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

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

#include "vtkCellArray.h"
#include "vtkDoubleArray.h"
#include "vtkLine.h"
#include "vtkObjectFactory.h"
#include "vtkTriangle.h"
#include "vtkPoints.h"
#include "vtkIncrementalPointLocator.h"

vtkStandardNewMacro(vtkTriangleStrip);

//----------------------------------------------------------------------------
vtkTriangleStrip::vtkTriangleStrip()
{
  this->Line = vtkLine::New();
  this->Triangle = vtkTriangle::New();
}

//----------------------------------------------------------------------------
vtkTriangleStrip::~vtkTriangleStrip()
{
  this->Line->Delete();
  this->Triangle->Delete();
}

//----------------------------------------------------------------------------
int vtkTriangleStrip::EvaluatePosition(double x[3], double* closestPoint,
                                      int& subId, double pcoords[3],
                                      double& minDist2, double *weights)
{
  double pc[3], dist2;
  int ignoreId, i, return_status, status;
  double tempWeights[3], activeWeights[3];
  double closest[3];

  pcoords[2] = 0.0;

  activeWeights[0] = 0.0;
  activeWeights[1] = 0.0;
  activeWeights[2] = 0.0;

  return_status = 0;
  for (minDist2=VTK_DOUBLE_MAX,i=0; i<this->Points->GetNumberOfPoints()-2; i++)
    {
    weights[i] = 0.0;
    this->Triangle->Points->SetPoint(0,this->Points->GetPoint(i));
    this->Triangle->Points->SetPoint(1,this->Points->GetPoint(i+1));
    this->Triangle->Points->SetPoint(2,this->Points->GetPoint(i+2));
    status = this->Triangle->EvaluatePosition(x,closest,ignoreId,pc,dist2,tempWeights);
    if ( status != -1 && dist2 < minDist2 )
      {
      return_status = status;
      if (closestPoint)
        {
        closestPoint[0] = closest[0];
        closestPoint[1] = closest[1];
        closestPoint[2] = closest[2];
        }
      subId = i;
      pcoords[0] = pc[0];
      pcoords[1] = pc[1];
      minDist2 = dist2;
      activeWeights[0] = tempWeights[0];
      activeWeights[1] = tempWeights[1];
      activeWeights[2] = tempWeights[2];
      }
    }

  weights[i] = 0.0;
  weights[i+1] = 0.0;

  weights[subId] = activeWeights[0];
  weights[subId+1] = activeWeights[1];
  weights[subId+2] = activeWeights[2];

  return return_status;
}

//----------------------------------------------------------------------------
void vtkTriangleStrip::EvaluateLocation(int& subId, double pcoords[3],
                                        double x[3], double *weights)
{
  int i;
  static int idx[2][3]={{0,1,2},{1,0,2}};
  int order = subId % 2;

  double pt1[3], pt2[3], pt3[3];
  this->Points->GetPoint(subId+idx[order][0], pt1);
  this->Points->GetPoint(subId+idx[order][1], pt2);
  this->Points->GetPoint(subId+idx[order][2], pt3);
  double u3 = 1.0 - pcoords[0] - pcoords[1];

  weights[0] = u3;
  weights[1] = pcoords[0];
  weights[2] = pcoords[1];

  for (i=0; i<3; i++)
    {
    x[i] = pt1[i]*weights[0] + pt2[i]*weights[1] + pt3[i]*weights[2];
    }
}

//----------------------------------------------------------------------------
int vtkTriangleStrip::CellBoundary(int subId, double pcoords[3], vtkIdList *pts)
{
  static int idx[2][3]={{0,1,2},{1,0,2}};
  int order;

  order = subId % 2;

  this->Triangle->PointIds->SetId(0,this->PointIds->GetId(subId + idx[order][0]));
  this->Triangle->PointIds->SetId(1,this->PointIds->GetId(subId + idx[order][1]));
  this->Triangle->PointIds->SetId(2,this->PointIds->GetId(subId + idx[order][2]));
  return this->Triangle->CellBoundary(0, pcoords, pts);
}

//----------------------------------------------------------------------------
void vtkTriangleStrip::Contour(double value, vtkDataArray *cellScalars,
                               vtkIncrementalPointLocator *locator, vtkCellArray *verts,
                               vtkCellArray *lines, vtkCellArray *polys,
                               vtkPointData *inPd, vtkPointData *outPd,
                               vtkCellData *inCd, vtkIdType cellId,
                               vtkCellData *outCd)
{
  int i, numTris=this->Points->GetNumberOfPoints()-2;
  vtkDataArray *triScalars=cellScalars->NewInstance();
  triScalars->SetNumberOfComponents(cellScalars->GetNumberOfComponents());
  triScalars->SetNumberOfTuples(3);

  for ( i=0; i < numTris; i++)
    {
    this->Triangle->Points->SetPoint(0,this->Points->GetPoint(i));
    this->Triangle->Points->SetPoint(1,this->Points->GetPoint(i+1));
    this->Triangle->Points->SetPoint(2,this->Points->GetPoint(i+2));

    if ( outPd )
      {
      this->Triangle->PointIds->SetId(0,this->PointIds->GetId(i));
      this->Triangle->PointIds->SetId(1,this->PointIds->GetId(i+1));
      this->Triangle->PointIds->SetId(2,this->PointIds->GetId(i+2));
      }

    triScalars->SetTuple(0,cellScalars->GetTuple(i));
    triScalars->SetTuple(1,cellScalars->GetTuple(i+1));
    triScalars->SetTuple(2,cellScalars->GetTuple(i+2));

    this->Triangle->Contour(value, triScalars, locator, verts,
                           lines, polys, inPd, outPd, inCd, cellId, outCd);
    }
  triScalars->Delete();
}


//----------------------------------------------------------------------------
vtkCell *vtkTriangleStrip::GetEdge(int edgeId)
{
  int id1, id2;

  if ( edgeId == 0 )
    {
    id1 = 0;
    id2 = 1;
    }
  else if ( edgeId == (this->GetNumberOfPoints()-1) )
    {
    id1 = edgeId - 1;
    id2 = edgeId;
    }
  else
    {
    id1 = edgeId - 1;
    id2 = edgeId + 1;
    }

  this->Line->PointIds->SetId(0,this->PointIds->GetId(id1));
  this->Line->PointIds->SetId(1,this->PointIds->GetId(id2));
  this->Line->Points->SetPoint(0,this->Points->GetPoint(id1));
  this->Line->Points->SetPoint(1,this->Points->GetPoint(id2));

  return this->Line;
}

//----------------------------------------------------------------------------
//
// Intersect sub-triangles
//
int vtkTriangleStrip::IntersectWithLine(double p1[3], double p2[3], double tol,
                                       double& t, double x[3], double pcoords[3],
                                       int& subId)
{
  int subTest, numTris=this->Points->GetNumberOfPoints()-2;

  for (subId=0; subId < numTris; subId++)
    {
    this->Triangle->Points->SetPoint(0,this->Points->GetPoint(subId));
    this->Triangle->Points->SetPoint(1,this->Points->GetPoint(subId+1));
    this->Triangle->Points->SetPoint(2,this->Points->GetPoint(subId+2));

    if (this->Triangle->IntersectWithLine(p1, p2, tol, t, x, pcoords, subTest) )
      {
      return 1;
      }
    }

  return 0;
}

//----------------------------------------------------------------------------
int vtkTriangleStrip::Triangulate(int vtkNotUsed(index), vtkIdList *ptIds,
                                  vtkPoints *pts)
{
  int numTris = this->Points->GetNumberOfPoints()-2;
  int i, order;
  static int idx[2][3]={{0,1,2},{1,0,2}};

  pts->Reset();
  ptIds->Reset();

  for (int subId=0; subId < numTris; subId++)
    {
    order = subId % 2;

    for ( i=0; i < 3; i++ )
      {
      ptIds->InsertNextId(this->PointIds->GetId(subId+idx[order][i]));
      pts->InsertNextPoint(this->Points->GetPoint(subId+idx[order][i]));
      }
    }

  return 1;
}

//----------------------------------------------------------------------------
void vtkTriangleStrip::Derivatives(int subId, double pcoords[3], double *values,
                                   int dim, double *derivs)
{
  this->Triangle->Points->SetPoint(0,this->Points->GetPoint(subId));
  this->Triangle->Points->SetPoint(1,this->Points->GetPoint(subId+1));
  this->Triangle->Points->SetPoint(2,this->Points->GetPoint(subId+2));

  this->Triangle->Derivatives(0, pcoords, values+dim*subId, dim, derivs);
}

//----------------------------------------------------------------------------
// Given a triangle strip, decompose it into (triangle) polygons. The
// polygons are appended to the end of the list of polygons.
void vtkTriangleStrip::DecomposeStrip(int npts, vtkIdType *pts,
                                      vtkCellArray *polys)
{
  int p1, p2, p3, i;

  p1 = pts[0];
  p2 = pts[1];
  for (i=0; i<(npts-2); i++)
    {
    p3 = pts[i+2];
    polys->InsertNextCell(3);
    if ( (i % 2) ) // flip ordering to preserve consistency
      {
      polys->InsertCellPoint(p2);
      polys->InsertCellPoint(p1);
      polys->InsertCellPoint(p3);
      }
    else
      {
      polys->InsertCellPoint(p1);
      polys->InsertCellPoint(p2);
      polys->InsertCellPoint(p3);
      }
    p1 = p2;
    p2 = p3;
    }
}

//----------------------------------------------------------------------------
void vtkTriangleStrip::Clip(double value, vtkDataArray *cellScalars,
                            vtkIncrementalPointLocator *locator, vtkCellArray *tris,
                            vtkPointData *inPd, vtkPointData *outPd,
                            vtkCellData *inCd, vtkIdType cellId,
                            vtkCellData *outCd, int insideOut)
{
  int i, numTris=this->Points->GetNumberOfPoints()-2;
  int id1, id2, id3;
  vtkDataArray *triScalars=cellScalars->NewInstance();
  triScalars->SetNumberOfComponents(cellScalars->GetNumberOfComponents());
  triScalars->SetNumberOfTuples(3);

  for ( i=0; i < numTris; i++)
    {
    if (i % 2)
      {
      id1 = i + 2; id2 = i + 1; id3 = i;
      }
    else
      {
      id1 = i; id2 = i + 1; id3 = i + 2;
      }

    this->Triangle->Points->SetPoint(0,this->Points->GetPoint(id1));
    this->Triangle->Points->SetPoint(1,this->Points->GetPoint(id2));
    this->Triangle->Points->SetPoint(2,this->Points->GetPoint(id3));

    this->Triangle->PointIds->SetId(0,this->PointIds->GetId(id1));
    this->Triangle->PointIds->SetId(1,this->PointIds->GetId(id2));
    this->Triangle->PointIds->SetId(2,this->PointIds->GetId(id3));

    triScalars->SetTuple(0,cellScalars->GetTuple(id1));
    triScalars->SetTuple(1,cellScalars->GetTuple(id2));
    triScalars->SetTuple(2,cellScalars->GetTuple(id3));

    this->Triangle->Clip(value, triScalars, locator, tris, inPd, outPd,
                        inCd, cellId, outCd, insideOut);
    }

  triScalars->Delete();
}

//----------------------------------------------------------------------------
// Return the center of the point cloud in parametric coordinates.
int vtkTriangleStrip::GetParametricCenter(double pcoords[3])
{
  pcoords[0] = pcoords[1] = 0.333333; pcoords[2] = 0.0;
  return ((this->Points->GetNumberOfPoints()-2) / 2);
}

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

  os << indent << "Line:\n";
  this->Line->PrintSelf(os,indent.GetNextIndent());
  os << indent << "Triangle:\n";
  this->Triangle->PrintSelf(os,indent.GetNextIndent());
}
