// Derived from VTK/Examples/Cxx/Medical2.cxx
// This example reads a volume dataset, extracts two isosurfaces that
// represent the skin and bone, and then displays them.
//

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkMarchingCubes.h>
#include <vtkMetaImageReader.h>
#include <vtkNamedColors.h>
#include <vtkOutlineFilter.h>
#include <vtkPolyDataMapper.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>
#include <vtkStripper.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkCallbackCommand.h>
#include <vtkCommand.h>
#include<iostream>

#include <array>
using namespace std;

int isoValueBone = 1150;
int isoValueSkin = 500;
vtkSmartPointer<vtkMarchingCubes> boneExtractor;
vtkSmartPointer<vtkMarchingCubes> skinExtractor;
vtkSmartPointer<vtkRenderWindow> renWin;

//resource : https://vtk.org/Wiki/VTK/Examples/Cxx/Interaction/KeypressObserver
void KeypressCallbackFunction(vtkObject* caller, long unsigned int vtkNotUsed(eventId), void* vtkNotUsed(clientData), void* vtkNotUsed(callData))
{
    std::cout << "Keypress callback" << std::endl;

    vtkRenderWindowInteractor *iren =
    static_cast<vtkRenderWindowInteractor*>(caller);

    string key = iren->GetKeySym();
    cout << "Pressed: " << iren->GetKeySym() << std::endl;
    if (key == "Up") {
        isoValueSkin = isoValueSkin + 50;
        cout << isoValueSkin << endl;
        cout << iren->GetKeySym();
        skinExtractor->SetValue(0, isoValueSkin);
        renWin->Render();
    }
    else if (key == "Down") {
        isoValueSkin = isoValueSkin - 50;
        cout << isoValueSkin << endl;
        cout << iren->GetKeySym();
        skinExtractor->SetValue(0, isoValueSkin);
        renWin->Render();
    }

    else if (key == "Left") {
        isoValueBone = isoValueBone + 50;
        cout << isoValueSkin << endl;
        cout << iren->GetKeySym();
        boneExtractor->SetValue(0, isoValueBone);
        renWin->Render();
    }
    else if (key == "Right") {
        isoValueSkin = isoValueSkin - 50;
        cout << isoValueSkin << endl;
        cout << iren->GetKeySym();
        boneExtractor->SetValue(0, isoValueBone);
        renWin->Render();
    }

}

int main (int argc, char *argv[])
{
  if (argc < 2)
  {
    cout << "Usage: " << argv[0] << " file.mhd" << endl;
    return EXIT_FAILURE;
  }

  vtkSmartPointer<vtkNamedColors> colors =
    vtkSmartPointer<vtkNamedColors>::New();

  // Set the colors.
  std::array<unsigned char , 4> skinColor{{255, 125, 64}};
    colors->SetColor("SkinColor", skinColor.data());
  std::array<unsigned char , 4> bkg{{51, 77, 102, 255}};
    colors->SetColor("BkgColor", bkg.data());

  // Create the renderer, the render window, and the interactor. The renderer
  // draws into the render window, the interactor enables mouse- and
  // keyboard-based interaction with the data within the render window.
  //

    vtkSmartPointer<vtkRenderer> aRenderer =
    vtkSmartPointer<vtkRenderer>::New();


    renWin = vtkRenderWindow::New();
    vtkSmartPointer<vtkRenderWindow>::New();
  renWin->AddRenderer(aRenderer);

  vtkSmartPointer<vtkRenderWindowInteractor> iren =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  iren->SetRenderWindow(renWin);

  vtkSmartPointer<vtkCallbackCommand> keypressCallback =
      vtkSmartPointer<vtkCallbackCommand>::New();
  keypressCallback->SetCallback(KeypressCallbackFunction);
  iren->AddObserver(vtkCommand::KeyPressEvent, keypressCallback);

  // The following reader is used to read a series of 2D slices (images)
  // that compose the volume. The slice dimensions are set, and the
  // pixel spacing. The data Endianness must also be specified. The reader
  // uses the FilePrefix in combination with the slice number to construct
  // filenames using the format FilePrefix.%d. (In this case the FilePrefix
  // is the root name of the file: quarter.)
  vtkSmartPointer<vtkMetaImageReader> reader =
    vtkSmartPointer<vtkMetaImageReader>::New();
  reader->SetFileName (argv[1]);



  // An isosurface, or contour value of 500 is known to correspond to the
  // skin of the patient.
  // The triangle stripper is used to create triangle strips from the
  // isosurface; these render much faster on many systems.
  skinExtractor = vtkSmartPointer<vtkMarchingCubes>::New();
  skinExtractor->SetInputConnection(reader->GetOutputPort());
  skinExtractor->SetValue(0, isoValueSkin);

  vtkSmartPointer<vtkStripper> skinStripper =
    vtkSmartPointer<vtkStripper>::New();
  skinStripper->SetInputConnection(skinExtractor->GetOutputPort());

  vtkSmartPointer<vtkPolyDataMapper> skinMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  skinMapper->SetInputConnection(skinStripper->GetOutputPort());
  skinMapper->ScalarVisibilityOff();

  vtkSmartPointer<vtkActor> skin =
    vtkSmartPointer<vtkActor>::New();
  skin->SetMapper(skinMapper);
  skin->GetProperty()->SetDiffuseColor(colors->GetColor3d("SkinColor").GetData());
  skin->GetProperty()->SetSpecular(.3);
  skin->GetProperty()->SetSpecularPower(20);
  skin->GetProperty()->SetOpacity(.5);

  // An isosurface, or contour value of 1150 is known to correspond to the
  // bone of the patient.
  // The triangle stripper is used to create triangle strips from the
  // isosurface; these render much faster on may systems.
 boneExtractor = vtkSmartPointer<vtkMarchingCubes>::New();
  boneExtractor->SetInputConnection(reader->GetOutputPort());
  boneExtractor->SetValue(0, isoValueBone);

  vtkSmartPointer<vtkStripper> boneStripper =
    vtkSmartPointer<vtkStripper>::New();
  boneStripper->SetInputConnection(boneExtractor->GetOutputPort());

  vtkSmartPointer<vtkPolyDataMapper> boneMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  boneMapper->SetInputConnection(boneStripper->GetOutputPort());
  boneMapper->ScalarVisibilityOff();

  vtkSmartPointer<vtkActor> bone =
    vtkSmartPointer<vtkActor>::New();
  bone->SetMapper(boneMapper);
  bone->GetProperty()->SetDiffuseColor(colors->GetColor3d("Ivory").GetData());

  // An outline provides context around the data.
  //
  vtkSmartPointer<vtkOutlineFilter> outlineData =
    vtkSmartPointer<vtkOutlineFilter>::New();
  outlineData->SetInputConnection(reader->GetOutputPort());

  vtkSmartPointer<vtkPolyDataMapper> mapOutline =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapOutline->SetInputConnection(outlineData->GetOutputPort());

  vtkSmartPointer<vtkActor> outline =
    vtkSmartPointer<vtkActor>::New();
  outline->SetMapper(mapOutline);
  outline->GetProperty()->SetColor(colors->GetColor3d("Black").GetData());

  // It is convenient to create an initial view of the data. The FocalPoint
  // and Position form a vector direction. Later on (ResetCamera() method)
  // this vector is used to position the camera to look at the data in
  // this direction.
  vtkSmartPointer<vtkCamera> aCamera = vtkSmartPointer<vtkCamera>::New();
  aCamera->SetViewUp (0, 0, -1);
  aCamera->SetPosition (0, -1, 0);
  aCamera->SetFocalPoint (0, 0, 0);
  aCamera->ComputeViewPlaneNormal();
  aCamera->Azimuth(30.0);
  aCamera->Elevation(30.0);

  // Actors are added to the renderer. An initial camera view is created.
  // The Dolly() method moves the camera towards the FocalPoint,
  // thereby enlarging the image.
  aRenderer->AddActor(outline);
  aRenderer->AddActor(skin);
  aRenderer->AddActor(bone);
  aRenderer->SetActiveCamera(aCamera);
  aRenderer->ResetCamera ();
  aCamera->Dolly(1.5);

  // Set a background color for the renderer and set the size of the
  // render window (expressed in pixels).
  aRenderer->SetBackground(colors->GetColor3d("BkgColor").GetData());
  renWin->SetSize(640, 480);

  // Note that when camera movement occurs (as it does in the Dolly()
  // method), the clipping planes often need adjusting. Clipping planes
  // consist of two planes: near and far along the view direction. The
  // near plane clips out objects in front of the plane; the far plane
  // clips out objects behind the plane. This way only what is drawn
  // between the planes is actually rendered.
  aRenderer->ResetCameraClippingRange ();

  // Initialize the event loop and then start it.
  renWin->Render();
  iren->Initialize();
  iren->Start();

  return EXIT_SUCCESS;
}