New helper class to transform out of image data

This helper class transforms the output of imaging filters that produce
vtkPointSets (e.g., vtkPolyData) to apply origin, spacing and direction.
Co-Authored-By: Will Schroeder <will.schroeder@kitware.com>

Common/DataModel/CMakeLists.txt

@@ -91,6 +91,7 @@ set(classes
   vtkHyperTreeGridOrientedGeometryCursor
   vtkImageData
   vtkImageIterator
+  vtkImageTransform
   vtkImplicitBoolean
   vtkImplicitDataSet
   vtkImplicitFunction

Common/DataModel/vtkImageTransform.cxx

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    vtkImageTransform.cxx
+
+  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.
+
+=========================================================================*/
+#include "vtkImageTransform.h"
+
+#include "vtkCellData.h"
+#include "vtkDataArray.h"
+#include "vtkImageData.h"
+#include "vtkMatrix3x3.h"
+#include "vtkMatrix4x4.h"
+#include "vtkObjectFactory.h"
+#include "vtkPointData.h"
+#include "vtkPointSet.h"
+#include "vtkSMPTools.h"
+
+vtkStandardNewMacro(vtkImageTransform);
+
+//============================================================================
+//----------------------------------------------------------------------------
+// Functors to support threaded execution
+namespace { //anonymous
+
+  template <typename T>
+  struct InPlaceTranslatePoints
+  {
+    T *Points;
+    double *Translation;
+
+    InPlaceTranslatePoints(double t[3], T *pts) : Points(pts), Translation(t) {}
+
+    void operator()(vtkIdType ptId, vtkIdType endPtId)
+    {
+      T *pIn = this->Points + 3*ptId;
+      T *pOut = pIn;
+
+      for ( ; ptId < endPtId; ++ptId )
+      {
+        *pIn++ = *pOut++ + this->Translation[0];
+        *pIn++ = *pOut++ + this->Translation[1];
+        *pIn++ = *pOut++ + this->Translation[2];
+      }
+    }
+
+    // Interface to vtkSMPTools
+    static void Execute(double t[3], vtkIdType num, T *pts)
+    {
+      InPlaceTranslatePoints<T> translate(t,pts);
+      vtkSMPTools::For(0,num,translate);
+    }
+  };//InPlaceTransformPoints
+
+  template <typename T>
+  struct InPlaceTransformPoints
+  {
+    T *Points;
+    vtkMatrix4x4 *M4;
+
+    InPlaceTransformPoints(vtkMatrix4x4 *m4, T *pts) : Points(pts), M4(m4) {}
+
+    void operator()(vtkIdType ptId, vtkIdType endPtId)
+    {
+      T *pIn = this->Points + 3*ptId;
+      T tmp[3] = {0, 0, 0};
+
+      for ( ; ptId < endPtId; ++ptId )
+      {
+        tmp[0] = M4->GetElement(0, 0) * pIn[0] +
+                 M4->GetElement(0, 1) * pIn[1] +
+                 M4->GetElement(0, 2) * pIn[2] +
+                 M4->GetElement(0, 3);
+        tmp[1] = M4->GetElement(1, 0) * pIn[0] +
+                 M4->GetElement(1, 1) * pIn[1] +
+                 M4->GetElement(1, 2) * pIn[2] +
+                 M4->GetElement(1, 3);
+        tmp[2] = M4->GetElement(2, 0) * pIn[0] +
+                 M4->GetElement(2, 1) * pIn[1] +
+                 M4->GetElement(2, 2) * pIn[2] +
+                 M4->GetElement(2, 3);
+        *pIn++ = tmp[0];
+        *pIn++ = tmp[1];
+        *pIn++ = tmp[2];
+      }
+    }
+
+    // Interface to vtkSMPTools
+    static void Execute(vtkMatrix4x4 *m4, vtkIdType num, T *pts)
+    {
+      InPlaceTransformPoints<T> transform(m4,pts);
+      vtkSMPTools::For(0,num,transform);
+    }
+  };//InPlaceTransformPoints
+
+  template <typename T>
+  struct InPlaceTransformNormals
+  {
+    T *Normals;
+    vtkMatrix3x3 *M3;
+    double Determinant;
+    double *Spacing;
+
+    InPlaceTransformNormals(vtkMatrix3x3 *m3, double* spacing, T *n) :
+      Normals(n),
+      M3(m3),
+      Determinant(m3->Determinant()),
+      Spacing(spacing)
+    {}
+
+    void operator()(vtkIdType ptId, vtkIdType endPtId)
+    {
+      T *nIn = this->Normals + 3*ptId;
+      T tmp[3] = {0, 0, 0};
+      T toUnit = 0;
+
+      for ( ; ptId < endPtId; ++ptId )
+      {
+        nIn[0] = nIn[0] / this->Spacing[0];
+        nIn[1] = nIn[1] / this->Spacing[1];
+        nIn[2] = nIn[2] / this->Spacing[2];
+        tmp[0] = M3->GetElement(0, 0) * nIn[0] +
+                 M3->GetElement(0, 1) * nIn[1] +
+                 M3->GetElement(0, 2) * nIn[2];
+        tmp[1] = M3->GetElement(1, 0) * nIn[0] +
+                 M3->GetElement(1, 1) * nIn[1] +
+                 M3->GetElement(1, 2) * nIn[2];
+        tmp[2] = M3->GetElement(2, 0) * nIn[0] +
+                 M3->GetElement(2, 1) * nIn[1] +
+                 M3->GetElement(2, 2) * nIn[2];
+        tmp[0] *= this->Determinant;
+        tmp[1] *= this->Determinant;
+        tmp[2] *= this->Determinant;
+        toUnit = 1 / sqrt(tmp[0]*tmp[0] + tmp[1]*tmp[1] + tmp[2]*tmp[2]);
+        *nIn++ = tmp[0] * toUnit;
+        *nIn++ = tmp[1] * toUnit;
+        *nIn++ = tmp[2] * toUnit;
+      }
+    }
+
+    // Interface to vtkSMPTools
+    static void Execute(vtkMatrix3x3 *m3, double* spacing, vtkIdType num, T *n)
+    {
+      InPlaceTransformNormals<T> transform(m3,spacing,n);
+      vtkSMPTools::For(0,num,transform);
+    }
+  };//InPlaceTransformNormals
+
+  template <typename T>
+  struct InPlaceTransformVectors
+  {
+    T *Vectors;
+    vtkMatrix3x3 *M3;
+    double *Spacing;
+
+    InPlaceTransformVectors(vtkMatrix3x3 *m3, double* spacing, T *v) :
+      Vectors(v),
+      M3(m3),
+      Spacing(spacing)
+    {}
+
+    void operator()(vtkIdType ptId, vtkIdType endPtId)
+    {
+      T *nIn = this->Vectors + 3*ptId;
+      T tmp[3] = {0, 0, 0};
+
+      for ( ; ptId < endPtId; ++ptId )
+      {
+        nIn[0] = nIn[0] / this->Spacing[0];
+        nIn[1] = nIn[1] / this->Spacing[1];
+        nIn[2] = nIn[2] / this->Spacing[2];
+        tmp[0] = M3->GetElement(0, 0) * nIn[0] +
+                 M3->GetElement(0, 1) * nIn[1] +
+                 M3->GetElement(0, 2) * nIn[2];
+        tmp[1] = M3->GetElement(1, 0) * nIn[0] +
+                 M3->GetElement(1, 1) * nIn[1] +
+                 M3->GetElement(1, 2) * nIn[2];
+        tmp[2] = M3->GetElement(2, 0) * nIn[0] +
+                 M3->GetElement(2, 1) * nIn[1] +
+                 M3->GetElement(2, 2) * nIn[2];
+        *nIn++ = tmp[0];
+        *nIn++ = tmp[1];
+        *nIn++ = tmp[2];
+      }
+    }
+
+    // Interface to vtkSMPTools
+    static void Execute(vtkMatrix3x3 *m3, double* spacing, vtkIdType num, T *v)
+    {
+      InPlaceTransformVectors<T> transform(m3,spacing,v);
+      vtkSMPTools::For(0,num,transform);
+    }
+  };//InPlaceTransformVectors
+
+}//anonymous namespace
+
+
+
+//============================================================================
+//----------------------------------------------------------------------------
+// Here is the VTK class proper.
+vtkImageTransform::vtkImageTransform()
+{
+}
+
+//----------------------------------------------------------------------------
+void vtkImageTransform::TransformPointSet(vtkImageData *im, vtkPointSet *ps)
+{
+  // Check input
+  if ( im == nullptr || ps == nullptr )
+  {
+    return;
+  }
+
+  // Nothing to do if the direction matrix is the identity
+  vtkMatrix4x4 *m4 = im->GetIndexToPhysicalMatrix();
+  if ( m4->IsIdentity() )
+  {
+    return;
+  }
+
+  // Make sure points are available
+  vtkIdType numPts = ps->GetNumberOfPoints();
+  if ( numPts < 1 )
+  {
+    return;
+  }
+
+  // Grab the points-related-data and process as appropriate
+  vtkDataArray *pts = ps->GetPoints()->GetData();
+  vtkMatrix3x3 *m3 = im->GetDirectionMatrix();
+  double *ar = im->GetSpacing();
+
+  // If there is no rotation or spacing, only translate
+  if ( m3->IsIdentity() && ar[0] == 1 && ar[1] == 1 && ar[2] == 1 )
+  {
+    vtkImageTransform::TranslatePoints(im->GetOrigin(),pts);
+    return;
+  }
+
+  vtkImageTransform::TransformPoints(m4,pts);
+
+  vtkDataArray *normals = ps->GetPointData()->GetNormals();
+  if ( normals != nullptr )
+  {
+    vtkImageTransform::TransformNormals(m3,ar,normals);
+  }
+
+  vtkDataArray *vectors = ps->GetPointData()->GetVectors();
+  if ( vectors != nullptr )
+  {
+    vtkImageTransform::TransformVectors(m3,ar,vectors);
+  }
+
+  // Grab the cells-related-data and process as appropriate
+  normals = ps->GetCellData()->GetNormals();
+  if ( normals != nullptr )
+  {
+    vtkImageTransform::TransformNormals(m3,ar,normals);
+  }
+
+  vectors = ps->GetCellData()->GetVectors();
+  if ( vectors != nullptr )
+  {
+    vtkImageTransform::TransformVectors(m3,ar,vectors);
+  }
+}
+
+//----------------------------------------------------------------------------
+void vtkImageTransform::TranslatePoints(double *t, vtkDataArray *da)
+{
+  void *pts = da->GetVoidPointer(0);
+  vtkIdType num = da->GetNumberOfTuples();
+
+  switch ( da->GetDataType() )
+  {
+      vtkTemplateMacro(InPlaceTranslatePoints<VTK_TT>::
+                       Execute(t,num,(VTK_TT*)pts));
+  }
+}
+
+//----------------------------------------------------------------------------
+void vtkImageTransform::TransformPoints(vtkMatrix4x4 *m4,vtkDataArray *da)
+{
+  void *pts = da->GetVoidPointer(0);
+  vtkIdType num = da->GetNumberOfTuples();
+
+  switch ( da->GetDataType() )
+  {
+      vtkTemplateMacro(InPlaceTransformPoints<VTK_TT>::
+                       Execute(m4,num,(VTK_TT*)pts));
+  }
+}
+
+//----------------------------------------------------------------------------
+void vtkImageTransform::TransformNormals(vtkMatrix3x3 *m3,
+                                         double spacing[3],
+                                         vtkDataArray *da)
+{
+  void *n = da->GetVoidPointer(0);
+  vtkIdType num = da->GetNumberOfTuples();
+
+  switch ( da->GetDataType() )
+  {
+    vtkTemplateMacro(InPlaceTransformNormals<VTK_TT>::
+                     Execute(m3,spacing,num,(VTK_TT*)n));
+  }
+}
+
+//----------------------------------------------------------------------------
+void vtkImageTransform::TransformVectors(vtkMatrix3x3 *m3,
+                                         double spacing[3],
+                                         vtkDataArray *da)
+{
+  void *v = da->GetVoidPointer(0);
+  vtkIdType num = da->GetNumberOfTuples();
+
+  switch ( da->GetDataType() )
+  {
+    vtkTemplateMacro(InPlaceTransformVectors<VTK_TT>::
+                     Execute(m3,spacing,num,(VTK_TT*)v));
+  }
+}
+
+//----------------------------------------------------------------------------
+void vtkImageTransform::PrintSelf(ostream& os, vtkIndent indent)
+{
+  this->Superclass::PrintSelf(os,indent);
+
+}

Common/DataModel/vtkImageTransform.h

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    vtkImageTransform.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.
+
+=========================================================================*/
+/**
+ * @class   vtkImageTransform
+ * @brief   helper class to transform output of non-axis-aligned images
+ *
+ * vtkImageTransform is a helper class to transform the output of
+ * image filters (i.e., filter that input vtkImageData) by applying the
+ * Index to Physical transformation frmo the input image, which can
+ * include origin, spacing, direction. The transformation process is
+ * threaded with vtkSMPTools for performance.
+ *
+ * Typically in application the single method TransformPointSet() is
+ * invoked to transform the output of an image algorithm (assuming
+ * that the image's direction/orientation matrix is
+ * non-identity). Note that vtkPointSets encompass vtkPolyData as well
+ * as vtkUnstructuredGrids. In the future other output types may be
+ * added. Note that specific methods for transforming points, normals,
+ * and vectors is also provided by this class in case additional
+ * output data arrays need to be transformed (since
+ * TransformPointSet() only processes data arrays labeled as points,
+ * normals, and vectors).
+ *
+ * @warning
+ * This class has been threaded with vtkSMPTools. Using TBB or other
+ * non-sequential type (set in the CMake variable
+ * VTK_SMP_IMPLEMENTATION_TYPE) may improve performance significantly.
+ *
+ */
+
+#ifndef vtkImageTransform_h
+#define vtkImageTransform_h
+
+#include "vtkCommonDataModelModule.h" // For export macro
+#include "vtkObject.h"
+
+class vtkDataArray;
+class vtkImageData;
+class vtkMatrix3x3;
+class vtkMatrix4x4;
+class vtkPointSet;
+
+class VTKCOMMONDATAMODEL_EXPORT vtkImageTransform : public vtkObject
+{
+public:
+  //@{
+  /**
+   * Standard methods for construction, type information, printing.
+   */
+  static vtkImageTransform *New();
+  vtkTypeMacro(vtkImageTransform,vtkObject);
+  void PrintSelf(ostream& os, vtkIndent indent) override;
+  //@}
+
+  /**
+   * Given a vtkImageData (and hence its associated orientation
+   * matrix), and an instance of vtkPointSet, transform its points, as
+   * well as any normals and vectors, associated with the
+   * vtkPointSet. This is a convenience function, internally it calls
+   * TranslatePoints(), TransformPoints(), TransformNormals(), and/or
+   * TransformVectors() as appropriate. Note that both the normals and
+   * vectors associated with the point and cell data are transformed.
+   */
+  static void TransformPointSet(vtkImageData *im, vtkPointSet *ps);
+
+  /**
+   * Given x-y-z points represented by a vtkDataArray,
+   * translate the points using the image origin. This
+   * method is useful if there is no orientation or
+   * spacing to apply.
+   */
+  static void TranslatePoints(double *t, vtkDataArray *da);
+
+  /**
+   * Given x-y-z points represented by a vtkDataArray,
+   * transform the points using the matrix provided.
+   */
+  static void TransformPoints(vtkMatrix4x4 *m4, vtkDataArray *da);
+
+  /**
+   * Given three-component normals represented by a vtkDataArray,
+   * transform the normals using the matrix provided.
+   */
+  static void TransformNormals(vtkMatrix3x3 *m3,
+                               double spacing[3],
+                               vtkDataArray *da);
+
+  /**
+   * Given three-component vectors represented by a vtkDataArray,
+   * transform the vectors using the matrix provided.
+   */
+  static void TransformVectors(vtkMatrix3x3 *m3,
+                               double spacing[3],
+                               vtkDataArray *da);
+
+
+protected:
+  vtkImageTransform();
+  ~vtkImageTransform() {}
+
+private:
+  vtkImageTransform(const vtkImageTransform&) = delete;
+  void operator=(const vtkImageTransform&) = delete;
+};
+
+#endif