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*/

#ifndef ASSIMP_BUILD_NO_MD2_IMPORTER

/** @file Implementation of the MD2 importer class */

#include "MD2Loader.h"

#include <assimp/ByteSwapper.h>

#include "MD2NormalTable.h" // shouldn't be included by other units

#include <assimp/DefaultLogger.hpp>

#include <assimp/Importer.hpp>

#include <assimp/IOSystem.hpp>

#include <assimp/scene.h>

#include <assimp/importerdesc.h>

#include <assimp/StringUtils.h>

#include <memory>

using namespace Assimp;

using namespace Assimp::MD2;

// helper macro to determine the size of an array

#if (!defined ARRAYSIZE)

#   define ARRAYSIZE(_array) (int(sizeof(_array) / sizeof(_array[0])))

#endif

static constexpr aiImporterDesc desc = {

    "Quake II Mesh Importer",

    "",

    "",

    "",

    aiImporterFlags_SupportBinaryFlavour,

    0,

    0,

    0,

    0,

    "md2"

};

// ------------------------------------------------------------------------------------------------

// Helper function to lookup a normal in Quake 2's pre-calculated table

void MD2::LookupNormalIndex(uint8_t iNormalIndex,aiVector3D& vOut)

{

    // make sure the normal index has a valid value

    if (iNormalIndex >= ARRAYSIZE(g_avNormals)) {

        ASSIMP_LOG_WARN("Index overflow in Quake II normal vector list");

        iNormalIndex = ARRAYSIZE(g_avNormals) - 1;

    }

    vOut = *((const aiVector3D*)(&g_avNormals[iNormalIndex]));

}

// ------------------------------------------------------------------------------------------------

// Constructor to be privately used by Importer

MD2Importer::MD2Importer()

    : configFrameID(),

    m_pcHeader(),

    mBuffer(),

    fileSize()

{}

// ------------------------------------------------------------------------------------------------

// Returns whether the class can handle the format of the given file.

bool MD2Importer::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool /*checkSig*/) const

{

    static constexpr uint32_t tokens[] = { AI_MD2_MAGIC_NUMBER_LE };

    return CheckMagicToken(pIOHandler,pFile,tokens,AI_COUNT_OF(tokens));

}

// ------------------------------------------------------------------------------------------------

// Get a list of all extensions supported by this loader

const aiImporterDesc* MD2Importer::GetInfo () const

{

    return &desc;

}

// ------------------------------------------------------------------------------------------------

// Setup configuration properties

void MD2Importer::SetupProperties(const Importer* pImp)

{

    // The

    // AI_CONFIG_IMPORT_MD2_KEYFRAME option overrides the

    // AI_CONFIG_IMPORT_GLOBAL_KEYFRAME option.

    configFrameID = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_MD2_KEYFRAME,-1);

    if(static_cast<unsigned int>(-1) == configFrameID){

        configFrameID = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_GLOBAL_KEYFRAME,0);

    }

}

// ------------------------------------------------------------------------------------------------

// Validate the file header

void MD2Importer::ValidateHeader( )

{

    // check magic number

    if (m_pcHeader->magic != AI_MD2_MAGIC_NUMBER_BE &&

        m_pcHeader->magic != AI_MD2_MAGIC_NUMBER_LE)

    {

        throw DeadlyImportError("Invalid MD2 magic word: expected IDP2, found ",

                                ai_str_toprintable((char *)&m_pcHeader->magic, 4));

    }

    // check file format version

    if (m_pcHeader->version != 8)

        ASSIMP_LOG_WARN( "Unsupported MD2 file version. Continuing happily ...");

    // check some values whether they are valid

    if (0 == m_pcHeader->numFrames)

        throw DeadlyImportError( "Invalid MD2 file: NUM_FRAMES is 0");

    if (m_pcHeader->offsetEnd > (uint32_t)fileSize)

        throw DeadlyImportError( "Invalid MD2 file: File is too small");

    if (m_pcHeader->numSkins > AI_MAX_ALLOC(MD2::Skin)) {

        throw DeadlyImportError("Invalid MD2 header: Too many skins, would overflow");

    }

    if (m_pcHeader->numVertices > AI_MAX_ALLOC(MD2::Vertex)) {

        throw DeadlyImportError("Invalid MD2 header: Too many vertices, would overflow");

    }

    if (m_pcHeader->numTexCoords > AI_MAX_ALLOC(MD2::TexCoord)) {

        throw DeadlyImportError("Invalid MD2 header: Too many texcoords, would overflow");

    }

    if (m_pcHeader->numTriangles > AI_MAX_ALLOC(MD2::Triangle)) {

        throw DeadlyImportError("Invalid MD2 header: Too many triangles, would overflow");

    }

    if (m_pcHeader->numFrames > AI_MAX_ALLOC(MD2::Frame)) {

        throw DeadlyImportError("Invalid MD2 header: Too many frames, would overflow");

    }

    // -1 because Frame already contains one

    unsigned int frameSize = sizeof (MD2::Frame) + (m_pcHeader->numVertices - 1) * sizeof(MD2::Vertex);

    if (m_pcHeader->offsetSkins     + m_pcHeader->numSkins * sizeof (MD2::Skin)         >= fileSize ||

        m_pcHeader->offsetTexCoords + m_pcHeader->numTexCoords * sizeof (MD2::TexCoord) >= fileSize ||

        m_pcHeader->offsetTriangles + m_pcHeader->numTriangles * sizeof (MD2::Triangle) >= fileSize ||

        m_pcHeader->offsetFrames    + m_pcHeader->numFrames * frameSize                 >= fileSize ||

        m_pcHeader->offsetEnd           > fileSize)

    {

        throw DeadlyImportError("Invalid MD2 header: Some offsets are outside the file");

    }

    if (m_pcHeader->numSkins > AI_MD2_MAX_SKINS)

        ASSIMP_LOG_WARN("The model contains more skins than Quake 2 supports");

    if ( m_pcHeader->numFrames > AI_MD2_MAX_FRAMES)

        ASSIMP_LOG_WARN("The model contains more frames than Quake 2 supports");

    if (m_pcHeader->numVertices > AI_MD2_MAX_VERTS)

        ASSIMP_LOG_WARN("The model contains more vertices than Quake 2 supports");

    if (m_pcHeader->numFrames <= configFrameID )

        throw DeadlyImportError("MD2: The requested frame (", configFrameID, ") does not exist in the file");

}

// ------------------------------------------------------------------------------------------------

// Imports the given file into the given scene structure.

void MD2Importer::InternReadFile( const std::string& pFile,

    aiScene* pScene, IOSystem* pIOHandler)

{

    std::unique_ptr<IOStream> file( pIOHandler->Open( pFile));

    // Check whether we can read from the file

    if (file == nullptr) {

        throw DeadlyImportError("Failed to open MD2 file ", pFile, "");

    }

    // check whether the md3 file is large enough to contain

    // at least the file header

    fileSize = (unsigned int)file->FileSize();

    if (fileSize < sizeof(MD2::Header)) {

        throw DeadlyImportError("MD2 File is too small");

    }

    std::vector<uint8_t> mBuffer2(fileSize);

    file->Read(&mBuffer2[0], 1, fileSize);

    mBuffer = &mBuffer2[0];

    m_pcHeader = (BE_NCONST MD2::Header*)mBuffer;

#ifdef AI_BUILD_BIG_ENDIAN

    ByteSwap::Swap4(&m_pcHeader->frameSize);

    ByteSwap::Swap4(&m_pcHeader->magic);

    ByteSwap::Swap4(&m_pcHeader->numFrames);

    ByteSwap::Swap4(&m_pcHeader->numGlCommands);

    ByteSwap::Swap4(&m_pcHeader->numSkins);

    ByteSwap::Swap4(&m_pcHeader->numTexCoords);

    ByteSwap::Swap4(&m_pcHeader->numTriangles);

    ByteSwap::Swap4(&m_pcHeader->numVertices);

    ByteSwap::Swap4(&m_pcHeader->offsetEnd);

    ByteSwap::Swap4(&m_pcHeader->offsetFrames);

    ByteSwap::Swap4(&m_pcHeader->offsetGlCommands);

    ByteSwap::Swap4(&m_pcHeader->offsetSkins);

    ByteSwap::Swap4(&m_pcHeader->offsetTexCoords);

    ByteSwap::Swap4(&m_pcHeader->offsetTriangles);

    ByteSwap::Swap4(&m_pcHeader->skinHeight);

    ByteSwap::Swap4(&m_pcHeader->skinWidth);

    ByteSwap::Swap4(&m_pcHeader->version);

#endif

    ValidateHeader();

    // there won't be more than one mesh inside the file

    pScene->mNumMaterials = 1;

    pScene->mRootNode = new aiNode();

    pScene->mRootNode->mNumMeshes = 1;

    pScene->mRootNode->mMeshes = new unsigned int[1];

    pScene->mRootNode->mMeshes[0] = 0;

    pScene->mMaterials = new aiMaterial*[1];

    pScene->mMaterials[0] = new aiMaterial();

    pScene->mNumMeshes = 1;

    pScene->mMeshes = new aiMesh*[1];

    aiMesh* pcMesh = pScene->mMeshes[0] = new aiMesh();

    pcMesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;

    // navigate to the begin of the current frame data

  BE_NCONST MD2::Frame* pcFrame = (BE_NCONST MD2::Frame*) ((uint8_t*)

    m_pcHeader + m_pcHeader->offsetFrames + (m_pcHeader->frameSize * configFrameID));

    // navigate to the begin of the triangle data

    MD2::Triangle* pcTriangles = (MD2::Triangle*) ((uint8_t*)

        m_pcHeader + m_pcHeader->offsetTriangles);

    // navigate to the begin of the tex coords data

    BE_NCONST MD2::TexCoord* pcTexCoords = (BE_NCONST MD2::TexCoord*) ((uint8_t*)

        m_pcHeader + m_pcHeader->offsetTexCoords);

    // navigate to the begin of the vertex data

    BE_NCONST MD2::Vertex* pcVerts = (BE_NCONST MD2::Vertex*) (pcFrame->vertices);

#ifdef AI_BUILD_BIG_ENDIAN

    for (uint32_t i = 0; i< m_pcHeader->numTriangles; ++i)

    {

        for (unsigned int p = 0; p < 3;++p)

        {

            ByteSwap::Swap2(& pcTriangles[i].textureIndices[p]);

            ByteSwap::Swap2(& pcTriangles[i].vertexIndices[p]);

        }

    }

    for (uint32_t i = 0; i < m_pcHeader->offsetTexCoords;++i)

    {

        ByteSwap::Swap2(& pcTexCoords[i].s);

        ByteSwap::Swap2(& pcTexCoords[i].t);

    }

    ByteSwap::Swap4( & pcFrame->scale[0] );

    ByteSwap::Swap4( & pcFrame->scale[1] );

    ByteSwap::Swap4( & pcFrame->scale[2] );

    ByteSwap::Swap4( & pcFrame->translate[0] );

    ByteSwap::Swap4( & pcFrame->translate[1] );

    ByteSwap::Swap4( & pcFrame->translate[2] );

#endif

    pcMesh->mNumFaces = m_pcHeader->numTriangles;

    pcMesh->mFaces = new aiFace[m_pcHeader->numTriangles];

    // allocate output storage

    pcMesh->mNumVertices = (unsigned int)pcMesh->mNumFaces*3;

    pcMesh->mVertices = new aiVector3D[pcMesh->mNumVertices];

    pcMesh->mNormals = new aiVector3D[pcMesh->mNumVertices];

    // Not sure whether there are MD2 files without texture coordinates

    // NOTE: texture coordinates can be there without a texture,

    // but a texture can't be there without a valid UV channel

    aiMaterial* pcHelper = (aiMaterial*)pScene->mMaterials[0];

    const int iMode = (int)aiShadingMode_Gouraud;

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

    if (m_pcHeader->numTexCoords && m_pcHeader->numSkins)

    {

        // navigate to the first texture associated with the mesh

        const MD2::Skin* pcSkins = (const MD2::Skin*) ((unsigned char*)m_pcHeader +

            m_pcHeader->offsetSkins);

        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 = 0.05f;

        pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_AMBIENT);

        const ai_uint32 MaxNameLength = AI_MAXLEN - 1; // one byte reserved for \0

        ai_uint32 iLen = static_cast<ai_uint32>(::strlen(pcSkins->name));

        bool nameTooLong = iLen > MaxNameLength;

        if (pcSkins->name[0] && !nameTooLong)

        {

            aiString szString;

            ::memcpy(szString.data, pcSkins->name, iLen);

            szString.data[iLen] = '\0';

            szString.length = iLen;

            pcHelper->AddProperty(&szString,AI_MATKEY_TEXTURE_DIFFUSE(0));

        }

        else if (nameTooLong) {

            ASSIMP_LOG_WARN("Texture file name is too long. It will be skipped.");

        }

        else{

            ASSIMP_LOG_WARN("Texture file name has zero length. It will be skipped.");

        }

    }

    else    {

        // apply a default material

        aiColor3D clr;

        clr.b = clr.g = clr.r = 0.6f;

        pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_DIFFUSE);

        pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_SPECULAR);

        clr.b = clr.g = clr.r = 0.05f;

        pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_AMBIENT);

        aiString szName;

        szName.Set(AI_DEFAULT_MATERIAL_NAME);

        pcHelper->AddProperty(&szName,AI_MATKEY_NAME);

        aiString sz;

        // TODO: Try to guess the name of the texture file from the model file name

        sz.Set("$texture_dummy.bmp");

        pcHelper->AddProperty(&sz,AI_MATKEY_TEXTURE_DIFFUSE(0));

    }

    // now read all triangles of the first frame, apply scaling and translation

    unsigned int iCurrent = 0;

    float fDivisorU = 1.0f,fDivisorV = 1.0f;

    if (m_pcHeader->numTexCoords)   {

        // allocate storage for texture coordinates, too

        pcMesh->mTextureCoords[0] = new aiVector3D[pcMesh->mNumVertices];

        pcMesh->mNumUVComponents[0] = 2;

        // check whether the skin width or height are zero (this would

        // cause a division through zero)

        if (!m_pcHeader->skinWidth) {

            ASSIMP_LOG_ERROR("MD2: No valid skin width given");

        }

        else fDivisorU = (float)m_pcHeader->skinWidth;

        if (!m_pcHeader->skinHeight){

            ASSIMP_LOG_ERROR("MD2: No valid skin height given");

        }

        else fDivisorV = (float)m_pcHeader->skinHeight;

    }

    for (unsigned int i = 0; i < (unsigned int)m_pcHeader->numTriangles;++i)    {

        // Allocate the face

        pScene->mMeshes[0]->mFaces[i].mIndices = new unsigned int[3];

        pScene->mMeshes[0]->mFaces[i].mNumIndices = 3;

        // copy texture coordinates

        // check whether they are different from the previous value at this index.

        // In this case, create a full separate set of vertices/normals/texcoords

        for (unsigned int c = 0; c < 3;++c,++iCurrent)  {

            // validate vertex indices

            unsigned int iIndex = (unsigned int)pcTriangles[i].vertexIndices[c];

            if (iIndex >= m_pcHeader->numVertices)  {

                ASSIMP_LOG_ERROR("MD2: Vertex index is outside the allowed range");

                iIndex = m_pcHeader->numVertices-1;

            }

            // read x,y, and z component of the vertex

            aiVector3D& vec = pcMesh->mVertices[iCurrent];

            vec.x = (float)pcVerts[iIndex].vertex[0] * pcFrame->scale[0];

            vec.x += pcFrame->translate[0];

            vec.y = (float)pcVerts[iIndex].vertex[1] * pcFrame->scale[1];

            vec.y += pcFrame->translate[1];

            vec.z = (float)pcVerts[iIndex].vertex[2] * pcFrame->scale[2];

            vec.z += pcFrame->translate[2];

            // read the normal vector from the precalculated normal table

            aiVector3D& vNormal = pcMesh->mNormals[iCurrent];

            LookupNormalIndex(pcVerts[iIndex].lightNormalIndex,vNormal);

            if (m_pcHeader->numTexCoords)   {

                // validate texture coordinates

                iIndex = pcTriangles[i].textureIndices[c];

                if (iIndex >= m_pcHeader->numTexCoords) {

                    ASSIMP_LOG_ERROR("MD2: UV index is outside the allowed range");

                    iIndex = m_pcHeader->numTexCoords-1;

                }

                aiVector3D& pcOut = pcMesh->mTextureCoords[0][iCurrent];

                // the texture coordinates are absolute values but we

                // need relative values between 0 and 1

                pcOut.x = pcTexCoords[iIndex].s / fDivisorU;

                pcOut.y = 1.f-pcTexCoords[iIndex].t / fDivisorV;

            }

            pScene->mMeshes[0]->mFaces[i].mIndices[c] = iCurrent;

        }

        // flip the face order

        std::swap( pScene->mMeshes[0]->mFaces[i].mIndices[0], pScene->mMeshes[0]->mFaces[i].mIndices[2] );

    }

    // Now rotate the whole scene 90 degrees around the x axis to convert to internal coordinate system

    pScene->mRootNode->mTransformation = aiMatrix4x4(

            1.f, 0.f, 0.f, 0.f,

            0.f, 0.f, 1.f, 0.f,

            0.f, -1.f, 0.f, 0.f,

            0.f, 0.f, 0.f, 1.f);

}

#endif // !! ASSIMP_BUILD_NO_MD2_IMPORTER