Method ComputeTransformedExtent

IO/Image/vtkImageReader.cxx:462–538

}

void vtkImageReader::ComputeTransformedExtent(int inExtent[6], int outExtent[6])
{
  double transformedExtent[3];
  int temp;
  int idx;
  int dataExtent[6];

  if (!this->Transform)
  {
    memcpy(outExtent, inExtent, 6 * sizeof(int));
    memcpy(dataExtent, this->DataExtent, 6 * sizeof(int));
  }
  else
  {
    // need to know how far to translate to start at 000
    // first transform the data extent
    transformedExtent[0] = this->DataExtent[0];
    transformedExtent[1] = this->DataExtent[2];
    transformedExtent[2] = this->DataExtent[4];
    this->Transform->TransformPoint(transformedExtent, transformedExtent);
    dataExtent[0] = (int)transformedExtent[0];
    dataExtent[2] = (int)transformedExtent[1];
    dataExtent[4] = (int)transformedExtent[2];

    transformedExtent[0] = this->DataExtent[1];
    transformedExtent[1] = this->DataExtent[3];
    transformedExtent[2] = this->DataExtent[5];
    this->Transform->TransformPoint(transformedExtent, transformedExtent);
    dataExtent[1] = (int)transformedExtent[0];
    dataExtent[3] = (int)transformedExtent[1];
    dataExtent[5] = (int)transformedExtent[2];

    for (idx = 0; idx < 6; idx += 2)
    {
      if (dataExtent[idx] > dataExtent[idx + 1])
      {
        temp = dataExtent[idx];
        dataExtent[idx] = dataExtent[idx + 1];
        dataExtent[idx + 1] = temp;
      }
    }

    // now transform the inExtent
    transformedExtent[0] = inExtent[0];
    transformedExtent[1] = inExtent[2];
    transformedExtent[2] = inExtent[4];
    this->Transform->TransformPoint(transformedExtent, transformedExtent);
    outExtent[0] = (int)transformedExtent[0];
    outExtent[2] = (int)transformedExtent[1];
    outExtent[4] = (int)transformedExtent[2];

    transformedExtent[0] = inExtent[1];
    transformedExtent[1] = inExtent[3];
    transformedExtent[2] = inExtent[5];
    this->Transform->TransformPoint(transformedExtent, transformedExtent);
    outExtent[1] = (int)transformedExtent[0];
    outExtent[3] = (int)transformedExtent[1];
    outExtent[5] = (int)transformedExtent[2];