/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined ( INCLUDED_TRANSFORMLIB_H )
#define INCLUDED_TRANSFORMLIB_H

#include "generic/constant.h"
#include "math/matrix.h"
#include "math/quaternion.h"


/// \brief A transform node.
class TransformNode
{
public:
STRING_CONSTANT( Name, "TransformNode" );
/// \brief Returns the transform which maps the node's local-space into the local-space of its parent node.
virtual const Matrix4& localToParent() const  = 0;
};

/// \brief A transform node which has no effect.
class IdentityTransform : public TransformNode
{
public:
/// \brief Returns the identity matrix.
const Matrix4& localToParent() const {
	return g_matrix4_identity;
}
};

/// \brief A transform node which stores a generic transformation matrix.
class MatrixTransform : public TransformNode
{
Matrix4 m_localToParent;
public:
MatrixTransform() : m_localToParent( g_matrix4_identity ){
}

Matrix4& localToParent(){
	return m_localToParent;
}
/// \brief Returns the stored local->parent transform.
const Matrix4& localToParent() const {
	return m_localToParent;
}
};


#include "generic/callback.h"

typedef Vector3 Translation;
typedef Quaternion Rotation;
typedef Vector3 Scale;

inline Matrix4 matrix4_transform_for_components( const Translation& translation, const Rotation& rotation, const Scale& scale ){
	Matrix4 result( matrix4_rotation_for_quaternion_quantised( rotation ) );
	vector4_to_vector3( result.x() ) *= scale.x();
	vector4_to_vector3( result.y() ) *= scale.y();
	vector4_to_vector3( result.z() ) *= scale.z();
	result.tx() = translation.x();
	result.ty() = translation.y();
	result.tz() = translation.z();
	return result;
}

typedef bool TransformModifierType;
const TransformModifierType TRANSFORM_PRIMITIVE = false;
const TransformModifierType TRANSFORM_COMPONENT = true;

/// \brief A transformable scene-graph instance.
///
/// A transformable instance may be translated, rotated or scaled.
/// The state of the instanced node's geometrical representation
/// will be the product of its geometry and the transforms of each
/// of its instances, applied in the order they appear in a graph
/// traversal.
/// Freezing the transform on an instance will cause its transform
/// to be permanently applied to the geometry of the node.
class Transformable
{
public:
STRING_CONSTANT( Name, "Transformable" );

virtual void setType( TransformModifierType type ) = 0;
virtual void setTranslation( const Translation& value ) = 0;
virtual void setRotation( const Rotation& value ) = 0;
virtual void setScale( const Scale& value ) = 0;
virtual void freezeTransform() = 0;
};

const Translation c_translation_identity = Translation( 0, 0, 0 );
const Rotation c_rotation_identity = c_quaternion_identity;
const Scale c_scale_identity = Scale( 1, 1, 1 );


class TransformModifier : public Transformable
{
Translation m_translation;
Rotation m_rotation;
Scale m_scale;
Callback<void()> m_changed;
Callback<void()> m_apply;
TransformModifierType m_type;
public:

TransformModifier( const Callback<void()>& changed, const Callback<void()>& apply ) :
	m_translation( c_translation_identity ),
	m_rotation( c_quaternion_identity ),
	m_scale( c_scale_identity ),
	m_changed( changed ),
	m_apply( apply ),
	m_type( TRANSFORM_PRIMITIVE ){
}
void setType( TransformModifierType type ){
	m_type = type;
}
TransformModifierType getType() const {
	return m_type;
}
void setTranslation( const Translation& value ){
	m_translation = value;
	m_changed();
}
void setRotation( const Rotation& value ){
	m_rotation = value;
	m_changed();
}
void setScale( const Scale& value ){
	m_scale = value;
	m_changed();
}
void freezeTransform(){
	if ( m_translation != c_translation_identity
		 || m_rotation != c_rotation_identity
		 || m_scale != c_scale_identity ) {
		m_apply();
		m_translation = c_translation_identity;
		m_rotation = c_rotation_identity;
		m_scale = c_scale_identity;
		m_changed();
	}
}
const Translation& getTranslation() const {
	return m_translation;
}
const Rotation& getRotation() const {
	return m_rotation;
}
const Scale& getScale() const {
	return m_scale;
}
Matrix4 calculateTransform() const {
	return matrix4_transform_for_components( getTranslation(), getRotation(), getScale() );
}
};


#endif
