AnyCamera.h

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/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
 
#ifndef META_OCEAN_MATH_ANY_CAMERA_H
#define META_OCEAN_MATH_ANY_CAMERA_H
 
#include "ocean/math/Math.h"
#include "ocean/math/Camera.h"
#include "ocean/math/FisheyeCamera.h"
#include "ocean/math/HomogenousMatrix4.h"
#include "ocean/math/PinholeCamera.h"
#include "ocean/math/Vector2.h"
#include "ocean/math/Vector3.h"
 
namespace Ocean
{
 
// Forward declaration.
template <typename T>
class AnyCameraT;
 
/**
 * Definition of an AnyCamera object with Scalar precision.
 * @see AnyCameraT
 * @ingroup math
 */
using AnyCamera = AnyCameraT<Scalar>;
 
/**
 * Definition of an AnyCamera object with double precision.
 * @see AnyCameraT
 * @ingroup math
 */
using AnyCameraD = AnyCameraT<double>;
 
/**
 * Definition of an AnyCamera object with float precision.
 * @see AnyCameraT
 * @ingroup math
 */
using AnyCameraF = AnyCameraT<float>;
 
/**
 * Definition of a shared pointer holding an AnyCamera object with Scalar precision.
 * @tparam T the data type of the scalar to be used either 'float' or 'double'
 * @see AnyCameraT
 * @ingroup math
 */
template <typename T>
using SharedAnyCameraT = std::shared_ptr<AnyCameraT<T>>;
 
/**
 * Definition of a shared pointer holding an AnyCamera object with Scalar precision.
 * @see AnyCameraT
 * @ingroup math
 */
using SharedAnyCamera = std::shared_ptr<AnyCamera>;
 
/**
 * Definition of a shared pointer holding an AnyCamera object with double precision.
 * @see AnyCameraT
 * @ingroup math
 */
using SharedAnyCameraD = std::shared_ptr<AnyCameraD>;
 
/**
 * Definition of a shared pointer holding an AnyCamera object with float precision.
 * @see AnyCameraT
 * @ingroup math
 */
using SharedAnyCameraF = std::shared_ptr<AnyCameraF>;
 
/**
 * Definition of a typename alias for vectors with shared AnyCameraT objects.
 * @tparam T the data type of the scalar to be used either 'float' or 'double'
 * @see VectorT2
 * @ingroup math
 */
template <typename T>
using SharedAnyCamerasT = std::vector<std::shared_ptr<AnyCameraT<T>>>;
 
/**
 * Definition of a vector holding AnyCamera objects.
 * @see AnyCamera
 * @ingroup math
 */
using SharedAnyCameras = SharedAnyCamerasT<Scalar>;
 
/**
 * Definition of a vector holding AnyCameraD objects.
 * @see AnyCameraD
 * @ingroup math
 */
using SharedAnyCamerasD = SharedAnyCamerasT<double>;
 
/**
 * Definition of a vector holding AnyCameraF objects.
 * @see AnyCameraF
 * @ingroup math
 */
using SharedAnyCamerasF = SharedAnyCamerasT<float>;
 
/**
 * Definition of individual camera types.
 * @ingroup math
 */
enum class AnyCameraType : uint32_t
{
    /// An invalid camera type.
    INVALID = 0u,
    /// A pinhole camera.
    PINHOLE,
    /// A fisheye camera.
    FISHEYE
};
 
/**
 * This class implements the abstract base class for all AnyCamera objects.
 * A custom camera object can be implemented by
 * - simply deriving a new class from this base class
 * - using the helper class AnyCameraWrappingT which helps reducing the implementation effort
 * @tparam T The data type of a scalar, 'float' or 'double'
 * @ingroup math
 */
template <typename T>
class AnyCameraT : public CameraT<T>
{
    public:
 
        /// The scalar data type of this object.
        using TScalar = T;
 
    public:
 
        /**
         * Destructs the AnyCamera object.
         */
        virtual ~AnyCameraT() = default;
 
        /**
         * Returns the type of this camera.
         * @return The camera's type
         */
        virtual AnyCameraType anyCameraType() const = 0;
 
        /**
         * Returns the name of this camera.
         * @return The camera's name
         */
        virtual std::string name() const = 0;
 
        /**
         * Returns a copy of this camera object.
         * The image resolution of the cloned camera must have the same aspect ratio as the current image resolution.
         * @param width The width of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @param height the height of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @return New instance of this camera object
         */
        virtual std::unique_ptr<AnyCameraT<T>> clone(const unsigned int width = 0u, const unsigned int height = 0u) const = 0;
 
        /**
         * Returns a copy of this camera object with float precision.
         * The image resolution of the cloned camera must have the same aspect ratio as the current image resolution.
         * @param width The width of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @param height the height of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @return New instance of this camera object
         */
        virtual std::unique_ptr<AnyCameraT<float>> cloneToFloat(const unsigned int width = 0u, const unsigned int height = 0u) const = 0;
 
        /**
         * Returns a copy of this camera object with double precision.
         * The image resolution of the cloned camera must have the same aspect ratio as the current image resolution.
         * @param width The width of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @param height the height of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @return New instance of this camera object
         */
        virtual std::unique_ptr<AnyCameraT<double>> cloneToDouble(const unsigned int width = 0u, const unsigned int height = 0u) const = 0;
 
        /**
         * Returns the width of the camera image.
         * @return Width of the camera image, in pixel, with range [0, infinity)
         */
        virtual unsigned int width() const = 0;
 
        /**
         * Returns the height of the camera image.
         * @return Height of the camera image, in pixel, with range [0, infinity)
         */
        virtual unsigned int height() const = 0;
 
        /**
         * Returns the coordinate of the principal point of the camera image in the pixel domain.
         * @return The 2D location of the principal point, with range (-infinity, infinity)x(-infinity, infinity)
         */
        virtual VectorT2<T> principalPoint() const = 0;
 
        /**
         * Returns the x-value of the principal point of the camera image in the pixel domain.
         * @return x-value of the principal point, with range (-infinity, infinity)
         */
        virtual T principalPointX() const = 0;
 
        /**
         * Returns the y-value of the principal point of the camera image in the pixel domain.
         * @return y-value of the principal point, with range (-infinity, infinity)
         */
        virtual T principalPointY() const = 0;
 
        /**
         * Returns the horizontal focal length parameter.
         * @return Horizontal focal length parameter in pixel domain, with range (0, infinity)
         */
        virtual T focalLengthX() const = 0;
 
        /**
         * Returns the vertical focal length parameter.
         * @return Vertical focal length parameter in pixel domain, with range (0, infinity)
         */
        virtual T focalLengthY() const = 0;
 
        /**
         * Returns the inverse horizontal focal length parameter.
         * @return Inverse horizontal focal length parameter in pixel domain, with range (0, infinity)
         */
        virtual T inverseFocalLengthX() const = 0;
 
        /**
         * Returns the inverse vertical focal length parameter.
         * @return Inverse vertical focal length parameter in pixel domain, with range (0, infinity)
         */
        virtual T inverseFocalLengthY() const = 0;
 
        /**
         * Returns the field of view in x direction of the camera.
         * The fov is the sum of the left and right part of the camera.
         * @return Field of view (in radian), with range (0, 2 * PI]
         */
        virtual T fovX() const = 0;
 
        /**
         * Returns the field of view in x direction of the camera.
         * The fov is the sum of the top and bottom part of the camera.
         * @return Field of view (in radian), with range (0, 2 * PI]
         */
        virtual T fovY() const = 0;
 
        /**
         * Returns whether a given 2D image point lies inside the camera frame.
         * Optional an explicit border can be defined to allow points slightly outside the camera image, or further inside the image.<br>
         * Defined a negative border size to allow image points outside the camera frame, or a positive border size to prevent points within the camera frame but close to the boundary.
         * @param imagePoint Image point to be checked, must be valid
         * @param signedBorder The optional border increasing or decreasing the rectangle in which the image point must be located, in pixels, with range (-infinity, std::min(width() / 2, height() / 2)
         * @return True, if the image point lies in the ranges [0, width())x[0, height())
         */
        virtual bool isInside(const VectorT2<T>& imagePoint, const T signedBorder = T(0)) const = 0;
 
        /**
         * Projects a 3D object point into the camera frame.
         * The projection is applied with a default camera pose, the camera is looking into the negative z-space with y-axis up.
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        virtual VectorT2<T> projectToImage(const VectorT3<T>& objectPoint) const = 0;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @param world_T_camera The camera pose, the default camera is looking into the negative z-space with y-axis up, transforming camera to world, must be valid
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        virtual VectorT2<T> projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>& objectPoint) const = 0;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * The projection is applied with a default camera pose, the camera is looking into the negative z-space with y-axis up.
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        virtual void projectToImage(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const = 0;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @param world_T_camera The camera pose, the default camera is looking into the negative z-space with y-axis up, transforming camera to world, must be valid
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        virtual void projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const = 0;
 
        /**
         * Projects a 3D object point into the camera frame.
         * The projection is applied with a default (inverted) and flipped camera pose, the camera is looking into the positive z-space with y-axis down.
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        virtual VectorT2<T> projectToImageIF(const VectorT3<T>& objectPoint) const = 0;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @param flippedCamera_T_world The inverted and flipped camera pose, the default flipped camera is looking into the positive z-space with y-axis down, transforming world to flipped camera, must be valid
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        virtual VectorT2<T> projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const = 0;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * The projection is applied with a default (inverted) and flipped camera pose, the camera is looking into the positive z-space with y-axis down.
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        virtual void projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const = 0;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @param flippedCamera_T_world The inverted and flipped camera pose, the default flipped camera is looking into the positive z-space with y-axis down, transforming world to flipped camera, must be valid
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        virtual void projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const = 0;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * The vector is determined for a default camera looking into the negative z-space with y-axis up.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         * @return Vector pointing into the negative z-space
         * @see vectorIF(), ray().
         */
        virtual VectorT3<T> vector(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector = true) const = 0;
 
        /**
         * Determines vectors starting at the camera's center and intersecting given 2D points in the image.
         * The vectors are determined for a default camera looking into the negative z-space with y-axis up.
         * @param distortedImagePoints 2D (distorted) positions within the image, with range [0, width())x[0, height()), must be valid
         * @param size The number of provided points, with range [1, infinity)
         * @param vectors The resulting vectors pointing into the negative z-space, one for each image point, must be valid
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         * @see vectorIF(), ray().
         */
        virtual void vector(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector = true) const = 0;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * The vector is determined for a default camera looking into the positive z-space with y-axis down.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         * @return Vector pointing into the positive z-space
         */
        virtual VectorT3<T> vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector = true) const = 0;
 
        /**
         * Returns vectors starting at the camera's center and intersecting a given 2D points in the image.
         * The vectors are determined for a default camera looking into the positive z-space with y-axis down.
         * @param distortedImagePoints 2D (distorted) positions within the image, with range [0, width())x[0, height()), must be valid
         * @param size The number of provided points, with range [1, infinity)
         * @param vectors The resulting vectors pointing into the positive z-space, one for each image point, must be valid
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         */
        virtual void vectorIF(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector = true) const = 0;
 
        /**
         * Returns a ray starting at the camera's center and intersecting a given 2D point in the image.
         * The ray is determined for a default camera looking into the negative z-space with y-axis up.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @param world_T_camera The pose of the camera, the extrinsic camera matrix, must be valid
         * @return The specified ray with direction pointing into the camera's negative z-space
         * @see vector().
         */
        virtual LineT3<T> ray(const VectorT2<T>& distortedImagePoint, const HomogenousMatrixT4<T>& world_T_camera) const = 0;
 
        /**
         * Returns a ray starting at the camera's center and intersecting a given 2D point in the image.
         * The ray is determined for a default camera looking into the negative z-space with y-axis up.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @return The specified ray with direction pointing into the camera's negative z-space
         * @see vector().
         */
        virtual LineT3<T> ray(const VectorT2<T>& distortedImagePoint) const = 0;
 
        /**
         * Calculates the 2x3 jacobian matrix for the 3D object point projection into the camera frame.
         * The resulting jacobian matrix has the following layout:
         * <pre>
         * | dfu / dx, dfu / dy, dfu / dz |
         * | dfv / dx, dfv / dy, dfv / dz |
         * with projection function
         * q = f(p)
         * q_u = fu(p), q_v = fv(p)
         * with 2D image point q = (q_u, q_v) and 3D object point p = (x, y, z)
         * </pre>
         * @param flippedCameraObjectPoint The 3D object point defined in relation to the inverted and flipped camera pose (camera looking into the positive z-space with y-axis pointing down).
         * @param jx The resulting first row of the Jacobian matrix, must contain three elements, must be valid
         * @param jy The resulting second row of the Jacobian matrix, must contain three elements, must be valid
         * @see pointJacobian2nx3IF().
         */
        virtual void pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const = 0;
 
        /**
         * Calculates the 2n x 3 jacobian matrix for the 3D object point projection into the camera frame.
         * The resulting jacobian matrix has the following layout:
         * <pre>
         * | dfu / dx, dfu / dy, dfu / dz | <- for object point 0
         * | dfv / dx, dfv / dy, dfv / dz |
         * |           ...                |
         * | dfu / dx, dfu / dy, dfu / dz | <- for object point n - 1
         * | dfv / dx, dfv / dy, dfv / dz |
         * with projection function
         * q = f(p)
         * q_u = fu(p), q_v = fv(p)
         * with 2D image point q = (q_u, q_v) and 3D object point p = (x, y, z)
         * </pre>
         * @param flippedCameraObjectPoints The 3D object points defined in relation to the inverted and flipped camera pose (camera looking into the positive z-space with y-axis pointing down).
         * @param numberObjectPoints The number of given 3D object points, with range [1, infinity)
         * @param jacobians The resulting 2n x 3 Jacobian matrix, with 2 * numberObjectPoints * 3 elements, must be valid
         * @see pointJacobian2x3IF().
         */
        virtual void pointJacobian2nx3IF(const VectorT3<T>* flippedCameraObjectPoints, const size_t numberObjectPoints, T* jacobians) const = 0;
 
        /**
         * Returns whether two camera objects are identical up to a given epsilon.
         * The image resolution must always be identical.
         * @param anyCamera The second camera to be used for comparison, can be invalid
         * @param eps The epsilon threshold to be used, with range [0, infinity)
         * @return True, if so
         */
        virtual bool isEqual(const AnyCameraT<T>& anyCamera, const T eps = NumericT<T>::eps()) const = 0;
 
        /**
         * Returns whether this camera is valid.
         * @return True, if so
         */
        virtual bool isValid() const = 0;
 
        /**
         * Converts an AnyCamera object with arbitrary scalar type to another AnyCamera object with arbitrary scalar type.
         * In case both scalar types are identical, the object is simply returned.
         * In case both scalar types are different, a clone is returned.
         * @param anyCamera The AnyCamera object to be converted, can be nullptr
         * @return The resulting AnyCamera object
         * @tparam U The scalar data type of the given AnyCamera object
         */
        template <typename U>
        static std::shared_ptr<AnyCameraT<T>> convert(const std::shared_ptr<AnyCameraT<U>>& anyCamera);
 
    protected:
 
        /**
         * Protected default constructor.
         */
        AnyCameraT() = default;
 
        /**
         * Protected copy constructor.
         * @param anyCamera The object to copy
         */
        AnyCameraT(const AnyCameraT<T>& anyCamera) = default;
 
        /**
         * Disabled move constructor.
         */
        AnyCameraT(AnyCameraT<T>&&) = delete;
 
        /**
         * Disabled assign operator.
         * @return Reference to this object
         */
        AnyCameraT& operator=(const AnyCameraT&) = delete;
 
        /**
         * Disabled move operator.
         * @return Reference to this object
         */
        AnyCameraT& operator=(AnyCameraT&&) = delete;
};
 
// Forward declaration.
template <typename T>
class AnyCameraClipperT;
 
/**
 * Definition of an AnyCamera clipper object with Scalar precision.
 * @see AnyCameraClipperT
 * @ingroup math
 */
using AnyCameraClipper = AnyCameraClipperT<Scalar>;
 
/**
 * Definition of an AnyCamera clipper object with double precision.
 * @see AnyCameraClipperT
 * @ingroup math
 */
using AnyCameraClipperD = AnyCameraClipperT<double>;
 
/**
 * Definition of an AnyCamera clipper object with float precision.
 * @see AnyCameraClipperT
 * @ingroup math
 */
using AnyCameraClipperF = AnyCameraClipperT<float>;
 
/**
 * This class implements a helper class allowing to check whether a 3D object point projects into the camera image (i.e., clipping against the camera's field of view).
 * The clipper uses normalized coordinates when verifying the projection behavior to avoid numerical issues when object points project far outside the image area.<br>
 * In contrast to AnyCamera::projectToImageIF() + AnyCamera::isInside(), the clipper is more precise but also more expensive.
 * @tparam T The data type of a scalar, 'float' or 'double'
 * @ingroup math
 */
template <typename T>
class AnyCameraClipperT
{
    public:
 
        /**
         * Default constructor creating an invalid object.
         */
        AnyCameraClipperT() = default;
 
        /**
         * Creates a new clipper object for a specified camera model.
         * @param camera The camera model defining the projection, must be valid
         * @param segmentSteps The number of segments to be used to determine the camera boundary, with range [2, infinity)
         */
        explicit AnyCameraClipperT(const SharedAnyCameraT<T>& camera, const size_t segmentSteps = 10);
 
        /**
         * Returns whether a 3D object point is located in front of the camera and projects into the camera image.
         * @param flippedCamera_T_world The inverted and flipped camera pose, the default flipped camera is looking into the positive z-space with y-axis down, transforming world to flipped camera, must be valid
         * @param objectPoint The 3D object point to be checked, defined in world
         * @param imagePoint Optional resulting 2D projected image point inside the camera image, nullptr if not of interest
         * @return True, if the object point projects into the camera image; False, if the object point is behind the camera or projects outside the camera image
         */
        bool projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint, VectorT2<T>* imagePoint = nullptr) const;
 
        /**
         * Returns the camera model of this clipper.
         * @return The clipper's camera model, nullptr if no camera model has been set
         */
        const SharedAnyCameraT<T>& camera() const;
 
        /**
         * Returns the width of the camera profile.
         * @return The camera image width in pixel, with range [0, infinity), 0 if no camera has been set
         */
        inline unsigned int width() const;
 
        /**
         * Returns the height of the camera profile.
         * @return The camera image height in pixel, with range [0, infinity), 0 if no camera has been set
         */
        inline unsigned int height() const;
 
        /**
         * Updates the clipper with a new camera model.
         * If the new camera is equal to the current camera, the function will return immediately without any updates.
         * @param camera The camera model defining the projection, must be valid
         * @param segmentSteps The number of segments to be used to determine the camera boundary, with range [1, infinity)
         */
        void update(const SharedAnyCameraT<T>& camera, const size_t segmentSteps = 10);
 
        /**
         * Updates the clipper with a new camera model based on a cloned copy of the provided camera.
         * If the new camera is equal to the current camera, the function will return immediately without any updates.
         * @param camera The camera model defining the projection, must be valid
         * @param segmentSteps The number of segments to be used to determine the camera boundary, with range [1, infinity)
         */
        void update(const AnyCameraT<T>& camera, const size_t segmentSteps = 10);
 
        /**
         * Returns the 2D line segments defined in the camera's normalized image plane defining the camera's boundary.
         * @return The camera boundary segments
         */
        const FiniteLinesT2<T>& cameraBoundarySegments() const;
 
        /**
         * Returns whether this clipper holds a valid camera model and is ready to be used.
         * @return True, if so
         */
        bool isValid() const;
 
    protected:
 
        /**
         * Determines the camera boundary of a given camera model in normalized image coordinates.
         * @param camera The camera model for which the boundary will be determined, must be valid
         * @param cameraBoundarySegments The resulting 2D line segments defining the camera's boundary
         * @param segmentSteps The number of segments to be used to determine the camera boundary, with range [1, infinity)
         * @return True, if succeeded
         */
        static bool determineCameraBoundary(const AnyCameraT<T>& camera, FiniteLinesT2<T>& cameraBoundarySegments, const size_t segmentSteps);
 
        /**
         * Returns whether a given normalized image point lies inside the camera's boundary.
         * @param cameraBoundarySegments The 2D line segments defining the camera's boundary, at least three
         * @param normalizedImagePoint The normalized image point to be checked
         * @return True, if if so
         */
        static bool isInside(const FiniteLinesT2<T>& cameraBoundarySegments, const VectorT2<T>& normalizedImagePoint);
 
        /**
         * Returns whether a given camera model is valid for a specified 2D image point in the camera image.
         * The function does not only check whether the provided image point re-projects back to the same image point but also whether additional image points sampled towards the principal point have the same behavior.
         * @param camera The camera model to be checked, must be valid
         * @param imagePoint The 2D image point to be checked, defined in the camera image, with range [0, width()]x[0, height()]
         * @param maximalReprojectionError The maximal allowed re-projection error in pixel, with range [0, infinity)
         * @param additionalChecksTowardsPrincipalPoint The number of additional image points sampled towards the principal point to be checked, with range [1, infinity)
         * @return True, if the camera model is valid for the specified image point
         */
        static bool isValidForPoint(const AnyCameraT<T>& camera, const VectorT2<T>& imagePoint, const T maximalReprojectionError = T(1), const unsigned int additionalChecksTowardsPrincipalPoint = 3u);
 
    protected:
 
        /// The actual camera model this clipper is based on.
        SharedAnyCameraT<T> camera_;
 
        /// The 2D line segments defined in the camera's normalized image plane defining the camera's boundary, defined in the flipped camera coordinate system with y-axis down.
        FiniteLinesT2<T> cameraBoundarySegments_;
};
 
/**
 * This class implements a specialized AnyCamera object wrapping the actual camera model.
 * The class is a helper class to simplify the implementation of specialized AnyCamera objects.
 * @tparam T The data type of a scalar, 'float' or 'double'
 * @tparam TCameraWrapper The data type of the class actually wrapping the camera object
 * @ingroup math
 */
template <typename T, typename TCameraWrapper>
class AnyCameraWrappingT final :
    public AnyCameraT<T>,
    public TCameraWrapper
{
    public:
 
        /// The scalar data type of this object.
        using TScalar = T;
 
        /// The class which is actually wrapping the camera object.
        using CameraWrapper = TCameraWrapper;
 
        /// The actual camera object wrapped by this class.
        using ActualCamera = typename TCameraWrapper::ActualCamera;
 
    public:
 
        /**
         * Creates a new AnyCamera object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit AnyCameraWrappingT(ActualCamera&& actualCamera);
 
        /**
         * Creates a new AnyCamera object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit AnyCameraWrappingT(const ActualCamera& actualCamera);
 
        /**
         * Returns the type of this camera.
         * @return The camera's type
         */
        AnyCameraType anyCameraType() const override;
 
        /**
         * Returns the name of this camera.
         * @return The camera's name
         */
        std::string name() const override;
 
        /**
         * Returns a copy of this camera object.
         * The image resolution of the cloned camera must have the same aspect ratio as the current image resolution.
         * @param width The width of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @param height the height of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @return New instance of this camera object
         */
        std::unique_ptr<AnyCameraT<T>> clone(const unsigned int width = 0u, const unsigned int height = 0u) const override;
 
        /**
         * Returns a copy of this camera object with float precision.
         * The image resolution of the cloned camera must have the same aspect ratio as the current image resolution.
         * @param width The width of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @param height the height of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @return New instance of this camera object
         */
        std::unique_ptr<AnyCameraT<float>> cloneToFloat(const unsigned int width = 0u, const unsigned int height = 0u) const override;
 
        /**
         * Returns a copy of this camera object with double precision.
         * The image resolution of the cloned camera must have the same aspect ratio as the current image resolution.
         * @param width The width of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @param height the height of the cloned camera in pixel, with range [1, infinity), 0 to use the current image resolution
         * @return New instance of this camera object
         */
        std::unique_ptr<AnyCameraT<double>> cloneToDouble(const unsigned int width = 0u, const unsigned int height = 0u) const override;
 
        /**
         * Returns the width of the camera image.
         * @return Width of the camera image, in pixel, with range [0, infinity)
         */
        unsigned int width() const override;
 
        /**
         * Returns the height of the camera image.
         * @return Height of the camera image, in pixel, with range [0, infinity)
         */
        unsigned int height() const override;
 
        /**
         * Returns the coordinate of the principal point of the camera image in the pixel domain.
         * @return The 2D location of the principal point, with range (-infinity, infinity)x(-infinity, infinity)
         */
        VectorT2<T> principalPoint() const override;
 
        /**
         * Returns the x-value of the principal point of the camera image in the pixel domain.
         * @return x-value of the principal point, with range (-infinity, infinity)
         */
        T principalPointX() const override;
 
        /**
         * Returns the y-value of the principal point of the camera image in the pixel domain.
         * @return y-value of the principal point, with range (-infinity, infinity)
         */
        T principalPointY() const override;
 
        /**
         * Returns the horizontal focal length parameter.
         * @return Horizontal focal length parameter in pixel domain, with range (0, infinity)
         */
        T focalLengthX() const override;
 
        /**
         * Returns the vertical focal length parameter.
         * @return Vertical focal length parameter in pixel domain, with range (0, infinity)
         */
        T focalLengthY() const override;
 
        /**
         * Returns the inverse horizontal focal length parameter.
         * @return Inverse horizontal focal length parameter in pixel domain, with range (0, infinity)
         */
        T inverseFocalLengthX() const override;
 
        /**
         * Returns the inverse vertical focal length parameter.
         * @return Inverse vertical focal length parameter in pixel domain, with range (0, infinity)
         */
        T inverseFocalLengthY() const override;
 
        /**
         * Returns the field of view in x direction of the camera.
         * The fov is the sum of the left and right part of the camera.
         * @return Field of view (in radian), with range (0, 2 * PI]
         */
        T fovX() const override;
 
        /**
         * Returns the field of view in x direction of the camera.
         * The fov is the sum of the top and bottom part of the camera.
         * @return Field of view (in radian), with range (0, 2 * PI]
         */
        T fovY() const override;
 
        /**
         * Returns whether a given 2D image point lies inside the camera frame.
         * Optional an explicit border can be defined to allow points slightly outside the camera image, or further inside the image.<br>
         * Defined a negative border size to allow image points outside the camera frame, or a positive border size to prevent points within the camera frame but close to the boundary.
         * @param imagePoint Image point to be checked, must be valid
         * @param signedBorder The optional border increasing or decreasing the rectangle in which the image point must be located, in pixels, with range (-infinity, std::min(width() / 2, height() / 2)
         * @return True, if the image point lies in the ranges [0, width())x[0, height())
         */
        bool isInside(const VectorT2<T>& imagePoint, const T signedBorder = T(0)) const override;
 
        /**
         * Projects a 3D object point into the camera frame.
         * The projection is applied with a default camera pose, the camera is looking into the negative z-space with y-axis up.
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        VectorT2<T> projectToImage(const VectorT3<T>& objectPoint) const override;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @param world_T_camera The camera pose, the default camera is looking into the negative z-space with y-axis up, transforming camera to world, must be valid
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        VectorT2<T> projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>& objectPoint) const override;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * The projection is applied with a default camera pose, the camera is looking into the negative z-space with y-axis up.
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        void projectToImage(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const override;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @param world_T_camera The camera pose, the default camera is looking into the negative z-space with y-axis up, transforming camera to world, must be valid
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        void projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const override;
 
        /**
         * Projects a 3D object point into the camera frame.
         * The projection is applied with a default (inverted) and flipped camera pose, the camera is looking into the positive z-space with y-axis down.
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        VectorT2<T> projectToImageIF(const VectorT3<T>& objectPoint) const override;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @param flippedCamera_T_world The inverted and flipped camera pose, the default flipped camera is looking into the positive z-space with y-axis down, transforming world to flipped camera, must be valid
         * @param objectPoint The 3D object point to project, defined in world
         * @return The projected 2D image point
         */
        VectorT2<T> projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const override;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * The projection is applied with a default (inverted) and flipped camera pose, the camera is looking into the positive z-space with y-axis down.
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        void projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const override;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @param flippedCamera_T_world The inverted and flipped camera pose, the default flipped camera is looking into the positive z-space with y-axis down, transforming world to flipped camera, must be valid
         * @param objectPoints The 3D object points to project, defined in world, must be valid
         * @param size The number of object points, with range [1, infinity)
         * @param imagePoints The resulting 2D image points, must be valid
         */
        void projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const override;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * The vector is determined for the default camera looking into the negative z-space with y-axis up.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         * @return Vector pointing into the negative z-space
         * @see vectorIF(), ray().
         */
        VectorT3<T> vector(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector = true) const override;
 
        /**
         * Determines vectors starting at the camera's center and intersecting given 2D points in the image.
         * The vectors are determined for a default camera looking into the negative z-space with y-axis up.
         * @param distortedImagePoints 2D (distorted) positions within the image, with range [0, width())x[0, height()), must be valid
         * @param size The number of provided points, with range [1, infinity)
         * @param vectors The resulting vectors pointing into the negative z-space, one for each image point, must be valid
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         * @see vectorIF(), ray().
         */
        void vector(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector = true) const override;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * The vector is determined for the default camera looking into the positive z-space with y-axis down.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         * @return Vector pointing into the positive z-space
         */
        VectorT3<T> vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector = true) const override;
 
        /**
         * Returns vectors starting at the camera's center and intersecting a given 2D points in the image.
         * The vectors are determined for a default camera looking into the positive z-space with y-axis down.
         * @param distortedImagePoints 2D (distorted) positions within the image, with range [0, width())x[0, height()), must be valid
         * @param size The number of provided points, with range [1, infinity)
         * @param vectors The resulting vectors pointing into the positive z-space, one for each image point, must be valid
         * @param makeUnitVector True, to return a vector with length 1; False, to return a vector with any length
         */
        void vectorIF(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector = true) const override;
 
        /**
         * Returns a ray starting at the camera's center and intersecting a given 2D point in the image.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @param world_T_camera The pose of the camera, the extrinsic camera matrix, must be valid
         * @return The specified ray with direction pointing into the camera's negative z-space
         * @see vector().
         */
        LineT3<T> ray(const VectorT2<T>& distortedImagePoint, const HomogenousMatrixT4<T>& world_T_camera) const override;
 
        /**
         * Returns a ray starting at the camera's center and intersecting a given 2D point in the image.
         * @param distortedImagePoint 2D (distorted) position within the image, with range [0, width())x[0, height())
         * @return The specified ray with direction pointing into the camera's negative z-space
         * @see vector().
         */
        LineT3<T> ray(const VectorT2<T>& distortedImagePoint) const override;
 
        /**
         * Calculates the 2x3 jacobian matrix for the 3D object point projection into the camera frame.
         * The resulting jacobian matrix has the following layout:
         * <pre>
         * | dfu / dx, dfu / dy, dfu / dz |
         * | dfv / dx, dfv / dy, dfv / dz |
         * with projection function
         * q = f(p)
         * q_u = fu(p), q_v = fv(p)
         * with 2D image point q = (q_u, q_v) and 3D object point p = (x, y, z)
         * </pre>
         * @param flippedCameraObjectPoint The 3D object point defined in relation to the inverted and flipped camera pose (camera looking into the positive z-space with y-axis pointing down).
         * @param jx The resulting first row of the Jacobian matrix, must contain three elements, must be valid
         * @param jy The resulting second row of the Jacobian matrix, must contain three elements, must be valid
         */
        void pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const override;
 
        /**
         * Calculates the 2n x 3 jacobian matrix for the 3D object point projection into the camera frame.
         * The resulting jacobian matrix has the following layout:
         * <pre>
         * | dfu / dx, dfu / dy, dfu / dz | <- for object point 0
         * | dfv / dx, dfv / dy, dfv / dz |
         * |           ...                |
         * | dfu / dx, dfu / dy, dfu / dz | <- for object point n - 1
         * | dfv / dx, dfv / dy, dfv / dz |
         * with projection function
         * q = f(p)
         * q_u = fu(p), q_v = fv(p)
         * with 2D image point q = (q_u, q_v) and 3D object point p = (x, y, z)
         * </pre>
         * @param flippedCameraObjectPoints The 3D object points defined in relation to the inverted and flipped camera pose (camera looking into the positive z-space with y-axis pointing down).
         * @param numberObjectPoints The number of given 3D object points, with range [1, infinity)
         * @param jacobians The resulting 2n x 3 Jacobian matrix, with 2 * numberObjectPoints * 3 elements, must be valid
         */
        void pointJacobian2nx3IF(const VectorT3<T>* flippedCameraObjectPoints, const size_t numberObjectPoints, T* jacobians) const override;
 
        /**
         * Returns whether two camera objects are identical up to a given epsilon.
         * The image resolution must always be identical.
         * @param anyCamera The second camera to be used for comparison, can be invalid
         * @param eps The epsilon threshold to be used, with range [0, infinity)
         * @return True, if so
         */
        bool isEqual(const AnyCameraT<T>& anyCamera, const T eps = NumericT<T>::eps()) const override;
 
        /**
         * Returns whether this camera is valid.
         * @return True, if so
         */
        bool isValid() const override;
};
 
/**
 * This class implements a wrapper for an actual camera object.
 * - TCameraWrapperBase implements the wrapper functions necessary for the individual camera models.
 * - CameraWrapperT implements some additional functions necessary to fully implement all necessary functions for AnyCameraT.
 * @tparam T The data type of a scalar, 'float' or 'double'
 * @tparam TCameraWrapperBase The base class implementing all functions necessary for the wrapped camera object.
 * @ingroup math
 */
template <typename T, typename TCameraWrapperBase>
class CameraWrapperT : public TCameraWrapperBase
{
    public:
 
        /**
         * Definition of the actual camera object which is wrapped in this class.
         */
        using typename TCameraWrapperBase::ActualCamera;
 
    public:
 
        /**
         * Creates a new CameraWrapperT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperT(ActualCamera&& actualCamera);
 
        /**
         * Creates a new CameraWrapperT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperT(const ActualCamera& actualCamera);
 
        /**
         * Returns the coordinate of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPoint().
         */
        inline VectorT2<T> principalPoint() const;
 
        /**
         * Returns the field of view in x direction of the camera.
         * @see AnyCameraT::fovX().
         */
        inline T fovX() const;
 
        /**
         * Returns the field of view in x direction of the camera.
         * @see AnyCameraT::fovY().
         */
        inline T fovY() const;
 
        /**
         * Returns whether a given 2D image point lies inside the camera frame.
         * @see AnyCameraT::isInside().
         */
        inline bool isInside(const VectorT2<T>& imagePoint, const T signedBorder = T(0)) const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see projectToImage().
         */
        inline VectorT2<T> projectToImage(const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see projectToImage().
         */
        inline VectorT2<T> projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see projectToImage().
         */
        inline void projectToImage(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see projectToImage().
         */
        inline void projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * @see AnyCameraT::vector().
         */
        inline VectorT3<T> vector(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const;
 
        /**
         * Determines vectors starting at the camera's center and intersecting given 2D points in the image.
         * @see AnyCameraT::vector().
         */
        inline void vector(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const;
 
        /**
         * Returns a ray starting at the camera's center and intersecting a given 2D point in the image.
         * @see ray().
         */
        inline LineT3<T> ray(const VectorT2<T>& distortedImagePoint, const HomogenousMatrixT4<T>& world_T_camera) const;
 
        /**
         * Returns a ray starting at the camera's center and intersecting a given 2D point in the image.
         * @see ray().
         */
        inline LineT3<T> ray(const VectorT2<T>& distortedImagePoint) const;
 
        /**
         * Calculates the 2x3 jacobian matrix for the 3D object point projection into the camera frame.
         * @see AnyCameraT::pointJacobian2nx3IF().
         */
        inline void pointJacobian2nx3IF(const VectorT3<T>* flippedCameraObjectPoints, const size_t numberObjectPoints, T* jacobians) const;
};
 
/**
 * This class implements the base wrapper around Ocean's pinhole camera profile.
 * The class can be used as 'TCameraWrapperBase' in 'CameraWrapperT' to create a full wrapper class e.g., 'CameraWrapperT<T, CameraWrapperBasePinholeT<T>>'.
 * @tparam T The data type of a scalar, 'float' or 'double'
 * @ingroup math
 */
template <typename T>
class CameraWrapperBasePinholeT
{
    public:
 
        /**
         * Definition of the actual camera object wrapped by this class.
         */
        using ActualCamera = PinholeCameraT<T>;
 
        /**
         * Definition of the parent WrappedCamera class using this base class.
         */
        using WrappedCamera = CameraWrapperT<T, CameraWrapperBasePinholeT<T>>;
 
    public:
 
        /**
         * Creates a new CameraWrapperBasePinholeT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperBasePinholeT(ActualCamera&& actualCamera);
 
        /**
         * Creates a new CameraWrapperBasePinholeT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperBasePinholeT(const ActualCamera& actualCamera);
 
        /**
         * Returns the actual camera object wrapped in this class.
         * @return The wrapped camera object
         */
        inline const ActualCamera& actualCamera() const;
 
        /**
         * Returns the width of the camera image.
         * @see AnyCameraT::width().
         */
        inline unsigned int width() const;
 
        /**
         * Returns the height of the camera image.
         * @see AnyCameraT::height().
         */
        inline unsigned int height() const;
 
        /**
         * Returns the x-value of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPointX().
         */
        inline T principalPointX() const;
 
        /**
         * Returns the y-value of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPointY().
         */
        inline T principalPointY() const;
 
        /**
         * Returns the horizontal focal length parameter.
         * @see AnyCameraT::focalLengthX().
         */
        inline T focalLengthX() const;
 
        /**
         * Returns the vertical focal length parameter.
         * @see AnyCameraT::focalLengthY().
         */
        inline T focalLengthY() const;
 
        /**
         * Returns the inverse horizontal focal length parameter.
         * @see AnyCameraT::inverseFocalLengthX().
         */
        inline T inverseFocalLengthX() const;
 
        /**
         * Returns the inverse vertical focal length parameter.
         * @see AnyCameraT::inverseFocalLengthY().
         */
        inline T inverseFocalLengthY() const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see AnyCameraT::projectToImageIF().
         */
        inline VectorT2<T> projectToImageIF(const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see AnyCameraT::projectToImageIF().
         */
        inline VectorT2<T> projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see AnyCameraT::projectToImageIF().
         */
        inline void projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see AnyCameraT::projectToImageIF().
         */
        inline void projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * @see AnyCameraT::vectorIF().
         */
        inline VectorT3<T> vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const;
 
        /**
         * Returns vectors starting at the camera's center and intersecting a given 2D points in the image.
         * @see AnyCameraT::vectorIF().
         */
        inline void vectorIF(const VectorT2<T>* distortedImagePoint, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const;
 
        /**
         * Calculates the 2x3 jacobian matrix for the 3D object point projection into the camera frame.
         * @see AnyCameraT::pointJacobian2x3IF().
         */
        inline void pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const;
 
        /**
         * Returns whether two camera objects are identical up to a given epsilon.
         * @see AnyCameraT::isEqual().
         */
        inline bool isEqual(const CameraWrapperBasePinholeT<T>& basePinhole, const T eps = NumericT<T>::eps()) const;
 
        /**
         * Returns whether this camera is valid.
         * @see AnyCameraT::isValid().
         */
        inline bool isValid() const;
 
        /**
         * Returns a copy of the actual camera object.
         * @return New instance of the actual camera object used in this wrapper.
         * @tparam U The scalar data type of the resulting cloned object, either 'float' or 'double'
         */
        template <typename U>
        inline std::unique_ptr<AnyCameraT<U>> clone(const unsigned int width = 0u, const unsigned int height = 0u) const;
 
        /**
         * Returns the type of this camera.
         * @see AnyCameraT::anyCameraType().
         */
        static inline AnyCameraType anyCameraType();
 
        /**
         * Returns the name of this camera.
         * @see AnyCameraT::name().
         */
        static inline std::string name();
 
    protected:
 
        /// The actual pinhole camera.
        ActualCamera actualCamera_;
};
 
/**
 * This class implements the base wrapper around Ocean's fisheye camera profile.
 * The class can be used as 'TCameraWrapperBase' in 'CameraWrapperT' to create a full wrapper class e.g., 'CameraWrapperT<T, CameraWrapperBaseFisheyeT<T>>'.
 * @tparam T The data type of a scalar, 'float' or 'double'
 * @ingroup math
 */
template <typename T>
class CameraWrapperBaseFisheyeT
{
    public:
 
        /**
         * Definition of the actual camera object wrapped by this class.
         */
        using ActualCamera = FisheyeCameraT<T>;
 
        /**
         * Definition of the parent WrappedCamera class using this base class.
         */
        using WrappedCamera = CameraWrapperT<T, CameraWrapperBaseFisheyeT<T>>;
 
    public:
 
        /**
         * Creates a new CameraWrapperBaseFisheyeT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperBaseFisheyeT(ActualCamera&& actualCamera);
 
        /**
         * Creates a new CameraWrapperBaseFisheyeT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperBaseFisheyeT(const ActualCamera& actualCamera);
 
        /**
         * Returns the actual camera object wrapped in this class.
         * @return The wrapped camera object
         */
        inline const ActualCamera& actualCamera() const;
 
        /**
         * Returns the width of the camera image.
         * @see AnyCameraT::width().
         */
        inline unsigned int width() const;
 
        /**
         * Returns the height of the camera image.
         * @see AnyCameraT::height().
         */
        inline unsigned int height() const;
 
        /**
         * Returns the coordinate of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPoint().
         */
        inline VectorT2<T> principalPoint() const;
 
        /**
         * Returns the x-value of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPointX().
         */
        inline T principalPointX() const;
 
        /**
         * Returns the y-value of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPointY().
         */
        inline T principalPointY() const;
 
        /**
         * Returns the horizontal focal length parameter.
         * @see AnyCameraT::focalLengthX().
         */
        inline T focalLengthX() const;
 
        /**
         * Returns the vertical focal length parameter.
         * @see AnyCameraT::focalLengthY().
         */
        inline T focalLengthY() const;
 
        /**
         * Returns the inverse horizontal focal length parameter.
         * @see AnyCameraT::inverseFocalLengthX().
         */
        inline T inverseFocalLengthX() const;
 
        /**
         * Returns the inverse vertical focal length parameter.
         * @see AnyCameraT::inverseFocalLengthY().
         */
        inline T inverseFocalLengthY() const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see AnyCameraT::projectToImageIF().
         */
        inline VectorT2<T> projectToImageIF(const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see AnyCameraT::projectToImageIF().
         */
        inline VectorT2<T> projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see AnyCameraT::projectToImageIF().
         */
        inline void projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see AnyCameraT::projectToImageIF().
         */
        inline void projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * @see AnyCameraT::vectorIF().
         */
        inline VectorT3<T> vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const;
 
        /**
         * Returns vectors starting at the camera's center and intersecting a given 2D points in the image.
         * @see AnyCameraT::vectorIF().
         */
        inline void vectorIF(const VectorT2<T>* distortedImagePoint, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const;
 
        /**
         * Calculates the 2x3 jacobian matrix for the 3D object point projection into the camera frame.
         * @see AnyCameraT::pointJacobian2x3IF().
         */
        inline void pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const;
 
        /**
         * Returns whether two camera objects are identical up to a given epsilon.
         * @see AnyCameraT::isEqual().
         */
        inline bool isEqual(const CameraWrapperBaseFisheyeT<T>& baseFisheye, const T eps = NumericT<T>::eps()) const;
 
        /**
         * Returns whether this camera is valid.
         * @return True, if so
         */
        inline bool isValid() const;
 
        /**
         * Returns a copy of the actual camera object.
         * @return New instance of the actual camera object used in this wrapper.
         */
        template <typename U>
        inline std::unique_ptr<AnyCameraT<U>> clone(const unsigned int width = 0u, const unsigned int height = 0u) const;
 
        /**
         * Returns the type of this camera.
         * @see AnyCamera::anyCameraType().
         */
        static inline AnyCameraType anyCameraType();
 
        /**
         * Returns the name of this camera.
         * @see AnyCamera::name().
         */
        static inline std::string name();
 
    protected:
 
        /// The actual fisheye camera object.
        ActualCamera actualCamera_;
};
 
/**
 * This class implements invalid camera profiles, e.g. when no intrinsic information is available.
 * @tparam T The data type of a 'Scalar', 'float' or 'double'
 * @ingroup math
 */
template <typename T>
class InvalidCameraT
{
    public:
 
        /**
         * Creates an invalid camera
         * @param reason The reason why no valid camera is available, must be valid
         */
        explicit InvalidCameraT(const std::string& reason);
 
        /**
         * Returns the reason of this invalid camera
         * @return The reason
         */
        const std::string& reason() const;
 
    protected:
 
        /// The reason why no valid camera is available.
        std::string reason_;
};
 
/**
 * Definition of an invalid camera object based with element precision 'Scalar'.
 * @see AnyCameraT, AnyCameraInvalidT.
 * @ingroup math
 */
using InvalidCamera = InvalidCameraT<Scalar>;
 
/**
 * Definition of an invalid camera object based with element precision 'double'.
 * @see AnyCameraT, AnyCameraInvalidT.
 * @ingroup math
 */
using InvalidCameraD = InvalidCameraT<double>;
 
/**
 * Definition of an invalid camera object based with element precision 'float'.
 * @see AnyCameraT, AnyCameraInvalidT.
 * @ingroup math
 */
using InvalidCameraF = InvalidCameraT<float>;
 
/**
 * This class implements the base wrapper around an invalid camera profile.
 * The class can be used as 'TCameraWrapperBase' in 'CameraWrapperT' to create a full wrapper class e.g., 'CameraWrapperT<T, CameraWrapperBaseInvalidT<T>>'.
 * @tparam T The data type of a scalar, 'float' or 'double'
 * @ingroup math
 */
template <typename T>
class CameraWrapperBaseInvalidT
{
    public:
 
        /**
         * Definition of the actual camera object wrapped by this class.
         */
        using ActualCamera = InvalidCameraT<T>;
 
        /**
         * Definition of the parent WrappedCamera class using this base class.
         */
        using WrappedCamera = CameraWrapperT<T, CameraWrapperBaseInvalidT<T>>;
 
    public:
 
        /**
         * Creates a new CameraWrapperBaseInvalidT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperBaseInvalidT(ActualCamera&& actualCamera);
 
        /**
         * Creates a new CameraWrapperBaseInvalidT object wrapping the actual camera model.
         * @param actualCamera The actual camera object to be wrapped
         */
        explicit CameraWrapperBaseInvalidT(const ActualCamera& actualCamera);
 
        /**
         * Returns the actual camera object wrapped in this class.
         * @return The wrapped camera object
         */
        inline const ActualCamera& actualCamera() const;
 
        /**
         * Returns the width of the camera image.
         * @see AnyCameraT::width().
         */
        inline unsigned int width() const;
 
        /**
         * Returns the height of the camera image.
         * @see AnyCameraT::height().
         */
        inline unsigned int height() const;
 
        /**
         * Returns the coordinate of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPoint().
         */
        inline VectorT2<T> principalPoint() const;
 
        /**
         * Returns the x-value of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPointX().
         */
        inline T principalPointX() const;
 
        /**
         * Returns the y-value of the principal point of the camera image in the pixel domain.
         * @see AnyCameraT::principalPointY().
         */
        inline T principalPointY() const;
 
        /**
         * Returns the horizontal focal length parameter.
         * @see AnyCameraT::focalLengthX().
         */
        inline T focalLengthX() const;
 
        /**
         * Returns the vertical focal length parameter.
         * @see AnyCameraT::focalLengthY().
         */
        inline T focalLengthY() const;
 
        /**
         * Returns the inverse horizontal focal length parameter.
         * @see AnyCameraT::inverseFocalLengthX().
         */
        inline T inverseFocalLengthX() const;
 
        /**
         * Returns the inverse vertical focal length parameter.
         * @see AnyCameraT::inverseFocalLengthY().
         */
        inline T inverseFocalLengthY() const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see AnyCameraT::projectToImageIF().
         */
        inline VectorT2<T> projectToImageIF(const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects a 3D object point into the camera frame.
         * @see AnyCameraT::projectToImageIF().
         */
        inline VectorT2<T> projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see AnyCameraT::projectToImageIF().
         */
        inline void projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Projects several 3D object points into the camera frame at once.
         * @see AnyCameraT::projectToImageIF().
         */
        inline void projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const;
 
        /**
         * Returns a vector starting at the camera's center and intersecting a given 2D point in the image.
         * @see AnyCameraT::vectorIF().
         */
        inline VectorT3<T> vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const;
 
        /**
         * Returns vectors starting at the camera's center and intersecting a given 2D points in the image.
         * @see AnyCameraT::vectorIF().
         */
        inline void vectorIF(const VectorT2<T>* distortedImagePoint, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const;
 
        /**
         * Calculates the 2x3 jacobian matrix for the 3D object point projection into the camera frame.
         * @see AnyCameraT::pointJacobian2x3IF().
         */
        inline void pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const;
 
        /**
         * Returns whether two camera objects are identical up to a given epsilon.
         * @see AnyCameraT::isEqual().
         */
        inline bool isEqual(const CameraWrapperBaseInvalidT<T>& baseInvalid, const T eps = NumericT<T>::eps()) const;
 
        /**
         * Returns whether this camera is valid.
         * @return True, if so
         */
        inline bool isValid() const;
 
        /**
         * Returns a copy of the actual camera object.
         * @return New instance of the actual camera object used in this wrapper.
         */
        template <typename U>
        inline std::unique_ptr<AnyCameraT<U>> clone(const unsigned int width = 0u, const unsigned int height = 0u) const;
 
        /**
         * Returns the type of this camera.
         * @see AnyCamera::anyCameraType().
         */
        static inline AnyCameraType anyCameraType();
 
        /**
         * Returns the name of this camera.
         * @see AnyCamera::name().
         */
        static inline std::string name();
 
    protected:
 
        /// The actual invalid camera.
        ActualCamera actualCamera_;
};
 
/**
 * Definition of an AnyCamera object based on Ocean's pinhole camera class with template parameter to define the element precision.
 * @tparam T The scalar data type
 * @see AnyCameraT, CameraWrapperBasePinholeT, AnyCameraPinhole, AnyCameraPinholeD, AnyCameraPinholeF.
 * @ingroup math
 */
template <typename T>
using AnyCameraPinholeT = AnyCameraWrappingT<T, CameraWrapperT<T, CameraWrapperBasePinholeT<T>>>;
 
/**
 * Definition of an AnyCamera object based on Ocean's pinhole camera class with element precision 'Scalar'.
 * @see AnyCameraT, AnyCameraPinholeT.
 * @ingroup math
 */
using AnyCameraPinhole = AnyCameraPinholeT<Scalar>;
 
/**
 * Definition of an AnyCamera object based on Ocean's pinhole camera class with element precision 'double'.
 * @see AnyCameraT, AnyCameraPinholeT.
 * @ingroup math
 */
using AnyCameraPinholeD = AnyCameraPinholeT<double>;
 
/**
 * Definition of an AnyCamera object based on Ocean's pinhole camera class with element precision 'float'.
 * @see AnyCameraT, AnyCameraPinholeT.
 * @ingroup math
 */
using AnyCameraPinholeF = AnyCameraPinholeT<float>;
 
/**
 * Definition of an AnyCamera object based on Ocean's fisheye camera class with template parameter to define the element precision.
 * @tparam T The scalar data type
 * @see AnyCameraT, CameraWrapperBaseFisheyeT, AnyCameraFisheye, AnyCameraFisheyeD, AnyCameraFisheyeF.
 * @ingroup math
 */
template <typename T>
using AnyCameraFisheyeT = AnyCameraWrappingT<T, CameraWrapperT<T, CameraWrapperBaseFisheyeT<T>>>;
 
/**
 * Definition of an AnyCamera object based on Ocean's fisheye camera class with element precision 'Scalar'.
 * @see AnyCameraT, AnyCameraFisheyeT.
 * @ingroup math
 */
using AnyCameraFisheye = AnyCameraFisheyeT<Scalar>;
 
/**
 * Definition of an AnyCamera object based on Ocean's fisheye camera class with element precision 'double'.
 * @see AnyCameraT, AnyCameraFisheyeT.
 * @ingroup math
 */
using AnyCameraFisheyeD = AnyCameraFisheyeT<double>;
 
/**
 * Definition of an AnyCamera object based on Ocean's fisheye camera class with element precision 'float'.
 * @see AnyCameraT, AnyCameraFisheyeT.
 * @ingroup math
 */
using AnyCameraFisheyeF = AnyCameraFisheyeT<float>;
 
/**
 * Definition of an AnyCamera object based on an invalid (by design) camera with template parameter to define the element precision.
 * @tparam T The scalar data type
 * @see AnyCameraT, CameraWrapperBaseFisheyeT, AnyCameraInvalid, AnyCameraInvalidD, AnyCameraInvalidF.
 * @ingroup math
 */
template <typename T>
using AnyCameraInvalidT = AnyCameraWrappingT<T, CameraWrapperT<T, CameraWrapperBaseInvalidT<T>>>;
 
/**
 * Definition of an AnyCamera object based on an invalid (by design) camera with element precision 'Scalar'.
 * @see AnyCameraT, AnyCameraInvalidT.
 * @ingroup math
 */
using AnyCameraInvalid = AnyCameraInvalidT<Scalar>;
 
/**
 * Definition of an AnyCamera object based on an invalid (by design) camera with element precision 'double'.
 * @see AnyCameraT, AnyCameraInvalidT.
 * @ingroup math
 */
using AnyCameraInvalidD = AnyCameraInvalidT<double>;
 
/**
 * Definition of an AnyCamera object based on an invalid (by design) camera with element precision 'float'.
 * @see AnyCameraT, AnyCameraInvalidT.
 * @ingroup math
 */
using AnyCameraInvalidF = AnyCameraInvalidT<float>;
 
template <typename T>
AnyCameraClipperT<T>::AnyCameraClipperT(const SharedAnyCameraT<T>& camera, const size_t segmentSteps)
{
    update(camera, segmentSteps);
}
 
template <typename T>
bool AnyCameraClipperT<T>::projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint, VectorT2<T>* imagePoint) const
{
    ocean_assert(camera_ != nullptr);
    ocean_assert(camera_->isValid());
    ocean_assert(flippedCamera_T_world.isValid());
 
    const VectorT3<T> cameraObjectPointIF = flippedCamera_T_world * objectPoint;
 
    if (cameraObjectPointIF.z() <= NumericT<T>::eps())
    {
        return false;
    }
 
    const T invZ = T(1) / cameraObjectPointIF.z();
 
    const VectorT2<T> normalizedImagePoint(cameraObjectPointIF.x() * invZ, cameraObjectPointIF.y() * invZ);
 
    if (!isInside(cameraBoundarySegments_, normalizedImagePoint))
    {
        return false;
    }
 
    if (imagePoint != nullptr)
    {
        *imagePoint = camera_->projectToImageIF(cameraObjectPointIF);
 
        ocean_assert_accuracy(camera_->isInside(*imagePoint, T(std::max(camera_->width(), camera_->height())) * T(-0.1)));
    }
 
    return true;
}
 
template <typename T>
const SharedAnyCameraT<T>& AnyCameraClipperT<T>::camera() const
{
    return camera_;
}
 
template <typename T>
inline unsigned int AnyCameraClipperT<T>::width() const
{
    if (camera_)
    {
        return camera_->width();
    }
 
    return 0u;
}
 
template <typename T>
inline unsigned int AnyCameraClipperT<T>::height() const
{
    if (camera_)
    {
        return camera_->height();
    }
 
    return 0u;
}
 
template <typename T>
void AnyCameraClipperT<T>::update(const SharedAnyCameraT<T>& camera, const size_t segmentSteps)
{
    ocean_assert(camera != nullptr && camera->isValid() && segmentSteps >= 1);
    if (camera == nullptr || !camera->isValid() || segmentSteps == 0)
    {
        return;
    }
 
    if (camera_ && camera_->isEqual(*camera))
    {
        ocean_assert(isValid());
        return;
    }
 
    cameraBoundarySegments_.clear();
 
    if (determineCameraBoundary(*camera, cameraBoundarySegments_, segmentSteps))
    {
        camera_ = camera;
    }
    else
    {
        camera_ = nullptr;
        cameraBoundarySegments_.clear();
    }
 
    ocean_assert(isValid());
}
 
template <typename T>
void AnyCameraClipperT<T>::update(const AnyCameraT<T>& camera, const size_t segmentSteps)
{
    ocean_assert(camera.isValid() && segmentSteps >= 1);
    if (!camera.isValid() || segmentSteps == 0)
    {
        return;
    }
 
    if (camera_ && camera_->isEqual(camera))
    {
        ocean_assert(isValid());
        return;
    }
 
    cameraBoundarySegments_.clear();
 
    if (determineCameraBoundary(camera, cameraBoundarySegments_, segmentSteps))
    {
        camera_ = camera.clone();
    }
    else
    {
        camera_ = nullptr;
        cameraBoundarySegments_.clear();
    }
 
    ocean_assert(isValid());
}
 
template <typename T>
const FiniteLinesT2<T>& AnyCameraClipperT<T>::cameraBoundarySegments() const
{
    return cameraBoundarySegments_;
}
 
template <typename T>
bool AnyCameraClipperT<T>::isValid() const
{
    ocean_assert(camera_ == nullptr || !cameraBoundarySegments_.empty());
 
    return camera_ != nullptr;
}
 
template <typename T>
bool AnyCameraClipperT<T>::determineCameraBoundary(const AnyCameraT<T>& camera, FiniteLinesT2<T>& cameraBoundarySegments, const size_t segmentSteps)
{
    ocean_assert(camera.isValid());
    if (!camera.isValid())
    {
        return false;
    }
 
    ocean_assert(segmentSteps >= 1);
    if (segmentSteps < 1)
    {
        return false;
    }
 
    constexpr unsigned int border = 0u;
 
    const std::array<VectorT2<T>, 4> corners =
    {
        VectorT2<T>(T(border), T(border)),
        VectorT2<T>(T(border), T(camera.height() - border - 1u)),
        VectorT2<T>(T(camera.width() - border - 1u), T(camera.height() - border - 1u)),
        VectorT2<T>(T(camera.width() - border - 1u), T(border))
    };
 
    const VectorT2<T> principalPoint = camera.principalPoint();
 
    constexpr T maximalSqrDistance = NumericT<T>::sqr(T(1));
 
    // let's first check whether the camera model is precise enough at the principal point
 
    const VectorT3<T> principalObjectPoint = camera.vectorIF(principalPoint, false /*makeUnitVector*/);
 
    const T sqrProjectionErrorPrincipalPoint = camera.projectToImageIF(principalObjectPoint).sqrDistance(principalPoint);
 
    if (sqrProjectionErrorPrincipalPoint > maximalSqrDistance)
    {
        ocean_assert(false && "The camera model is not precise enough");
        return false;
    }
 
    VectorsT2<T> normalizedImagePoints;
    normalizedImagePoints.reserve(corners.size() * segmentSteps);
 
    for (size_t nCorner = 0; nCorner < corners.size(); ++nCorner)
    {
        const VectorT2<T>& corner0 = corners[nCorner];
        const VectorT2<T>& corner1 = corners[(nCorner + 1u) % corners.size()];
 
        for (size_t nStep = 0; nStep < segmentSteps; ++nStep)
        {
            const T factor = T(nStep) / T(segmentSteps);
 
            const VectorT2<T> distortedImagePoint = corner0 * (T(1) - factor) + corner1 * factor;
 
            const VectorT2<T> offsetTowardsPrincipalPoint = (principalPoint - distortedImagePoint).normalizedOrZero() * T(1.0); // one pixel towards the principal point
 
            VectorT3<T> objectPoint = VectorT3<T>::minValue();
 
            if (isValidForPoint(camera, distortedImagePoint, maximalSqrDistance, 3u))
            {
                objectPoint = camera.vectorIF(distortedImagePoint, false /*makeUnitVector*/);
            }
            else
            {
                // un-projecting and re-projecting the distorted image point did not result in a similar image point, so the camera model is not well defined in this area
                // so let's try to find the point closest to the image boundary which is precise enough
 
                // | image boundary             ideal point              principal point |
 
                VectorT2<T> boundaryImagePoint = distortedImagePoint;
                VectorT2<T> centerImagePoint = principalPoint;
 
                objectPoint = principalObjectPoint;
 
                constexpr unsigned int iterations = 20u;
 
                for (unsigned int nIteration = 0u; nIteration < iterations; ++nIteration)
                {
                    if (boundaryImagePoint.sqrDistance(centerImagePoint) <= maximalSqrDistance)
                    {
                        break;
                    }
 
                    const VectorT2<T> middleImagePoint = (boundaryImagePoint + centerImagePoint) * T(0.5);
 
                    const VectorT3<T> middleObjectPoint = camera.vectorIF(middleImagePoint, false /*makeUnitVector*/);
                    const VectorT2<T> projectedMiddleObjectPoint = camera.projectToImageIF(middleObjectPoint);
 
                    const T sqrMiddleDistance = middleImagePoint.sqrDistance(projectedMiddleObjectPoint);
 
                    if (sqrMiddleDistance <= maximalSqrDistance)
                    {
                        centerImagePoint = middleImagePoint;
 
                        objectPoint = camera.vectorIF(middleImagePoint + offsetTowardsPrincipalPoint, false /*makeUnitVector*/);
                    }
                    else
                    {
                        boundaryImagePoint = middleImagePoint;
                    }
                }
            }
 
            if (objectPoint != VectorT3<T>::minValue())
            {
                ocean_assert(objectPoint.z() >= NumericT<T>::eps());
                const VectorT2<T> normalizedImagePoint  = objectPoint.xy() / objectPoint.z();
 
                normalizedImagePoints.emplace_back(normalizedImagePoint.x(), normalizedImagePoint.y());
            }
        }
    }
 
    ocean_assert(normalizedImagePoints.size() >= 3);
 
    ocean_assert(cameraBoundarySegments.empty());
    cameraBoundarySegments.clear();
 
    cameraBoundarySegments.reserve(normalizedImagePoints.size());
 
    for (size_t n = 1; n < normalizedImagePoints.size(); ++n)
    {
        cameraBoundarySegments.emplace_back(normalizedImagePoints[n - 1], normalizedImagePoints[n]);
    }
 
    cameraBoundarySegments.emplace_back(normalizedImagePoints.back(), normalizedImagePoints.front());
 
    return true;
}
 
template <typename T>
bool AnyCameraClipperT<T>::isInside(const FiniteLinesT2<T>& cameraBoundarySegments, const VectorT2<T>& normalizedImagePoint)
{
    ocean_assert(cameraBoundarySegments.size() >= 3);
 
    size_t counter = 0;
 
    for (const FiniteLineT2<T>& cameraBoundarySegment : cameraBoundarySegments)
    {
        // let's check whether the point is above or below the line segment
 
        const bool segmentTopDown = cameraBoundarySegment.point0().y() < cameraBoundarySegment.point1().y();
 
        if (segmentTopDown)
        {
            if (cameraBoundarySegment.point1().y() < normalizedImagePoint.y() || normalizedImagePoint.y() < cameraBoundarySegment.point0().y())
            {
                continue;
            }
        }
        else
        {
            if (cameraBoundarySegment.point0().y() < normalizedImagePoint.y() || normalizedImagePoint.y() < cameraBoundarySegment.point1().y())
            {
                continue;
            }
        }
 
        if (cameraBoundarySegment.isOnLine(normalizedImagePoint))
        {
            // the point is on the line segment, so we know the point is inside the camera boundary
 
            return true;
        }
 
        if (cameraBoundarySegment.isLeftOfLine(normalizedImagePoint) == segmentTopDown)
        {
            // the point is on the left side of the line segment, we only count points on the right side
            continue;
        }
 
        ++counter;
    }
 
    return counter % 2 == 1;
}
 
template <typename T>
bool AnyCameraClipperT<T>::isValidForPoint(const AnyCameraT<T>& camera, const VectorT2<T>& imagePoint, const T maximalReprojectionError, const unsigned int additionalChecksTowardsPrincipalPoint)
{
    ocean_assert(camera.isValid());
    ocean_assert(camera.isInside(imagePoint, T(-1)));
    ocean_assert(maximalReprojectionError >= T(0));
    ocean_assert(additionalChecksTowardsPrincipalPoint >= 1u);
 
    const VectorT3<T> objectPoint = camera.vectorIF(imagePoint, false /*makeUnitVector*/);
    const VectorT2<T> projectedObjectPoint = camera.projectToImageIF(objectPoint);
 
    if (imagePoint.sqrDistance(projectedObjectPoint) > NumericT<T>::sqr(maximalReprojectionError))
    {
        // simple case, the point does not re-project back to the same image point
        return false;
    }
 
    const VectorT2<T> principalPoint = camera.principalPoint();
 
    const VectorT2<T> direction = (principalPoint - imagePoint).normalizedOrZero();
 
    if (direction.isNull())
    {
        // we check the principal point
        return true;
    }
 
    for (unsigned int n = 0u; n < std::min(additionalChecksTowardsPrincipalPoint, 10u); ++n)
    {
        const VectorT2<T> additionalImagePoint = imagePoint + direction * T(n + 1u);
 
        const VectorT3<T> additionalObjectPoint = camera.vectorIF(additionalImagePoint, false /*makeUnitVector*/);
        const VectorT2<T> additionalProjectedObjectPoint = camera.projectToImageIF(additionalObjectPoint);
 
        if (additionalImagePoint.sqrDistance(additionalProjectedObjectPoint) > NumericT<T>::sqr(maximalReprojectionError))
        {
            return false;
        }
    }
 
    return true;
}
 
template <>
template <>
inline std::shared_ptr<AnyCameraT<float>> AnyCameraT<float>::convert(const std::shared_ptr<AnyCameraT<double>>& anyCamera)
{
    if (anyCamera)
    {
        return anyCamera->cloneToFloat();
    }
 
    return nullptr;
}
 
template <>
template <>
inline std::shared_ptr<AnyCameraT<double>> AnyCameraT<double>::convert(const std::shared_ptr<AnyCameraT<float>>& anyCamera)
{
    if (anyCamera)
    {
        return anyCamera->cloneToDouble();
    }
 
    return nullptr;
}
 
template <typename T>
template <typename U>
std::shared_ptr<AnyCameraT<T>> AnyCameraT<T>::convert(const std::shared_ptr<AnyCameraT<U>>& anyCamera)
{
    static_assert(std::is_same<T, U>::value, "Invalid data types!");
 
    return anyCamera;
}
 
template <typename T, typename TCameraWrapper>
AnyCameraWrappingT<T, TCameraWrapper>::AnyCameraWrappingT(ActualCamera&& actualCamera) :
    TCameraWrapper(std::move(actualCamera))
{
    // nothing to do here
}
 
template <typename T, typename TCameraWrapper>
AnyCameraWrappingT<T, TCameraWrapper>::AnyCameraWrappingT(const ActualCamera& actualCamera) :
    TCameraWrapper(actualCamera)
{
    // nothing to do here
}
 
template <typename T, typename TCameraWrapper>
AnyCameraType AnyCameraWrappingT<T, TCameraWrapper>::anyCameraType() const
{
    return TCameraWrapper::anyCameraType();
}
 
template <typename T, typename TCameraWrapper>
std::string AnyCameraWrappingT<T, TCameraWrapper>::name() const
{
    return TCameraWrapper::name();
}
 
template <typename T, typename TCameraWrapper>
std::unique_ptr<AnyCameraT<T>> AnyCameraWrappingT<T, TCameraWrapper>::clone(const unsigned int width, const unsigned int height) const
{
    return TCameraWrapper::template clone<T>(width, height);
}
 
template <typename T, typename TCameraWrapper>
std::unique_ptr<AnyCameraT<float>> AnyCameraWrappingT<T, TCameraWrapper>::cloneToFloat(const unsigned int width, const unsigned int height) const
{
    return TCameraWrapper::template clone<float>(width, height);
}
 
template <typename T, typename TCameraWrapper>
std::unique_ptr<AnyCameraT<double>> AnyCameraWrappingT<T, TCameraWrapper>::cloneToDouble(const unsigned int width, const unsigned int height) const
{
    return TCameraWrapper::template clone<double>(width, height);
}
 
template <typename T, typename TCameraWrapper>
unsigned int AnyCameraWrappingT<T, TCameraWrapper>::width() const
{
    return TCameraWrapper::width();
}
 
template <typename T, typename TCameraWrapper>
unsigned int AnyCameraWrappingT<T, TCameraWrapper>::height() const
{
    return TCameraWrapper::height();
}
 
template <typename T, typename TCameraWrapper>
VectorT2<T> AnyCameraWrappingT<T, TCameraWrapper>::principalPoint() const
{
    return TCameraWrapper::principalPoint();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::principalPointX() const
{
    return TCameraWrapper::principalPointX();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::principalPointY() const
{
    return TCameraWrapper::principalPointY();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::focalLengthX() const
{
    return TCameraWrapper::focalLengthX();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::focalLengthY() const
{
    return TCameraWrapper::focalLengthY();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::inverseFocalLengthX() const
{
    return TCameraWrapper::inverseFocalLengthX();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::inverseFocalLengthY() const
{
    return TCameraWrapper::inverseFocalLengthY();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::fovX() const
{
    return TCameraWrapper::fovX();
}
 
template <typename T, typename TCameraWrapper>
T AnyCameraWrappingT<T, TCameraWrapper>::fovY() const
{
    return TCameraWrapper::fovY();
}
 
template <typename T, typename TCameraWrapper>
bool AnyCameraWrappingT<T, TCameraWrapper>::isInside(const VectorT2<T>& imagePoint, const T signedBorder) const
{
    return TCameraWrapper::isInside(imagePoint, signedBorder);
}
 
template <typename T, typename TCameraWrapper>
VectorT2<T> AnyCameraWrappingT<T, TCameraWrapper>::projectToImage(const VectorT3<T>& objectPoint) const
{
    return TCameraWrapper::projectToImage(objectPoint);
}
 
template <typename T, typename TCameraWrapper>
VectorT2<T> AnyCameraWrappingT<T, TCameraWrapper>::projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>& objectPoint) const
{
    return TCameraWrapper::projectToImage(world_T_camera, objectPoint);
}
 
template <typename T, typename TCameraWrapper>
VectorT2<T> AnyCameraWrappingT<T, TCameraWrapper>::projectToImageIF(const VectorT3<T>& objectPoint) const
{
    return TCameraWrapper::projectToImageIF(objectPoint);
}
 
template <typename T, typename TCameraWrapper>
VectorT2<T> AnyCameraWrappingT<T, TCameraWrapper>::projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const
{
    return TCameraWrapper::projectToImageIF(flippedCamera_T_world, objectPoint);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::projectToImage(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    return TCameraWrapper::projectToImage(objectPoints, size, imagePoints);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    return TCameraWrapper::projectToImage(world_T_camera, objectPoints, size, imagePoints);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    return TCameraWrapper::projectToImageIF(objectPoints, size, imagePoints);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    return TCameraWrapper::projectToImageIF(flippedCamera_T_world, objectPoints, size, imagePoints);
}
 
template <typename T, typename TCameraWrapper>
VectorT3<T> AnyCameraWrappingT<T, TCameraWrapper>::vector(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const
{
    return TCameraWrapper::vector(distortedImagePoint, makeUnitVector);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::vector(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const
{
    return TCameraWrapper::vector(distortedImagePoints, size, vectors, makeUnitVector);
}
 
template <typename T, typename TCameraWrapper>
VectorT3<T> AnyCameraWrappingT<T, TCameraWrapper>::vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const
{
    return TCameraWrapper::vectorIF(distortedImagePoint, makeUnitVector);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::vectorIF(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const
{
    return TCameraWrapper::vectorIF(distortedImagePoints, size, vectors, makeUnitVector);
}
 
template <typename T, typename TCameraWrapper>
LineT3<T> AnyCameraWrappingT<T, TCameraWrapper>::ray(const VectorT2<T>& distortedImagePoint, const HomogenousMatrixT4<T>& world_T_camera) const
{
    return TCameraWrapper::ray(distortedImagePoint, world_T_camera);
}
 
template <typename T, typename TCameraWrapper>
LineT3<T> AnyCameraWrappingT<T, TCameraWrapper>::ray(const VectorT2<T>& distortedImagePoint) const
{
    return TCameraWrapper::ray(distortedImagePoint);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const
{
    return TCameraWrapper::pointJacobian2x3IF(flippedCameraObjectPoint, jx, jy);
}
 
template <typename T, typename TCameraWrapper>
void AnyCameraWrappingT<T, TCameraWrapper>::pointJacobian2nx3IF(const VectorT3<T>* flippedCameraObjectPoints, const size_t numberObjectPoints, T* jacobians) const
{
    return TCameraWrapper::pointJacobian2nx3IF(flippedCameraObjectPoints, numberObjectPoints, jacobians);
}
 
template <typename T, typename TCameraWrapper>
bool AnyCameraWrappingT<T, TCameraWrapper>::isEqual(const AnyCameraT<T>& anyCamera, const T eps) const
{
    ocean_assert(eps >= T(0));
 
    if (isValid() != anyCamera.isValid())
    {
        // one camera is value, one is not valid
        return false;
    }
 
    if (!isValid())
    {
        // both cameras are invalid
        return true;
    }
 
    if (name() != anyCamera.name())
    {
        return false;
    }
 
    return TCameraWrapper::isEqual((const AnyCameraWrappingT<T, TCameraWrapper>&)(anyCamera), eps);
}
 
template <typename T, typename TCameraWrapper>
bool AnyCameraWrappingT<T, TCameraWrapper>::isValid() const
{
    return TCameraWrapper::isValid();
}
 
template <typename T, typename TCameraWrapperBase>
CameraWrapperT<T, TCameraWrapperBase>::CameraWrapperT(ActualCamera&& actualCamera) :
    TCameraWrapperBase(std::move(actualCamera))
{
    // nothing to do here
}
 
template <typename T, typename TCameraWrapperBase>
CameraWrapperT<T, TCameraWrapperBase>::CameraWrapperT(const ActualCamera& actualCamera) :
    TCameraWrapperBase(actualCamera)
{
    // nothing to do here
}
 
template <typename T, typename TCameraWrapperBase>
inline VectorT2<T> CameraWrapperT<T, TCameraWrapperBase>::principalPoint() const
{
    return VectorT2<T>(TCameraWrapperBase::principalPointX(), TCameraWrapperBase::principalPointY());
}
 
template <typename T, typename TCameraWrapperBase>
inline T CameraWrapperT<T, TCameraWrapperBase>::fovX() const
{
    ocean_assert(TCameraWrapperBase::isValid());
 
    /**
     * x = Fx * X / Z + mx
     *
     * (x - mx) / Fx = X / Z
     */
 
    if (NumericT<T>::isEqualEps(TCameraWrapperBase::focalLengthX()))
    {
        return T(0);
    }
 
    const T leftAngle = NumericT<T>::abs(NumericT<T>::atan(-TCameraWrapperBase::principalPointX() * TCameraWrapperBase::inverseFocalLengthX()));
 
    if (T(TCameraWrapperBase::width()) <= TCameraWrapperBase::principalPointX())
    {
        ocean_assert(false && "Invalid principal point");
        return T(2) * leftAngle;
    }
 
    const T rightAngle = NumericT<T>::atan((T(TCameraWrapperBase::width()) - TCameraWrapperBase::principalPointX()) * TCameraWrapperBase::inverseFocalLengthX());
 
    return leftAngle + rightAngle;
}
 
template <typename T, typename TCameraWrapperBase>
inline T CameraWrapperT<T, TCameraWrapperBase>::fovY() const
{
    ocean_assert(TCameraWrapperBase::isValid());
 
    /**
     * y = Fy * Y / Z + my
     *
     * (y - my) / Fy = Y / Z
     */
 
    if (NumericT<T>::isEqualEps(TCameraWrapperBase::focalLengthY()))
    {
        return T(0);
    }
 
    const T topAngle = NumericT<T>::abs(NumericT<T>::atan(-TCameraWrapperBase::principalPointY() * TCameraWrapperBase::inverseFocalLengthY()));
 
    if (T(TCameraWrapperBase::height()) <= TCameraWrapperBase::principalPointY())
    {
        ocean_assert(false && "Invalid principal point");
        return T(2) * topAngle;
    }
 
    const T bottomAngle = NumericT<T>::atan((T(TCameraWrapperBase::height()) - TCameraWrapperBase::principalPointY()) * TCameraWrapperBase::inverseFocalLengthY());
 
    return topAngle + bottomAngle;
}
 
template <typename T, typename TCameraWrapperBase>
inline bool CameraWrapperT<T, TCameraWrapperBase>::isInside(const VectorT2<T>& imagePoint, const T signedBorder) const
{
    ocean_assert(TCameraWrapperBase::isValid());
 
    const unsigned int cameraWidth = TCameraWrapperBase::width();
    const unsigned int cameraHeight = TCameraWrapperBase::height();
 
    ocean_assert(signedBorder < T(std::min(cameraWidth / 2u, cameraHeight / 2u)));
 
    return imagePoint.x() >= signedBorder && imagePoint.y() >= signedBorder
            && imagePoint.x() < T(cameraWidth) - signedBorder && imagePoint.y() < T(cameraHeight) - signedBorder;
}
 
template <typename T, typename TCameraWrapperBase>
inline VectorT2<T> CameraWrapperT<T, TCameraWrapperBase>::projectToImage(const VectorT3<T>& objectPoint) const
{
    return TCameraWrapperBase::projectToImageIF(VectorT3<T>(objectPoint.x(), -objectPoint.y(), -objectPoint.z()));
}
 
template <typename T, typename TCameraWrapperBase>
inline VectorT2<T> CameraWrapperT<T, TCameraWrapperBase>::projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>& objectPoint) const
{
    return TCameraWrapperBase::projectToImageIF(CameraT<T>::standard2InvertedFlipped(world_T_camera), objectPoint);
}
 
template <typename T, typename TCameraWrapperBase>
inline void CameraWrapperT<T, TCameraWrapperBase>::projectToImage(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    ocean_assert(size == 0 || objectPoints != nullptr);
    ocean_assert(size == 0 || imagePoints != nullptr);
 
    for (size_t n = 0; n < size; ++n)
    {
        const VectorT3<T>& objectPoint = objectPoints[n];
        imagePoints[n] = TCameraWrapperBase::projectToImageIF(VectorT3<T>(objectPoint.x(), -objectPoint.y(), -objectPoint.z()));
    }
}
 
template <typename T, typename TCameraWrapperBase>
inline void CameraWrapperT<T, TCameraWrapperBase>::projectToImage(const HomogenousMatrixT4<T>& world_T_camera, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    return TCameraWrapperBase::projectToImageIF(CameraT<T>::standard2InvertedFlipped(world_T_camera), objectPoints, size, imagePoints);
}
 
template <typename T, typename TCameraWrapperBase>
inline VectorT3<T> CameraWrapperT<T, TCameraWrapperBase>::vector(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const
{
    const VectorT3<T> localVectorIF(TCameraWrapperBase::vectorIF(distortedImagePoint, makeUnitVector));
 
    return VectorT3<T>(localVectorIF.x(), -localVectorIF.y(), -localVectorIF.z());
}
 
template <typename T, typename TCameraWrapperBase>
inline void CameraWrapperT<T, TCameraWrapperBase>::vector(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const
{
    TCameraWrapperBase::vectorIF(distortedImagePoints, size, vectors, makeUnitVector);
 
    for (size_t n = 0; n < size; ++n)
    {
        const VectorT3<T>& localVectorIF = vectors[n];
 
        vectors[n] = VectorT3<T>(localVectorIF.x(), -localVectorIF.y(), -localVectorIF.z());
    }
}
 
template <typename T, typename TCameraWrapperBase>
inline LineT3<T> CameraWrapperT<T, TCameraWrapperBase>::ray(const VectorT2<T>& distortedImagePoint, const HomogenousMatrixT4<T>& world_T_camera) const
{
    ocean_assert(TCameraWrapperBase::isValid() && world_T_camera.isValid());
 
    return LineT3<T>(world_T_camera.translation(), world_T_camera.rotationMatrix(vector(distortedImagePoint, true /*makeUnitVector*/)));
}
 
template <typename T, typename TCameraWrapperBase>
inline LineT3<T> CameraWrapperT<T, TCameraWrapperBase>::ray(const VectorT2<T>& distortedImagePoint) const
{
    ocean_assert(TCameraWrapperBase::isValid());
 
    return LineT3<T>(VectorT3<T>(0, 0, 0), vector(distortedImagePoint, true /*makeUnitVector*/));
}
 
template <typename T, typename TCameraWrapperBase>
inline void CameraWrapperT<T, TCameraWrapperBase>::pointJacobian2nx3IF(const VectorT3<T>* flippedCameraObjectPoints, const size_t numberObjectPoints, T* jacobians) const
{
    ocean_assert(flippedCameraObjectPoints != nullptr);
    ocean_assert(numberObjectPoints >= 1);
    ocean_assert(jacobians != nullptr);
 
    for (size_t n = 0; n < numberObjectPoints; ++n)
    {
        TCameraWrapperBase::pointJacobian2x3IF(flippedCameraObjectPoints[n], jacobians + 0, jacobians + 3);
        jacobians += 6;
    }
}
 
template <typename T>
CameraWrapperBasePinholeT<T>::CameraWrapperBasePinholeT(ActualCamera&& actualCamera) :
    actualCamera_(std::move(actualCamera))
{
    // nothing to do here
}
 
template <typename T>
CameraWrapperBasePinholeT<T>::CameraWrapperBasePinholeT(const ActualCamera& actualCamera) :
    actualCamera_(actualCamera)
{
    // nothing to do here
}
 
template <typename T>
inline const typename CameraWrapperBasePinholeT<T>::ActualCamera& CameraWrapperBasePinholeT<T>::actualCamera() const
{
    return actualCamera_;
}
 
template <typename T>
inline unsigned int CameraWrapperBasePinholeT<T>::width() const
{
    return actualCamera_.width();
}
 
template <typename T>
inline unsigned int CameraWrapperBasePinholeT<T>::height() const
{
    return actualCamera_.height();
}
 
template <typename T>
inline T CameraWrapperBasePinholeT<T>::principalPointX() const
{
    return T(actualCamera_.principalPointX());
}
 
template <typename T>
inline T CameraWrapperBasePinholeT<T>::principalPointY() const
{
    return T(actualCamera_.principalPointY());
}
 
template <typename T>
inline T CameraWrapperBasePinholeT<T>::focalLengthX() const
{
    return T(actualCamera_.focalLengthX());
}
 
template <typename T>
inline T CameraWrapperBasePinholeT<T>::focalLengthY() const
{
    return T(actualCamera_.focalLengthY());
}
 
template <typename T>
inline T CameraWrapperBasePinholeT<T>::inverseFocalLengthX() const
{
    return T(actualCamera_.inverseFocalLengthX());
}
 
template <typename T>
inline T CameraWrapperBasePinholeT<T>::inverseFocalLengthY() const
{
    return T(actualCamera_.inverseFocalLengthY());
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBasePinholeT<T>::projectToImageIF(const VectorT3<T>& objectPoint) const
{
    return VectorT2<T>(actualCamera_.template projectToImageIF<true>(HomogenousMatrixT4<T>(true), objectPoint, true));
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBasePinholeT<T>::projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const
{
    return VectorT2<T>(actualCamera_.template projectToImageIF<true>(flippedCamera_T_world, objectPoint, true));
}
 
template <typename T>
inline void CameraWrapperBasePinholeT<T>::projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    ocean_assert(size == 0 || objectPoints != nullptr);
    ocean_assert(size == 0 || imagePoints != nullptr);
 
    for (size_t n = 0; n < size; ++n)
    {
        imagePoints[n] = projectToImageIF(objectPoints[n]);
    }
}
 
template <typename T>
inline void CameraWrapperBasePinholeT<T>::projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    ocean_assert(size == 0 || objectPoints != nullptr);
    ocean_assert(size == 0 || imagePoints != nullptr);
 
    for (size_t n = 0; n < size; ++n)
    {
        imagePoints[n] = projectToImageIF(flippedCamera_T_world, objectPoints[n]);
    }
}
 
template <typename T>
inline VectorT3<T> CameraWrapperBasePinholeT<T>::vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const
{
    const VectorT2<T> undistortedImagePoint(actualCamera_.template undistort<true>(distortedImagePoint));
 
    return VectorT3<T>(actualCamera_.vectorIF(undistortedImagePoint, makeUnitVector));
}
 
template <typename T>
inline void CameraWrapperBasePinholeT<T>::vectorIF(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const
{
    ocean_assert(distortedImagePoints != nullptr && size > 0);
    ocean_assert(vectors != nullptr);
 
    for (size_t n = 0; n < size; ++n)
    {
        vectors[n] = vectorIF(distortedImagePoints[n], makeUnitVector);
    }
}
 
template <typename T>
inline void CameraWrapperBasePinholeT<T>::pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const
{
    ocean_assert(jx != nullptr && jy != nullptr);
    actualCamera_.template pointJacobian2x3IF<T, true>(flippedCameraObjectPoint, jx, jy);
}
 
template <typename T>
inline bool CameraWrapperBasePinholeT<T>::isEqual(const CameraWrapperBasePinholeT<T>& basePinhole, const T eps) const
{
    ocean_assert(eps >= T(0));
 
    return actualCamera_.isEqual(basePinhole.actualCamera_, eps);
}
 
template <typename T>
inline bool CameraWrapperBasePinholeT<T>::isValid() const
{
    return actualCamera_.isValid();
}
 
template <typename T>
template <typename U>
inline std::unique_ptr<AnyCameraT<U>> CameraWrapperBasePinholeT<T>::clone(const unsigned int width, const unsigned int height) const
{
    ocean_assert(actualCamera_.isValid());
 
    if constexpr (std::is_same<T, U>::value)
    {
        if ((width == 0u && height == 0u) || (width == actualCamera_.width() && height == actualCamera_.height()))
        {
            return std::make_unique<AnyCameraWrappingT<U, CameraWrapperT<U, CameraWrapperBasePinholeT<U>>>>(actualCamera_);
        }
 
        const unsigned int validWidth = (height * actualCamera_.width() + actualCamera_.height() / 2u) / actualCamera_.height();
        const unsigned int validHeight = (width * actualCamera_.height() + actualCamera_.width() / 2u) / actualCamera_.width();
 
        if (!NumericT<unsigned int>::isEqual(width, validWidth, 1u) && !NumericT<unsigned int>::isEqual(height, validHeight, 1u)) // either of the valid width/height needs to be close by 1 pixel
        {
            ocean_assert(false && "Wrong aspect ratio!");
            return nullptr;
        }
 
        return std::make_unique<AnyCameraWrappingT<U, CameraWrapperT<U, CameraWrapperBasePinholeT<U>>>>(PinholeCameraT<U>(width, height, actualCamera_));
    }
    else
    {
        const PinholeCameraT<U> convertedPinholeCamera(actualCamera_);
 
        if ((width == 0u && height == 0u) || (width == actualCamera_.width() && height == actualCamera_.height()))
        {
            return std::make_unique<AnyCameraWrappingT<U, CameraWrapperT<U, CameraWrapperBasePinholeT<U>>>>(convertedPinholeCamera);
        }
 
        const unsigned int validWidth = (height * actualCamera_.width() + actualCamera_.height() / 2u) / actualCamera_.height();
        const unsigned int validHeight = (width * actualCamera_.height() + actualCamera_.width() / 2u) / actualCamera_.width();
 
        if (!NumericT<unsigned int>::isEqual(width, validWidth, 1u) && !NumericT<unsigned int>::isEqual(height, validHeight, 1u)) // either of the valid width/height needs to be close by 1 pixel
        {
            ocean_assert(false && "Wrong aspect ratio!");
            return nullptr;
        }
 
        return std::make_unique<AnyCameraWrappingT<U, CameraWrapperT<U, CameraWrapperBasePinholeT<U>>>>(PinholeCameraT<U>(width, height, convertedPinholeCamera));
    }
}
 
template <typename T>
inline AnyCameraType CameraWrapperBasePinholeT<T>::anyCameraType()
{
    return AnyCameraType::PINHOLE;
}
 
template <typename T>
inline std::string CameraWrapperBasePinholeT<T>::name()
{
    return std::string("Ocean Pinhole");
}
 
template <typename T>
CameraWrapperBaseFisheyeT<T>::CameraWrapperBaseFisheyeT(ActualCamera&& camera) :
    actualCamera_(std::move(camera))
{
    // nothing to do here
}
 
template <typename T>
CameraWrapperBaseFisheyeT<T>::CameraWrapperBaseFisheyeT(const ActualCamera& camera) :
    actualCamera_(camera)
{
    // nothing to do here
}
 
template <typename T>
inline const typename CameraWrapperBaseFisheyeT<T>::ActualCamera& CameraWrapperBaseFisheyeT<T>::actualCamera() const
{
    return actualCamera_;
}
 
template <typename T>
inline unsigned int CameraWrapperBaseFisheyeT<T>::width() const
{
    return actualCamera_.width();
}
 
template <typename T>
inline unsigned int CameraWrapperBaseFisheyeT<T>::height() const
{
    return actualCamera_.height();
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBaseFisheyeT<T>::principalPoint() const
{
    return actualCamera_.principalPoint();
}
 
template <typename T>
inline T CameraWrapperBaseFisheyeT<T>::principalPointX() const
{
    return actualCamera_.principalPointX();
}
 
template <typename T>
inline T CameraWrapperBaseFisheyeT<T>::principalPointY() const
{
    return actualCamera_.principalPointY();
}
 
template <typename T>
inline T CameraWrapperBaseFisheyeT<T>::focalLengthX() const
{
    return actualCamera_.focalLengthX();
}
 
template <typename T>
inline T CameraWrapperBaseFisheyeT<T>::focalLengthY() const
{
    return actualCamera_.focalLengthY();
}
 
template <typename T>
inline T CameraWrapperBaseFisheyeT<T>::inverseFocalLengthX() const
{
    return actualCamera_.inverseFocalLengthX();
}
 
template <typename T>
inline T CameraWrapperBaseFisheyeT<T>::inverseFocalLengthY() const
{
    return actualCamera_.inverseFocalLengthY();
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBaseFisheyeT<T>::projectToImageIF(const VectorT3<T>& objectPoint) const
{
    return actualCamera_.projectToImageIF(objectPoint);
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBaseFisheyeT<T>::projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>& objectPoint) const
{
    return actualCamera_.projectToImageIF(flippedCamera_T_world, objectPoint);
}
 
template <typename T>
inline void CameraWrapperBaseFisheyeT<T>::projectToImageIF(const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    ocean_assert(size == 0 || objectPoints != nullptr);
    ocean_assert(size == 0 || imagePoints != nullptr);
 
    for (size_t n = 0; n < size; ++n)
    {
        imagePoints[n] = projectToImageIF(objectPoints[n]);
    }
}
 
template <typename T>
inline void CameraWrapperBaseFisheyeT<T>::projectToImageIF(const HomogenousMatrixT4<T>& flippedCamera_T_world, const VectorT3<T>* objectPoints, const size_t size, VectorT2<T>* imagePoints) const
{
    ocean_assert(size == 0 || objectPoints != nullptr);
    ocean_assert(size == 0 || imagePoints != nullptr);
 
    for (size_t n = 0; n < size; ++n)
    {
        imagePoints[n] = projectToImageIF(flippedCamera_T_world, objectPoints[n]);
    }
}
 
template <typename T>
inline VectorT3<T> CameraWrapperBaseFisheyeT<T>::vectorIF(const VectorT2<T>& distortedImagePoint, const bool makeUnitVector) const
{
    return actualCamera_.vectorIF(distortedImagePoint, makeUnitVector);
}
 
template <typename T>
inline void CameraWrapperBaseFisheyeT<T>::vectorIF(const VectorT2<T>* distortedImagePoints, const size_t size, VectorT3<T>* vectors, const bool makeUnitVector) const
{
    ocean_assert(distortedImagePoints != nullptr && size > 0);
    ocean_assert(vectors != nullptr);
 
    for (size_t n = 0; n < size; ++n)
    {
        vectors[n] = vectorIF(distortedImagePoints[n], makeUnitVector);
    }
}
 
template <typename T>
inline void CameraWrapperBaseFisheyeT<T>::pointJacobian2x3IF(const VectorT3<T>& flippedCameraObjectPoint, T* jx, T* jy) const
{
    actualCamera_.pointJacobian2x3IF(flippedCameraObjectPoint, jx, jy);
}
 
template <typename T>
inline bool CameraWrapperBaseFisheyeT<T>::isEqual(const CameraWrapperBaseFisheyeT& baseFisheye, const T eps) const
{
    ocean_assert(eps >= T(0));
 
    return actualCamera_.isEqual(baseFisheye.actualCamera_, eps);
}
 
template <typename T>
inline bool CameraWrapperBaseFisheyeT<T>::isValid() const
{
    return actualCamera_.isValid();
}
 
template <typename T>
template <typename U>
inline std::unique_ptr<AnyCameraT<U>> CameraWrapperBaseFisheyeT<T>::clone(const unsigned int width, const unsigned int height) const
{
    ocean_assert(actualCamera_.isValid());
 
    if ((width == 0u && height == 0u) || (width == actualCamera_.width() && height == actualCamera_.height()))
    {
        return std::make_unique<AnyCameraWrappingT<U, CameraWrapperT<U, CameraWrapperBaseFisheyeT<U>>>>(FisheyeCameraT<U>(actualCamera_));
    }
 
    const unsigned int validWidth = (height * actualCamera_.width() + actualCamera_.height() / 2u) / actualCamera_.height();
    const unsigned int validHeight = (width * actualCamera_.height() + actualCamera_.width() / 2u) / actualCamera_.width();
 
    if (!NumericT<unsigned int>::isEqual(width, validWidth, 1u) && !NumericT<unsigned int>::isEqual(height, validHeight, 1u))
    {
        ocean_assert(false && "Wrong aspect ratio!");
        return nullptr;
    }
 
    const T xFactor = T(width) / T(actualCamera_.width());
    const T yFactor = T(height) / T(actualCamera_.height());
 
    const U newPrincipalX = U(actualCamera_.principalPointX() * xFactor);
    const U newPrincipalY = U(actualCamera_.principalPointY() * yFactor);
 
    const U newFocalLengthX = U(actualCamera_.focalLengthX() * xFactor);
    const U newFocalLengthY = U(actualCamera_.focalLengthY() * yFactor);
 
    U radialDistortion[6];
    for (unsigned int n = 0u; n < 6u; ++n)
    {
        radialDistortion[n] = U(actualCamera_.radialDistortion()[n]);
    }
 
    const U tangentialDistortion[2] =
    {
        U(actualCamera_.tangentialDistortion()[0]),
        U(actualCamera_.tangentialDistortion()[1])
    };
 
    return std::make_unique<AnyCameraWrappingT<U, CameraWrapperT<U, CameraWrapperBaseFisheyeT<U>>>>(FisheyeCameraT<U>(width, height, newFocalLengthX, newFocalLengthY, newPrincipalX, newPrincipalY, radialDistortion, tangentialDistortion));
}
 
template <typename T>
inline AnyCameraType CameraWrapperBaseFisheyeT<T>::anyCameraType()
{
    return AnyCameraType::FISHEYE;
}
 
template <typename T>
inline std::string CameraWrapperBaseFisheyeT<T>::name()
{
    return std::string("Ocean Fisheye");
}
 
template <typename T>
CameraWrapperBaseInvalidT<T>::CameraWrapperBaseInvalidT(ActualCamera&& camera) :
    actualCamera_(std::move(camera))
{
    // nothing to do here
}
 
template <typename T>
CameraWrapperBaseInvalidT<T>::CameraWrapperBaseInvalidT(const ActualCamera& camera) :
    actualCamera_(camera)
{
    // nothing to do here
}
 
template <typename T>
inline const typename CameraWrapperBaseInvalidT<T>::ActualCamera& CameraWrapperBaseInvalidT<T>::actualCamera() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return actualCamera_;
}
 
template <typename T>
inline unsigned int CameraWrapperBaseInvalidT<T>::width() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return (unsigned int)(-1);
}
 
template <typename T>
inline unsigned int CameraWrapperBaseInvalidT<T>::height() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return (unsigned int)(-1);
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBaseInvalidT<T>::principalPoint() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return VectorT2<T>(NumericT<T>::minValue(), NumericT<T>::minValue());
}
 
template <typename T>
inline T CameraWrapperBaseInvalidT<T>::principalPointX() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return NumericT<T>::minValue();
}
 
template <typename T>
inline T CameraWrapperBaseInvalidT<T>::principalPointY() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return NumericT<T>::minValue();
}
 
template <typename T>
inline T CameraWrapperBaseInvalidT<T>::focalLengthX() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return NumericT<T>::minValue();
}
 
template <typename T>
inline T CameraWrapperBaseInvalidT<T>::focalLengthY() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return NumericT<T>::minValue();
}
 
template <typename T>
inline T CameraWrapperBaseInvalidT<T>::inverseFocalLengthX() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return NumericT<T>::minValue();
}
 
template <typename T>
inline T CameraWrapperBaseInvalidT<T>::inverseFocalLengthY() const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return NumericT<T>::minValue();
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBaseInvalidT<T>::projectToImageIF(const VectorT3<T>& /*objectPoint*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return VectorT2<T>(NumericT<T>::minValue(), NumericT<T>::minValue());
}
 
template <typename T>
inline VectorT2<T> CameraWrapperBaseInvalidT<T>::projectToImageIF(const HomogenousMatrixT4<T>& /*flippedCamera_T_world*/, const VectorT3<T>& /*objectPoint*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return VectorT2<T>(NumericT<T>::minValue(), NumericT<T>::minValue());
}
 
template <typename T>
inline void CameraWrapperBaseInvalidT<T>::projectToImageIF(const VectorT3<T>* /*objectPoints*/, const size_t /*size*/, VectorT2<T>* /*imagePoints*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
}
 
template <typename T>
inline void CameraWrapperBaseInvalidT<T>::projectToImageIF(const HomogenousMatrixT4<T>& /*flippedCamera_T_world*/, const VectorT3<T>* /*objectPoints*/, const size_t /*size*/, VectorT2<T>* /*imagePoints*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
}
 
template <typename T>
inline VectorT3<T> CameraWrapperBaseInvalidT<T>::vectorIF(const VectorT2<T>& /*distortedImagePoint*/, const bool /*makeUnitVector*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return VectorT3<T>(NumericT<T>::minValue(), NumericT<T>::minValue(), NumericT<T>::minValue());
}
 
template <typename T>
inline void CameraWrapperBaseInvalidT<T>::vectorIF(const VectorT2<T>* /*distortedImagePoints*/, const size_t /*size*/, VectorT3<T>* /*vectors*/, const bool /*makeUnitVector*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
}
 
template <typename T>
inline void CameraWrapperBaseInvalidT<T>::pointJacobian2x3IF(const VectorT3<T>& /*flippedCameraObjectPoint*/, T* /*jx*/, T* /*jy*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
}
 
template <typename T>
inline bool CameraWrapperBaseInvalidT<T>::isEqual(const CameraWrapperBaseInvalidT& /*baseFisheye*/, const T /*eps*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return false;
}
 
template <typename T>
inline bool CameraWrapperBaseInvalidT<T>::isValid() const
{
    return false;
}
 
template <typename T>
template <typename U>
inline std::unique_ptr<AnyCameraT<U>> CameraWrapperBaseInvalidT<T>::clone(const unsigned int /*width*/, const unsigned int /*height*/) const
{
    Log::error() << "Invalid camera: " << actualCamera_.reason();
 
    ocean_assert(false && "This function must never be called.");
 
    return nullptr;
}
 
template <typename T>
inline AnyCameraType CameraWrapperBaseInvalidT<T>::anyCameraType()
{
    return AnyCameraType::INVALID;
}
 
template <typename T>
inline std::string CameraWrapperBaseInvalidT<T>::name()
{
    return std::string("Invalid camera");
}
 
template <typename T>
InvalidCameraT<T>::InvalidCameraT(const std::string& reason) :
    reason_(reason)
{
    // nothing to do here
}
 
template <typename T>
const std::string& InvalidCameraT<T>::reason() const
{
    return reason_;
}
 
}
 
#endif // META_OCEAN_MATH_ANY_CAMERA_H