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

#ifndef ASSIMP_BUILD_NO_MD5_IMPORTER

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

using namespace Assimp;

// Minimum weight value. Weights inside [-n ... n] are ignored
#define AI_MD5_WEIGHT_EPSILON Math::getEpsilon<float>()

static constexpr 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(nullptr),
        mBuffer(),
        mFileSize(),
        mLineNumber(),
        mScene(),
        mHadMD5Mesh(),
        mHadMD5Anim(),
        mHadMD5Camera(),
        mCconfigNoAutoLoad(false) {
    // empty
}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file.
bool MD5Importer::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool /*checkSig*/) const {
    static const char *tokens[] = { "MD5Version" };
    return SearchFileHeaderForToken(pIOHandler, pFile, tokens, AI_COUNT_OF(tokens));
}

// ------------------------------------------------------------------------------------------------
// 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
    mCconfigNoAutoLoad = (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) {
    mIOHandler = pIOHandler;
    mScene = _pScene;
    mHadMD5Mesh = mHadMD5Anim = mHadMD5Camera = 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 (mCconfigNoAutoLoad || 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 (!mHadMD5Mesh && !mHadMD5Anim && !mHadMD5Camera) {
        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
    mScene->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 (!mHadMD5Mesh) {
        mScene->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(nullptr != file);
    mFileSize = (unsigned int)file->FileSize();
    ai_assert(mFileSize);

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

    // append a terminal 0
    mBuffer[mFileSize] = '\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 = nullptr;
    mFileSize = 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 = static_cast<unsigned int>(meshSrc.mFaces.size() * 3);
    unsigned int iNewIndex = static_cast<unsigned int>(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 (FaceArray::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, BoneArray &bones) {
    ai_assert(nullptr != piParent);
    ai_assert(!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, AnimBoneArray &bones, const aiNodeAnim **node_anims) {
    ai_assert(nullptr != piParent);
    ai_assert(!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 filename = mFile + "md5mesh";
    std::unique_ptr<IOStream> file(mIOHandler->Open(filename, "rb"));

    // Check whether we can read from the file
    if (file == nullptr || !file->FileSize()) {
        ASSIMP_LOG_WARN("Failed to access MD5MESH file: ", filename);
        return;
    }
    mHadMD5Mesh = true;
    LoadFileIntoMemory(file.get());

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

    // 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
    mScene->mRootNode = new aiNode("<MD5_Root>");
    mScene->mRootNode->mNumChildren = 2;
    mScene->mRootNode->mChildren = new aiNode *[2];

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

    pcNode = mScene->mRootNode->mChildren[0] = new aiNode();
    pcNode->mName.Set("<MD5_Mesh>");
    pcNode->mParent = mScene->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()) {
            ++mScene->mNumMaterials;
        }
    }

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

    //  storage for node mesh indices
    pcNode->mNumMeshes = mScene->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 = mScene->mMeshes[n] = new aiMesh();
        mesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;

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

        std::string name(meshSrc.mShader.C_Str());
        name += ".msh";
        mesh->mName = name;
        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::VertexArray::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::VertexArray::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 &weightDesc = meshSrc.mWeights[w];
                /* FIX for some invalid exporters */
                if (!(weightDesc.mWeight < AI_MD5_WEIGHT_EPSILON && weightDesc.mWeight >= -AI_MD5_WEIGHT_EPSILON)) {
                    ++piCount[weightDesc.mBone];
                }
            }
        }

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

        // just for safety
        if (mesh->mNumBones) {
            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);
            }

            pv = mesh->mVertices;
            for (MD5::VertexArray::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 ...
                ai_real fSum = 0.0;
                for (unsigned int jub = (*iter).mFirstWeight, w = jub; w < jub + (*iter).mNumWeights; ++w) {
                    fSum += meshSrc.mWeights[w].mWeight;
                }
                if (!fSum) {
                    ASSIMP_LOG_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 &weightDesc = meshSrc.mWeights[w];
                    if (weightDesc.mWeight < AI_MD5_WEIGHT_EPSILON && weightDesc.mWeight >= -AI_MD5_WEIGHT_EPSILON) {
                        continue;
                    }

                    const ai_real fNewWeight = weightDesc.mWeight / fSum;

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

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

        // generate a material for the mesh
        aiMaterial *mat = new aiMaterial();
        mScene->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(mIOHandler->Open(pFile, "rb"));

    // Check whether we can read from the file
    if (!file || !file->FileSize()) {
        ASSIMP_LOG_WARN("Failed to read MD5ANIM file: ", pFile);
        return;
    }

    LoadFileIntoMemory(file.get());

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

    // 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()) {
        ASSIMP_LOG_ERROR("MD5ANIM: No frames or animated bones loaded");
    } else {
        mHadMD5Anim = true;

        mScene->mAnimations = new aiAnimation *[mScene->mNumAnimations = 1];
        aiAnimation *anim = mScene->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 (FrameArray::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 (AnimBoneArray::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 (!mScene->mRootNode) {
            mScene->mRootNode = new aiNode();
            mScene->mRootNode->mName.Set("<MD5_Hierarchy>");

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

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

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

    // Check whether we can read from the file
    if (!file || !file->FileSize()) {
        throw DeadlyImportError("Failed to read MD5CAMERA file: ", pFile);
    }
    mHadMD5Camera = true;
    LoadFileIntoMemory(file.get());

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

    // 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 = mScene->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
    mScene->mCameras = new aiCamera *[mScene->mNumCameras = 1];
    aiCamera *cam = mScene->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(static_cast<unsigned int>(frames.size() - 1));
    } else {
        cuts.insert(cuts.begin(), 0);

        if (cuts.back() < frames.size() - 1)
            cuts.push_back(static_cast<unsigned int>(frames.size() - 1));
    }

    mScene->mNumAnimations = static_cast<unsigned int>(cuts.size() - 1);
    aiAnimation **tmp = mScene->mAnimations = new aiAnimation *[mScene->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, AI_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
