/*
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LIMITED USE SOFTWARE LICENSE AGREEMENT, a copy of which is included with the
GtkRadiant sources (see LICENSE_ID). If you did not receive a copy of 
LICENSE_ID, please contact Id Software immediately at info@idsoftware.com.

All changes and additions to the original source which have been developed by
other contributors (see CONTRIBUTORS) are provided under the terms of the
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LICENSE_ID. If you did not receive a copy of the contributor license,
please contact the GtkRadiant maintainers at info@gtkradiant.com immediately.

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 A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef __MATH_QUATERNION_H__
#define __MATH_QUATERNION_H__

#include <assert.h>
#include <math.h>

class idVec3_t;
class angles_t;
class mat3_t;

class quat_t {
public:
	float			x;
	float			y;
	float			z;
	float			w;

					quat_t();
					quat_t( float x, float y, float z, float w );

	friend void		toQuat( idVec3_t &src, quat_t &dst );
	friend void		toQuat( angles_t &src, quat_t &dst );
	friend void		toQuat( mat3_t &src, quat_t &dst );

	float			*vec4( void );
			
	float			operator[]( int index ) const;
	float			&operator[]( int index );

	void 			set( float x, float y, float z, float w );

	void			operator=( quat_t a );

	friend quat_t	operator+( quat_t a, quat_t b );
	quat_t			&operator+=( quat_t a );

	friend quat_t	operator-( quat_t a, quat_t b );
	quat_t			&operator-=( quat_t a );

	friend quat_t	operator*( quat_t a, float b );
	friend quat_t	operator*( float a, quat_t b );
	quat_t			&operator*=( float a );

	friend int		operator==(	quat_t a, quat_t b );
	friend int		operator!=(	quat_t a, quat_t b );

	float			Length( void );
	quat_t			&Normalize( void );

	quat_t			operator-();
};

inline quat_t::quat_t() {
}

inline quat_t::quat_t( float x, float y, float z, float w ) {
	this->x = x;
	this->y = y;
	this->z = z;
	this->w = w;
}

inline float *quat_t::vec4( void ) {
	return &x;
}

inline float quat_t::operator[]( int index ) const {
	assert( ( index >= 0 ) && ( index < 4 ) );
	return ( &x )[ index ];
}

inline float& quat_t::operator[]( int index ) {
	assert( ( index >= 0 ) && ( index < 4 ) );
	return ( &x )[ index ];
}

inline void quat_t::set( float x, float y, float z, float w ) {
	this->x = x;
	this->y = y;
	this->z = z;
	this->w = w;
}

inline void quat_t::operator=( quat_t a ) {
	x = a.x;
	y = a.y;
	z = a.z;
	w = a.w;
}

inline quat_t operator+( quat_t a, quat_t b ) {
	return quat_t( a.x + b.x, a.y + b.y, a.z + b.z, a.w + b.w );
}

inline quat_t& quat_t::operator+=( quat_t a ) {
	x += a.x;
	y += a.y;
	z += a.z;
	w += a.w;

	return *this;
}

inline quat_t operator-( quat_t a, quat_t b ) {
	return quat_t( a.x - b.x, a.y - b.y, a.z - b.z, a.w - b.w );
}

inline quat_t& quat_t::operator-=( quat_t a ) {
	x -= a.x;
	y -= a.y;
	z -= a.z;
	w -= a.w;

	return *this;
}

inline quat_t operator*( quat_t a, float b ) {
	return quat_t( a.x * b, a.y * b, a.z * b, a.w * b );
}

inline quat_t operator*( float a, quat_t b ) {
	return b * a;
}

inline quat_t& quat_t::operator*=( float a ) {
	x *= a;
	y *= a;
	z *= a;
	w *= a;

	return *this;
}

inline int operator==( quat_t a, quat_t b ) {
	return ( ( a.x == b.x ) && ( a.y == b.y ) && ( a.z == b.z ) && ( a.w == b.w ) );
}

inline int operator!=( quat_t a, quat_t b ) {
	return ( ( a.x != b.x ) || ( a.y != b.y ) || ( a.z != b.z ) && ( a.w != b.w ) );
}

inline float quat_t::Length( void ) {
	float length;
	
	length = x * x + y * y + z * z + w * w;
	return ( float )sqrt( length );
}

inline quat_t& quat_t::Normalize( void ) {
	float length;
	float ilength;

	length = this->Length();
	if ( length ) {
		ilength = 1 / length;
		x *= ilength;
		y *= ilength;
		z *= ilength;
		w *= ilength;
	}
		
	return *this;
}

inline quat_t quat_t::operator-() {
	return quat_t( -x, -y, -z, -w );
}

#endif /* !__MATH_QUATERNION_H__ */