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

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


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

Redistribution and use in source and binary forms, with or without
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
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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 "vtkCell.h"

// Construct cell.
vtkCell::vtkCell()
{
  this->Points = vtkPoints::New();
  this->PointIds = vtkIdList::New();
}  

vtkCell::~vtkCell()
{
  this->Points->Delete();
  this->PointIds->Delete();
}


//
// Instantiate cell from outside
//
void vtkCell::Initialize(int npts, int *pts, vtkPoints *p)
{
  this->PointIds->Reset();
  this->Points->Reset();

  for (int i=0; i<npts; i++)
    {
    this->PointIds->InsertId(i,pts[i]);
    this->Points->InsertPoint(i,p->GetPoint(pts[i]));
    }
}
 
void vtkCell::ShallowCopy(vtkCell *c)
{
  this->Points->ShallowCopy(c->Points);
  if ( this->PointIds )
    {
    this->PointIds->Delete();
    this->PointIds = c->PointIds;
    this->PointIds->Register(this);
    }
}

void vtkCell::DeepCopy(vtkCell *c)
{
  this->Points->DeepCopy(c->Points);
  this->PointIds->DeepCopy(c->PointIds);
}

#define VTK_RIGHT 0
#define VTK_LEFT 1
#define VTK_MIDDLE 2

// Bounding box intersection modified from Graphics Gems Vol I. The method
// returns a non-zero value if the bounding box is hit. Origin[3] starts
// the ray, dir[3] is the vector components of the ray in the x-y-z
// directions, coord[3] is the location of hit, and t is the parametric
// coordinate along line. (Notes: the intersection ray dir[3] is NOT
// normalized.  Valid intersections will only occur between 0<=t<=1.)
char vtkCell::HitBBox (float bounds[6], float origin[3], float dir[3], 
                      float coord[3], float& t)
{
  char    inside=1;
  char    quadrant[3];
  int     i, whichPlane=0;
  float   maxT[3], candidatePlane[3];

  //  First find closest planes
  //
  for (i=0; i<3; i++) 
    {
    if ( origin[i] < bounds[2*i] ) 
      {
      quadrant[i] = VTK_LEFT;
      candidatePlane[i] = bounds[2*i];
      inside = 0;
      }
    else if ( origin[i] > bounds[2*i+1] ) 
      {
      quadrant[i] = VTK_RIGHT;
      candidatePlane[i] = bounds[2*i+1];
      inside = 0;
      }
    else 
      {
      quadrant[i] = VTK_MIDDLE;
      }
    }

  //  Check whether origin of ray is inside bbox
  //
  if (inside) 
    {
    coord[0] = origin[0];
    coord[1] = origin[1];
    coord[2] = origin[2];
    t = 0;
    return 1;
    }
  
  //  Calculate parametric distances to plane
  //
  for (i=0; i<3; i++)
    {
    if ( quadrant[i] != VTK_MIDDLE && dir[i] != 0.0 )
      {
      maxT[i] = (candidatePlane[i]-origin[i]) / dir[i];
      }
    else
      {
      maxT[i] = -1.0;
      }
    }

  //  Find the largest parametric value of intersection
  //
  for (i=0; i<3; i++)
    {
    if ( maxT[whichPlane] < maxT[i] )
      {
      whichPlane = i;
      }
    }

  //  Check for valid intersection along line
  //
  if ( maxT[whichPlane] > 1.0 || maxT[whichPlane] < 0.0 )
    {
    return 0;
    }
  else
    {
    t = maxT[whichPlane];
    }

  //  Intersection point along line is okay.  Check bbox.
  //
  for (i=0; i<3; i++) 
    {
    if (whichPlane != i) 
      {
      coord[i] = origin[i] + maxT[whichPlane]*dir[i];
      if ( coord[i] < bounds[2*i] || coord[i] > bounds[2*i+1] )
	{
        return 0;
	}
      } 
    else 
      {
      coord[i] = candidatePlane[i];
      }
    }

    return 1;
}

// Compute cell bounding box (xmin,xmax,ymin,ymax,zmin,zmax). Return pointer
// to array of six float values.
float *vtkCell::GetBounds ()
{
  float *x;
  int i, numPts=this->Points->GetNumberOfPoints();

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

  for (i=0; i<numPts; i++)
    {
    x = this->Points->GetPoint(i);

    this->Bounds[0] = (x[0] < this->Bounds[0] ? x[0] : this->Bounds[0]);
    this->Bounds[1] = (x[0] > this->Bounds[1] ? x[0] : this->Bounds[1]);
    this->Bounds[2] = (x[1] < this->Bounds[2] ? x[1] : this->Bounds[2]);
    this->Bounds[3] = (x[1] > this->Bounds[3] ? x[1] : this->Bounds[3]);
    this->Bounds[4] = (x[2] < this->Bounds[4] ? x[2] : this->Bounds[4]);
    this->Bounds[5] = (x[2] > this->Bounds[5] ? x[2] : this->Bounds[5]);
    
    }
  return this->Bounds;
}

// Compute cell bounding box (xmin,xmax,ymin,ymax,zmin,zmax). Copy result into
// user provided array.
void vtkCell::GetBounds(float bounds[6])
{
  this->GetBounds();
  for (int i=0; i < 6; i++)
    {
    bounds[i] = this->Bounds[i];
    }
}

// Compute Length squared of cell (i.e., bounding box diagonal squared).
float vtkCell::GetLength2 ()
{
  float diff, l=0.0;
  int i;

  this->GetBounds();
  for (i=0; i<3; i++)
    {
    diff = this->Bounds[2*i+1] - this->Bounds[2*i];
    l += diff * diff;
    }
 
  return l;
}

// Return center of the cell in parametric coordinates.
// Note that the parametric center is not always located 
// at (0.5,0.5,0.5). The return value is the subId that
// the center is in (if a composite cell). If you want the
// center in x-y-z space, invoke the EvaluateLocation() method.
int vtkCell::GetParametricCenter(float pcoords[3])
{
  pcoords[0] = pcoords[1] = pcoords[2] = 0.5;
  return 0;
}

void vtkCell::PrintSelf(ostream& os, vtkIndent indent)
{
  int numIds=this->PointIds->GetNumberOfIds();

  vtkObject::PrintSelf(os,indent);

  os << indent << "Number Of Points: " << numIds << "\n";

  if ( numIds > 0 )
    {
    float *bounds=this->GetBounds();

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

    os << indent << "  Point ids are: ";
    for (int i=0; i < numIds; i++)
      {
      os << this->PointIds->GetId(i);
      if ( i && !(i % 12) )
	{
	os << "\n\t";
	}
      else
	{
	if ( i != (numIds-1) )
	  {
	  os << ", ";
	  }
	}
      }
    os << indent << "\n";
    }
}
