/*
---------------------------------------------------------------------------
Open Asset Import Library (assimp)
---------------------------------------------------------------------------

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  following disclaimer.

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*/

/** @file  MD5Loader.cpp
 *  @brief Implementation of the MD5 importer class
 */


#ifndef ASSIMP_BUILD_NO_MD5_IMPORTER

// internal headers
#include "RemoveComments.h"
#include "MD5Loader.h"
#include "StringComparison.h"
#include "fast_atof.h"
#include "SkeletonMeshBuilder.h"
#include <assimp/Importer.hpp>
#include <assimp/scene.h>
#include <assimp/IOSystem.hpp>
#include <assimp/DefaultLogger.hpp>
#include <memory>

using namespace Assimp;

// Minimum weight value. Weights inside [-n ... n] are ignored
#define AI_MD5_WEIGHT_EPSILON 1e-5f


static const aiImporterDesc desc = {
    "Doom 3 / MD5 Mesh Importer",
    "",
    "",
    "",
    aiImporterFlags_SupportBinaryFlavour,
    0,
    0,
    0,
    0,
    "md5mesh md5camera md5anim"
};

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
MD5Importer::MD5Importer()
    : mIOHandler()
    , mBuffer()
    , fileSize()
    , iLineNumber()
    , pScene()
    , pIOHandler()
    , bHadMD5Mesh()
    , bHadMD5Anim()
    , bHadMD5Camera()
    , configNoAutoLoad (false)
{}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
MD5Importer::~MD5Importer()
{}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file.
bool MD5Importer::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
{
    const std::string extension = GetExtension(pFile);

    if (extension == "md5anim" || extension == "md5mesh" || extension == "md5camera")
        return true;
    else if (!extension.length() || checkSig)   {
        if (!pIOHandler) {
            return true;
        }
        const char* tokens[] = {"MD5Version"};
        return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
    }
    return false;
}

// ------------------------------------------------------------------------------------------------
// Get list of all supported extensions
const aiImporterDesc* MD5Importer::GetInfo () const
{
    return &desc;
}

// ------------------------------------------------------------------------------------------------
// Setup import properties
void MD5Importer::SetupProperties(const Importer* pImp)
{
    // AI_CONFIG_IMPORT_MD5_NO_ANIM_AUTOLOAD
    configNoAutoLoad = (0 !=  pImp->GetPropertyInteger(AI_CONFIG_IMPORT_MD5_NO_ANIM_AUTOLOAD,0));
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure.
void MD5Importer::InternReadFile( const std::string& pFile,
                                 aiScene* _pScene, IOSystem* _pIOHandler)
{
    pIOHandler = _pIOHandler;
    pScene     = _pScene;
    bHadMD5Mesh = bHadMD5Anim = bHadMD5Camera = false;

    // remove the file extension
    const std::string::size_type pos = pFile.find_last_of('.');
    mFile = (std::string::npos == pos ? pFile : pFile.substr(0,pos+1));

    const std::string extension = GetExtension(pFile);
    try {
        if (extension == "md5camera") {
            LoadMD5CameraFile();
        }
        else if (configNoAutoLoad || extension == "md5anim") {
            // determine file extension and process just *one* file
            if (extension.length() == 0) {
                throw DeadlyImportError("Failure, need file extension to determine MD5 part type");
            }
            if (extension == "md5anim") {
                LoadMD5AnimFile();
            }
            else if (extension == "md5mesh") {
                LoadMD5MeshFile();
            }
        }
        else {
            LoadMD5MeshFile();
            LoadMD5AnimFile();
        }
    }
    catch ( ... ) { // std::exception, Assimp::DeadlyImportError
        UnloadFileFromMemory();
        throw;
    }

    // make sure we have at least one file
    if (!bHadMD5Mesh && !bHadMD5Anim && !bHadMD5Camera) {
        throw DeadlyImportError("Failed to read valid contents out of this MD5* file");
    }

    // Now rotate the whole scene 90 degrees around the x axis to match our 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);

    // the output scene wouldn't pass the validation without this flag
    if (!bHadMD5Mesh) {
        pScene->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;
    }

    // clean the instance -- the BaseImporter instance may be reused later.
    UnloadFileFromMemory();
}

// ------------------------------------------------------------------------------------------------
// Load a file into a memory buffer
void MD5Importer::LoadFileIntoMemory (IOStream* file)
{
    // unload the previous buffer, if any
    UnloadFileFromMemory();

    ai_assert(NULL != file);
    fileSize = (unsigned int)file->FileSize();
    ai_assert(fileSize);

    // allocate storage and copy the contents of the file to a memory buffer
    mBuffer = new char[fileSize+1];
    file->Read( (void*)mBuffer, 1, fileSize);
    iLineNumber = 1;

    // append a terminal 0
    mBuffer[fileSize] = '\0';

    // now remove all line comments from the file
    CommentRemover::RemoveLineComments("//",mBuffer,' ');
}

// ------------------------------------------------------------------------------------------------
// Unload the current memory buffer
void MD5Importer::UnloadFileFromMemory ()
{
    // delete the file buffer
    delete[] mBuffer;
    mBuffer = NULL;
    fileSize = 0;
}

// ------------------------------------------------------------------------------------------------
// Build unique vertices
void MD5Importer::MakeDataUnique (MD5::MeshDesc& meshSrc)
{
    std::vector<bool> abHad(meshSrc.mVertices.size(),false);

    // allocate enough storage to keep the output structures
    const unsigned int iNewNum = meshSrc.mFaces.size()*3;
    unsigned int iNewIndex = meshSrc.mVertices.size();
    meshSrc.mVertices.resize(iNewNum);

    // try to guess how much storage we'll need for new weights
    const float fWeightsPerVert = meshSrc.mWeights.size() / (float)iNewIndex;
    const unsigned int guess = (unsigned int)(fWeightsPerVert*iNewNum);
    meshSrc.mWeights.reserve(guess + (guess >> 3)); // + 12.5% as buffer

    for (FaceList::const_iterator iter = meshSrc.mFaces.begin(),iterEnd = meshSrc.mFaces.end();iter != iterEnd;++iter){
        const aiFace& face = *iter;
        for (unsigned int i = 0; i < 3;++i) {
            if (face.mIndices[0] >= meshSrc.mVertices.size()) {
                throw DeadlyImportError("MD5MESH: Invalid vertex index");
            }

            if (abHad[face.mIndices[i]])    {
                // generate a new vertex
                meshSrc.mVertices[iNewIndex] = meshSrc.mVertices[face.mIndices[i]];
                face.mIndices[i] = iNewIndex++;
            }
            else abHad[face.mIndices[i]] = true;
        }
        // swap face order
        std::swap(face.mIndices[0],face.mIndices[2]);
    }
}

// ------------------------------------------------------------------------------------------------
// Recursive node graph construction from a MD5MESH
void MD5Importer::AttachChilds_Mesh(int iParentID,aiNode* piParent, BoneList& bones)
{
    ai_assert(NULL != piParent && !piParent->mNumChildren);

    // First find out how many children we'll have
    for (int i = 0; i < (int)bones.size();++i)  {
        if (iParentID != i && bones[i].mParentIndex == iParentID)   {
            ++piParent->mNumChildren;
        }
    }
    if (piParent->mNumChildren) {
        piParent->mChildren = new aiNode*[piParent->mNumChildren];
        for (int i = 0; i < (int)bones.size();++i)  {
            // (avoid infinite recursion)
            if (iParentID != i && bones[i].mParentIndex == iParentID)   {
                aiNode* pc;
                // setup a new node
                *piParent->mChildren++ = pc = new aiNode();
                pc->mName = aiString(bones[i].mName);
                pc->mParent = piParent;

                // get the transformation matrix from rotation and translational components
                aiQuaternion quat;
                MD5::ConvertQuaternion ( bones[i].mRotationQuat, quat );

                bones[i].mTransform = aiMatrix4x4 ( quat.GetMatrix());
                bones[i].mTransform.a4 = bones[i].mPositionXYZ.x;
                bones[i].mTransform.b4 = bones[i].mPositionXYZ.y;
                bones[i].mTransform.c4 = bones[i].mPositionXYZ.z;

                // store it for later use
                pc->mTransformation = bones[i].mInvTransform = bones[i].mTransform;
                bones[i].mInvTransform.Inverse();

                // the transformations for each bone are absolute, so we need to multiply them
                // with the inverse of the absolute matrix of the parent joint
                if (-1 != iParentID)    {
                    pc->mTransformation = bones[iParentID].mInvTransform * pc->mTransformation;
                }

                // add children to this node, too
                AttachChilds_Mesh( i, pc, bones);
            }
        }
        // undo offset computations
        piParent->mChildren -= piParent->mNumChildren;
    }
}

// ------------------------------------------------------------------------------------------------
// Recursive node graph construction from a MD5ANIM
void MD5Importer::AttachChilds_Anim(int iParentID,aiNode* piParent, AnimBoneList& bones,const aiNodeAnim** node_anims)
{
    ai_assert(NULL != piParent && !piParent->mNumChildren);

    // First find out how many children we'll have
    for (int i = 0; i < (int)bones.size();++i)  {
        if (iParentID != i && bones[i].mParentIndex == iParentID)   {
            ++piParent->mNumChildren;
        }
    }
    if (piParent->mNumChildren) {
        piParent->mChildren = new aiNode*[piParent->mNumChildren];
        for (int i = 0; i < (int)bones.size();++i)  {
            // (avoid infinite recursion)
            if (iParentID != i && bones[i].mParentIndex == iParentID)
            {
                aiNode* pc;
                // setup a new node
                *piParent->mChildren++ = pc = new aiNode();
                pc->mName = aiString(bones[i].mName);
                pc->mParent = piParent;

                // get the corresponding animation channel and its first frame
                const aiNodeAnim** cur = node_anims;
                while ((**cur).mNodeName != pc->mName)++cur;

                aiMatrix4x4::Translation((**cur).mPositionKeys[0].mValue,pc->mTransformation);
                pc->mTransformation = pc->mTransformation * aiMatrix4x4((**cur).mRotationKeys[0].mValue.GetMatrix()) ;

                // add children to this node, too
                AttachChilds_Anim( i, pc, bones,node_anims);
            }
        }
        // undo offset computations
        piParent->mChildren -= piParent->mNumChildren;
    }
}

// ------------------------------------------------------------------------------------------------
// Load a MD5MESH file
void MD5Importer::LoadMD5MeshFile ()
{
    std::string pFile = mFile + "md5mesh";
    std::unique_ptr<IOStream> file( pIOHandler->Open( pFile, "rb"));

    // Check whether we can read from the file
    if( file.get() == NULL || !file->FileSize())    {
        DefaultLogger::get()->warn("Failed to access MD5MESH file: " + pFile);
        return;
    }
    bHadMD5Mesh = true;
    LoadFileIntoMemory(file.get());

    // now construct a parser and parse the file
    MD5::MD5Parser parser(mBuffer,fileSize);

    // load the mesh information from it
    MD5::MD5MeshParser meshParser(parser.mSections);

    // create the bone hierarchy - first the root node and dummy nodes for all meshes
    pScene->mRootNode = new aiNode("<MD5_Root>");
    pScene->mRootNode->mNumChildren = 2;
    pScene->mRootNode->mChildren = new aiNode*[2];

    // build the hierarchy from the MD5MESH file
    aiNode* pcNode = pScene->mRootNode->mChildren[1] = new aiNode();
    pcNode->mName.Set("<MD5_Hierarchy>");
    pcNode->mParent = pScene->mRootNode;
    AttachChilds_Mesh(-1,pcNode,meshParser.mJoints);

    pcNode = pScene->mRootNode->mChildren[0] = new aiNode();
    pcNode->mName.Set("<MD5_Mesh>");
    pcNode->mParent = pScene->mRootNode;

#if 0
    if (pScene->mRootNode->mChildren[1]->mNumChildren) /* start at the right hierarchy level */
        SkeletonMeshBuilder skeleton_maker(pScene,pScene->mRootNode->mChildren[1]->mChildren[0]);
#else

    // FIX: MD5 files exported from Blender can have empty meshes
    for (std::vector<MD5::MeshDesc>::const_iterator it  = meshParser.mMeshes.begin(),end = meshParser.mMeshes.end(); it != end;++it) {
        if (!(*it).mFaces.empty() && !(*it).mVertices.empty())
            ++pScene->mNumMaterials;
    }

    // generate all meshes
    pScene->mNumMeshes = pScene->mNumMaterials;
    pScene->mMeshes = new aiMesh*[pScene->mNumMeshes];
    pScene->mMaterials = new aiMaterial*[pScene->mNumMeshes];

    //  storage for node mesh indices
    pcNode->mNumMeshes = pScene->mNumMeshes;
    pcNode->mMeshes = new unsigned int[pcNode->mNumMeshes];
    for (unsigned int m = 0; m < pcNode->mNumMeshes;++m)
        pcNode->mMeshes[m] = m;

    unsigned int n = 0;
    for (std::vector<MD5::MeshDesc>::iterator it  = meshParser.mMeshes.begin(),end = meshParser.mMeshes.end(); it != end;++it) {
        MD5::MeshDesc& meshSrc = *it;
        if (meshSrc.mFaces.empty() || meshSrc.mVertices.empty())
            continue;

        aiMesh* mesh = pScene->mMeshes[n] = new aiMesh();
        mesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;

        // generate unique vertices in our internal verbose format
        MakeDataUnique(meshSrc);

        mesh->mNumVertices = (unsigned int) meshSrc.mVertices.size();
        mesh->mVertices = new aiVector3D[mesh->mNumVertices];
        mesh->mTextureCoords[0] = new aiVector3D[mesh->mNumVertices];
        mesh->mNumUVComponents[0] = 2;

        // copy texture coordinates
        aiVector3D* pv = mesh->mTextureCoords[0];
        for (MD5::VertexList::const_iterator iter =  meshSrc.mVertices.begin();iter != meshSrc.mVertices.end();++iter,++pv) {
            pv->x = (*iter).mUV.x;
            pv->y = 1.0f-(*iter).mUV.y; // D3D to OpenGL
            pv->z = 0.0f;
        }

        // sort all bone weights - per bone
        unsigned int* piCount = new unsigned int[meshParser.mJoints.size()];
        ::memset(piCount,0,sizeof(unsigned int)*meshParser.mJoints.size());

        for (MD5::VertexList::const_iterator iter =  meshSrc.mVertices.begin();iter != meshSrc.mVertices.end();++iter,++pv) {
            for (unsigned int jub = (*iter).mFirstWeight, w = jub; w < jub + (*iter).mNumWeights;++w)
            {
                MD5::WeightDesc& desc = meshSrc.mWeights[w];
                /* FIX for some invalid exporters */
                if (!(desc.mWeight < AI_MD5_WEIGHT_EPSILON && desc.mWeight >= -AI_MD5_WEIGHT_EPSILON ))
                    ++piCount[desc.mBone];
            }
        }

        // check how many we will need
        for (unsigned int p = 0; p < meshParser.mJoints.size();++p)
            if (piCount[p])mesh->mNumBones++;

        if (mesh->mNumBones) // just for safety
        {
            mesh->mBones = new aiBone*[mesh->mNumBones];
            for (unsigned int q = 0,h = 0; q < meshParser.mJoints.size();++q)
            {
                if (!piCount[q])continue;
                aiBone* p = mesh->mBones[h] = new aiBone();
                p->mNumWeights = piCount[q];
                p->mWeights = new aiVertexWeight[p->mNumWeights];
                p->mName = aiString(meshParser.mJoints[q].mName);
                p->mOffsetMatrix = meshParser.mJoints[q].mInvTransform;

                // store the index for later use
                MD5::BoneDesc& boneSrc = meshParser.mJoints[q];
                boneSrc.mMap = h++;

                // compute w-component of quaternion
                MD5::ConvertQuaternion( boneSrc.mRotationQuat, boneSrc.mRotationQuatConverted );
            }

            //unsigned int g = 0;
            pv = mesh->mVertices;
            for (MD5::VertexList::const_iterator iter =  meshSrc.mVertices.begin();iter != meshSrc.mVertices.end();++iter,++pv) {
                // compute the final vertex position from all single weights
                *pv = aiVector3D();

                // there are models which have weights which don't sum to 1 ...
                float fSum = 0.0f;
                for (unsigned int jub = (*iter).mFirstWeight, w = jub; w < jub + (*iter).mNumWeights;++w)
                    fSum += meshSrc.mWeights[w].mWeight;
                if (!fSum) {
                    DefaultLogger::get()->error("MD5MESH: The sum of all vertex bone weights is 0");
                    continue;
                }

                // process bone weights
                for (unsigned int jub = (*iter).mFirstWeight, w = jub; w < jub + (*iter).mNumWeights;++w)   {
                    if (w >= meshSrc.mWeights.size())
                        throw DeadlyImportError("MD5MESH: Invalid weight index");

                    MD5::WeightDesc& desc = meshSrc.mWeights[w];
                    if ( desc.mWeight < AI_MD5_WEIGHT_EPSILON && desc.mWeight >= -AI_MD5_WEIGHT_EPSILON) {
                        continue;
                    }

                    const float fNewWeight = desc.mWeight / fSum;

                    // transform the local position into worldspace
                    MD5::BoneDesc& boneSrc = meshParser.mJoints[desc.mBone];
                    const aiVector3D v = boneSrc.mRotationQuatConverted.Rotate (desc.vOffsetPosition);

                    // use the original weight to compute the vertex position
                    // (some MD5s seem to depend on the invalid weight values ...)
                    *pv += ((boneSrc.mPositionXYZ+v)* desc.mWeight);

                    aiBone* bone = mesh->mBones[boneSrc.mMap];
                    *bone->mWeights++ = aiVertexWeight((unsigned int)(pv-mesh->mVertices),fNewWeight);
                }
            }

            // undo our nice offset tricks ...
            for (unsigned int p = 0; p < mesh->mNumBones;++p) {
                mesh->mBones[p]->mWeights -= mesh->mBones[p]->mNumWeights;
            }
        }

        delete[] piCount;

        // now setup all faces - we can directly copy the list
        // (however, take care that the aiFace destructor doesn't delete the mIndices array)
        mesh->mNumFaces = (unsigned int)meshSrc.mFaces.size();
        mesh->mFaces = new aiFace[mesh->mNumFaces];
        for (unsigned int c = 0; c < mesh->mNumFaces;++c)   {
            mesh->mFaces[c].mNumIndices = 3;
            mesh->mFaces[c].mIndices = meshSrc.mFaces[c].mIndices;
            meshSrc.mFaces[c].mIndices = NULL;
        }

        // generate a material for the mesh
        aiMaterial* mat = new aiMaterial();
        pScene->mMaterials[n] = mat;

        // insert the typical doom3 textures:
        // nnn_local.tga  - normal map
        // nnn_h.tga      - height map
        // nnn_s.tga      - specular map
        // nnn_d.tga      - diffuse map
        if (meshSrc.mShader.length && !strchr(meshSrc.mShader.data,'.')) {

            aiString temp(meshSrc.mShader);
            temp.Append("_local.tga");
            mat->AddProperty(&temp,AI_MATKEY_TEXTURE_NORMALS(0));

            temp =  aiString(meshSrc.mShader);
            temp.Append("_s.tga");
            mat->AddProperty(&temp,AI_MATKEY_TEXTURE_SPECULAR(0));

            temp =  aiString(meshSrc.mShader);
            temp.Append("_d.tga");
            mat->AddProperty(&temp,AI_MATKEY_TEXTURE_DIFFUSE(0));

            temp =  aiString(meshSrc.mShader);
            temp.Append("_h.tga");
            mat->AddProperty(&temp,AI_MATKEY_TEXTURE_HEIGHT(0));

            // set this also as material name
            mat->AddProperty(&meshSrc.mShader,AI_MATKEY_NAME);
        }
        else mat->AddProperty(&meshSrc.mShader,AI_MATKEY_TEXTURE_DIFFUSE(0));
        mesh->mMaterialIndex = n++;
    }
#endif
}

// ------------------------------------------------------------------------------------------------
// Load an MD5ANIM file
void MD5Importer::LoadMD5AnimFile ()
{
    std::string pFile = mFile + "md5anim";
    std::unique_ptr<IOStream> file( pIOHandler->Open( pFile, "rb"));

    // Check whether we can read from the file
    if( !file.get() || !file->FileSize())   {
        DefaultLogger::get()->warn("Failed to read MD5ANIM file: " + pFile);
        return;
    }
    LoadFileIntoMemory(file.get());

    // parse the basic file structure
    MD5::MD5Parser parser(mBuffer,fileSize);

    // load the animation information from the parse tree
    MD5::MD5AnimParser animParser(parser.mSections);

    // generate and fill the output animation
    if (animParser.mAnimatedBones.empty() || animParser.mFrames.empty() ||
        animParser.mBaseFrames.size() != animParser.mAnimatedBones.size())  {

        DefaultLogger::get()->error("MD5ANIM: No frames or animated bones loaded");
    }
    else {
        bHadMD5Anim = true;

        pScene->mAnimations = new aiAnimation*[pScene->mNumAnimations = 1];
        aiAnimation* anim = pScene->mAnimations[0] = new aiAnimation();
        anim->mNumChannels = (unsigned int)animParser.mAnimatedBones.size();
        anim->mChannels = new aiNodeAnim*[anim->mNumChannels];
        for (unsigned int i = 0; i < anim->mNumChannels;++i)    {
            aiNodeAnim* node = anim->mChannels[i] = new aiNodeAnim();
            node->mNodeName = aiString( animParser.mAnimatedBones[i].mName );

            // allocate storage for the keyframes
            node->mPositionKeys = new aiVectorKey[animParser.mFrames.size()];
            node->mRotationKeys = new aiQuatKey[animParser.mFrames.size()];
        }

        // 1 tick == 1 frame
        anim->mTicksPerSecond = animParser.fFrameRate;

        for (FrameList::const_iterator iter = animParser.mFrames.begin(), iterEnd = animParser.mFrames.end();iter != iterEnd;++iter){
            double dTime = (double)(*iter).iIndex;
            aiNodeAnim** pcAnimNode = anim->mChannels;
            if (!(*iter).mValues.empty() || iter == animParser.mFrames.begin()) /* be sure we have at least one frame */
            {
                // now process all values in there ... read all joints
                MD5::BaseFrameDesc* pcBaseFrame = &animParser.mBaseFrames[0];
                for (AnimBoneList::const_iterator iter2 = animParser.mAnimatedBones.begin(); iter2 != animParser.mAnimatedBones.end();++iter2,
                    ++pcAnimNode,++pcBaseFrame)
                {
                    if((*iter2).iFirstKeyIndex >= (*iter).mValues.size()) {

                        // Allow for empty frames
                        if ((*iter2).iFlags != 0) {
                            throw DeadlyImportError("MD5: Keyframe index is out of range");

                        }
                        continue;
                    }
                    const float* fpCur = &(*iter).mValues[(*iter2).iFirstKeyIndex];
                    aiNodeAnim* pcCurAnimBone = *pcAnimNode;

                    aiVectorKey* vKey = &pcCurAnimBone->mPositionKeys[pcCurAnimBone->mNumPositionKeys++];
                    aiQuatKey* qKey = &pcCurAnimBone->mRotationKeys  [pcCurAnimBone->mNumRotationKeys++];
                    aiVector3D vTemp;

                    // translational component
                    for (unsigned int i = 0; i < 3; ++i) {
                        if ((*iter2).iFlags & (1u << i)) {
                            vKey->mValue[i] =  *fpCur++;
                        }
                        else vKey->mValue[i] = pcBaseFrame->vPositionXYZ[i];
                    }

                    // orientation component
                    for (unsigned int i = 0; i < 3; ++i) {
                        if ((*iter2).iFlags & (8u << i)) {
                            vTemp[i] =  *fpCur++;
                        }
                        else vTemp[i] = pcBaseFrame->vRotationQuat[i];
                    }

                    MD5::ConvertQuaternion(vTemp, qKey->mValue);
                    qKey->mTime = vKey->mTime = dTime;
                }
            }

            // compute the duration of the animation
            anim->mDuration = std::max(dTime,anim->mDuration);
        }

        // If we didn't build the hierarchy yet (== we didn't load a MD5MESH),
        // construct it now from the data given in the MD5ANIM.
        if (!pScene->mRootNode) {
            pScene->mRootNode = new aiNode();
            pScene->mRootNode->mName.Set("<MD5_Hierarchy>");

            AttachChilds_Anim(-1,pScene->mRootNode,animParser.mAnimatedBones,(const aiNodeAnim**)anim->mChannels);

            // Call SkeletonMeshBuilder to construct a mesh to represent the shape
            if (pScene->mRootNode->mNumChildren) {
                SkeletonMeshBuilder skeleton_maker(pScene,pScene->mRootNode->mChildren[0]);
            }
        }
    }
}

// ------------------------------------------------------------------------------------------------
// Load an MD5CAMERA file
void MD5Importer::LoadMD5CameraFile ()
{
    std::string pFile = mFile + "md5camera";
    std::unique_ptr<IOStream> file( pIOHandler->Open( pFile, "rb"));

    // Check whether we can read from the file
    if( !file.get() || !file->FileSize())   {
        throw DeadlyImportError("Failed to read MD5CAMERA file: " + pFile);
    }
    bHadMD5Camera = true;
    LoadFileIntoMemory(file.get());

    // parse the basic file structure
    MD5::MD5Parser parser(mBuffer,fileSize);

    // load the camera animation data from the parse tree
    MD5::MD5CameraParser cameraParser(parser.mSections);

    if (cameraParser.frames.empty()) {
        throw DeadlyImportError("MD5CAMERA: No frames parsed");
    }

    std::vector<unsigned int>& cuts = cameraParser.cuts;
    std::vector<MD5::CameraAnimFrameDesc>& frames = cameraParser.frames;

    // Construct output graph - a simple root with a dummy child.
    // The root node performs the coordinate system conversion
    aiNode* root = pScene->mRootNode = new aiNode("<MD5CameraRoot>");
    root->mChildren = new aiNode*[root->mNumChildren = 1];
    root->mChildren[0] = new aiNode("<MD5Camera>");
    root->mChildren[0]->mParent = root;

    // ... but with one camera assigned to it
    pScene->mCameras = new aiCamera*[pScene->mNumCameras = 1];
    aiCamera* cam = pScene->mCameras[0] = new aiCamera();
    cam->mName = "<MD5Camera>";

    // FIXME: Fov is currently set to the first frame's value
    cam->mHorizontalFOV = AI_DEG_TO_RAD( frames.front().fFOV );

    // every cut is written to a separate aiAnimation
    if (!cuts.size()) {
        cuts.push_back(0);
        cuts.push_back(frames.size()-1);
    }
    else {
        cuts.insert(cuts.begin(),0);

        if (cuts.back() < frames.size()-1)
            cuts.push_back(frames.size()-1);
    }

    pScene->mNumAnimations = cuts.size()-1;
    aiAnimation** tmp = pScene->mAnimations = new aiAnimation*[pScene->mNumAnimations];
    for (std::vector<unsigned int>::const_iterator it = cuts.begin(); it != cuts.end()-1; ++it) {

        aiAnimation* anim = *tmp++ = new aiAnimation();
        anim->mName.length = ::ai_snprintf(anim->mName.data, MAXLEN, "anim%u_from_%u_to_%u",(unsigned int)(it-cuts.begin()),(*it),*(it+1));

        anim->mTicksPerSecond = cameraParser.fFrameRate;
        anim->mChannels = new aiNodeAnim*[anim->mNumChannels = 1];
        aiNodeAnim* nd  = anim->mChannels[0] = new aiNodeAnim();
        nd->mNodeName.Set("<MD5Camera>");

        nd->mNumPositionKeys = nd->mNumRotationKeys = *(it+1) - (*it);
        nd->mPositionKeys = new aiVectorKey[nd->mNumPositionKeys];
        nd->mRotationKeys = new aiQuatKey  [nd->mNumRotationKeys];
        for (unsigned int i = 0; i < nd->mNumPositionKeys; ++i) {

            nd->mPositionKeys[i].mValue = frames[*it+i].vPositionXYZ;
            MD5::ConvertQuaternion(frames[*it+i].vRotationQuat,nd->mRotationKeys[i].mValue);
            nd->mRotationKeys[i].mTime = nd->mPositionKeys[i].mTime = *it+i;
        }
    }
}

#endif // !! ASSIMP_BUILD_NO_MD5_IMPORTER
