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

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


Copyright (c) 1993-1998 Ken Martin, Will Schroeder, Bill Lorensen.

This software is copyrighted by Ken Martin, Will Schroeder and Bill Lorensen.
The following terms apply to all files associated with the software unless
explicitly disclaimed in individual files. This copyright specifically does
not apply to the related textbook "The Visualization Toolkit" ISBN
013199837-4 published by Prentice Hall which is covered by its own copyright.

The authors hereby grant permission to use, copy, and distribute this
software and its documentation for any purpose, provided that existing
copyright notices are retained in all copies and that this notice is included
verbatim in any distributions. Additionally, the authors grant permission to
modify this software and its documentation for any purpose, provided that
such modifications are not distributed without the explicit consent of the
authors and that existing copyright notices are retained in all copies. Some
of the algorithms implemented by this software are patented, observe all
applicable patent law.

IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF,
EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, AND NON-INFRINGEMENT.  THIS SOFTWARE IS PROVIDED ON AN
"AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.


=========================================================================*/
#include "vtkSampleFunction.h"
#include "vtkMath.h"
#include "vtkFloatScalars.h"
#include "vtkFloatNormals.h"

// Description:
// Construct with ModelBounds=(-1,1,-1,1,-1,1), SampleDimensions=(50,50,50),
// Capping turned off, and normal generation on.
vtkSampleFunction::vtkSampleFunction()
{
  this->ModelBounds[0] = -1.0;
  this->ModelBounds[1] = 1.0;
  this->ModelBounds[2] = -1.0;
  this->ModelBounds[3] = 1.0;
  this->ModelBounds[4] = -1.0;
  this->ModelBounds[5] = 1.0;

  this->SampleDimensions[0] = 50;
  this->SampleDimensions[1] = 50;
  this->SampleDimensions[2] = 50;

  this->Capping = 0;
  this->CapValue = VTK_LARGE_FLOAT;

  this->ImplicitFunction = NULL;

  this->ComputeNormals = 1;
  this->Scalars = NULL;
}
vtkSampleFunction::~vtkSampleFunction() 
  {
  if (this->Scalars != NULL) 
    {
    this->Scalars->Delete();
    }
  }

// Description:
// Specify the dimensions of the data on which to sample.
void vtkSampleFunction::SetSampleDimensions(int i, int j, int k)
{
  int dim[3];

  dim[0] = i;
  dim[1] = j;
  dim[2] = k;

  this->SetSampleDimensions(dim);
}

// Description:
// Specify the dimensions of the data on which to sample.
void vtkSampleFunction::SetSampleDimensions(int dim[3])
{
  vtkDebugMacro(<< " setting SampleDimensions to (" << dim[0] << "," << dim[1] << "," << dim[2] << ")");

  if ( dim[0] != this->SampleDimensions[0] || dim[1] != SampleDimensions[1] ||
  dim[2] != SampleDimensions[2] )
    {
    for ( int i=0; i<3; i++) 
      this->SampleDimensions[i] = (dim[i] > 0 ? dim[i] : 1);
    this->Modified();
    }
}

// Description:
// Specify the region in space over which the sampling occurs.
void vtkSampleFunction::SetModelBounds(float xmin, float xmax, float ymin, 
                                       float ymax, float zmin, float zmax)
{
  float bounds[6];

  bounds[0] = xmin;
  bounds[1] = xmax;
  bounds[2] = ymin;
  bounds[3] = ymax;
  bounds[4] = zmin;
  bounds[5] = zmax;

  this->SetModelBounds(bounds);
}

void vtkSampleFunction::Execute()
{
  int ptId, i;
  vtkFloatNormals *newNormals=NULL;
  int numPts;
  float *p, s, ar[3], origin[3];
  if (this->Scalars == NULL) 
    {
    this->Scalars = new vtkFloatScalars;
    }
  vtkStructuredPoints *output=(vtkStructuredPoints *)this->Output;

  vtkDebugMacro(<< "Sampling implicit function");
//
// Initialize self; create output objects
//

  if ( !this->ImplicitFunction )
    {
    vtkErrorMacro(<<"No implicit function specified");
    return;
    }

  numPts = this->SampleDimensions[0] * this->SampleDimensions[1] 
           * this->SampleDimensions[2];
  this->Scalars->SetNumberOfScalars(numPts);

  // Compute origin and aspect ratio
  output->SetDimensions(this->GetSampleDimensions());
  for (i=0; i < 3; i++)
    {
    origin[i] = this->ModelBounds[2*i];
    if ( this->SampleDimensions[i] <= 1 )
      {
      ar[i] = 1;
      }
    else
      {
      ar[i] = (this->ModelBounds[2*i+1] - this->ModelBounds[2*i])
              / (this->SampleDimensions[i] - 1);
      }
    }
  output->SetOrigin(origin);
  output->SetSpacing(ar);
//
// Traverse all points evaluating implicit function at each point
//
  for (ptId=0; ptId < numPts; ptId++ )
    {
    p = output->GetPoint(ptId);
    s = this->ImplicitFunction->FunctionValue(p);
    this->Scalars->SetScalar(ptId,s);
    }
//
// If normal computation turned on, compute them
//
  if ( this->ComputeNormals )
    {
    float n[3];
    newNormals = new vtkFloatNormals(numPts); 
    newNormals->SetNumberOfNormals(numPts);
    for (ptId=0; ptId < numPts; ptId++ )
      {
      p = output->GetPoint(ptId);
      this->ImplicitFunction->FunctionGradient(p, n);
      n[0] *= -1;
      n[1] *= -1;
      n[2] *= -1;
      vtkMath::Normalize(n);
      newNormals->SetNormal(ptId,n);
      }
    }
//
// If capping is turned on, set the distances of the outside of the volume
// to the CapValue.
//
  if ( this->Capping )
    {
    this->Cap(this->Scalars);
    }
//
// Update self
//
  output->GetPointData()->SetScalars(this->Scalars);

  if (newNormals)
    {
    output->GetPointData()->SetNormals(newNormals);
    newNormals->Delete();
    }
}


unsigned long vtkSampleFunction::GetMTime()
{
  unsigned long mTime=this->vtkSource::GetMTime();
  unsigned long impFuncMTime;

  if ( this->ImplicitFunction != NULL )
    {
    impFuncMTime = this->ImplicitFunction->GetMTime();
    mTime = ( impFuncMTime > mTime ? impFuncMTime : mTime );
    }

  return mTime;
}

void vtkSampleFunction::Cap(vtkScalars *s)
{
  int i,j,k;
  int idx;
  int d01=this->SampleDimensions[0]*this->SampleDimensions[1];

// i-j planes
  k = 0;
  for (j=0; j<this->SampleDimensions[1]; j++)
    for (i=0; i<this->SampleDimensions[0]; i++)
      s->SetScalar(i+j*this->SampleDimensions[1], this->CapValue);

  k = this->SampleDimensions[2] - 1;
  idx = k*d01;
  for (j=0; j<this->SampleDimensions[1]; j++)
    for (i=0; i<this->SampleDimensions[0]; i++)
      s->SetScalar(idx+i+j*this->SampleDimensions[1], this->CapValue);

// j-k planes
  i = 0;
  for (k=0; k<this->SampleDimensions[2]; k++)
    for (j=0; j<this->SampleDimensions[1]; j++)
      s->SetScalar(j*this->SampleDimensions[0]+k*d01, this->CapValue);

  i = this->SampleDimensions[0] - 1;
  for (k=0; k<this->SampleDimensions[2]; k++)
    for (j=0; j<this->SampleDimensions[1]; j++)
      s->SetScalar(i+j*this->SampleDimensions[0]+k*d01, this->CapValue);

// i-k planes
  j = 0;
  for (k=0; k<this->SampleDimensions[2]; k++)
    for (i=0; i<this->SampleDimensions[0]; i++)
      s->SetScalar(i+k*d01, this->CapValue);

  j = this->SampleDimensions[1] - 1;
  idx = j*this->SampleDimensions[0];
  for (k=0; k<this->SampleDimensions[2]; k++)
    for (i=0; i<this->SampleDimensions[0]; i++)
      s->SetScalar(idx+i+k*d01, this->CapValue);

}


void vtkSampleFunction::PrintSelf(ostream& os, vtkIndent indent)
{
  vtkStructuredPointsSource::PrintSelf(os,indent);

  os << indent << "Sample Dimensions: (" << this->SampleDimensions[0] << ", "
               << this->SampleDimensions[1] << ", "
               << this->SampleDimensions[2] << ")\n";
  os << indent << "ModelBounds: \n";
  os << indent << "  Xmin,Xmax: (" << this->ModelBounds[0] << ", " << this->ModelBounds[1] << ")\n";
  os << indent << "  Ymin,Ymax: (" << this->ModelBounds[2] << ", " << this->ModelBounds[3] << ")\n";
  os << indent << "  Zmin,Zmax: (" << this->ModelBounds[4] << ", " << this->ModelBounds[5] << ")\n";

  if ( this->ImplicitFunction )
    os << indent << "Implicit Function: " << this->ImplicitFunction << "\n";
  else
    os << indent << "No Implicit function defined\n";

  os << indent << "Capping: " << (this->Capping ? "On\n" : "Off\n");
  os << indent << "Cap Value: " << this->CapValue << "\n";

  os << indent << "Compute Normals: " << (this->ComputeNormals ? "On\n" : "Off\n");
}

