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

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


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

    THIS CLASS IS PATENTED UNDER UNITED STATES PATENT NUMBER 4,710,876
    "System and Method for the Display of Surface Structures Contained
    Within The Interior Region of a Solid body".
    Application of this software for commercial purposes requires 
    a license grant from GE. Contact:
        Jerald Roehling
        GE Licensing
        One Independence Way
        PO Box 2023
        Princeton, N.J. 08540
        phone 609-734-9823
        e-mail:Roehlinj@gerlmo.ge.com
    for more information.

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 <math.h>
#include "vtkMarchingSquares.h"
#include "vtkMarchingSquaresCases.h"
#include "vtkStructuredPoints.h"
#include "vtkMergePoints.h"
#include "vtkCharArray.h"
#include "vtkUnsignedCharArray.h"
#include "vtkShortArray.h"
#include "vtkUnsignedShortArray.h"
#include "vtkIntArray.h"
#include "vtkUnsignedIntArray.h"
#include "vtkLongArray.h"
#include "vtkUnsignedLongArray.h"
#include "vtkDoubleArray.h"
#include "vtkFloatArray.h"
#include "vtkObjectFactory.h"



//------------------------------------------------------------------------------
vtkMarchingSquares* vtkMarchingSquares::New()
{
  // First try to create the object from the vtkObjectFactory
  vtkObject* ret = vtkObjectFactory::CreateInstance("vtkMarchingSquares");
  if(ret)
    {
    return (vtkMarchingSquares*)ret;
    }
  // If the factory was unable to create the object, then create it here.
  return new vtkMarchingSquares;
}




// Description:
// Construct object with initial scalar range (0,1) and single contour value
// of 0.0. The ImageRange are set to extract the first k-plane.
vtkMarchingSquares::vtkMarchingSquares()
{
  this->ContourValues = vtkContourValues::New();

  this->ImageRange[0] = 0; this->ImageRange[1] = VTK_LARGE_INTEGER;
  this->ImageRange[2] = 0; this->ImageRange[3] = VTK_LARGE_INTEGER;
  this->ImageRange[4] = 0; this->ImageRange[5] = 0;

  this->Locator = NULL;
}

vtkMarchingSquares::~vtkMarchingSquares()
{
  this->ContourValues->Delete();
  if ( this->Locator )
    {
    this->Locator->UnRegister(this);
    this->Locator = NULL;
    }
}


//----------------------------------------------------------------------------
void vtkMarchingSquares::SetInput(vtkImageData *input)
{
  this->vtkProcessObject::SetNthInput(0, input);
}

//----------------------------------------------------------------------------
vtkImageData *vtkMarchingSquares::GetInput()
{
  if (this->NumberOfInputs < 1)
    {
    return NULL;
    }
  
  return (vtkImageData *)(this->Inputs[0]);
}



void vtkMarchingSquares::SetImageRange(int imin, int imax, int jmin, int jmax, 
                                       int kmin, int kmax)
{
  int dim[6];

  dim[0] = imin;
  dim[1] = imax;
  dim[2] = jmin;
  dim[3] = jmax;
  dim[4] = kmin;
  dim[5] = kmax;

  this->SetImageRange(dim);
}

// Description:
// Overload standard modified time function. If contour values are modified,
// then this object is modified as well.
unsigned long vtkMarchingSquares::GetMTime()
{
  unsigned long mTime=this->vtkPolyDataSource::GetMTime();
  unsigned long mTime2=this->ContourValues->GetMTime();

  mTime = ( mTime2 > mTime ? mTime2 : mTime );
  if (this->Locator)
    {
    mTime2=this->Locator->GetMTime();
    mTime = ( mTime2 > mTime ? mTime2 : mTime );
    }

  return mTime;
}

//
// Contouring filter specialized for images
//
template <class T>
static void ContourImage(T *scalars, vtkScalars *newScalars, int roi[6], int dir[3],
                  int start[2], int end[2], int offset[3], float ar[3], 
                  float origin[3], float *values, int numValues, 
                  vtkPointLocator *p, vtkCellArray *lines)
{
  int i, j;
  int ptIds[2];
  float t, *x1, *x2, x[3], xp, yp;
  float pts[4][3], min, max;
  int contNum, jOffset, idx, ii, jj, index, *vert;
  static int CASE_MASK[4] = {1,2,8,4};  LINE_CASES *lineCase;
  static int edges[4][2] = { {0,1}, {1,3}, {2,3}, {0,2} };
  EDGE_LIST  *edge;
  float value, s[4];

//
// Get min/max contour values
//
  if ( numValues < 1 )
    {
    return;
    }
  for ( min=max=values[0], i=1; i < numValues; i++)
    {
    if ( values[i] < min )
      {
      min = values[i];
      }
    if ( values[i] > max )
      {
      max = values[i];
      }
    }

  //assign coordinate value to non-varying coordinate direction
  x[dir[2]] = origin[dir[2]] + roi[dir[2]*2]*ar[dir[2]];

  // Traverse all pixel cells, generating line segements using marching squares.
  for ( j=roi[start[1]]; j < roi[end[1]]; j++ )
    {

    jOffset = j * offset[1];
    pts[0][dir[1]] = origin[dir[1]] + j*ar[dir[1]];
    yp = origin[dir[1]] + (j+1)*ar[dir[1]];

    for ( i=roi[start[0]]; i < roi[end[0]]; i++)
      {
       //get scalar values
      idx = i * offset[0] + jOffset + offset[2];
      s[0] = scalars[idx];
      s[1] = scalars[idx+offset[0]];
      s[2] = scalars[idx + offset[1]];
      s[3] = scalars[idx+offset[0] + offset[1]];

      if ( (s[0] < min && s[1] < min && s[2] < min && s[3] < min) ||
      (s[0] > max && s[1] > max && s[2] > max && s[3] > max) )
        {
        continue; // no contours possible
        }

      //create pixel points
      pts[0][dir[0]] = origin[dir[0]] + i*ar[dir[0]];
      xp = origin[dir[0]] + (i+1)*ar[dir[0]];

      pts[1][dir[0]] = xp;
      pts[1][dir[1]] = pts[0][dir[1]];

      pts[2][dir[0]] = pts[0][dir[0]];
      pts[2][dir[1]] = yp;

      pts[3][dir[0]] = xp;
      pts[3][dir[1]] = yp;

      // Loop over contours in this pixel
      for (contNum=0; contNum < numValues; contNum++)
        {
        value = values[contNum];

        // Build the case table
        for ( ii=0, index = 0; ii < 4; ii++)
	  {
          if ( s[ii] >= value )
	    {
	    index |= CASE_MASK[ii];
	    }
	  }
        if ( index == 0 || index == 15 )
	  {
	  continue; //no lines
	  }

        lineCase = lineCases + index;
        edge = lineCase->edges;

        for ( ; edge[0] > -1; edge += 2 )
          {
          for (ii=0; ii<2; ii++) //insert line
            {
            vert = edges[edge[ii]];
            t = (value - s[vert[0]]) / (s[vert[1]] - s[vert[0]]);
            x1 = pts[vert[0]];
            x2 = pts[vert[1]];
            for (jj=0; jj<2; jj++) //only need to interpolate two values
              {
              x[dir[jj]] = x1[dir[jj]] + t * (x2[dir[jj]] - x1[dir[jj]]);
              }
            if ( p->InsertUniquePoint(x, ptIds[ii]) )
              {
              newScalars->InsertScalar(ptIds[ii],value);
              }
            }
          
          if ( ptIds[0] != ptIds[1] ) //check for degenerate line
            {
            lines->InsertNextCell(2,ptIds);
            }

          }//for each line
        }//for all contours
      }//for i
    }//for j
}

//
// Contouring filter specialized for images (or slices from images)
//
void vtkMarchingSquares::Execute()
{
  vtkImageData *input = this->GetInput();
  vtkPointData *pd;
  vtkPoints *newPts;
  vtkCellArray *newLines;
  vtkScalars *inScalars, *newScalars = NULL;
  int i, dims[3], roi[6], dataSize, dim, plane=0;
  int *ext;
  float origin[3], ar[3];
  vtkPolyData *output = this->GetOutput();
  int start[2], end[2], offset[3], dir[3], estimatedSize;
  int numContours=this->ContourValues->GetNumberOfContours();
  float *values=this->ContourValues->GetValues();

  vtkDebugMacro(<< "Executing marching squares");
//
// Initialize and check input
//
  if (input == NULL)
    {
    vtkErrorMacro(<<"Input is NULL");
    return;
    }
  pd=input->GetPointData();
  if (pd ==NULL)
    {
    vtkErrorMacro(<<"PointData is NULL");
    return;
    }
  inScalars=pd->GetScalars();
  if ( inScalars == NULL )
    {
    vtkErrorMacro(<<"Scalars must be defined for contouring");
    return;
    }
//
// Check dimensionality of data and get appropriate form
//
  input->GetDimensions(dims);
  ext = input->GetExtent();
  input->GetOrigin(origin);
  input->GetSpacing(ar);
  dataSize = dims[0] * dims[1] * dims[2];

  if ( input->GetDataDimension() != 2 )
    {
    for (i=0; i < 6; i++)
      {
      roi[i] = this->ImageRange[i];
      }
    }
  else
    {
    input->GetExtent(roi);
    }

  // check the final region of interest to make sure its acceptable
  for ( dim=0, i=0; i < 3; i++ )
    {
    if ( roi[2*i+1] > ext[2*i+1] )
      {
      roi[2*i+1] = ext[2*i+1];
      }
    else if ( roi[2*i+1] < ext[2*i] )
      {
      roi[2*i+1] = ext[2*i];
      }

    if ( roi[2*i] > roi[2*i+1] )
      {
      roi[2*i] = roi[2*i+1];
      }
    else if ( roi[2*i] < ext[2*i] )
      {
      roi[2*i] = ext[2*i];
      }

    if ( (roi[2*i+1]-roi[2*i]) > 0 )
      {
      dim++;
      }
    else
      {
      plane = i;
      }
    }

  if ( dim != 2 )
    {
    vtkErrorMacro(<<"Marching squares requires 2D data");
    return;
    }
//
// Setup indices and offsets (since can have x-y or z-plane)
//
  if ( plane == 0 ) //x-plane
    {
    start[0] = 2; end[0] = 3;
    start[1] = 4; end[1] = 5;
    offset[0] = dims[0];
    offset[1] = dims[0]*dims[1];
    offset[2] = (roi[0]-ext[0]);
    dir[0] = 1; dir[1] = 2; dir[2] = 0;
    }
  else if ( plane == 1 ) //y-plane
    {
    start[0] = 0; end[0] = 1;
    start[1] = 4; end[1] = 5;
    offset[0] = 1;
    offset[1] = dims[0]*dims[1];
    offset[2] = (roi[2]-ext[2])*dims[0];
    dir[0] = 0; dir[1] = 2; dir[2] = 1;
    }
  else //z-plane
    {
    start[0] = 0; end[0] = 1;
    start[1] = 2; end[1] = 3;
    offset[0] = 1;
    offset[1] = dims[0];
    offset[2] = (roi[4]-ext[4])*dims[0]*dims[1];
    dir[0] = 0; dir[1] = 1; dir[2] = 2;
    }
//
// Allocate necessary objects
//
  estimatedSize = (int) (numContours * sqrt((double)dims[0]*dims[1]));
  estimatedSize = estimatedSize / 1024 * 1024; //multiple of 1024
  if (estimatedSize < 1024)
    {
    estimatedSize = 1024;
    }

  newPts = vtkPoints::New();
  newPts->Allocate(estimatedSize,estimatedSize);
  newLines = vtkCellArray::New();
  newLines->Allocate(newLines->EstimateSize(estimatedSize,2));

  // locator used to merge potentially duplicate points
  if ( this->Locator == NULL )
    {
    this->CreateDefaultLocator();
    }
  this->Locator->InitPointInsertion (newPts, this->GetInput()->GetBounds());
  //
  // Check data type and execute appropriate function
  //
  if (inScalars->GetNumberOfComponents() == 1 )
    {
    switch (inScalars->GetDataType())
      {
      case VTK_CHAR:
	{
	char *scalars = ((vtkCharArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_CHAR,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_UNSIGNED_CHAR:
	{
	unsigned char *scalars = ((vtkUnsignedCharArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_UNSIGNED_CHAR,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_SHORT:
	{
	short *scalars = ((vtkShortArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_SHORT,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_UNSIGNED_SHORT:
	{
	unsigned short *scalars = ((vtkUnsignedShortArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_UNSIGNED_SHORT,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_INT:
	{
	int *scalars = ((vtkIntArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_INT,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_UNSIGNED_INT:
	{
	unsigned int *scalars = ((vtkUnsignedIntArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_UNSIGNED_INT,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_LONG:
	{
	long *scalars = ((vtkLongArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_LONG,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_UNSIGNED_LONG:
	{
	unsigned long *scalars = ((vtkUnsignedLongArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_UNSIGNED_LONG,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_FLOAT:
	{
	float *scalars = ((vtkFloatArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_FLOAT,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      case VTK_DOUBLE:
	{
	double *scalars = ((vtkDoubleArray *)inScalars->GetData())->GetPointer(0);
	newScalars = vtkScalars::New(VTK_DOUBLE,1);
	newScalars->Allocate(5000,25000);
	ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		     values,numContours,this->Locator,newLines);
	}
      break;
      }//switch
    }

  else //multiple components - have to convert
    {
    vtkScalars *image = vtkScalars::New();
    image->Allocate(dataSize);
    inScalars->GetScalars(0,dataSize,image);
    newScalars = vtkScalars::New(VTK_FLOAT);
    newScalars->Allocate(5000,25000);
    float *scalars = ((vtkFloatArray *)image->GetData())->GetPointer(0);
    ContourImage(scalars,newScalars,roi,dir,start,end,offset,ar,origin,
		 values,numContours,this->Locator,newLines);
    image->Delete();
    }

  vtkDebugMacro(<<"Created: " 
               << newPts->GetNumberOfPoints() << " points, " 
               << newLines->GetNumberOfCells() << " lines");
  //
  // Update ourselves.  Because we don't know up front how many lines
  // we've created, take care to reclaim memory. 
  //
  output->SetPoints(newPts);
  newPts->Delete();

  output->SetLines(newLines);
  newLines->Delete();

  output->GetPointData()->SetScalars(newScalars);
  newScalars->Delete();

  this->Locator->Initialize();
  output->Squeeze();
}

// Description:
// Specify a spatial locator for merging points. By default, 
// an instance of vtkMergePoints is used.
void vtkMarchingSquares::SetLocator(vtkPointLocator *locator)
{
  if ( this->Locator == locator)
    {
    return;
    }

  if ( this->Locator )
    {
    this->Locator->UnRegister(this);
    this->Locator = NULL;
    }
  
  if ( locator )
    {
    locator->Register(this);
    }
  
  this->Locator = locator;
  this->Modified();
}

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

void vtkMarchingSquares::PrintSelf(ostream& os, vtkIndent indent)
{
  vtkPolyDataSource::PrintSelf(os,indent);

  this->ContourValues->PrintSelf(os,indent);

  os << indent << "Image Range: ( " 
     << this->ImageRange[0] << ", "
     << this->ImageRange[1] << ", "
     << this->ImageRange[2] << ", "
     << this->ImageRange[3] << ", "
     << this->ImageRange[4] << ", "
     << this->ImageRange[5] << " )\n";

  if ( this->Locator )
    {
    os << indent << "Locator: " << this->Locator << "\n";
    }
  else
    {
    os << indent << "Locator: (none)\n";
    }
}


