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

  Program:   Visualization Toolkit
  Module:    $RCSfile: expCos.cxx,v $

  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.

=========================================================================*/
//
// Brute force computation of Bessel functions. Might be better to create a
// filter (or source) object. Might also consider vtkSampleFunction.

#include "vtkActor.h"
#include "vtkCamera.h"
#include "vtkDataSetMapper.h"
#include "vtkDebugLeaks.h"
#include "vtkFloatArray.h"
#include "vtkPlaneSource.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"
#include "vtkRegressionTestImage.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"
#include "vtkTransform.h"
#include "vtkTransformPolyDataFilter.h"
#include "vtkWarpScalar.h"

int expCos( int argc, char *argv[] )
{
  int i, numPts;
  double x[3];
  double r, deriv;

  vtkRenderer *ren = vtkRenderer::New();
  vtkRenderWindow *renWin = vtkRenderWindow::New();
  renWin->AddRenderer(ren);

  vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
  iren->SetRenderWindow(renWin);
  
  // create plane to warp
  vtkPlaneSource *plane = vtkPlaneSource::New();
  plane->SetResolution (300,300);

  vtkTransform *transform = vtkTransform::New();
  transform->Scale(10.0,10.0,1.0);

  vtkTransformPolyDataFilter *transF = vtkTransformPolyDataFilter::New();
  transF->SetInputConnection(plane->GetOutputPort());
  transF->SetTransform(transform);
  transF->Update();
  
  // compute Bessel function and derivatives. This portion could be 
  // encapsulated into source or filter object.
  //
  vtkPolyData *input = transF->GetOutput();
  numPts = input->GetNumberOfPoints();
  
  vtkPoints *newPts = vtkPoints::New();
  newPts->SetNumberOfPoints(numPts);

  vtkFloatArray *derivs = vtkFloatArray::New();
  derivs->SetNumberOfTuples(numPts);

  vtkPolyData *bessel = vtkPolyData::New();
  bessel->CopyStructure(input);
  bessel->SetPoints(newPts);
  bessel->GetPointData()->SetScalars(derivs);

  for (i=0; i<numPts; i++)
    {
    input->GetPoint(i,x);
    r = sqrt((double)x[0]*x[0] + x[1]*x[1]);
    x[2] = exp(-r) * cos (10.0*r);
    newPts->SetPoint(i,x);
    deriv = -exp(-r) * (cos(10.0*r) + 10.0*sin(10.0*r));
    derivs->SetValue(i,deriv);
    }
  newPts->Delete(); //reference counting - it's ok
  derivs->Delete();
  
  // warp plane
  vtkWarpScalar *warp = vtkWarpScalar::New();
  warp->SetInput(bessel);
  warp->XYPlaneOn();
  warp->SetScaleFactor(0.5);
  
  // mapper and actor
  vtkDataSetMapper *mapper = vtkDataSetMapper::New();
  mapper->SetInputConnection(warp->GetOutputPort());
  double tmp[2];
  bessel->GetScalarRange(tmp);
  mapper->SetScalarRange(tmp[0],tmp[1]);
  
  vtkActor *carpet = vtkActor::New();
  carpet->SetMapper(mapper);

  // assign our actor to the renderer
  ren->AddActor(carpet);
  ren->SetBackground(1,1,1);
  renWin->SetSize(300,300);

  // draw the resulting scene
  ren->ResetCamera();
  ren->GetActiveCamera()->Zoom(1.4);
  ren->GetActiveCamera()->Elevation(-55);
  ren->GetActiveCamera()->Azimuth(25);
  ren->ResetCameraClippingRange();
  renWin->Render();

  int retVal = vtkRegressionTestImage( renWin );
  if ( retVal == vtkRegressionTester::DO_INTERACTOR)
    {
    iren->Start();
    }

  // Clean up
  ren->Delete();
  renWin->Delete();
  iren->Delete();
  plane->Delete();
  transform->Delete();
  transF->Delete();
  bessel->Delete();
  warp->Delete();
  mapper->Delete();
  carpet->Delete();

  return !retVal;
}