/** @file

    @brief Header

    Must be c-safe!

    @date 2014

    @author

    Sensics, Inc.

    <http://sensics.com/osvr>

*/

/*

// Copyright 2014 Sensics, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

*/

#ifndef INCLUDED_QuaternionC_h_GUID_1470A5FE_8209_41A6_C19E_46077FDF9C66

#define INCLUDED_QuaternionC_h_GUID_1470A5FE_8209_41A6_C19E_46077FDF9C66

/* Internal Includes */

#include <osvr/Util/APIBaseC.h>

/* Library/third-party includes */

/* none */

/* Standard includes */

/* none */

OSVR_EXTERN_C_BEGIN

/** @addtogroup UtilMath

    @{

*/

/** @brief A structure defining a quaternion, often a unit quaternion

 * representing 3D rotation.

*/

typedef struct OSVR_Quaternion {

    /** @brief Internal data - direct access not recommended */

    double data[4];

} OSVR_Quaternion;

#define OSVR_QUAT_MEMBER(COMPONENT, INDEX)                                     \

    /** @brief Accessor for quaternion component COMPONENT */                  \

    OSVR_INLINE double osvrQuatGet##COMPONENT(OSVR_Quaternion const *q) {      \

        return q->data[INDEX];                                                 \

    }                                                                          \

Unexecuted instantiation: osvrQuatGetX

Unexecuted instantiation: osvrQuatGetY

Unexecuted instantiation: osvrQuatGetZ

Unexecuted instantiation: osvrQuatGetW

    /** @brief Setter for quaternion component COMPONENT */                    \

    OSVR_INLINE void osvrQuatSet##COMPONENT(OSVR_Quaternion *q, double val) {  \

        q->data[INDEX] = val;                                                  \

    }

Unexecuted instantiation: osvrQuatSetW

Unexecuted instantiation: osvrQuatSetX

Unexecuted instantiation: osvrQuatSetY

Unexecuted instantiation: osvrQuatSetZ

OSVR_QUAT_MEMBER(W, 0)

OSVR_QUAT_MEMBER(X, 1)

OSVR_QUAT_MEMBER(Y, 2)

OSVR_QUAT_MEMBER(Z, 3)

#undef OSVR_QUAT_MEMBER

/** @brief Set a quaternion to the identity rotation */

OSVR_INLINE void osvrQuatSetIdentity(OSVR_Quaternion *q) {

    osvrQuatSetW(q, 1);

    osvrQuatSetX(q, 0);

    osvrQuatSetY(q, 0);

    osvrQuatSetZ(q, 0);

}

/** @} */

OSVR_EXTERN_C_END

#ifdef __cplusplus

template <typename StreamType>

inline StreamType &operator<<(StreamType &os, OSVR_Quaternion const &quat) {

    os << "(" << osvrQuatGetW(&quat) << ", (" << osvrQuatGetX(&quat) << ", "

       << osvrQuatGetY(&quat) << ", " << osvrQuatGetZ(&quat) << "))";

    return os;

}

#endif

#endif