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*/

/** @file  FBXDConverter.h
 *  @brief FBX DOM to aiScene conversion
 */
#ifndef INCLUDED_AI_FBX_CONVERTER_H
#define INCLUDED_AI_FBX_CONVERTER_H

#include "FBXParser.h"
#include "FBXMeshGeometry.h"
#include "FBXDocument.h"
#include "FBXUtil.h"
#include "FBXProperties.h"
#include "FBXImporter.h"
#include <assimp/anim.h>
#include <assimp/material.h>
#include <assimp/light.h>
#include <assimp/texture.h>
#include <assimp/camera.h>
#include <assimp/StringComparison.h>
#include <unordered_map>
#include <unordered_set>

struct aiScene;
struct aiNode;
struct aiMaterial;

struct morphKeyData {
    std::vector<unsigned int> values;
    std::vector<float> weights;
};
typedef std::map<int64_t, morphKeyData*> morphAnimData;

namespace Assimp {
namespace FBX {

class Document;

enum class FbxUnit {
    cm = 0,
    m,
    km,
    NumUnits,

    Undefined
};

/** 
 *  Convert a FBX #Document to #aiScene
 *  @param out Empty scene to be populated
 *  @param doc Parsed FBX document
 *  @param removeEmptyBones Will remove bones, which do not have any references to vertices.
 */
void ConvertToAssimpScene(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit);

/** Dummy class to encapsulate the conversion process */
class FBXConverter {
public:
    /**
    *  The different parts that make up the final local transformation of a fbx-node
    */
    enum TransformationComp {
        TransformationComp_GeometricScalingInverse = 0,
        TransformationComp_GeometricRotationInverse,
        TransformationComp_GeometricTranslationInverse,
        TransformationComp_Translation,
        TransformationComp_RotationOffset,
        TransformationComp_RotationPivot,
        TransformationComp_PreRotation,
        TransformationComp_Rotation,
        TransformationComp_PostRotation,
        TransformationComp_RotationPivotInverse,
        TransformationComp_ScalingOffset,
        TransformationComp_ScalingPivot,
        TransformationComp_Scaling,
        TransformationComp_ScalingPivotInverse,
        TransformationComp_GeometricTranslation,
        TransformationComp_GeometricRotation,
        TransformationComp_GeometricScaling,

        TransformationComp_MAXIMUM
    };

public:
    FBXConverter(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit);
    ~FBXConverter();

private:
    // ------------------------------------------------------------------------------------------------
    // find scene root and trigger recursive scene conversion
    void ConvertRootNode();

    // ------------------------------------------------------------------------------------------------
    // collect and assign child nodes
    void ConvertNodes(uint64_t id, aiNode& parent, const aiMatrix4x4& parent_transform = aiMatrix4x4());

    // ------------------------------------------------------------------------------------------------
    void ConvertLights(const Model& model, const std::string &orig_name );

    // ------------------------------------------------------------------------------------------------
    void ConvertCameras(const Model& model, const std::string &orig_name );

    // ------------------------------------------------------------------------------------------------
    void ConvertLight( const Light& light, const std::string &orig_name );

    // ------------------------------------------------------------------------------------------------
    void ConvertCamera( const Camera& cam, const std::string &orig_name );

    // ------------------------------------------------------------------------------------------------
    void GetUniqueName( const std::string &name, std::string& uniqueName );

    // ------------------------------------------------------------------------------------------------
    // this returns unified names usable within assimp identifiers (i.e. no space characters -
    // while these would be allowed, they are a potential trouble spot so better not use them).
    const char* NameTransformationComp(TransformationComp comp);

    // ------------------------------------------------------------------------------------------------
    // note: this returns the REAL fbx property names
    const char* NameTransformationCompProperty(TransformationComp comp);

    // ------------------------------------------------------------------------------------------------
    aiVector3D TransformationCompDefaultValue(TransformationComp comp);

    // ------------------------------------------------------------------------------------------------
    void GetRotationMatrix(Model::RotOrder mode, const aiVector3D& rotation, aiMatrix4x4& out);
    // ------------------------------------------------------------------------------------------------
    /**
    *  checks if a node has more than just scaling, rotation and translation components
    */
    bool NeedsComplexTransformationChain(const Model& model);

    // ------------------------------------------------------------------------------------------------
    // note: name must be a FixNodeName() result
    std::string NameTransformationChainNode(const std::string& name, TransformationComp comp);

    // ------------------------------------------------------------------------------------------------
    /**
    *  note: memory for output_nodes will be managed by the caller
    */
    void GenerateTransformationNodeChain(const Model& model, std::vector<aiNode*>& output_nodes, std::vector<aiNode*>& post_output_nodes);

    // ------------------------------------------------------------------------------------------------
    void SetupNodeMetadata(const Model& model, aiNode& nd);

    // ------------------------------------------------------------------------------------------------
    void ConvertModel(const Model& model, aiNode& nd, const aiMatrix4x4& node_global_transform);
    
    // ------------------------------------------------------------------------------------------------
    // MeshGeometry -> aiMesh, return mesh index + 1 or 0 if the conversion failed
    std::vector<unsigned int> ConvertMesh(const MeshGeometry& mesh, const Model& model,
        const aiMatrix4x4& node_global_transform, aiNode& nd);

    // ------------------------------------------------------------------------------------------------
    std::vector<unsigned int> ConvertLine(const LineGeometry& line, const Model& model,
        const aiMatrix4x4& node_global_transform, aiNode& nd);

    // ------------------------------------------------------------------------------------------------
    aiMesh* SetupEmptyMesh(const Geometry& mesh, aiNode& nd);

    // ------------------------------------------------------------------------------------------------
    unsigned int ConvertMeshSingleMaterial(const MeshGeometry& mesh, const Model& model,
        const aiMatrix4x4& node_global_transform, aiNode& nd);

    // ------------------------------------------------------------------------------------------------
    std::vector<unsigned int> ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model,
        const aiMatrix4x4& node_global_transform, aiNode& nd);

    // ------------------------------------------------------------------------------------------------
    unsigned int ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model,
        MatIndexArray::value_type index,
        const aiMatrix4x4& node_global_transform, aiNode& nd);

    // ------------------------------------------------------------------------------------------------
    static const unsigned int NO_MATERIAL_SEPARATION = /* std::numeric_limits<unsigned int>::max() */
        static_cast<unsigned int>(-1);

    // ------------------------------------------------------------------------------------------------
    /**
    *  - if materialIndex == NO_MATERIAL_SEPARATION, materials are not taken into
    *    account when determining which weights to include.
    *  - outputVertStartIndices is only used when a material index is specified, it gives for
    *    each output vertex the DOM index it maps to.
    */
    void ConvertWeights(aiMesh* out, const Model& model, const MeshGeometry& geo,
        const aiMatrix4x4& node_global_transform = aiMatrix4x4(),
        unsigned int materialIndex = NO_MATERIAL_SEPARATION,
        std::vector<unsigned int>* outputVertStartIndices = NULL);

    // ------------------------------------------------------------------------------------------------
    void ConvertCluster(std::vector<aiBone*>& bones, const Model& /*model*/, const Cluster& cl,
        std::vector<size_t>& out_indices,
        std::vector<size_t>& index_out_indices,
        std::vector<size_t>& count_out_indices,
        const aiMatrix4x4& node_global_transform);

    // ------------------------------------------------------------------------------------------------
    void ConvertMaterialForMesh(aiMesh* out, const Model& model, const MeshGeometry& geo,
        MatIndexArray::value_type materialIndex);

    // ------------------------------------------------------------------------------------------------
    unsigned int GetDefaultMaterial();

    // ------------------------------------------------------------------------------------------------
    // Material -> aiMaterial
    unsigned int ConvertMaterial(const Material& material, const MeshGeometry* const mesh);

    // ------------------------------------------------------------------------------------------------
    // Video -> aiTexture
    unsigned int ConvertVideo(const Video& video);

    // ------------------------------------------------------------------------------------------------
    // convert embedded texture if necessary and return actual texture path
    aiString GetTexturePath(const Texture* tex);

    // ------------------------------------------------------------------------------------------------
    void TrySetTextureProperties(aiMaterial* out_mat, const TextureMap& textures,
        const std::string& propName,
        aiTextureType target, const MeshGeometry* const mesh);

    // ------------------------------------------------------------------------------------------------
    void TrySetTextureProperties(aiMaterial* out_mat, const LayeredTextureMap& layeredTextures,
        const std::string& propName,
        aiTextureType target, const MeshGeometry* const mesh);

    // ------------------------------------------------------------------------------------------------
    void SetTextureProperties(aiMaterial* out_mat, const TextureMap& textures, const MeshGeometry* const mesh);

    // ------------------------------------------------------------------------------------------------
    void SetTextureProperties(aiMaterial* out_mat, const LayeredTextureMap& layeredTextures, const MeshGeometry* const mesh);

    // ------------------------------------------------------------------------------------------------
    aiColor3D GetColorPropertyFromMaterial(const PropertyTable& props, const std::string& baseName,
        bool& result);
    aiColor3D GetColorPropertyFactored(const PropertyTable& props, const std::string& colorName,
        const std::string& factorName, bool& result, bool useTemplate = true);
    aiColor3D GetColorProperty(const PropertyTable& props, const std::string& colorName,
        bool& result, bool useTemplate = true);

    // ------------------------------------------------------------------------------------------------
    void SetShadingPropertiesCommon(aiMaterial* out_mat, const PropertyTable& props);
    void SetShadingPropertiesRaw(aiMaterial* out_mat, const PropertyTable& props, const TextureMap& textures, const MeshGeometry* const mesh);

    // ------------------------------------------------------------------------------------------------
    // get the number of fps for a FrameRate enumerated value
    static double FrameRateToDouble(FileGlobalSettings::FrameRate fp, double customFPSVal = -1.0);

    // ------------------------------------------------------------------------------------------------
    // convert animation data to aiAnimation et al
    void ConvertAnimations();

    // ------------------------------------------------------------------------------------------------
    // takes a fbx node name and returns the identifier to be used in the assimp output scene.
    // the function is guaranteed to provide consistent results over multiple invocations
    // UNLESS RenameNode() is called for a particular node name.
    std::string FixNodeName(const std::string& name);
    std::string FixAnimMeshName(const std::string& name);

    typedef std::map<const AnimationCurveNode*, const AnimationLayer*> LayerMap;

    // XXX: better use multi_map ..
    typedef std::map<std::string, std::vector<const AnimationCurveNode*> > NodeMap;

    // ------------------------------------------------------------------------------------------------
    void ConvertAnimationStack(const AnimationStack& st);

    // ------------------------------------------------------------------------------------------------
    void ProcessMorphAnimDatas(std::map<std::string, morphAnimData*>* morphAnimDatas, const BlendShapeChannel* bsc, const AnimationCurveNode* node);

    // ------------------------------------------------------------------------------------------------
    void GenerateNodeAnimations(std::vector<aiNodeAnim*>& node_anims,
        const std::string& fixed_name,
        const std::vector<const AnimationCurveNode*>& curves,
        const LayerMap& layer_map,
        int64_t start, int64_t stop,
        double& max_time,
        double& min_time);

    // ------------------------------------------------------------------------------------------------
    bool IsRedundantAnimationData(const Model& target,
        TransformationComp comp,
        const std::vector<const AnimationCurveNode*>& curves);

    // ------------------------------------------------------------------------------------------------
    aiNodeAnim* GenerateRotationNodeAnim(const std::string& name,
        const Model& target,
        const std::vector<const AnimationCurveNode*>& curves,
        const LayerMap& layer_map,
        int64_t start, int64_t stop,
        double& max_time,
        double& min_time);

    // ------------------------------------------------------------------------------------------------
    aiNodeAnim* GenerateScalingNodeAnim(const std::string& name,
        const Model& /*target*/,
        const std::vector<const AnimationCurveNode*>& curves,
        const LayerMap& layer_map,
        int64_t start, int64_t stop,
        double& max_time,
        double& min_time);

    // ------------------------------------------------------------------------------------------------
    aiNodeAnim* GenerateTranslationNodeAnim(const std::string& name,
        const Model& /*target*/,
        const std::vector<const AnimationCurveNode*>& curves,
        const LayerMap& layer_map,
        int64_t start, int64_t stop,
        double& max_time,
        double& min_time,
        bool inverse = false);

    // ------------------------------------------------------------------------------------------------
    // generate node anim, extracting only Rotation, Scaling and Translation from the given chain
    aiNodeAnim* GenerateSimpleNodeAnim(const std::string& name,
        const Model& target,
        NodeMap::const_iterator chain[TransformationComp_MAXIMUM],
        NodeMap::const_iterator iter_end,
        const LayerMap& layer_map,
        int64_t start, int64_t stop,
        double& max_time,
        double& min_time,
        bool reverse_order = false);

    // key (time), value, mapto (component index)
    typedef std::tuple<std::shared_ptr<KeyTimeList>, std::shared_ptr<KeyValueList>, unsigned int > KeyFrameList;
    typedef std::vector<KeyFrameList> KeyFrameListList;

    // ------------------------------------------------------------------------------------------------
    KeyFrameListList GetKeyframeList(const std::vector<const AnimationCurveNode*>& nodes, int64_t start, int64_t stop);

    // ------------------------------------------------------------------------------------------------
    KeyTimeList GetKeyTimeList(const KeyFrameListList& inputs);

    // ------------------------------------------------------------------------------------------------
    void InterpolateKeys(aiVectorKey* valOut, const KeyTimeList& keys, const KeyFrameListList& inputs,
        const aiVector3D& def_value,
        double& max_time,
        double& min_time);

    // ------------------------------------------------------------------------------------------------
    void InterpolateKeys(aiQuatKey* valOut, const KeyTimeList& keys, const KeyFrameListList& inputs,
        const aiVector3D& def_value,
        double& maxTime,
        double& minTime,
        Model::RotOrder order);

    // ------------------------------------------------------------------------------------------------
    void ConvertTransformOrder_TRStoSRT(aiQuatKey* out_quat, aiVectorKey* out_scale,
        aiVectorKey* out_translation,
        const KeyFrameListList& scaling,
        const KeyFrameListList& translation,
        const KeyFrameListList& rotation,
        const KeyTimeList& times,
        double& maxTime,
        double& minTime,
        Model::RotOrder order,
        const aiVector3D& def_scale,
        const aiVector3D& def_translate,
        const aiVector3D& def_rotation);

    // ------------------------------------------------------------------------------------------------
    // euler xyz -> quat
    aiQuaternion EulerToQuaternion(const aiVector3D& rot, Model::RotOrder order);

    // ------------------------------------------------------------------------------------------------
    void ConvertScaleKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes, const LayerMap& /*layers*/,
        int64_t start, int64_t stop,
        double& maxTime,
        double& minTime);

    // ------------------------------------------------------------------------------------------------
    void ConvertTranslationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes,
        const LayerMap& /*layers*/,
        int64_t start, int64_t stop,
        double& maxTime,
        double& minTime);

    // ------------------------------------------------------------------------------------------------
    void ConvertRotationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes,
        const LayerMap& /*layers*/,
        int64_t start, int64_t stop,
        double& maxTime,
        double& minTime,
        Model::RotOrder order);

    void ConvertGlobalSettings();

    // ------------------------------------------------------------------------------------------------
    //  Will perform the conversion from a given unit to the requested unit.
    void ConvertToUnitScale(FbxUnit unit);

    // ------------------------------------------------------------------------------------------------
    // copy generated meshes, animations, lights, cameras and textures to the output scene
    void TransferDataToScene();

private:
    // 0: not assigned yet, others: index is value - 1
    unsigned int defaultMaterialIndex;

    std::vector<aiMesh*> meshes;
    std::vector<aiMaterial*> materials;
    std::vector<aiAnimation*> animations;
    std::vector<aiLight*> lights;
    std::vector<aiCamera*> cameras;
    std::vector<aiTexture*> textures;

    using MaterialMap = std::map<const Material*, unsigned int>;
    MaterialMap materials_converted;

    using VideoMap = std::map<const Video*, unsigned int>;
    VideoMap textures_converted;

    using MeshMap = std::map<const Geometry*, std::vector<unsigned int> >;
    MeshMap meshes_converted;

    // fixed node name -> which trafo chain components have animations?
    using NodeAnimBitMap = std::map<std::string, unsigned int> ;
    NodeAnimBitMap node_anim_chain_bits;

    // number of nodes with the same name
    using NodeAnimNameMap = std::unordered_map<std::string, unsigned int>;
    NodeAnimNameMap mNodeNameInstances;

    using NodeNameCache = std::unordered_set<std::string>;
    NodeNameCache mNodeNames;

    double anim_fps;

    aiScene* const out;
    const FBX::Document& doc;

    bool mRemoveEmptyBones;

    FbxUnit mCurrentUnit;
};

}
}

#endif // INCLUDED_AI_FBX_CONVERTER_H