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

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

  Copyright (c) 1993-2002 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 "vtkTriangularTCoords.h"

#include "vtkFloatArray.h"
#include "vtkObjectFactory.h"
#include "vtkPolyData.h"

#include <math.h>

vtkCxxRevisionMacro(vtkTriangularTCoords, "1.24");
vtkStandardNewMacro(vtkTriangularTCoords);

void vtkTriangularTCoords::Execute()
{
  vtkIdType tmp;
  int j;
  vtkPoints *inPts;
  vtkPointData *pd;
  vtkCellArray *inPolys,*inStrips;
  vtkIdType numNewPts, numNewPolys, polyAllocSize;
  vtkFloatArray *newTCoords;
  vtkIdType newId, numCells, cellId;
  vtkIdType *pts = 0;
  vtkIdType newIds[3];
  vtkIdType npts = 0;;
  int errorLogging = 1;
  vtkPoints *newPoints;
  vtkCellArray *newPolys;
  float *p1, *p2, *p3;
  float tCoords[6];
  vtkPolyData *input = this->GetInput();
  vtkPolyData *output = this->GetOutput();
  vtkPointData *pointData = output->GetPointData(); 

  // Initialize
  //
  vtkDebugMacro(<<"Generating triangular texture coordinates");

  inPts = input->GetPoints();
  pd = input->GetPointData();

  inPolys = input->GetPolys();
  inStrips = input->GetStrips();

  // Count the number of new points and other primitives that 
  // need to be created.
  //
  numNewPts = input->GetNumberOfVerts();

  numNewPolys = 0;
  polyAllocSize = 0;

  for (inPolys->InitTraversal(); inPolys->GetNextCell(npts,pts); )
    {
    numNewPts += npts;
    numNewPolys++;
    polyAllocSize += npts + 1;
    }
  for (inStrips->InitTraversal(); inStrips->GetNextCell(npts,pts); )
    {
    numNewPts += (npts-2) * 3;
    polyAllocSize += (npts - 2) * 4;
    }
  numCells = inPolys->GetNumberOfCells() + inStrips->GetNumberOfCells();

  //  Allocate texture data
  //
  newTCoords = vtkFloatArray::New();
  newTCoords->SetNumberOfComponents(2);
  newTCoords->Allocate(2*numNewPts);

  // Allocate
  //
  newPoints = vtkPoints::New();
  newPoints->Allocate(numNewPts);

  newPolys = vtkCellArray::New();
  newPolys->Allocate(polyAllocSize);

  pointData->CopyTCoordsOff();
  pointData->CopyAllocate(pd);

  // Texture coordinates are the same for each triangle
  //
  tCoords[0]= 0.0;
  tCoords[1]= 0.0;
  tCoords[2]= 1.0;
  tCoords[3]= 0.0;
  tCoords[4]= 0.5;
  tCoords[5]= sqrt(3.0)/2.0;

  int abort=0;
  vtkIdType progressInterval=numCells/20 + 1;
  for (cellId=0, inPolys->InitTraversal(); 
       inPolys->GetNextCell(npts,pts) && !abort; cellId++)
    {
    if ( !(cellId % progressInterval) )
      {
      this->UpdateProgress((float)cellId/numCells);
      abort = this->GetAbortExecute();
      }
    
    if (npts != 3)
      {
      if (errorLogging) vtkWarningMacro(
        << "No texture coordinates for this cell, it is not a triangle");
      errorLogging = 0;
      continue;
      }
    newPolys->InsertNextCell(npts);
    for (j=0; j<npts; j++)
      {
      p1 = inPts->GetPoint(pts[j]);
      newId = newPoints->InsertNextPoint(p1);
      newPolys->InsertCellPoint(newId);
      pointData->CopyData(pd,pts[j],newId);
      newTCoords->SetTuple (newId,&tCoords[2*j]);
      }
    }

  // Triangle strips
  //
  for (inStrips->InitTraversal(); 
       inStrips->GetNextCell(npts,pts) && !abort; cellId++)
    {
    if ( !(cellId % progressInterval) )
      {
      this->UpdateProgress((float)cellId/numCells);
      abort = this->GetAbortExecute();
      }

    for (j=0; j<(npts-2); j++)
      {
      p1 = inPts->GetPoint(pts[j]);
      p2 = inPts->GetPoint(pts[j+1]);
      p3 = inPts->GetPoint(pts[j+2]);

      newIds[0] = newPoints->InsertNextPoint(p1);
      pointData->CopyData(pd,pts[j],newIds[0]);
      newTCoords->SetTuple (newIds[0],&tCoords[0]);

      newIds[1] = newPoints->InsertNextPoint(p2);
      pointData->CopyData(pd,pts[j+1],newIds[1]);
      newTCoords->SetTuple (newIds[1],&tCoords[2]);

      newIds[2] = newPoints->InsertNextPoint(p3);
      pointData->CopyData(pd,pts[j+2],newIds[2]);
      newTCoords->SetTuple (newIds[2],&tCoords[4]);

      // flip orientation for odd tris
      if (j%2) 
        {
        tmp = newIds[0];
        newIds[0] = newIds[2];
        newIds[2] = tmp;
        }
      newPolys->InsertNextCell(3,newIds);
      }
    }

  // Update self and release memory
  //
  output->SetPoints(newPoints);
  newPoints->Delete();

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

  output->GetPointData()->SetTCoords(newTCoords);
  newTCoords->Delete();
}

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