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

  Program:   Visualization Toolkit
  Module:    vtkStructuredGridGeometryFilter.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 "vtkStructuredGridGeometryFilter.h"

#include "vtkCellArray.h"
#include "vtkCellData.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkStructuredGrid.h"

vtkStandardNewMacro(vtkStructuredGridGeometryFilter);

// Construct with initial extent of all the data
vtkStructuredGridGeometryFilter::vtkStructuredGridGeometryFilter()
{
  this->Extent[0] = 0;
  this->Extent[1] = VTK_INT_MAX;
  this->Extent[2] = 0;
  this->Extent[3] = VTK_INT_MAX;
  this->Extent[4] = 0;
  this->Extent[5] = VTK_INT_MAX;
}

int vtkStructuredGridGeometryFilter::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  // get the info objects
  vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);
  vtkInformation* outInfo = outputVector->GetInformationObject(0);

  // get the input and output
  vtkStructuredGrid* input =
    vtkStructuredGrid::SafeDownCast(inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkPolyData* output = vtkPolyData::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));

  int *dims, dimension, dir[3], diff[3];
  int i, j, k, extent[6], *inExt;
  vtkIdType ptIds[4], idx, startIdx, startCellIdx, cellId;
  vtkPoints* newPts = nullptr;
  vtkCellArray* newVerts = nullptr;
  vtkCellArray* newLines = nullptr;
  vtkCellArray* newPolys = nullptr;
  vtkIdType totPoints, pos, cellPos;
  int offset[3], cellOffset[3], numPolys;
  double x[3];
  vtkPointData *pd, *outPD;
  vtkCellData *cd, *outCD;

  vtkDebugMacro(<< "Extracting structured points geometry");

  if (input->GetPoints() == nullptr)
  {
    vtkDebugMacro(<< "No data to extract");
    return 1;
  }

  pd = input->GetPointData();
  outPD = output->GetPointData();
  outPD->CopyNormalsOff();
  cd = input->GetCellData();
  outCD = output->GetCellData();
  dims = input->GetDimensions();
  inExt = input->GetExtent();

  // Based on the dimensions of the structured data, and the extent of
  // the geometry, compute the combined extent plus the dimensionality
  // of the data.
  //
  dimension = 3;
  for (i = 0; i < 3; i++)
  {
    extent[2 * i] = this->Extent[2 * i];
    if (extent[2 * i] < inExt[2 * i])
    {
      extent[2 * i] = inExt[2 * i];
    }
    extent[2 * i + 1] = this->Extent[2 * i + 1];
    if (extent[2 * i + 1] > inExt[2 * i + 1])
    {
      extent[2 * i + 1] = inExt[2 * i + 1];
    }

    // Handle empty extent.
    if (extent[2 * i] > extent[2 * i + 1])
    {
      return 1;
    }

    // Compute dimensions.
    if ((extent[2 * i + 1] - extent[2 * i]) == 0)
    {
      dimension--;
    }
  }

  // The easiest way to handle the rest of this is to use the "electric slide".
  // Translate the input extent so that it has minimums 0, 0, 0.
  // It is only internal to this method, so it is OK.
  extent[0] -= inExt[0];
  extent[1] -= inExt[0];
  extent[2] -= inExt[2];
  extent[3] -= inExt[2];
  extent[4] -= inExt[4];
  extent[5] -= inExt[4];

  // Now create polygonal data based on dimension of data
  //
  // Compute starting index of the point and cell. First the starting
  // point index.
  startIdx = (extent[0]) + (extent[2]) * dims[0] + (extent[4]) * dims[0] * dims[1];

  // The cell index is a bit more complicated at the boundaries
  if (dims[0] == 1)
  {
    startCellIdx = extent[0];
  }
  else
  {
    startCellIdx = (extent[0] < dims[0] - 1) ? extent[0] : extent[0] - 1;
  }
  if (dims[1] == 1)
  {
    startCellIdx += extent[2] * (dims[0] - 1);
  }
  else
  {
    startCellIdx +=
      (extent[2] < dims[1] - 1) ? extent[2] * (dims[0] - 1) : (extent[2] - 1) * (dims[0] - 1);
  }
  if (dims[2] == 1)
  {
    startCellIdx += extent[4] * (dims[0] - 1) * (dims[1] - 1);
  }
  else
  {
    startCellIdx += (extent[4] < dims[2] - 1) ? extent[4] * (dims[0] - 1) * (dims[1] - 1)
                                              : (extent[4] - 1) * (dims[0] - 1) * (dims[1] - 1);
  }
  switch (dimension)
  {
    default:
      break;

    case 0: // --------------------- build point -----------------------

      if (input->IsPointVisible(startIdx))
      {
        newPts = vtkPoints::New();
        newPts->Allocate(1);
        newVerts = vtkCellArray::New();
        newVerts->AllocateEstimate(1, 1);
        outPD->CopyAllocate(pd, 1);
        outCD->CopyAllocate(cd, 1);

        ptIds[0] = newPts->InsertNextPoint(input->GetPoint(startIdx));
        outPD->CopyData(pd, startIdx, ptIds[0]);

        cellId = newVerts->InsertNextCell(1, ptIds);
        outCD->CopyData(cd, startIdx, cellId);
      }
      break;

    case 1: // --------------------- build line -----------------------

      for (dir[0] = dir[1] = dir[2] = totPoints = 0, i = 0; i < 3; i++)
      {
        if ((diff[i] = extent[2 * i + 1] - extent[2 * i]) > 0)
        {
          dir[0] = i;
          totPoints = diff[i] + 1;
          break;
        }
      }
      newPts = vtkPoints::New();
      newPts->Allocate(totPoints);
      newLines = vtkCellArray::New();
      newLines->AllocateEstimate(totPoints - 1, 2);
      outPD->CopyAllocate(pd, totPoints);
      outCD->CopyAllocate(cd, totPoints - 1);

      //  Load data
      //
      if (dir[0] == 0)
      {
        offset[0] = 1;
        cellOffset[0] = 1;
      }
      else if (dir[0] == 1)
      {
        offset[0] = dims[0];
        cellOffset[0] = dims[0] - 1;
      }
      else
      {
        offset[0] = dims[0] * dims[1];
        cellOffset[0] = (dims[0] - 1) * (dims[1] - 1);
      }

      for (i = 0; i < totPoints; i++)
      {
        idx = startIdx + i * offset[0];
        input->GetPoint(idx, x);
        ptIds[0] = newPts->InsertNextPoint(x);
        outPD->CopyData(pd, idx, ptIds[0]);
      }

      for (i = 0; i < (totPoints - 1); i++)
      {
        if (input->IsPointVisible(startIdx + i * offset[0]) &&
          input->IsPointVisible(startIdx + (i + 1) * offset[0]))
        {
          idx = startCellIdx + i * cellOffset[0];
          ptIds[0] = i;
          ptIds[1] = i + 1;
          cellId = newLines->InsertNextCell(2, ptIds);
          outCD->CopyData(cd, idx, cellId);
        }
      }
      break;

    case 2: // --------------------- build plane -----------------------

      //  Create the data objects
      //
      for (dir[0] = dir[1] = dir[2] = idx = 0, i = 0; i < 3; i++)
      {
        if ((diff[i] = extent[2 * i + 1] - extent[2 * i]) != 0)
        {
          dir[idx++] = i;
        }
        else
        {
          dir[2] = i;
        }
      }

      totPoints = (diff[dir[0]] + 1) * (diff[dir[1]] + 1);
      numPolys = diff[dir[0]] * diff[dir[1]];

      newPts = vtkPoints::New();
      newPts->Allocate(totPoints);
      newPolys = vtkCellArray::New();
      newPolys->AllocateEstimate(numPolys, 4);
      outPD->CopyAllocate(pd, totPoints);
      outCD->CopyAllocate(cd, numPolys);

      //  Create polygons
      //
      for (i = 0; i < 2; i++)
      {
        if (dir[i] == 0)
        {
          offset[i] = 1;
          cellOffset[i] = 1;
        }
        else if (dir[i] == 1)
        {
          offset[i] = dims[0];
          cellOffset[i] = (dims[0] - 1);
        }
        else if (dir[i] == 2)
        {
          offset[i] = dims[0] * dims[1];
          cellOffset[i] = (dims[0] - 1) * (dims[1] - 1);
        }
      }

      // Create points whether visible or not.  Makes coding easier
      // but generates extra data.
      for (pos = startIdx, j = 0; j < (diff[dir[1]] + 1); j++)
      {
        for (i = 0; i < (diff[dir[0]] + 1); i++)
        {
          idx = pos + i * offset[0];
          input->GetPoint(idx, x);
          ptIds[0] = newPts->InsertNextPoint(x);
          outPD->CopyData(pd, idx, ptIds[0]);
        }
        pos += offset[1];
      }

      for (pos = startIdx, cellPos = startCellIdx, j = 0; j < diff[dir[1]]; j++)
      {
        for (i = 0; i < diff[dir[0]]; i++)
        {
          if (input->IsPointVisible(pos + i * offset[0]) &&
            input->IsPointVisible(pos + (i + 1) * offset[0]) &&
            input->IsPointVisible(pos + i * offset[0] + offset[1]) &&
            input->IsPointVisible(pos + (i + 1) * offset[0] + offset[1]))
          {
            idx = cellPos + i * cellOffset[0];
            ptIds[0] = i + j * (diff[dir[0]] + 1);
            ptIds[1] = ptIds[0] + 1;
            ptIds[2] = ptIds[1] + diff[dir[0]] + 1;
            ptIds[3] = ptIds[2] - 1;
            cellId = newPolys->InsertNextCell(4, ptIds);
            outCD->CopyData(cd, idx, cellId);
          }
        }
        cellPos += cellOffset[1];
        pos += offset[1];
      }
      break;

    case 3: // ------------------- grab points in volume  --------------

      // Create data objects
      //
      for (i = 0; i < 3; i++)
      {
        diff[i] = extent[2 * i + 1] - extent[2 * i];
      }

      totPoints = (diff[0] + 1) * (diff[1] + 1) * (diff[2] + 1);

      newPts = vtkPoints::New();
      newPts->Allocate(totPoints);
      newVerts = vtkCellArray::New();
      newVerts->AllocateEstimate(totPoints, 1);
      outPD->CopyAllocate(pd, totPoints);
      outCD->CopyAllocate(cd, totPoints);

      // Create vertices
      //
      offset[0] = dims[0];
      offset[1] = dims[0] * dims[1];

      for (k = 0; k < (diff[2] + 1); k++)
      {
        for (j = 0; j < (diff[1] + 1); j++)
        {
          pos = startIdx + j * offset[0] + k * offset[1];

          // avoid accessing cells past the end of the grid
          vtkIdType cellK = (k == dims[2] - 1) ? k - 1 : k;
          vtkIdType cellJ = (j == dims[1] - 1) ? j - 1 : j;
          cellPos = startCellIdx + (cellK * (dims[1] - 1) + cellJ) * (dims[0] - 1);

          for (i = 0; i < (diff[0] + 1); i++)
          {
            if (input->IsPointVisible(pos + i))
            {
              vtkIdType cellI = (i == dims[0] - 1) ? i - 1 : i;
              input->GetPoint(pos + i, x);
              ptIds[0] = newPts->InsertNextPoint(x);
              outPD->CopyData(pd, pos + i, ptIds[0]);
              cellId = newVerts->InsertNextCell(1, ptIds);
              outCD->CopyData(cd, cellPos + cellI, cellId);
            }
          }
        }
      }
      break; /* end this case */

  } // switch

  // Update self and release memory
  //
  if (newPts)
  {
    output->SetPoints(newPts);
    newPts->Delete();
  }

  if (newVerts)
  {
    output->SetVerts(newVerts);
    newVerts->Delete();
  }

  if (newLines)
  {
    output->SetLines(newLines);
    newLines->Delete();
  }

  if (newPolys)
  {
    output->SetPolys(newPolys);
    newPolys->Delete();
  }

  return 1;
}

// Specify (imin,imax, jmin,jmax, kmin,kmax) indices.
void vtkStructuredGridGeometryFilter::SetExtent(
  int iMin, int iMax, int jMin, int jMax, int kMin, int kMax)
{
  int extent[6];

  extent[0] = iMin;
  extent[1] = iMax;
  extent[2] = jMin;
  extent[3] = jMax;
  extent[4] = kMin;
  extent[5] = kMax;

  this->SetExtent(extent);
}

// Specify (imin,imax, jmin,jmax, kmin,kmax) indices in array form.
void vtkStructuredGridGeometryFilter::SetExtent(int 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] < 0)
      {
        extent[2 * i] = 0;
      }
      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];
    }
  }
}

int vtkStructuredGridGeometryFilter::RequestUpdateExtent(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** inputVector, vtkInformationVector* vtkNotUsed(outputVector))
{
  // get the info objects
  vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);

  int* wholeExt = inInfo->Get(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT());

  // Copy whole extent only if present
  int ext[6];
  memcpy(ext, this->Extent, 6 * sizeof(int));

  if (wholeExt)
  {
    // Clamp to whole extent
    for (int i = 0; i < 3; i++)
    {
      if (ext[2 * i] < wholeExt[2 * i])
      {
        ext[2 * i] = wholeExt[2 * i];
      }
      if (ext[2 * i + 1] > wholeExt[2 * i + 1])
      {
        ext[2 * i + 1] = wholeExt[2 * i + 1];
      }
    }
  }

  // Set the update extent of the input.
  inInfo->Set(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT(), ext, 6);
  return 1;
}

int vtkStructuredGridGeometryFilter::FillInputPortInformation(int, vtkInformation* info)
{
  info->Set(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkStructuredGrid");
  return 1;
}

void vtkStructuredGridGeometryFilter::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);

  os << indent << "Extent: \n";
  os << indent << "  Imin,Imax: (" << this->Extent[0] << ", " << this->Extent[1] << ")\n";
  os << indent << "  Jmin,Jmax: (" << this->Extent[2] << ", " << this->Extent[3] << ")\n";
  os << indent << "  Kmin,Kmax: (" << this->Extent[4] << ", " << this->Extent[5] << ")\n";
}
