/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkRigid2DTransform.h,v $
  Language:  C++
  Date:      $Date: 2005/08/11 16:44:08 $
  Version:   $Revision: 1.18 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef __itkRigid2DTransform_h
#define __itkRigid2DTransform_h

#include <iostream>
#include "itkMatrixOffsetTransformBase.h"
#include "itkExceptionObject.h"

namespace itk
{

/** \brief Rigid2DTransform of a vector space (e.g. space coordinates)
 *
 * This transform applies a rigid transformation in 2D space.
 * The transform is specified as a rotation around a arbitrary center
 * and is followed by a translation.
 *
 * The parameters for this transform can be set either using
 * individual Set methods or in serialized form using
 * SetParameters() and SetFixedParameters().
 *
 * The serialization of the optimizable parameters is an array of 3 elements
 * ordered as follows:
 * p[0] = angle
 * p[1] = x component of the translation
 * p[2] = y component of the translation
 *
 * The serialization of the fixed parameters is an array of 2 elements
 * ordered as follows:
 * p[0] = x coordinate of the center
 * p[1] = y coordinate of the center
 *
 * Access methods for the center, translation and underlying matrix
 * offset vectors are documented in the superclass MatrixOffsetTransformBase.
 *
 * \sa Transfrom
 * \sa MatrixOffsetTransformBase
 *
 * \ingroup Transforms
 */
template < class TScalarType=double >    // Data type for scalars (float or double)
class ITK_EXPORT Rigid2DTransform : 
        public MatrixOffsetTransformBase< TScalarType, 2, 2> // Dimensions of input and output spaces
{
public:
  /** Standard class typedefs. */
  typedef Rigid2DTransform Self;
  typedef MatrixOffsetTransformBase< TScalarType, 2, 2 > Superclass;
  typedef SmartPointer<Self>        Pointer;
  typedef SmartPointer<const Self>  ConstPointer;
  
  /** Run-time type information (and related methods). */
  itkTypeMacro( Rigid2DTransform, MatrixOffsetTransformBase );

  /** New macro for creation of through a Smart Pointer */
  itkNewMacro( Self );

  /** Dimension of the space. */
  itkStaticConstMacro(InputSpaceDimension, unsigned int, 2);
  itkStaticConstMacro(OutputSpaceDimension, unsigned int, 2);
  itkStaticConstMacro(ParametersDimension, unsigned int, 3);

  /** Scalar type. */
  typedef typename Superclass::ScalarType  ScalarType;

  /** Parameters type. */
  typedef typename Superclass::ParametersType  ParametersType;

  /** Jacobian type. */
  typedef typename Superclass::JacobianType  JacobianType;

  /// Standard matrix type for this class
  typedef typename Superclass::MatrixType MatrixType;

  /// Standard vector type for this class
  typedef typename Superclass::OffsetType OffsetType;

  /// Standard vector type for this class
  typedef typename Superclass::InputVectorType InputVectorType;
  typedef typename Superclass::OutputVectorType OutputVectorType;

  /// Standard covariant vector type for this class
  typedef typename Superclass::InputCovariantVectorType InputCovariantVectorType;
  typedef typename Superclass::OutputCovariantVectorType OutputCovariantVectorType;

  /// Standard vnl_vector type for this class
  typedef typename Superclass::InputVnlVectorType InputVnlVectorType;
  typedef typename Superclass::OutputVnlVectorType OutputVnlVectorType;

  /// Standard coordinate point type for this class
  typedef typename Superclass::InputPointType    InputPointType;
  typedef typename Superclass::OutputPointType    OutputPointType;

  /**
   * Set the rotation Matrix of a Rigid2D Transform
   *
   * This method sets the 2x2 matrix representing the rotation
   * in the transform.  The Matrix is expected to be orthogonal
   * with a certain tolerance.
   *
   * \warning This method will throw an exception is the matrix
   * provided as argument is not orthogonal.
   *
   * \sa MatrixOffsetTransformBase::SetMatrix()
   **/
  virtual void SetMatrix( const MatrixType & matrix );

  /**
   * Set/Get the rotation matrix. These methods are old and are
   * retained for backward compatibility. Instead, use SetMatrix()
   * GetMatrix().
   **/
  virtual void SetRotationMatrix(const MatrixType &matrix)
    { this->SetMatrix( matrix ); }
   const MatrixType & GetRotationMatrix() const
    { return this->GetMatrix(); }


  /**
   * Compose the transformation with a translation
   *
   * This method modifies self to include a translation of the
   * origin.  The translation is precomposed with self if pre is
   * true, and postcomposed otherwise.
   **/
  void Translate(const OffsetType &offset, bool pre=false);

  /**
   * Back transform by an rigid transformation.
   *
   * The BackTransform() methods are slated to be removed from ITK.  
   * Instead, please use GetInverse() or CloneInverseTo() to generate 
   * an inverse transform and  then perform the transform using that 
   * inverted transform.
   **/
  inline InputPointType      BackTransform(const OutputPointType  &point ) const;
  inline InputVectorType     BackTransform(const OutputVectorType &vector) const;
  inline InputVnlVectorType  BackTransform(const OutputVnlVectorType &vector) const;

  inline InputCovariantVectorType BackTransform(
                                     const OutputCovariantVectorType &vector) const;

  /** Set/Get the angle of rotation in radians */
  void SetAngle(TScalarType angle);
  itkGetConstReferenceMacro( Angle, TScalarType );

  /** Set the angle of rotation in degrees. */
  void SetAngleInDegrees(TScalarType angle);

  /** Set/Get the angle of rotation in radians. These methods
   * are old and are retained for backward compatibility.
   * Instead, use SetAngle() and GetAngle(). */
  void SetRotation(TScalarType angle)
    { this->SetAngle(angle); }
  virtual const TScalarType & GetRotation() const
    { return m_Angle; }  

  /** Set the transformation from a container of parameters
   * This is typically used by optimizers.
   * There are 3 parameters. The first one represents the
   * angle of rotation in radians and the last two represents the translation.
   * The center of rotation is fixed.
   * 
   * \sa Transform::SetParameters()
   * \sa Transform::SetFixedParameters() */
  void SetParameters( const ParametersType & parameters );

  /** Get the parameters that uniquely define the transform
   * This is typically used by optimizers.
   * There are 3 parameters. The first one represents the
   * angle or rotation in radians and the last two represents the translation. 
   * The center of rotation is fixed.
   *
   * \sa Transform::GetParameters()
   * \sa Transform::GetFixedParameters() */
  const ParametersType & GetParameters( void ) const;
  
  /** This method computes the Jacobian matrix of the transformation
   * at a given input point.
   *
   * \sa Transform::GetJacobian() */
  const JacobianType & GetJacobian(const InputPointType  &point ) const;

  /**
   * This method creates and returns a new Rigid2DTransform object
   * which is the inverse of self.
   **/
  void CloneInverseTo( Pointer & newinverse ) const;

  /**
   * This method creates and returns a new Rigid2DTransform object
   * which has the same parameters.
   **/
  void CloneTo( Pointer & clone ) const;

  /** Reset the parameters to create and identity transform. */
  virtual void SetIdentity(void);

protected:
  Rigid2DTransform();
  Rigid2DTransform( unsigned int outputSpaceDimension, 
                    unsigned int parametersDimension);
 
 ~Rigid2DTransform();
 
 /**
   * Print contents of an Rigid2DTransform
   **/
  void PrintSelf(std::ostream &os, Indent indent) const;

  /** Compute the matrix from angle. This is used in Set methods
   * to update the underlying matrix whenever a transform parameter 
   * is changed. */
  virtual void ComputeMatrix(void);

  /** Compute the angle from the matrix. This is used to compute
   * transform parameters from a given matrix. This is used in
   * MatrixOffsetTransformBase::Compose() and 
   * MatrixOffsetTransformBase::GetInverse(). */
  virtual void ComputeMatrixParameters(void);

  /** Update angle without recomputation of other internal variables. */
  void SetVarAngle( TScalarType angle )
    { m_Angle = angle; }

private:
  Rigid2DTransform(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented
  
  TScalarType         m_Angle; 

}; //class Rigid2DTransform


}  // namespace itk


#ifndef ITK_MANUAL_INSTANTIATION
#include "itkRigid2DTransform.txx"
#endif

#endif /* __itkRigid2DTransform_h */
