vtkExtractUnstructuredGrid.cxx

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

  Program:   Visualization Toolkit
  Module:    vtkExtractUnstructuredGrid.cxx
  Language:  C++
  Date:      $Date$
  Version:   $Revision$


Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

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modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the names
   of any contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

 * Modified source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=========================================================================*/
#include "vtkExtractUnstructuredGrid.h"
#include "vtkMergePoints.h"
#include "vtkObjectFactory.h"


//--------------------------------------------------------------------------
vtkExtractUnstructuredGrid* vtkExtractUnstructuredGrid::New()
{
  // First try to create the object from the vtkObjectFactory
  vtkObject* ret = vtkObjectFactory::CreateInstance("vtkExtractUnstructuredGrid");
  if(ret)
    {
    return (vtkExtractUnstructuredGrid*)ret;
    }
  // If the factory was unable to create the object, then create it here.
  return new vtkExtractUnstructuredGrid;
}

// Construct with all types of clipping turned off.
vtkExtractUnstructuredGrid::vtkExtractUnstructuredGrid()
{
  this->PointMinimum = 0;
  this->PointMaximum = VTK_LARGE_INTEGER;

  this->CellMinimum = 0;
  this->CellMaximum = VTK_LARGE_INTEGER;

  this->Extent[0] = -VTK_LARGE_FLOAT;
  this->Extent[1] = VTK_LARGE_FLOAT;
  this->Extent[2] = -VTK_LARGE_FLOAT;
  this->Extent[3] = VTK_LARGE_FLOAT;
  this->Extent[4] = -VTK_LARGE_FLOAT;
  this->Extent[5] = VTK_LARGE_FLOAT;

  this->PointClipping = 0;
  this->CellClipping = 0;
  this->ExtentClipping = 0;

  this->Merging = 0;
  this->Locator = NULL;
}

// Specify a (xmin,xmax, ymin,ymax, zmin,zmax) bounding box to clip data.
void vtkExtractUnstructuredGrid::SetExtent(float xMin,float xMax, float yMin,
                                     float yMax, float zMin, float zMax)
{
  float extent[6];

  extent[0] = xMin;
  extent[1] = xMax;
  extent[2] = yMin;
  extent[3] = yMax;
  extent[4] = zMin;
  extent[5] = zMax;

  this->SetExtent(extent);
}

// Specify a (xmin,xmax, ymin,ymax, zmin,zmax) bounding box to clip data.
void vtkExtractUnstructuredGrid::SetExtent(float extent[6])
{
  int i;

  if ( extent[0] != this->Extent[0] || extent[1] != this->Extent[1] ||
  extent[2] != this->Extent[2] || extent[3] != this->Extent[3] ||
  extent[4] != this->Extent[4] || extent[5] != this->Extent[5] )
    {
    this->Modified();
    for (i=0; i<3; i++)
      {
      if ( extent[2*i+1] < extent[2*i] )
	{
	extent[2*i+1] = extent[2*i];
	}
      this->Extent[2*i] = extent[2*i];
      this->Extent[2*i+1] = extent[2*i+1];
      }
    }
}

// Extract cells and pass points and point data through. Also handles
// cell data.
void vtkExtractUnstructuredGrid::Execute()
{
  int cellId, i, newCellId, newPtId;
  vtkUnstructuredGrid *input=this->GetInput();
  int numPts=input->GetNumberOfPoints();
  int numCells=input->GetNumberOfCells();
  vtkPoints *inPts=input->GetPoints(), *newPts;
  char *cellVis;
  vtkCell *cell;
  float *x;
  vtkIdList *ptIds, *cellIds=vtkIdList::New();
  int ptId;
  vtkPointData *pd = input->GetPointData();
  vtkCellData *cd = input->GetCellData();
  int allVisible, numIds;
  vtkUnstructuredGrid *output = this->GetOutput();
  vtkPointData *outputPD = output->GetPointData();
  vtkCellData *outputCD = output->GetCellData();
  int *pointMap = NULL;
  
  vtkDebugMacro(<<"Executing geometry filter");

  if ( numPts < 1 || numCells < 1 || !inPts )
    {
    vtkErrorMacro(<<"No data to extract!");
    return;
    }

  if ( (!this->CellClipping) && (!this->PointClipping) && 
  (!this->ExtentClipping) )
    {
    allVisible = 1;
    cellVis = NULL;
    }
  else
    {
    allVisible = 0;
    cellVis = new char[numCells];
    }

  // Mark cells as being visible or not
  if ( ! allVisible )
    {
    for(cellId=0; cellId < numCells; cellId++)
      {
      if ( this->CellClipping && cellId < this->CellMinimum ||
      cellId > this->CellMaximum )
        {
        cellVis[cellId] = 0;
        }
      else
        {
        cell = input->GetCell(cellId);
        ptIds = cell->GetPointIds();
        numIds = ptIds->GetNumberOfIds();
        for (i=0; i < numIds; i++) 
          {
          ptId = ptIds->GetId(i);
          x = input->GetPoint(ptId);

          if ( (this->PointClipping && (ptId < this->PointMinimum ||
          ptId > this->PointMaximum) ) ||
          (this->ExtentClipping && 
          (x[0] < this->Extent[0] || x[0] > this->Extent[1] ||
          x[1] < this->Extent[2] || x[1] > this->Extent[3] ||
          x[2] < this->Extent[4] || x[2] > this->Extent[5] )) )
            {
            cellVis[cellId] = 0;
            break;
            }
          }
        if ( i >= numIds )
	  {
	  cellVis[cellId] = 1;
	  }
        }
      }
    }

  // Allocate
  newPts = vtkPoints::New();
  newPts->Allocate(numPts);
  output->Allocate(numCells);
  outputPD->CopyAllocate(pd,numPts,numPts/2);
  outputCD->CopyAllocate(cd,numCells,numCells/2);

  if ( this->Merging )
    {
    if ( this->Locator == NULL )
      {
      this->CreateDefaultLocator();
      }
    this->Locator->InitPointInsertion (newPts, input->GetBounds());
    }
  else
    {
    pointMap = new int[numPts];
    for (i=0; i<numPts; i++)
      {
      pointMap[i] = (-1); //initialize as unused
      }
    }

  // Traverse cells to extract geometry
  for(cellId=0; cellId < numCells; cellId++)
    {
    if ( allVisible || cellVis[cellId] )
      {
      cell = input->GetCell(cellId);
      numIds = cell->PointIds->GetNumberOfIds();
      cellIds->Reset();
      if ( this->Merging )
        {
        for (i=0; i < numIds; i++)
          {
          ptId = cell->PointIds->GetId(i);
          x = input->GetPoint(ptId);
          if ( this->Locator->InsertUniquePoint(x, newPtId) )
            {
            outputPD->CopyData(pd,ptId,newPtId);
            }
          cellIds->InsertNextId(newPtId);
          }
        }//merging coincident points
      else
        {
        for (i=0; i < numIds; i++)
          {
          ptId = cell->PointIds->GetId(i);
          if ( pointMap[ptId] < 0 )
            {
            pointMap[ptId] = newPtId 
              = newPts->InsertNextPoint(inPts->GetPoint(ptId));
            outputPD->CopyData(pd, ptId, newPtId);
            }
          cellIds->InsertNextId(pointMap[ptId]);
          }
        }//keeping original point list

      newCellId = output->InsertNextCell(input->GetCellType(cellId), cellIds);
      outputCD->CopyData(cd, cellId, newCellId);
	
      } //if cell is visible
    } //for all cells

  vtkDebugMacro(<<"Extracted " << output->GetNumberOfPoints() << " points,"
                << output->GetNumberOfCells() << " cells.");

  // Update ourselves and release memory
  output->SetPoints(newPts);
  newPts->Delete();

  if ( this->Merging && this->Locator )
    {
    this->Locator->Initialize(); 
    }
  else
    {
    delete [] pointMap;
    }
  output->Squeeze();
  
  if ( cellVis )
    {
    delete [] cellVis;
    }
  cellIds->Delete();
}

unsigned long int vtkExtractUnstructuredGrid::GetMTime()
{
  unsigned long mTime=
    this->vtkUnstructuredGridToUnstructuredGridFilter::GetMTime();
  unsigned long time;

  if ( this->Locator != NULL )
    {
    time = this->Locator->GetMTime();
    mTime = ( time > mTime ? time : mTime );
    }
  return mTime;
}

void vtkExtractUnstructuredGrid::CreateDefaultLocator()
{
  if ( this->Locator == NULL )
    {
    this->Locator = vtkMergePoints::New();
    }
}

// Specify a spatial locator for merging points. By
// default an instance of vtkMergePoints is used.
void vtkExtractUnstructuredGrid::SetLocator(vtkPointLocator *locator)
{
  if ( this->Locator == locator ) 
    {
    return;
    }
  if ( this->Locator )
    {
    this->Locator->UnRegister(this);
    this->Locator = NULL;
    }    
  if ( locator )
    {
    locator->Register(this);
    }
  this->Locator = locator;
  this->Modified();
}

void vtkExtractUnstructuredGrid::PrintSelf(ostream& os, vtkIndent indent)
{
  vtkUnstructuredGridToUnstructuredGridFilter::PrintSelf(os,indent);

  os << indent << "Point Minimum : " << this->PointMinimum << "\n";
  os << indent << "Point Maximum : " << this->PointMaximum << "\n";

  os << indent << "Cell Minimum : " << this->CellMinimum << "\n";
  os << indent << "Cell Maximum : " << this->CellMaximum << "\n";

  os << indent << "Extent: \n";
  os << indent << "  Xmin,Xmax: (" << this->Extent[0] << ", " << this->Extent[1] << ")\n";
  os << indent << "  Ymin,Ymax: (" << this->Extent[2] << ", " << this->Extent[3] << ")\n";
  os << indent << "  Zmin,Zmax: (" << this->Extent[4] << ", " << this->Extent[5] << ")\n";

  os << indent << "PointClipping: " << (this->PointClipping ? "On\n" : "Off\n");
  os << indent << "CellClipping: " << (this->CellClipping ? "On\n" : "Off\n");
  os << indent << "ExtentClipping: " << (this->ExtentClipping ? "On\n" : "Off\n");

  os << indent << "Merging: " << (this->Merging ? "On\n" : "Off\n");
  if ( this->Locator )
    {
    os << indent << "Locator: " << this->Locator << "\n";
    }
  else
    {
    os << indent << "Locator: (none)\n";
    }
}