/******************************************************************************
	libx42.net - skinned vertex animation library (.NET API)
	Copyright (C) 2007 HermitWorks Entertainment Corporation

	This program is free software; you can redistribute it and/or modify it
	under the terms of the GNU General Public License as published by the Free
	Software Foundation; either version 2 of the License, or (at your option)
	any later version.

	This program is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
	for more details.

	You should have received a copy of the GNU General Public License along
	with this program; if not, write to the
	
		Free Software Foundation, Inc.
		51 Franklin Street, Fifth Floor
		Boston, MA  02110-1301, USA.
******************************************************************************/

#pragma once

#include "Vector.h"
#include "Angle.h"
#include "Affine.h"

namespace Libx42
{
namespace Math
{

public value struct Quaternion : IFormattable
{
	float i, j, k, w;

	Quaternion( float i, float j, float k, float w ) : i( i ), j( j ), k( k ), w( w ) { }
	Quaternion( Vector3 ijk, float w ) : i( ijk.x ), j( ijk.y ), k( ijk.z ), w( w ) { }

	[ComponentModel::EditorBrowsable( ComponentModel::EditorBrowsableState::Advanced )]
	Quaternion( const ::x42::math::quat &q ) : i( q.i ), j( q.j ), k( q.k ), w( q.w ) { }

	static Quaternion Slerp( Quaternion a, Quaternion b, float t );
	static Quaternion Conjugate( Quaternion q );
	Quaternion Conjugate( void )
	{
		return Conjugate( *this );
	}

	static Quaternion operator * ( Quaternion a, Quaternion b );
	
	void ToAxisAngle(
		[::System::Runtime::InteropServices::Out] Vector3 %axis,
		[::System::Runtime::InteropServices::Out] Angle %angle );
	static Quaternion FromAxisAngle( Vector3 axis, Angle angle );

	Affine ToAffine( void );

	String^ ToString( IFormatProvider ^formatProvider )
	{
		return String::Format( formatProvider, "<{0} {1} {2} {3}>", i, j, k, w );
	}

	virtual String^ ToString( void ) override
	{
		return ToString( nullptr );
	}

	bool Equals( Quaternion q ) new;
	virtual bool Equals( Object ^obj ) override;

	static bool operator == ( Quaternion a, Quaternion b )
	{
		return a.Equals( b );
	}

	static bool operator != ( Quaternion a, Quaternion b )
	{
		return !a.Equals( b );
	}

	static property Quaternion Identity { Quaternion get( void ) { return Quaternion( 0, 0, 0, 1 ); } }

private:
	virtual String^ ToString( String^ /* format */, IFormatProvider ^formatProvider ) sealed =
		IFormattable::ToString
	{
		return ToString( formatProvider );
	}
};

};
};