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

  Program:   Visualization Toolkit
  Module:    vtkGeneralTransform.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/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 notice for more information.

=========================================================================*/
// .NAME vtkGeneralTransform - allows operations on any transforms
// .SECTION Description
// vtkGeneralTransform is like vtkTransform and vtkPerspectiveTransform,
// but it will work with any vtkAbstractTransform as input.  It is
// not as efficient as the other two, however, because arbitrary
// transformations cannot be concatenated by matrix multiplication.
// Transform concatenation is simulated by passing each input point
// through each transform in turn.  
// .SECTION see also
// vtkTransform vtkPerspectiveTransform

#ifndef __vtkGeneralTransform_h
#define __vtkGeneralTransform_h

#include "vtkAbstractTransform.h"

#include "vtkMatrix4x4.h" // Needed for inline methods

class VTK_COMMON_EXPORT vtkGeneralTransform : public vtkAbstractTransform
{
public:
  static vtkGeneralTransform *New();

  vtkTypeMacro(vtkGeneralTransform,vtkAbstractTransform);
  void PrintSelf(ostream& os, vtkIndent indent);
  
  // Description:
  // Set this transformation to the identity transformation.  If 
  // the transform has an Input, then the transformation will be
  // reset so that it is the same as the Input.
  void Identity() { this->Concatenation->Identity(); this->Modified(); };

  // Description:
  // Invert the transformation.  This will also set a flag so that
  // the transformation will use the inverse of its Input, if an Input
  // has been set.
  void Inverse() { this->Concatenation->Inverse(); this->Modified(); };

  // Description:
  // Create a translation matrix and concatenate it with the current
  // transformation according to PreMultiply or PostMultiply semantics.
  void Translate(double x, double y, double z) {
    this->Concatenation->Translate(x,y,z); };
  void Translate(const double x[3]) { this->Translate(x[0], x[1], x[2]); };
  void Translate(const float x[3]) { this->Translate(x[0], x[1], x[2]); };

  // Description:
  // Create a rotation matrix and concatenate it with the current
  // transformation according to PreMultiply or PostMultiply semantics.
  // The angle is in degrees, and (x,y,z) specifies the axis that the
  // rotation will be performed around. 
  void RotateWXYZ(double angle, double x, double y, double z) {
    this->Concatenation->Rotate(angle,x,y,z); };
  void RotateWXYZ(double angle, const double axis[3]) {
    this->RotateWXYZ(angle, axis[0], axis[1], axis[2]); };
  void RotateWXYZ(double angle, const float axis[3]) {
    this->RotateWXYZ(angle, axis[0], axis[1], axis[2]); };

  // Description:
  // Create a rotation matrix about the X, Y, or Z axis and concatenate
  // it with the current transformation according to PreMultiply or
  // PostMultiply semantics.  The angle is expressed in degrees.
  void RotateX(double angle) { this->RotateWXYZ(angle, 1, 0, 0); };
  void RotateY(double angle) { this->RotateWXYZ(angle, 0, 1, 0); };
  void RotateZ(double angle) { this->RotateWXYZ(angle, 0, 0, 1); };

  // Description:
  // Create a scale matrix (i.e. set the diagonal elements to x, y, z)
  // and concatenate it with the current transformation according to
  // PreMultiply or PostMultiply semantics.
  void Scale(double x, double y, double z) {
    this->Concatenation->Scale(x,y,z); };
  void Scale(const double s[3]) { this->Scale(s[0], s[1], s[2]); };
  void Scale(const float s[3]) { this->Scale(s[0], s[1], s[2]); };

  // Description:
  // Concatenates the matrix with the current transformation according
  // to PreMultiply or PostMultiply semantics.
  void Concatenate(vtkMatrix4x4 *matrix) { 
    this->Concatenate(*matrix->Element); };
  void Concatenate(const double elements[16]) {
    this->Concatenation->Concatenate(elements); };

  // Description:
  // Concatenate the specified transform with the current transformation
  // according to PreMultiply or PostMultiply semantics.
  // The concatenation is pipelined, meaning that if any of the
  // transformations are changed, even after Concatenate() is called,
  // those changes will be reflected when you call TransformPoint().
  void Concatenate(vtkAbstractTransform *transform);

  // Description:
  // Sets the internal state of the transform to PreMultiply. All subsequent
  // operations will occur before those already represented in the
  // current transformation.  In homogeneous matrix notation, M = M*A where
  // M is the current transformation matrix and A is the applied matrix.
  // The default is PreMultiply.
  void PreMultiply() { 
    if (this->Concatenation->GetPreMultiplyFlag()) { return; }
    this->Concatenation->SetPreMultiplyFlag(1); this->Modified(); };

  // Description:
  // Sets the internal state of the transform to PostMultiply. All subsequent
  // operations will occur after those already represented in the
  // current transformation.  In homogeneous matrix notation, M = A*M where
  // M is the current transformation matrix and A is the applied matrix.
  // The default is PreMultiply.
  void PostMultiply()  { 
    if (!this->Concatenation->GetPreMultiplyFlag()) { return; }
    this->Concatenation->SetPreMultiplyFlag(0); this->Modified(); };

  // Description:
  // Get the total number of transformations that are linked into this
  // one via Concatenate() operations or via SetInput().
  int GetNumberOfConcatenatedTransforms() {
    return this->Concatenation->GetNumberOfTransforms() + 
      (this->Input == NULL ? 0 : 1); };

  // Description
  // Get one of the concatenated transformations as a vtkAbstractTransform.
  // These transformations are applied, in series, every time the 
  // transformation of a coordinate occurs.  This method is provided
  // to make it possible to decompose a transformation into its
  // constituents, for example to save a transformation to a file.
  vtkAbstractTransform *GetConcatenatedTransform(int i) {
    if (this->Input == NULL) {
      return this->Concatenation->GetTransform(i); }
    else if (i < this->Concatenation->GetNumberOfPreTransforms()) {
      return this->Concatenation->GetTransform(i); }
    else if (i > this->Concatenation->GetNumberOfPreTransforms()) {
      return this->Concatenation->GetTransform(i-1); } 
    else if (this->GetInverseFlag()) {
      return this->Input->GetInverse(); }
    else {
      return this->Input; } };

  // Description:
  // Set the input for this transformation.  This will be used as the
  // base transformation if it is set.  This method allows you to build
  // a transform pipeline: if the input is modified, then this transformation
  // will automatically update accordingly.  Note that the InverseFlag,
  // controlled via Inverse(), determines whether this transformation
  // will use the Input or the inverse of the Input.
  void SetInput(vtkAbstractTransform *input);
  vtkAbstractTransform *GetInput() { return this->Input; };

  // Description:
  // Get the inverse flag of the transformation.  This controls
  // whether it is the Input or the inverse of the Input that
  // is used as the base transformation.  The InverseFlag is
  // flipped every time Inverse() is called.  The InverseFlag
  // is off when a transform is first created.
  int GetInverseFlag() {
    return this->Concatenation->GetInverseFlag(); };

  // Description:
  // Pushes the current transformation onto the transformation stack.
  void Push() { if (this->Stack == NULL) { 
                    this->Stack = vtkTransformConcatenationStack::New(); }
                this->Stack->Push(&this->Concatenation); 
                this->Modified(); };

  // Description:
  // Deletes the transformation on the top of the stack and sets the top 
  // to the next transformation on the stack.
  void Pop() { if (this->Stack == NULL) { return; }
               this->Stack->Pop(&this->Concatenation);
               this->Modified(); };

  // Description:
  // This will calculate the transformation without calling Update.
  // Meant for use only within other VTK classes.
  void InternalTransformPoint(const float in[3], float out[3]);
  void InternalTransformPoint(const double in[3], double out[3]);

  // Description:
  // This will calculate the transformation as well as its derivative
  // without calling Update.  Meant for use only within other VTK
  // classes.
  void InternalTransformDerivative(const float in[3], float out[3],
                                   float derivative[3][3]);
  void InternalTransformDerivative(const double in[3], double out[3],
                                   double derivative[3][3]);

  // Description:
  // Check for self-reference.  Will return true if concatenating
  // with the specified transform, setting it to be our inverse,
  // or setting it to be our input will create a circular reference.
  // CircuitCheck is automatically called by SetInput(), SetInverse(),
  // and Concatenate(vtkXTransform *).  Avoid using this function,
  // it is experimental.
  int CircuitCheck(vtkAbstractTransform *transform);

  // Description:
  // Make another transform of the same type.
  vtkAbstractTransform *MakeTransform();

  // Description:
  // Override GetMTime to account for input and concatenation.
  unsigned long GetMTime();

protected:
  vtkGeneralTransform();
  ~vtkGeneralTransform();

  void InternalDeepCopy(vtkAbstractTransform *t);
  void InternalUpdate();

  vtkAbstractTransform *Input;
  vtkTransformConcatenation *Concatenation;
  vtkTransformConcatenationStack *Stack;
private:
  vtkGeneralTransform(const vtkGeneralTransform&);  // Not implemented.
  void operator=(const vtkGeneralTransform&);  // Not implemented.
};


#endif