Method GetTransform

Interaction/Widgets/vtkBoxWidget.cxx:1222–1289

}

void vtkBoxWidget::GetTransform(vtkTransform* t)
{
  double* pts = static_cast<vtkDoubleArray*>(this->Points->GetData())->GetPointer(0);
  double* p0 = pts;
  double* p1 = pts + 3 * 1;
  double* p3 = pts + 3 * 3;
  double* p4 = pts + 3 * 4;
  double* p14 = pts + 3 * 14;
  double center[3], translate[3], scale[3], scaleVec[3][3];
  double InitialCenter[3];
  int i;

  // The transformation is relative to the initial bounds.
  // Initial bounds are set when PlaceWidget() is invoked.
  t->Identity();

  // Translation
  for (i = 0; i < 3; i++)
  {
    InitialCenter[i] = (this->InitialBounds[2 * i + 1] + this->InitialBounds[2 * i]) / 2.0;
    center[i] = p14[i] - InitialCenter[i];
  }
  translate[0] = center[0] + InitialCenter[0];
  translate[1] = center[1] + InitialCenter[1];
  translate[2] = center[2] + InitialCenter[2];
  t->Translate(translate[0], translate[1], translate[2]);

  // Orientation
  vtkMatrix4x4* matrix = vtkMatrix4x4::New();
  this->PositionHandles();
  this->ComputeNormals();
  for (i = 0; i < 3; i++)
  {
    matrix->SetElement(i, 0, this->N[1][i]);
    matrix->SetElement(i, 1, this->N[3][i]);
    matrix->SetElement(i, 2, this->N[5][i]);
  }
  t->Concatenate(matrix);
  matrix->Delete();

  // Scale
  for (i = 0; i < 3; i++)
  {
    scaleVec[0][i] = (p1[i] - p0[i]);
    scaleVec[1][i] = (p3[i] - p0[i]);
    scaleVec[2][i] = (p4[i] - p0[i]);
  }

  scale[0] = vtkMath::Norm(scaleVec[0]);
  if (this->InitialBounds[1] != this->InitialBounds[0])
  {
    scale[0] = scale[0] / (this->InitialBounds[1] - this->InitialBounds[0]);
  }
  scale[1] = vtkMath::Norm(scaleVec[1]);
  if (this->InitialBounds[3] != this->InitialBounds[2])
  {
    scale[1] = scale[1] / (this->InitialBounds[3] - this->InitialBounds[2]);
  }