/********************************************************************************
* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/      *
* Copyright (c) 2010-2012 Daniel Chappuis                                       *
*********************************************************************************
*                                                                               *
* This software is provided 'as-is', without any express or implied warranty.   *
* In no event will the authors be held liable for any damages arising from the  *
* use of this software.                                                         *
*                                                                               *
* Permission is granted to anyone to use this software for any purpose,         *
* including commercial applications, and to alter it and redistribute it        *
* freely, subject to the following restrictions:                                *
*                                                                               *
* 1. The origin of this software must not be misrepresented; you must not claim *
*    that you wrote the original software. If you use this software in a        *
*    product, an acknowledgment in the product documentation would be           *
*    appreciated but is not required.                                           *
*                                                                               *
* 2. Altered source versions must be plainly marked as such, and must not be    *
*    misrepresented as being the original software.                             *
*                                                                               *
* 3. This notice may not be removed or altered from any source distribution.    *
*                                                                               *
********************************************************************************/

#ifndef TRANSFORM_H
#define	TRANSFORM_H

// Libraries
#include "Matrix3x3.h"
#include "Vector3.h"
#include "Quaternion.h"

// ReactPhysiscs3D namespace
namespace reactphysics3d {

/*  -------------------------------------------------------------------
    Class Transform :
        This class represents a position and an orientation in 3D. It can
        also be seen as representing a translation and a rotation
    -------------------------------------------------------------------
*/
class Transform {
    private :
        Vector3 position;               // Position
        Quaternion orientation;         // Orientation

    public :
        Transform();                                                           // Constructor
        Transform(const Vector3& position, const Matrix3x3& orientation);      // Constructor
        Transform(const Vector3& position, const Quaternion& orientation);     // Constructor
        ~Transform();                                                          // Destructor

        const Vector3& getPosition() const;                                     // Return the origin of the transform
        void setPosition(const Vector3& position);                              // Set the origin of the transform
        const Quaternion& getOrientation() const;                               // Return the orientation quaternion
        void setOrientation(const Quaternion& orientation);                     // Set the rotation quaternion
        void setToIdentity();                                                   // Set the transform to the identity transform
        void setFromOpenGL(decimal* openglMatrix);                              // Set the transform from an OpenGL transform matrix
        void getOpenGLMatrix(decimal* openglMatrix) const;                      // Get the OpenGL matrix of the transform
        Transform inverse() const;                                              // Return the inverse of the transform
        static Transform interpolateTransforms(const Transform& oldTransform,
                                               const Transform& newTransform,
                                               decimal interpolationFactor);    // Return an interpolated transform

        Vector3 operator*(const Vector3& vector) const;                         // Return the transformed vector
        Transform operator*(const Transform& transform2) const;                 // Operator of multiplication of a transform with another one
        bool operator==(const Transform& transform2) const;                     // Return true if the two transforms are equal
        bool operator!=(const Transform& transform2) const;                     // Return true if the two transforms are different
};

// Return the position of the transform
inline const Vector3& Transform::getPosition() const {
    return position;
}

// Set the origin of the transform
inline void Transform::setPosition(const Vector3& position) {
    this->position = position;
}

// Return the rotation matrix
inline const Quaternion& Transform::getOrientation() const {
    return orientation;
}

// Set the rotation matrix of the transform
inline void Transform::setOrientation(const Quaternion& orientation) {
    this->orientation = orientation;
}

// Set the transform to the identity transform
inline void Transform::setToIdentity() {
    position = Vector3(0.0, 0.0, 0.0);
    orientation = Quaternion::identity();
}                                           

// Set the transform from an OpenGL transform matrix
inline void Transform::setFromOpenGL(decimal* openglMatrix) {
    Matrix3x3 matrix(openglMatrix[0], openglMatrix[4], openglMatrix[8],
                     openglMatrix[1], openglMatrix[5], openglMatrix[9],
                     openglMatrix[2], openglMatrix[6], openglMatrix[10]);
    orientation = Quaternion(matrix);
    position.setAllValues(openglMatrix[12], openglMatrix[13], openglMatrix[14]);
}

// Get the OpenGL matrix of the transform
inline void Transform::getOpenGLMatrix(decimal* openglMatrix) const {
    const Matrix3x3& matrix = orientation.getMatrix();
    openglMatrix[0] = matrix.getValue(0, 0); openglMatrix[1] = matrix.getValue(1, 0); openglMatrix[2] = matrix.getValue(2, 0); openglMatrix[3] = 0.0;
    openglMatrix[4] = matrix.getValue(0, 1); openglMatrix[5] = matrix.getValue(1, 1); openglMatrix[6] = matrix.getValue(2, 1); openglMatrix[7] = 0.0;
    openglMatrix[8] = matrix.getValue(0, 2); openglMatrix[9] = matrix.getValue(1, 2); openglMatrix[10] = matrix.getValue(2, 2); openglMatrix[11] = 0.0;
    openglMatrix[12] = position.getX(); openglMatrix[13] = position.getY(); openglMatrix[14] = position.getZ(); openglMatrix[15] = 1.0;
}

// Return the inverse of the transform
inline Transform Transform::inverse() const {
    const Quaternion& invQuaternion = orientation.getInverse();
    Matrix3x3 invMatrix = invQuaternion.getMatrix();
    return Transform(invMatrix * (-position), invQuaternion);
}

// Return an interpolated transform
inline Transform Transform::interpolateTransforms(const Transform& oldTransform, const Transform& newTransform, decimal interpolationFactor) {
    Vector3 interPosition = oldTransform.position * (1.0 - interpolationFactor) + newTransform.position * interpolationFactor;
    Quaternion interOrientation = Quaternion::slerp(oldTransform.orientation, newTransform.orientation, interpolationFactor);
    return Transform(interPosition, interOrientation);
}

// Return the transformed vector
inline Vector3 Transform::operator*(const Vector3& vector) const {
    return (orientation.getMatrix() * vector) + position;
}

// Operator of multiplication of a transform with another one
inline Transform Transform::operator*(const Transform& transform2) const {
    return Transform(position + orientation.getMatrix() * transform2.position, orientation * transform2.orientation);
}

// Return true if the two transforms are equal
inline bool Transform::operator==(const Transform& transform2) const {
    return (position == transform2.position) && (orientation == transform2.orientation);
}    

// Return true if the two transforms are different
inline bool Transform::operator!=(const Transform& transform2) const {
    return !(*this == transform2);
}                    

} // End of the ReactPhysics3D namespace

#endif