assimp.assimp/code/AssetLib/FBX/FBXDocument.h

/*
Open Asset Import Library (assimp)
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All rights reserved.

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  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
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  contributors may be used to endorse or promote products
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*/

/** @file  FBXDocument.h
 *  @brief FBX DOM
 */
#ifndef INCLUDED_AI_FBX_DOCUMENT_H
#define INCLUDED_AI_FBX_DOCUMENT_H

#include <numeric>
#include <unordered_set>
#include <stdint.h>
#include <assimp/mesh.h>
#include "FBXProperties.h"
#include "FBXParser.h"

#define _AI_CONCAT(a,b)  a ## b
#define  AI_CONCAT(a,b)  _AI_CONCAT(a,b)


namespace Assimp {
namespace FBX {

// Use an 'illegal' default FOV value to detect if the FBX camera has set the FOV.
static const float kFovUnknown = -1.0f;


class Parser;
class Object;
struct ImportSettings;

class PropertyTable;
class Document;
class Material;
class ShapeGeometry;
class LineGeometry;
class Geometry;

class Video;

class AnimationCurve;
class AnimationCurveNode;
class AnimationLayer;
class AnimationStack;

class BlendShapeChannel;
class BlendShape;
class Skin;
class Cluster;

#define new_LazyObject new (allocator.Allocate(sizeof(LazyObject))) LazyObject
#define new_Connection new (allocator.Allocate(sizeof(Connection))) Connection
#define delete_LazyObject(_p) (_p)->~LazyObject()
#define delete_Connection(_p) (_p)->~Connection()

/** Represents a delay-parsed FBX objects. Many objects in the scene
 *  are not needed by assimp, so it makes no sense to parse them
 *  upfront. */
class LazyObject {
public:
    LazyObject(uint64_t id, const Element& element, const Document& doc);

    ~LazyObject() = default;

    const Object* Get(bool dieOnError = false);

    template <typename T>
    const T* Get(bool dieOnError = false) {
        const Object* const ob = Get(dieOnError);
        return ob ? dynamic_cast<const T *>(ob) : nullptr;
    }

    uint64_t ID() const {
        return id;
    }

    bool IsBeingConstructed() const {
        return (flags & BEING_CONSTRUCTED) != 0;
    }

    bool FailedToConstruct() const {
        return (flags & FAILED_TO_CONSTRUCT) != 0;
    }

    const Element& GetElement() const {
        return element;
    }

    const Document& GetDocument() const {
        return doc;
    }

private:
    const Document& doc;
    const Element& element;
    std::unique_ptr<const Object> object;

    const uint64_t id;

    enum Flags {
        BEING_CONSTRUCTED = 0x1,
        FAILED_TO_CONSTRUCT = 0x2
    };

    unsigned int flags;
};

/** Base class for in-memory (DOM) representations of FBX objects */
class Object {
public:
    Object(uint64_t id, const Element& element, const std::string& name);

    virtual ~Object() = default;

    const Element& SourceElement() const {
        return element;
    }

    const std::string& Name() const {
        return name;
    }

    uint64_t ID() const {
        return id;
    }

protected:
    const Element& element;
    const std::string name;
    const uint64_t id;
};

/** DOM class for generic FBX NoteAttribute blocks. NoteAttribute's just hold a property table,
 *  fixed members are added by deriving classes. */
class NodeAttribute : public Object {
public:
    NodeAttribute(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~NodeAttribute() = default;

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

private:
    std::shared_ptr<const PropertyTable> props;
};

/** DOM base class for FBX camera settings attached to a node */
class CameraSwitcher : public NodeAttribute {
public:
    CameraSwitcher(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~CameraSwitcher() = default;

    int CameraID() const {
        return cameraId;
    }

    const std::string& CameraName() const {
        return cameraName;
    }

    const std::string& CameraIndexName() const {
        return cameraIndexName;
    }

private:
    int cameraId;
    std::string cameraName;
    std::string cameraIndexName;
};

#define fbx_stringize(a) #a

#define fbx_simple_property(name, type, default_value) \
    type name() const { \
        return PropertyGet<type>(Props(), fbx_stringize(name), (default_value)); \
    }

// XXX improve logging
#define fbx_simple_enum_property(name, type, default_value) \
    type name() const { \
        const int ival = PropertyGet<int>(Props(), fbx_stringize(name), static_cast<int>(default_value)); \
        if (ival < 0 || ival >= AI_CONCAT(type, _MAX)) { \
            ai_assert(static_cast<int>(default_value) >= 0); \
            ai_assert(static_cast<int>(default_value) < AI_CONCAT(type, _MAX)); \
            return static_cast<type>(default_value); \
        } \
        return static_cast<type>(ival); \
}


/** DOM base class for FBX cameras attached to a node */
class Camera : public NodeAttribute {
public:
    Camera(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual  ~Camera() = default;

    fbx_simple_property(Position, aiVector3D, aiVector3D(0,0,0))
    fbx_simple_property(UpVector, aiVector3D, aiVector3D(0,1,0))
    fbx_simple_property(InterestPosition, aiVector3D, aiVector3D(0,0,0))

    fbx_simple_property(AspectWidth, float, 1.0f)
    fbx_simple_property(AspectHeight, float, 1.0f)
    fbx_simple_property(FilmWidth, float, 1.0f)
    fbx_simple_property(FilmHeight, float, 1.0f)

    fbx_simple_property(NearPlane, float, 0.1f)
    fbx_simple_property(FarPlane, float, 100.0f)

    fbx_simple_property(FilmAspectRatio, float, 1.0f)
    fbx_simple_property(ApertureMode, int, 0)

    fbx_simple_property(FieldOfView, float, kFovUnknown)
    fbx_simple_property(FocalLength, float, 1.0f)
};

/** DOM base class for FBX null markers attached to a node */
class Null : public NodeAttribute {
public:
    Null(uint64_t id, const Element& element, const Document& doc, const std::string& name);
    virtual ~Null() = default;
};

/** DOM base class for FBX limb node markers attached to a node */
class LimbNode : public NodeAttribute {
public:
    LimbNode(uint64_t id, const Element& element, const Document& doc, const std::string& name);
    virtual ~LimbNode() = default;
};

/** DOM base class for FBX lights attached to a node */
class Light : public NodeAttribute {
public:
    Light(uint64_t id, const Element& element, const Document& doc, const std::string& name);
    virtual ~Light() = default;

    enum Type {
        Type_Point,
        Type_Directional,
        Type_Spot,
        Type_Area,
        Type_Volume,

        Type_MAX // end-of-enum sentinel
    };

    enum Decay {
        Decay_None,
        Decay_Linear,
        Decay_Quadratic,
        Decay_Cubic,

        Decay_MAX // end-of-enum sentinel
    };

    fbx_simple_property(Color, aiVector3D, aiVector3D(1,1,1))
    fbx_simple_enum_property(LightType, Type, 0)
    fbx_simple_property(CastLightOnObject, bool, false)
    fbx_simple_property(DrawVolumetricLight, bool, true)
    fbx_simple_property(DrawGroundProjection, bool, true)
    fbx_simple_property(DrawFrontFacingVolumetricLight, bool, false)
    fbx_simple_property(Intensity, float, 100.0f)
    fbx_simple_property(InnerAngle, float, 0.0f)
    fbx_simple_property(OuterAngle, float, 45.0f)
    fbx_simple_property(Fog, int, 50)
    fbx_simple_enum_property(DecayType, Decay, 2)
    fbx_simple_property(DecayStart, float, 1.0f)
    fbx_simple_property(FileName, std::string, "")

    fbx_simple_property(EnableNearAttenuation, bool, false)
    fbx_simple_property(NearAttenuationStart, float, 0.0f)
    fbx_simple_property(NearAttenuationEnd, float, 0.0f)
    fbx_simple_property(EnableFarAttenuation, bool, false)
    fbx_simple_property(FarAttenuationStart, float, 0.0f)
    fbx_simple_property(FarAttenuationEnd, float, 0.0f)

    fbx_simple_property(CastShadows, bool, true)
    fbx_simple_property(ShadowColor, aiVector3D, aiVector3D(0,0,0))

    fbx_simple_property(AreaLightShape, int, 0)

    fbx_simple_property(LeftBarnDoor, float, 20.0f)
    fbx_simple_property(RightBarnDoor, float, 20.0f)
    fbx_simple_property(TopBarnDoor, float, 20.0f)
    fbx_simple_property(BottomBarnDoor, float, 20.0f)
    fbx_simple_property(EnableBarnDoor, bool, true)
};

/** DOM base class for FBX models (even though its semantics are more "node" than "model" */
class Model : public Object {
public:
    enum RotOrder {
        RotOrder_EulerXYZ = 0,
        RotOrder_EulerXZY,
        RotOrder_EulerYZX,
        RotOrder_EulerYXZ,
        RotOrder_EulerZXY,
        RotOrder_EulerZYX,

        RotOrder_SphericXYZ,

        RotOrder_MAX // end-of-enum sentinel
    };

    enum TransformInheritance {
        TransformInheritance_RrSs = 0,
        TransformInheritance_RSrs,
        TransformInheritance_Rrs,

        TransformInheritance_MAX // end-of-enum sentinel
    };

    Model(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~Model() = default;

    fbx_simple_property(QuaternionInterpolate, int, 0)

    fbx_simple_property(RotationOffset, aiVector3D, aiVector3D())
    fbx_simple_property(RotationPivot, aiVector3D, aiVector3D())
    fbx_simple_property(ScalingOffset, aiVector3D, aiVector3D())
    fbx_simple_property(ScalingPivot, aiVector3D, aiVector3D())
    fbx_simple_property(TranslationActive, bool, false)

    fbx_simple_property(TranslationMin, aiVector3D, aiVector3D())
    fbx_simple_property(TranslationMax, aiVector3D, aiVector3D())

    fbx_simple_property(TranslationMinX, bool, false)
    fbx_simple_property(TranslationMaxX, bool, false)
    fbx_simple_property(TranslationMinY, bool, false)
    fbx_simple_property(TranslationMaxY, bool, false)
    fbx_simple_property(TranslationMinZ, bool, false)
    fbx_simple_property(TranslationMaxZ, bool, false)

    fbx_simple_enum_property(RotationOrder, RotOrder, 0)
    fbx_simple_property(RotationSpaceForLimitOnly, bool, false)
    fbx_simple_property(RotationStiffnessX, float, 0.0f)
    fbx_simple_property(RotationStiffnessY, float, 0.0f)
    fbx_simple_property(RotationStiffnessZ, float, 0.0f)
    fbx_simple_property(AxisLen, float, 0.0f)

    fbx_simple_property(PreRotation, aiVector3D, aiVector3D())
    fbx_simple_property(PostRotation, aiVector3D, aiVector3D())
    fbx_simple_property(RotationActive, bool, false)

    fbx_simple_property(RotationMin, aiVector3D, aiVector3D())
    fbx_simple_property(RotationMax, aiVector3D, aiVector3D())

    fbx_simple_property(RotationMinX, bool, false)
    fbx_simple_property(RotationMaxX, bool, false)
    fbx_simple_property(RotationMinY, bool, false)
    fbx_simple_property(RotationMaxY, bool, false)
    fbx_simple_property(RotationMinZ, bool, false)
    fbx_simple_property(RotationMaxZ, bool, false)
    fbx_simple_enum_property(InheritType, TransformInheritance, 0)

    fbx_simple_property(ScalingActive, bool, false)
    fbx_simple_property(ScalingMin, aiVector3D, aiVector3D())
    fbx_simple_property(ScalingMax, aiVector3D, aiVector3D(1.f,1.f,1.f))
    fbx_simple_property(ScalingMinX, bool, false)
    fbx_simple_property(ScalingMaxX, bool, false)
    fbx_simple_property(ScalingMinY, bool, false)
    fbx_simple_property(ScalingMaxY, bool, false)
    fbx_simple_property(ScalingMinZ, bool, false)
    fbx_simple_property(ScalingMaxZ, bool, false)

    fbx_simple_property(GeometricTranslation, aiVector3D, aiVector3D())
    fbx_simple_property(GeometricRotation, aiVector3D, aiVector3D())
    fbx_simple_property(GeometricScaling, aiVector3D, aiVector3D(1.f, 1.f, 1.f))

    fbx_simple_property(MinDampRangeX, float, 0.0f)
    fbx_simple_property(MinDampRangeY, float, 0.0f)
    fbx_simple_property(MinDampRangeZ, float, 0.0f)
    fbx_simple_property(MaxDampRangeX, float, 0.0f)
    fbx_simple_property(MaxDampRangeY, float, 0.0f)
    fbx_simple_property(MaxDampRangeZ, float, 0.0f)

    fbx_simple_property(MinDampStrengthX, float, 0.0f)
    fbx_simple_property(MinDampStrengthY, float, 0.0f)
    fbx_simple_property(MinDampStrengthZ, float, 0.0f)
    fbx_simple_property(MaxDampStrengthX, float, 0.0f)
    fbx_simple_property(MaxDampStrengthY, float, 0.0f)
    fbx_simple_property(MaxDampStrengthZ, float, 0.0f)

    fbx_simple_property(PreferredAngleX, float, 0.0f)
    fbx_simple_property(PreferredAngleY, float, 0.0f)
    fbx_simple_property(PreferredAngleZ, float, 0.0f)

    fbx_simple_property(Show, bool, true)
    fbx_simple_property(LODBox, bool, false)
    fbx_simple_property(Freeze, bool, false)

    const std::string& Shading() const {
        return shading;
    }

    const std::string& Culling() const {
        return culling;
    }

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

    /** Get material links */
    const std::vector<const Material*>& GetMaterials() const {
        return materials;
    }

    /** Get geometry links */
    const std::vector<const Geometry*>& GetGeometry() const {
        return geometry;
    }

    /** Get node attachments */
    const std::vector<const NodeAttribute*>& GetAttributes() const {
        return attributes;
    }

    /** convenience method to check if the node has a Null node marker */
    bool IsNull() const;

private:
    void ResolveLinks(const Element& element, const Document& doc);

private:
    std::vector<const Material*> materials;
    std::vector<const Geometry*> geometry;
    std::vector<const NodeAttribute*> attributes;

    std::string shading;
    std::string culling;
    std::shared_ptr<const PropertyTable> props;
};

/** DOM class for generic FBX textures */
class Texture : public Object {
public:
    Texture(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~Texture();

    const std::string& Type() const {
        return type;
    }

    const std::string& FileName() const {
        return fileName;
    }

    const std::string& RelativeFilename() const {
        return relativeFileName;
    }

    const std::string& AlphaSource() const {
        return alphaSource;
    }

    const aiVector2D& UVTranslation() const {
        return uvTrans;
    }

    const aiVector2D& UVScaling() const {
        return uvScaling;
    }

    const ai_real &UVRotation() const {
        return uvRotation;
    }

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

    // return a 4-tuple
    const unsigned int* Crop() const {
        return crop;
    }

    const Video* Media() const {
        return media;
    }

private:
    aiVector2D uvTrans;
    aiVector2D uvScaling;
    ai_real    uvRotation;

    std::string type;
    std::string relativeFileName;
    std::string fileName;
    std::string alphaSource;
    std::shared_ptr<const PropertyTable> props;

    unsigned int crop[4];

    const Video* media;
};

/** DOM class for layered FBX textures */
class LayeredTexture : public Object {
public:
    LayeredTexture(uint64_t id, const Element& element, const Document& doc, const std::string& name);
    virtual ~LayeredTexture();

    // Can only be called after construction of the layered texture object due to construction flag.
    void fillTexture(const Document& doc);

    enum BlendMode {
        BlendMode_Translucent,
        BlendMode_Additive,
        BlendMode_Modulate,
        BlendMode_Modulate2,
        BlendMode_Over,
        BlendMode_Normal,
        BlendMode_Dissolve,
        BlendMode_Darken,
        BlendMode_ColorBurn,
        BlendMode_LinearBurn,
        BlendMode_DarkerColor,
        BlendMode_Lighten,
        BlendMode_Screen,
        BlendMode_ColorDodge,
        BlendMode_LinearDodge,
        BlendMode_LighterColor,
        BlendMode_SoftLight,
        BlendMode_HardLight,
        BlendMode_VividLight,
        BlendMode_LinearLight,
        BlendMode_PinLight,
        BlendMode_HardMix,
        BlendMode_Difference,
        BlendMode_Exclusion,
        BlendMode_Subtract,
        BlendMode_Divide,
        BlendMode_Hue,
        BlendMode_Saturation,
        BlendMode_Color,
        BlendMode_Luminosity,
        BlendMode_Overlay,
        BlendMode_BlendModeCount
    };

    const Texture* getTexture(int index=0) const {
		return textures[index];
    }
	int textureCount() const {
		return static_cast<int>(textures.size());
	}
    BlendMode GetBlendMode() const {
        return blendMode;
    }
    float Alpha() {
        return alpha;
    }

private:
	std::vector<const Texture*> textures;
    BlendMode blendMode;
    float alpha;
};

using TextureMap = std::fbx_unordered_map<std::string, const Texture*>;
using LayeredTextureMap = std::fbx_unordered_map<std::string, const LayeredTexture*>;

/** DOM class for generic FBX videos */
class Video : public Object {
public:
    Video(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~Video();

    const std::string& Type() const {
        return type;
    }

    const std::string& FileName() const {
        return fileName;
    }

    const std::string& RelativeFilename() const {
        return relativeFileName;
    }

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

    const uint8_t* Content() const {
        ai_assert(content);
        return content;
    }

    uint64_t ContentLength() const {
        return contentLength;
    }

    uint8_t* RelinquishContent() {
        uint8_t* ptr = content;
        content = nullptr;
        return ptr;
    }

private:
    std::string type;
    std::string relativeFileName;
    std::string fileName;
    std::shared_ptr<const PropertyTable> props;

    uint64_t contentLength;
    uint8_t* content;
};

/** DOM class for generic FBX materials */
class Material final : public Object {
public:
    Material(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    ~Material() override = default;

    const std::string& GetShadingModel() const {
        return shading;
    }

    bool IsMultilayer() const {
        return multilayer;
    }

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

    const TextureMap& Textures() const {
        return textures;
    }

    const LayeredTextureMap& LayeredTextures() const {
        return layeredTextures;
    }

private:
    std::string shading;
    bool multilayer;
    std::shared_ptr<const PropertyTable> props;

    TextureMap textures;
    LayeredTextureMap layeredTextures;
};

using KeyTimeList = std::vector<int64_t>;
using KeyValueList = std::vector<float>;

/** Represents a FBX animation curve (i.e. a 1-dimensional set of keyframes and values therefore) */
class AnimationCurve : public Object {
public:
    AnimationCurve(uint64_t id, const Element& element, const std::string& name, const Document& doc);
    virtual ~AnimationCurve() = default;

    /** get list of keyframe positions (time).
     *  Invariant: |GetKeys()| > 0 */
    const KeyTimeList& GetKeys() const {
        return keys;
    }

    /** get list of keyframe values.
      * Invariant: |GetKeys()| == |GetValues()| && |GetKeys()| > 0*/
    const KeyValueList& GetValues() const {
        return values;
    }

    const std::vector<float>& GetAttributes() const {
        return attributes;
    }

    const std::vector<unsigned int>& GetFlags() const {
        return flags;
    }

private:
    KeyTimeList keys;
    KeyValueList values;
    std::vector<float> attributes;
    std::vector<unsigned int> flags;
};

// property-name -> animation curve
using AnimationCurveMap = std::map<std::string, const AnimationCurve*>;

/** Represents a FBX animation curve (i.e. a mapping from single animation curves to nodes) */
class AnimationCurveNode : public Object {
public:
    /* the optional white list specifies a list of property names for which the caller
    wants animations for. If the curve node does not match one of these, std::range_error
    will be thrown. */
    AnimationCurveNode(uint64_t id, const Element& element, const std::string& name, const Document& doc,
            const char *const *target_prop_whitelist = nullptr, size_t whitelist_size = 0);

    virtual ~AnimationCurveNode() = default;

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }


    const AnimationCurveMap& Curves() const;

    /** Object the curve is assigned to, this can be nullptr if the
     *  target object has no DOM representation or could not
     *  be read for other reasons.*/
    const Object* Target() const {
        return target;
    }

    const Model* TargetAsModel() const {
        return dynamic_cast<const Model*>(target);
    }

    const NodeAttribute* TargetAsNodeAttribute() const {
        return dynamic_cast<const NodeAttribute*>(target);
    }

    /** Property of Target() that is being animated*/
    const std::string& TargetProperty() const {
        return prop;
    }

private:
    const Object* target;
    std::shared_ptr<const PropertyTable> props;
    mutable AnimationCurveMap curves;

    std::string prop;
    const Document& doc;
};

using AnimationCurveNodeList = std::vector<const AnimationCurveNode*>;

/** Represents a FBX animation layer (i.e. a list of node animations) */
class AnimationLayer : public Object {
public:
    AnimationLayer(uint64_t id, const Element& element, const std::string& name, const Document& doc);
    virtual ~AnimationLayer() = default;

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

    /* the optional white list specifies a list of property names for which the caller
    wants animations for. Curves not matching this list will not be added to the
    animation layer. */
    AnimationCurveNodeList Nodes(const char* const * target_prop_whitelist = nullptr, size_t whitelist_size = 0) const;

private:
    std::shared_ptr<const PropertyTable> props;
    const Document& doc;
};

using AnimationLayerList = std::vector<const AnimationLayer*>;

/** Represents a FBX animation stack (i.e. a list of animation layers) */
class AnimationStack : public Object {
public:
    AnimationStack(uint64_t id, const Element& element, const std::string& name, const Document& doc);
    virtual ~AnimationStack() = default;

    fbx_simple_property(LocalStart, int64_t, 0L)
    fbx_simple_property(LocalStop, int64_t, 0L)
    fbx_simple_property(ReferenceStart, int64_t, 0L)
    fbx_simple_property(ReferenceStop, int64_t, 0L)

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

    const AnimationLayerList& Layers() const {
        return layers;
    }

private:
    std::shared_ptr<const PropertyTable> props;
    AnimationLayerList layers;
};


/** DOM class for deformers */
class Deformer : public Object {
public:
    Deformer(uint64_t id, const Element& element, const Document& doc, const std::string& name);
    virtual ~Deformer() = default;

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

private:
    std::shared_ptr<const PropertyTable> props;
};

using WeightArray = std::vector<float>;
using WeightIndexArray = std::vector<unsigned int>;


/** DOM class for BlendShapeChannel deformers */
class BlendShapeChannel : public Deformer {
public:
    BlendShapeChannel(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~BlendShapeChannel() = default;

    float DeformPercent() const {
        return percent;
    }

    const WeightArray& GetFullWeights() const {
        return fullWeights;
    }

    const std::unordered_set<const ShapeGeometry*>& GetShapeGeometries() const {
        return shapeGeometries;
    }

private:
    float percent;
    WeightArray fullWeights;
    std::unordered_set<const ShapeGeometry*> shapeGeometries;
};

/** DOM class for BlendShape deformers */
class BlendShape : public Deformer {
public:
    BlendShape(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~BlendShape() = default;

    const std::unordered_set<const BlendShapeChannel*>& BlendShapeChannels() const {
        return blendShapeChannels;
    }

private:
    std::unordered_set<const BlendShapeChannel*> blendShapeChannels;
};

/** DOM class for skin deformer clusters (aka sub-deformers) */
class Cluster : public Deformer {
public:
    Cluster(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~Cluster() = default;

    /** get the list of deformer weights associated with this cluster.
     *  Use #GetIndices() to get the associated vertices. Both arrays
     *  have the same size (and may also be empty). */
    const WeightArray& GetWeights() const {
        return weights;
    }

    /** get indices into the vertex data of the geometry associated
     *  with this cluster. Use #GetWeights() to get the associated weights.
     *  Both arrays have the same size (and may also be empty). */
    const WeightIndexArray& GetIndices() const {
        return indices;
    }

    /** */
    const aiMatrix4x4& Transform() const {
        return transform;
    }

    const aiMatrix4x4& TransformLink() const {
        return transformLink;
    }

    const Model* TargetNode() const {
        return node;
    }

private:
    WeightArray weights;
    WeightIndexArray indices;

    aiMatrix4x4 transform;
    aiMatrix4x4 transformLink;

    const Model* node;
};

/** DOM class for skin deformers */
class Skin : public Deformer {
public:
    Skin(uint64_t id, const Element& element, const Document& doc, const std::string& name);

    virtual ~Skin() = default;

    float DeformAccuracy() const {
        return accuracy;
    }

    const std::vector<const Cluster*>& Clusters() const {
        return clusters;
    }

private:
    float accuracy;
    std::vector<const Cluster*> clusters;
};

/** Represents a link between two FBX objects. */
class Connection {
public:
    Connection(uint64_t insertionOrder,  uint64_t src, uint64_t dest, const std::string& prop, const Document& doc);

    ~Connection() = default;

    // note: a connection ensures that the source and dest objects exist, but
    // not that they have DOM representations, so the return value of one of
    // these functions can still be nullptr.
    const Object* SourceObject() const;
    const Object* DestinationObject() const;

    // these, however, are always guaranteed to be valid
    LazyObject& LazySourceObject() const;
    LazyObject& LazyDestinationObject() const;


    /** return the name of the property the connection is attached to.
      * this is an empty string for object to object (OO) connections. */
    const std::string& PropertyName() const {
        return prop;
    }

    uint64_t InsertionOrder() const {
        return insertionOrder;
    }

    int CompareTo(const Connection* c) const {
        ai_assert( nullptr != c );

        // note: can't subtract because this would overflow uint64_t
        if(InsertionOrder() > c->InsertionOrder()) {
            return 1;
        }
        else if(InsertionOrder() < c->InsertionOrder()) {
            return -1;
        }
        return 0;
    }

    bool Compare(const Connection* c) const {
        ai_assert( nullptr != c );

        return InsertionOrder() < c->InsertionOrder();
    }

public:
    uint64_t insertionOrder;
    const std::string prop;

    uint64_t src, dest;
    const Document& doc;
};

// XXX again, unique_ptr would be useful. shared_ptr is too
// bloated since the objects have a well-defined single owner
// during their entire lifetime (Document). FBX files have
// up to many thousands of objects (most of which we never use),
// so the memory overhead for them should be kept at a minimum.
using ObjectMap = std::fbx_unordered_map<uint64_t, LazyObject*> ;
using PropertyTemplateMap = std::fbx_unordered_map<std::string, std::shared_ptr<const PropertyTable> > ;
using ConnectionMap = std::fbx_unordered_multimap<uint64_t, const Connection*>;

/** DOM class for global document settings, a single instance per document can
 *  be accessed via Document.Globals(). */
class FileGlobalSettings {
public:
    FileGlobalSettings(const Document& doc, std::shared_ptr<const PropertyTable> props);

    ~FileGlobalSettings() = default;

    const PropertyTable& Props() const {
        ai_assert(props.get());
        return *props;
    }

    const Document& GetDocument() const {
        return doc;
    }

    fbx_simple_property(UpAxis, int, 1)
    fbx_simple_property(UpAxisSign, int, 1)
    fbx_simple_property(FrontAxis, int, 2)
    fbx_simple_property(FrontAxisSign, int, 1)
    fbx_simple_property(CoordAxis, int, 0)
    fbx_simple_property(CoordAxisSign, int, 1)
    fbx_simple_property(OriginalUpAxis, int, 0)
    fbx_simple_property(OriginalUpAxisSign, int, 1)
    fbx_simple_property(UnitScaleFactor, float, 1)
    fbx_simple_property(OriginalUnitScaleFactor, float, 1)
    fbx_simple_property(AmbientColor, aiVector3D, aiVector3D(0,0,0))
    fbx_simple_property(DefaultCamera, std::string, "")


    enum FrameRate {
        FrameRate_DEFAULT = 0,
        FrameRate_120 = 1,
        FrameRate_100 = 2,
        FrameRate_60 = 3,
        FrameRate_50 = 4,
        FrameRate_48 = 5,
        FrameRate_30 = 6,
        FrameRate_30_DROP = 7,
        FrameRate_NTSC_DROP_FRAME = 8,
        FrameRate_NTSC_FULL_FRAME = 9,
        FrameRate_PAL = 10,
        FrameRate_CINEMA = 11,
        FrameRate_1000 = 12,
        FrameRate_CINEMA_ND = 13,
        FrameRate_CUSTOM = 14,

        FrameRate_MAX// end-of-enum sentinel
    };

    fbx_simple_enum_property(TimeMode, FrameRate, FrameRate_DEFAULT)
    fbx_simple_property(TimeSpanStart, uint64_t, 0L)
    fbx_simple_property(TimeSpanStop, uint64_t, 0L)
    fbx_simple_property(CustomFrameRate, float, -1.0f)

private:
    std::shared_ptr<const PropertyTable> props;
    const Document& doc;
};

/** DOM root for a FBX file */
class Document {
public:
    Document(Parser& parser, const ImportSettings& settings);

    ~Document();

    LazyObject* GetObject(uint64_t id) const;

    bool IsBinary() const {
        return parser.IsBinary();
    }

    unsigned int FBXVersion() const {
        return fbxVersion;
    }

    const std::string& Creator() const {
        return creator;
    }

    // elements (in this order): Year, Month, Day, Hour, Second, Millisecond
    const unsigned int* CreationTimeStamp() const {
        return creationTimeStamp;
    }

    const FileGlobalSettings& GlobalSettings() const {
        ai_assert(globals.get());
        return *globals;
    }

    const PropertyTemplateMap& Templates() const {
        return templates;
    }

    const ObjectMap& Objects() const {
        return objects;
    }

    const ImportSettings& Settings() const {
        return settings;
    }

    const ConnectionMap& ConnectionsBySource() const {
        return src_connections;
    }

    const ConnectionMap& ConnectionsByDestination() const {
        return dest_connections;
    }

    // note: the implicit rule in all DOM classes is to always resolve
    // from destination to source (since the FBX object hierarchy is,
    // with very few exceptions, a DAG, this avoids cycles). In all
    // cases that may involve back-facing edges in the object graph,
    // use LazyObject::IsBeingConstructed() to check.

    std::vector<const Connection*> GetConnectionsBySourceSequenced(uint64_t source) const;
    std::vector<const Connection*> GetConnectionsByDestinationSequenced(uint64_t dest) const;

    std::vector<const Connection*> GetConnectionsBySourceSequenced(uint64_t source, const char* classname) const;
    std::vector<const Connection*> GetConnectionsByDestinationSequenced(uint64_t dest, const char* classname) const;

    std::vector<const Connection*> GetConnectionsBySourceSequenced(uint64_t source,
        const char* const* classnames, size_t count) const;
    std::vector<const Connection*> GetConnectionsByDestinationSequenced(uint64_t dest,
        const char* const* classnames,
        size_t count) const;

    const std::vector<const AnimationStack*>& AnimationStacks() const;

private:
    std::vector<const Connection*> GetConnectionsSequenced(uint64_t id, const ConnectionMap&) const;
    std::vector<const Connection*> GetConnectionsSequenced(uint64_t id, bool is_src,
        const ConnectionMap&,
        const char* const* classnames,
        size_t count) const;
    void ReadHeader();
    void ReadObjects();
    void ReadPropertyTemplates();
    void ReadConnections();
    void ReadGlobalSettings();

private:
    const ImportSettings& settings;

    ObjectMap objects;
    Parser& parser;

    PropertyTemplateMap templates;
    ConnectionMap src_connections;
    ConnectionMap dest_connections;

    unsigned int fbxVersion;
    std::string creator;
    unsigned int creationTimeStamp[7];

    std::vector<uint64_t> animationStacks;
    mutable std::vector<const AnimationStack*> animationStacksResolved;

    std::unique_ptr<FileGlobalSettings> globals;
};

} // Namespace FBX
} // Namespace Assimp

#endif // INCLUDED_AI_FBX_DOCUMENT_H