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

Copyright (c) 2006-2020, assimp team


All rights reserved.

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

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
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* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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----------------------------------------------------------------------
*/

/** @file quaternion.h
 *  @brief Quaternion structure, including operators when compiling in C++
 */
#pragma once
#ifndef AI_QUATERNION_H_INC
#define AI_QUATERNION_H_INC

#ifdef __cplusplus

#ifdef __GNUC__
#   pragma GCC system_header
#endif

#include <assimp/defs.h>

template <typename TReal> class aiVector3t;
template <typename TReal> class aiMatrix3x3t;

// ---------------------------------------------------------------------------
/** Represents a quaternion in a 4D vector. */
template <typename TReal>
class aiQuaterniont
{
public:
    aiQuaterniont() AI_NO_EXCEPT : w(1.0), x(), y(), z() {}
    aiQuaterniont(TReal pw, TReal px, TReal py, TReal pz)
        : w(pw), x(px), y(py), z(pz) {}

    /** Construct from rotation matrix. Result is undefined if the matrix is not orthonormal. */
    explicit aiQuaterniont( const aiMatrix3x3t<TReal>& pRotMatrix);

    /** Construct from euler angles */
    aiQuaterniont( TReal rotx, TReal roty, TReal rotz);

    /** Construct from an axis-angle pair */
    aiQuaterniont( aiVector3t<TReal> axis, TReal angle);

    /** Construct from a normalized quaternion stored in a vec3 */
    explicit aiQuaterniont( aiVector3t<TReal> normalized);

    /** Returns a matrix representation of the quaternion */
    aiMatrix3x3t<TReal> GetMatrix() const;

public:

    bool operator== (const aiQuaterniont& o) const;
    bool operator!= (const aiQuaterniont& o) const;

    bool Equal(const aiQuaterniont& o, TReal epsilon = 1e-6) const;

public:

    /** Normalize the quaternion */
    aiQuaterniont& Normalize();

    /** Compute quaternion conjugate */
    aiQuaterniont& Conjugate ();

    /** Rotate a point by this quaternion */
    aiVector3t<TReal> Rotate (const aiVector3t<TReal>& in) const;

    /** Multiply two quaternions */
    aiQuaterniont operator* (const aiQuaterniont& two) const;

public:

    /** Performs a spherical interpolation between two quaternions and writes the result into the third.
     * @param pOut Target object to received the interpolated rotation.
     * @param pStart Start rotation of the interpolation at factor == 0.
     * @param pEnd End rotation, factor == 1.
     * @param pFactor Interpolation factor between 0 and 1. Values outside of this range yield undefined results.
     */
    static void Interpolate( aiQuaterniont& pOut, const aiQuaterniont& pStart,
        const aiQuaterniont& pEnd, TReal pFactor);

public:

    //! w,x,y,z components of the quaternion
    TReal w, x, y, z;
} ;

typedef aiQuaterniont<ai_real> aiQuaternion;

#else

struct aiQuaternion {
    ai_real w, x, y, z;
};

#endif

#endif // AI_QUATERNION_H_INC
