                    ePhong = (*a).eType;
                }

                // general opacity        -----------------------------------
                if (PLY::EST_Opacity == (*a).Semantic) {
                    iOpacity = _a;
                    eOpacity = (*a).eType;
                }

                // diffuse color channels -----------------------------------
                if (PLY::EST_DiffuseRed == (*a).Semantic) {
                    aaiPositions[0][0] = _a;
                    aaiTypes[0][0] = (*a).eType;
                } else if (PLY::EST_DiffuseGreen == (*a).Semantic) {
                    aaiPositions[0][1] = _a;
                    aaiTypes[0][1] = (*a).eType;
                } else if (PLY::EST_DiffuseBlue == (*a).Semantic) {
                    aaiPositions[0][2] = _a;
                    aaiTypes[0][2] = (*a).eType;
                } else if (PLY::EST_DiffuseAlpha == (*a).Semantic) {
                    aaiPositions[0][3] = _a;
                    aaiTypes[0][3] = (*a).eType;
                }
                // specular color channels -----------------------------------
                else if (PLY::EST_SpecularRed == (*a).Semantic) {
                    aaiPositions[1][0] = _a;
                    aaiTypes[1][0] = (*a).eType;
                } else if (PLY::EST_SpecularGreen == (*a).Semantic) {
                    aaiPositions[1][1] = _a;
                    aaiTypes[1][1] = (*a).eType;
                } else if (PLY::EST_SpecularBlue == (*a).Semantic) {
                    aaiPositions[1][2] = _a;
                    aaiTypes[1][2] = (*a).eType;
                } else if (PLY::EST_SpecularAlpha == (*a).Semantic) {
                    aaiPositions[1][3] = _a;
                    aaiTypes[1][3] = (*a).eType;
                }
                // ambient color channels -----------------------------------
                else if (PLY::EST_AmbientRed == (*a).Semantic) {
                    aaiPositions[2][0] = _a;
                    aaiTypes[2][0] = (*a).eType;
                } else if (PLY::EST_AmbientGreen == (*a).Semantic) {
                    aaiPositions[2][1] = _a;
                    aaiTypes[2][1] = (*a).eType;
                } else if (PLY::EST_AmbientBlue == (*a).Semantic) {
                    aaiPositions[2][2] = _a;
                    aaiTypes[2][2] = (*a).eType;
                } else if (PLY::EST_AmbientAlpha == (*a).Semantic) {
                    aaiPositions[2][3] = _a;
                    aaiTypes[2][3] = (*a).eType;
                }
            }
            break;
        } else if (PLY::EEST_TextureFile == (*i).eSemantic) {
            defaultTexture = (*i).szName;
        }
    }
    // check whether we have a valid source for the material data
    if (nullptr != pcList) {
        for (std::vector<ElementInstance>::const_iterator i = pcList->alInstances.begin(); i != pcList->alInstances.end(); ++i) {
            aiColor4D clrOut;
            aiMaterial *pcHelper = new aiMaterial();

            // build the diffuse material color
            GetMaterialColor((*i).alProperties, aaiPositions[0], aaiTypes[0], &clrOut);
            pcHelper->AddProperty<aiColor4D>(&clrOut, 1, AI_MATKEY_COLOR_DIFFUSE);

            // build the specular material color
            GetMaterialColor((*i).alProperties, aaiPositions[1], aaiTypes[1], &clrOut);
            pcHelper->AddProperty<aiColor4D>(&clrOut, 1, AI_MATKEY_COLOR_SPECULAR);

            // build the ambient material color
            GetMaterialColor((*i).alProperties, aaiPositions[2], aaiTypes[2], &clrOut);
            pcHelper->AddProperty<aiColor4D>(&clrOut, 1, AI_MATKEY_COLOR_AMBIENT);

            // handle phong power and shading mode
            int iMode = (int)aiShadingMode_Gouraud;
            if (0xFFFFFFFF != iPhong) {
                ai_real fSpec = PLY::PropertyInstance::ConvertTo<ai_real>(GetProperty((*i).alProperties, iPhong).avList.front(), ePhong);

                // if shininess is 0 (and the pow() calculation would therefore always
                // become 1, not depending on the angle), use gouraud lighting
                if (fSpec) {
                    // scale this with 15 ... hopefully this is correct
                    fSpec *= 15;
                    pcHelper->AddProperty<ai_real>(&fSpec, 1, AI_MATKEY_SHININESS);

                    iMode = (int)aiShadingMode_Phong;
                }
            }
            pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

            // handle opacity
            if (0xFFFFFFFF != iOpacity) {
                ai_real fOpacity = PLY::PropertyInstance::ConvertTo<ai_real>(GetProperty((*i).alProperties, iPhong).avList.front(), eOpacity);
                pcHelper->AddProperty<ai_real>(&fOpacity, 1, AI_MATKEY_OPACITY);
            }

            // The face order is absolutely undefined for PLY, so we have to
            // use two-sided rendering to be sure it's ok.
            const int two_sided = 1;
            pcHelper->AddProperty(&two_sided, 1, AI_MATKEY_TWOSIDED);

            // default texture
            if (!defaultTexture.empty()) {
                const aiString name(defaultTexture.c_str());
                pcHelper->AddProperty(&name, _AI_MATKEY_TEXTURE_BASE, aiTextureType_DIFFUSE, 0);
            }

            if (!pointsOnly) {
                pcHelper->AddProperty(&two_sided, 1, AI_MATKEY_TWOSIDED);
            }

            // set to wireframe, so when using this material info we can switch to points rendering
            if (pointsOnly) {
                const int wireframe = 1;
                pcHelper->AddProperty(&wireframe, 1, AI_MATKEY_ENABLE_WIREFRAME);
            }

            // add the newly created material instance to the list
            pvOut->push_back(pcHelper);
        }
    } else {
        // generate a default material
        aiMaterial *pcHelper = new aiMaterial();

        // fill in a default material
        int iMode = (int)aiShadingMode_Gouraud;
        pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

        // generate white material most 3D engine just multiply ambient / diffuse color with actual ambient / light color
        aiColor3D clr;
        clr.b = clr.g = clr.r = 1.0f;
        pcHelper->AddProperty<aiColor3D>(&clr, 1, AI_MATKEY_COLOR_DIFFUSE);
        pcHelper->AddProperty<aiColor3D>(&clr, 1, AI_MATKEY_COLOR_SPECULAR);

        clr.b = clr.g = clr.r = 1.0f;
        pcHelper->AddProperty<aiColor3D>(&clr, 1, AI_MATKEY_COLOR_AMBIENT);

        // The face order is absolutely undefined for PLY, so we have to
        // use two-sided rendering to be sure it's ok.
        if (!pointsOnly) {
            const int two_sided = 1;
            pcHelper->AddProperty(&two_sided, 1, AI_MATKEY_TWOSIDED);
        }

        // default texture
        if (!defaultTexture.empty()) {
            const aiString name(defaultTexture.c_str());
            pcHelper->AddProperty(&name, _AI_MATKEY_TEXTURE_BASE, aiTextureType_DIFFUSE, 0);
        }

        // set to wireframe, so when using this material info we can switch to points rendering
        if (pointsOnly) {
            const int wireframe = 1;
            pcHelper->AddProperty(&wireframe, 1, AI_MATKEY_ENABLE_WIREFRAME);
        }

        pvOut->push_back(pcHelper);
    }
}

} // namespace Assimp

#endif // !! ASSIMP_BUILD_NO_PLY_IMPORTER