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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkSelectVisiblePoints.cxx,v $
  Language:  C++
  Date:      $Date: 2002/09/30 20:34:38 $
  Version:   $Revision: 1.27 $

  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 "vtkSelectVisiblePoints.h"

#include "vtkCamera.h"
#include "vtkCellArray.h"
#include "vtkDataSet.h"
#include "vtkMatrix4x4.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"
#include "vtkRenderWindow.h"
#include "vtkRenderer.h"

vtkCxxRevisionMacro(vtkSelectVisiblePoints, "$Revision: 1.27 $");
vtkStandardNewMacro(vtkSelectVisiblePoints);

// Instantiate object with no renderer; window selection turned off; 
// tolerance set to 0.01; and select invisible off.
vtkSelectVisiblePoints::vtkSelectVisiblePoints()
{
  this->Renderer = NULL;
  this->SelectionWindow = 0;
  this->Selection[0] = this->Selection[2] = 0;
  this->Selection[1] = this->Selection[3] = 1600;
  this->Tolerance = 0.01;
  this->SelectInvisible = 0;
}

vtkSelectVisiblePoints::~vtkSelectVisiblePoints()
{
  this->SetRenderer(NULL);
}

void vtkSelectVisiblePoints::Execute()
{
  vtkIdType ptId, id;
  int visible;
  vtkPoints *outPts;
  vtkCellArray *outputVertices;
  vtkDataSet *input= this->GetInput();
  vtkPolyData *output=this->GetOutput();
  vtkPointData *inPD=input->GetPointData();
  vtkPointData *outPD=output->GetPointData();
  vtkIdType numPts=input->GetNumberOfPoints();
  float x[4], dx[3], z, diff;
  int selection[4];
  
  if ( this->Renderer == NULL )
    {
    vtkErrorMacro(<<"Renderer must be set");
    return;
    }

  if ( numPts < 1 )
    {
    return;
    }
  
  outPts = vtkPoints::New();
  outPts->Allocate(numPts/2+1);
  outPD->CopyAllocate(inPD);

  outputVertices = vtkCellArray::New();
  output->SetVerts(outputVertices);
  outputVertices->Delete();

  int *size = this->Renderer->GetRenderWindow()->GetSize();

  // specify a selection window to avoid querying 
  if ( this->SelectionWindow )
    {
      for (int i=0; i<4; i++)
      {
      selection[i] = this->Selection[i];
      }
    }
  else
    {
    selection[0] = selection[2] = 0;
    selection[1] = size[0] - 1;
    selection[3] = size[1] - 1;
    }

  // Grab the composite perspective transform.  This matrix is used to convert
  // each point to view coordinates.  vtkRenderer provides a WorldToView()
  // method but it computes the composite perspective transform each time
  // WorldToView() is called.  This is expensive, so we get the matrix once
  // and handle the transformation ourselves.
  vtkMatrix4x4 *matrix = vtkMatrix4x4::New();
  float view[4];
  matrix->DeepCopy(this->Renderer->GetActiveCamera()->
                   GetCompositePerspectiveTransformMatrix(1,0,1));

  // If we have more than a few query points, we grab the z-buffer for the
  // selection region all at once and probe the resulting array.  When we
  // have just a few points, we perform individual z-buffer queries.
  const int SimpleQueryLimit = 25;
  float *zPtr = NULL;
  if (numPts > SimpleQueryLimit)
    {
    zPtr = this->Renderer->GetRenderWindow()->
      GetZbufferData(selection[0], selection[2], selection[1], selection[3]);
    }
  
  int abort=0;
  vtkIdType progressInterval=numPts/20+1;
  x[3] = 1.0;
  for (id=(-1), ptId=0; ptId < numPts && !abort; ptId++)
    {
    // perform conversion
    input->GetPoint(ptId,x);
    matrix->MultiplyPoint(x, view);
    if (view[3] == 0.0)
      {
      continue;
      }
    this->Renderer->SetViewPoint(view[0]/view[3], view[1]/view[3],
                                 view[2]/view[3]);
    this->Renderer->ViewToDisplay();
    this->Renderer->GetDisplayPoint(dx);
    visible = 0;

    if ( ! (ptId % progressInterval) ) 
      {
      this->UpdateProgress((float)ptId/numPts);
      abort = this->GetAbortExecute();
      }

    // check whether visible and in selection window 
    if ( dx[0] >= selection[0] && dx[0] <= selection[1] &&
         dx[1] >= selection[2] && dx[1] <= selection[3] )
      {
      if (numPts > SimpleQueryLimit)
        {
        // Access the value from the captured zbuffer.  Note, we only
        // captured a portion of the zbuffer, so we need to offset dx by
        // the selection window.
        z = zPtr[(int)dx[0] - selection[0]
                 + ((int)dx[1] - selection[2])
                 *(selection[1] - selection[0] + 1)];
        }
      else
        {
        z = this->Renderer->GetZ(static_cast<int>(dx[0]), 
                                 static_cast<int>(dx[1]));
        }
      diff = fabs(z-dx[2]);
      if ( diff <= this->Tolerance )
        {
        visible = 1;
        }
      }

    if ( (visible && !this->SelectInvisible) ||
         (!visible && this->SelectInvisible) )
      {
      id = outPts->InsertNextPoint(x);
      output->InsertNextCell(VTK_VERTEX, 1, &id);
      outPD->CopyData(inPD,ptId,id);
      }
    }//for all points

  output->SetPoints(outPts);
  outPts->Delete();
  output->Squeeze();

  matrix->Delete();

  if (zPtr)
    {
    delete [] zPtr;
    }

  vtkDebugMacro(<<"Selected " << id + 1 << " out of " 
                << numPts << " original points");
}

unsigned long int vtkSelectVisiblePoints::GetMTime()
{
  unsigned long mTime=this->vtkDataSetToPolyDataFilter::GetMTime();
  unsigned long time;
 
  if ( this->Renderer != NULL )
    {
    time = this->Renderer->GetMTime();
    mTime = ( time > mTime ? time : mTime );
    }

  return mTime;
}

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

  os << indent << "Renderer: " << this->Renderer << "\n";
  os << indent << "Selection Window: " 
     << (this->SelectionWindow ? "On\n" : "Off\n");

  os << indent << "Selection: \n";
  os << indent << "  Xmin,Xmax: (" << this->Selection[0] << ", " 
     << this->Selection[1] << ")\n";
  os << indent << "  Ymin,Ymax: (" << this->Selection[2] << ", " 
     << this->Selection[3] << ")\n";

  os << indent << "Tolerance: " << this->Tolerance << "\n";
  os << indent << "Select Invisible: " 
     << (this->SelectInvisible ? "On\n" : "Off\n");
}
