Bug in vtkRectilinearGrid.cxx

[Alexander Prokop]

Hi all,

I found a Bug in vtkRectilinearGrid.cxx
The bug occured, when I used Streamlines.
I use VTK version 2.0, I corrected the bugs in the code below. 
For the fixing see the comments NEW INSERTED (2 times)

Dipl.-Ing. Alexander Prokop
Development Engineer
CST Computer Simulation Technology GmbH

Email: prokop at temf.tu-darmstadt.de
Web:   http://www.cst.de

---------------------------------------------------------------------

int vtkRectilinearGrid::FindPoint(float x[3])
{
  int i, j, loc[3];
  float xPrev, xNext;
  vtkScalars *scalars[3];

  scalars[0] = this->XCoordinates;
  scalars[1] = this->YCoordinates;
  scalars[2] = this->ZCoordinates;
//
// Find coordinates in x-y-z direction
//
  for ( j=0; j < 3; j++ )
    {
    loc[j] = 0;
    xPrev = scalars[j]->GetScalar(0);
    xNext = scalars[j]->GetScalar(scalars[j]->GetNumberOfScalars()-1);
    if ( x[j] < xPrev || x[j] > xNext ) return -1;

    for (i=1; i < scalars[j]->GetNumberOfScalars(); i++)
      {
      xNext = scalars[j]->GetScalar(i);
      xPrev = scalars[j]->GetScalar(i-1); // NEW INSERTED
      if ( x[j] >= xPrev && x[j] <= xNext )
        {
        if ( (x[j]-xPrev) < (xNext-x[j]) ) loc[j] = i-1;
        else loc[j] = i;
        }
      }
    }
//
//  From this location get the point id
//
  return loc[2]*this->Dimensions[0]*this->Dimensions[1] +
         loc[1]*this->Dimensions[0] + loc[0];
  
}


int vtkRectilinearGrid::ComputeStructuredCoordinates(float x[3], int ijk[3], 
                                                      float pcoords[3])
{
  int i, j, loc[3];
  float xPrev, xNext;
  vtkScalars *scalars[3];

  scalars[0] = this->XCoordinates;
  scalars[1] = this->YCoordinates;
  scalars[2] = this->ZCoordinates;
//
// Find locations in x-y-z direction
//
  ijk[0] = ijk[1] = ijk[2] = 0;
  pcoords[0] = pcoords[1] = pcoords[2] = 0.0;

  for ( j=0; j < 3; j++ )
    {
    loc[j] = 0;
    xPrev = scalars[j]->GetScalar(0);
    xNext = scalars[j]->GetScalar(scalars[j]->GetNumberOfScalars()-1);
    if ( x[j] < xPrev || x[j] > xNext ) return 0;

    for (i=1; i < scalars[j]->GetNumberOfScalars(); i++)
      {
      xNext = scalars[j]->GetScalar(i);
      xPrev = scalars[j]->GetScalar(i-1); // NEW INSERTED
      if ( x[j] >= xPrev && x[j] < xNext )
        {
        ijk[j] = i - 1;
        pcoords[j] = (x[j]-xPrev) / (xNext-xPrev);
        break;
        }

      else if ( x[j] == xNext )
        {
        ijk[j] = i - 1;
        pcoords[j] = 1.0;
        break;
        }
      }
    }

  return 1;
}



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