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

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

#include "vtkByteSwap.h"
#include "vtkCellArray.h"
#include "vtkFloatArray.h"
#include "vtkMergePoints.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"
#include "vtkShortArray.h"
#include "vtkIncrementalPointLocator.h"

vtkStandardNewMacro(vtkUGFacetReader);

// Construct object to extract all parts, and with point merging
// turned on.
vtkUGFacetReader::vtkUGFacetReader()
{
  this->FileName = NULL;
  this->PartColors = NULL;
  this->PartNumber = (-1); //extract all parts

  this->Merging = 1;
  this->Locator = NULL;

  this->SetNumberOfInputPorts(0);
}

vtkUGFacetReader::~vtkUGFacetReader()
{
  if ( this->FileName )
    {
    delete [] this->FileName;
    }
  if ( this->PartColors )
    {
    this->PartColors->Delete();
    }
  if (this->Locator != NULL)
    {
    this->Locator->UnRegister(this);
    this->Locator = NULL;
    }
}

// Overload standard modified time function. If locator is modified,
// then this object is modified as well.
unsigned long vtkUGFacetReader::GetMTime()
{
  unsigned long mTime1=this->Superclass::GetMTime();
  unsigned long mTime2;
  
  if (this->Locator)
    {
    mTime2 = this->Locator->GetMTime();
    mTime1 = ( mTime1 > mTime2 ? mTime1 : mTime2 );
    }
  
  return mTime1;
}


int vtkUGFacetReader::RequestData(
  vtkInformation *vtkNotUsed(request),
  vtkInformationVector **vtkNotUsed(inputVector),
  vtkInformationVector *outputVector)
{
  // get the info object
  vtkInformation *outInfo = outputVector->GetInformationObject(0);

  // get the ouptut
  vtkPolyData *output = vtkPolyData::SafeDownCast(
    outInfo->Get(vtkDataObject::DATA_OBJECT()));

  FILE *fp;
  char header[36];
  struct {float  v1[3], v2[3], v3[3], n1[3], n2[3], n3[3];} facet;
  vtkIdType ptId[3];
  short ugiiColor, direction;
  int numberTris, numFacetSets, setNumber, facetNumber;
  vtkPoints *newPts, *mergedPts;
  vtkFloatArray *newNormals, *mergedNormals;
  vtkCellArray *newPolys, *mergedPolys;
  fpos_t pos;
  int triEstimate;

  vtkDebugMacro(<<"Reading UG facet file...");
  if ( this->FileName == NULL || strlen(this->FileName) == 0)
    {
    vtkErrorMacro(<<"No FileName specified...please specify one.");
    return 0;
    }

  // open the file
  if ( (fp = fopen(this->FileName, "rb")) == NULL) 
    {
    vtkErrorMacro(<<"Cannot open file specified.");
    return 0;
    }

  // read the header stuff
  if ( fread (header, 1, 2, fp) <= 0 ||
  fread (&numFacetSets, 4, 1, fp) <= 0 ||
  fread (header, 1, 36, fp) <= 0 )
    {
    vtkErrorMacro(<<"File ended prematurely");
    return 0;
    }

  // swap bytes since this is a binary file format
  vtkByteSwap::Swap4BE(&numFacetSets);
  
  // Estimate how much space we need - find out the size of the
  // file and divide by 72 bytes per triangle
  fgetpos( fp, &pos );
  fseek( fp, 0L, SEEK_END );
  triEstimate = ftell( fp ) / 72;
  fsetpos( fp, &pos );

  // allocate memory
  if ( ! this->PartColors ) 
    {
    this->PartColors = vtkShortArray::New();
    this->PartColors->Allocate(100);
    }
  else 
    {
    this->PartColors->Reset();
    }

  newPts = vtkPoints::New();
  newPts->Allocate(triEstimate,triEstimate);
  newNormals = vtkFloatArray::New();
  newNormals->SetNumberOfComponents(3);
  newNormals->Allocate(3*triEstimate,3*triEstimate);
  newPolys = vtkCellArray::New();
  newPolys->Allocate(newPolys->EstimateSize(triEstimate,3),triEstimate);

  // loop over all facet sets, extracting triangles
  for (setNumber=0; setNumber < numFacetSets; setNumber++) 
    {

    if ( fread (&ugiiColor, 2, 1, fp) <= 0 ||
    fread (&direction, 2, 1, fp) <= 0 ||
    fread (&numberTris, 4, 1, fp) <= 0 )
      {
      vtkErrorMacro(<<"File ended prematurely");
      break;
      }

    // swap bytes if necc
    vtkByteSwap::Swap4BE(&numberTris);
    vtkByteSwap::Swap2BERange(&ugiiColor,1);
    vtkByteSwap::Swap2BERange(&direction,1);
    
    this->PartColors->InsertNextValue(ugiiColor);

    for (facetNumber=0; facetNumber < numberTris; facetNumber++)
      {
      if ( fread(&facet,72,1,fp) <= 0 )
        {
        vtkErrorMacro(<<"File ended prematurely");
        break;
        }

      // swap bytes if necc
      vtkByteSwap::Swap4BERange((float *)(&facet),18);
      
      if ( this->PartNumber == -1 || this->PartNumber == setNumber )
        {
        ptId[0] = newPts->InsertNextPoint(facet.v1);
        ptId[1] = newPts->InsertNextPoint(facet.v2);
        ptId[2] = newPts->InsertNextPoint(facet.v3);

        newNormals->InsertTuple(ptId[0],facet.n1);
        newNormals->InsertTuple(ptId[1],facet.n2);
        newNormals->InsertTuple(ptId[2],facet.n3);

        newPolys->InsertNextCell(3,ptId);
        }//if appropriate part
      }//for all facets in this set
    }//for this facet set

  // update output
  vtkDebugMacro(<<"Read " 
                << newPts->GetNumberOfPoints() << " points, "
                << newPolys->GetNumberOfCells() << " triangles.");

  fclose(fp);

  //
  // Merge points/triangles if requested
  //
  if ( this->Merging )
    {
    int i;
    vtkIdType *pts = 0;
    vtkIdType nodes[3];
    vtkIdType npts;
    double *x;

    mergedPts = vtkPoints::New();
    mergedPts->Allocate(newPts->GetNumberOfPoints()/3);
    mergedNormals = vtkFloatArray::New();
    mergedNormals->SetNumberOfComponents(3);
    mergedNormals->Allocate(newNormals->GetNumberOfTuples());
    mergedPolys = vtkCellArray::New();
    mergedPolys->Allocate(newPolys->GetSize());

    if ( this->Locator == NULL )
      {
      this->CreateDefaultLocator();
      }
    this->Locator->InitPointInsertion (mergedPts, newPts->GetBounds());

    for (newPolys->InitTraversal(); newPolys->GetNextCell(npts,pts); )
      {
      for (i=0; i < 3; i++) 
        {
        x = newPts->GetPoint(pts[i]);
        if ( this->Locator->InsertUniquePoint(x, nodes[i]) )
          {
          mergedNormals->InsertTuple(nodes[i],newNormals->GetTuple(pts[i]));
          }
        }

      if ( nodes[0] != nodes[1] && nodes[0] != nodes[2] && 
      nodes[1] != nodes[2] )
        {
        mergedPolys->InsertNextCell(3,nodes);
        }
      }

      newPts->Delete();
      newNormals->Delete();
      newPolys->Delete();

      vtkDebugMacro(<< "Merged to: " 
                   << mergedPts->GetNumberOfPoints() << " points, " 
                   << mergedPolys->GetNumberOfCells() << " triangles");
    }
  else
    {
    mergedPts = newPts;
    mergedNormals = newNormals;
    mergedPolys = newPolys;
    }
//
// Update ourselves
//
  output->SetPoints(mergedPts);
  mergedPts->Delete();

  output->GetPointData()->SetNormals(mergedNormals);
  mergedNormals->Delete();

  output->SetPolys(mergedPolys);
  mergedPolys->Delete();

  if (this->Locator)
    {
    this->Locator->Initialize(); //free storage
    }

  output->Squeeze();

  return 1;
}

int vtkUGFacetReader::GetNumberOfParts()
{
  char header[36];
  FILE *fp;
  int numberOfParts;

  if ( this->FileName == NULL || strlen(this->FileName) == 0)
    {
    vtkErrorMacro(<<"No FileName specified...please specify one.");
    return 0;
    }

  // open the file
  if ( (fp = fopen(this->FileName, "rb")) == NULL) 
    {
    vtkErrorMacro(<<"Cannot open file specified.");
    return 0;
    }

  // read the header stuff
  if ( fread (header, 1, 2, fp) <= 0 ||
  fread (&numberOfParts, 4, 1, fp) <= 0 ||
  fread (header, 1, 36, fp) <= 0 )
    {
    vtkErrorMacro(<<"File ended prematurely");
    fclose(fp);
    return 0;
    }

  // swap bytes if necc
  vtkByteSwap::Swap4BE(&numberOfParts);
  
  fclose(fp);
  return numberOfParts;
}

// Retrieve color index for the parts in the file.
short vtkUGFacetReader::GetPartColorIndex(int partId)
{
  if ( this->PartColors == NULL )
    {
    this->Update();
    }

  if ( !this->PartColors || 
  partId < 0 || partId > this->PartColors->GetMaxId() )
    {
    return 0;
    }
  else
    {
    return this->PartColors->GetValue(partId);
    }
}

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

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

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

  os << indent << "File Name: " 
     << (this->FileName ? this->FileName : "(none)") << "\n";

  os << indent << "Part Number: " << this->PartNumber << "\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";
    }
}