// Derived from VTK/Examples/Cxx/Medical4.cxx
// This example reads a volume dataset and displays it via volume rendering.
//

#include <vtkCamera.h>
#include <vtkColorTransferFunction.h>
#include <vtkFixedPointVolumeRayCastMapper.h>
#include <vtkMetaImageReader.h>
#include <vtkNamedColors.h>
#include <vtkPiecewiseFunction.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>
#include <vtkVolume.h>
#include <vtkVolumeProperty.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkCallbackCommand.h>
#include <vtkCommand.h>
#include "vtkVolume16Reader.h"

#include <array>

int step = 5;

double aneurism[4] = { 1, 1, 1, 256 };
double head[4] = { 3.2, 3.2, 1.5, 93 };
double frog[4] = { 1, 1, 2.2, 44 };

vtkSmartPointer<vtkColorTransferFunction>volumeColor;
vtkSmartPointer<vtkPiecewiseFunction> volumeScalarOpacity;
//vtkSmartPointer<vtkPiecewiseFunction> volumeGradientOpacity;
vtkSmartPointer<vtkVolumeProperty> volumeProperty;
vtkSmartPointer<vtkRenderWindow> renWin;

void KeypressCallbackFunction(
	vtkObject* caller,
	long unsigned int eventId,
	void* clientData,
	void* callData);

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();

  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 scene.
  vtkSmartPointer<vtkRenderer> ren =
    vtkSmartPointer<vtkRenderer>::New();
  renWin = vtkSmartPointer<vtkRenderWindow>::New();
  renWin->AddRenderer(ren);
  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]);

 //  vtkVolumeReader16 reads in the head CT data set.
  vtkSmartPointer<vtkVolume16Reader> reader =
	     vtkSmartPointer<vtkVolume16Reader>::New();
//  reader = vtkVolume16Reader::New();
  reader->SetDataDimensions(256, 256);
  reader->SetImageRange(1, aneurism[3]);
  reader->SetDataByteOrderToLittleEndian();
  reader->SetFilePrefix("../data/aneurism/aneurism");
  reader->SetDataSpacing(aneurism[0], aneurism[1], aneurism[2]);

  // The volume will be displayed by ray-cast alpha compositing.
  // A ray-cast mapper is needed to do the ray-casting.
  vtkSmartPointer<vtkFixedPointVolumeRayCastMapper> volumeMapper =
    vtkSmartPointer<vtkFixedPointVolumeRayCastMapper>::New();
  volumeMapper->SetInputConnection(reader->GetOutputPort());

  // The color transfer function maps voxel intensities to colors.
  // It is modality-specific, and often anatomy-specific as well.
  // The goal is to one color for flesh (between 500 and 1000)
  // and another color for bone (1150 and over).
  volumeColor = vtkSmartPointer<vtkColorTransferFunction>::New();
  volumeColor->AddRGBPoint(0,   0.0, 0.0, 0.0);
  volumeColor->AddRGBPoint(50,  0.4, 0.2, 0.1);
  volumeColor->AddRGBPoint(100, 0.8, 0.4, 0.2);
  volumeColor->AddRGBPoint(150, 1.0, 0.6, 0.3);
  volumeColor->AddRGBPoint(200, 1.0, 1.0, 0.4);

  // The opacity transfer function is used to control the opacity
  // of different tissue types.
  volumeScalarOpacity = vtkSmartPointer<vtkPiecewiseFunction>::New();
  volumeScalarOpacity->AddPoint(0,   0.00);
  volumeScalarOpacity->AddPoint(50,  0.00);
  volumeScalarOpacity->AddPoint(100, 0.30);
  volumeScalarOpacity->AddPoint(150, 0.50);
  volumeScalarOpacity->AddPoint(200, 0.90);

  // The gradient opacity function is used to decrease the opacity
  // in the "flat" regions of the volume while maintaining the opacity
  // at the boundaries between tissue types.  The gradient is measured
  // as the amount by which the intensity changes over unit distance.
  // For most medical data, the unit distance is 1mm.
/*  volumeGradientOpacity = vtkSmartPointer<vtkPiecewiseFunction>::New();
  volumeGradientOpacity->AddPoint(0,   0.0);
  volumeGradientOpacity->AddPoint(90,  0.5);
  volumeGradientOpacity->AddPoint(100, 1.0);
*/
  // The VolumeProperty attaches the color and opacity functions to the
  // volume, and sets other volume properties.  The interpolation should
  // be set to linear to do a high-quality rendering.  The ShadeOn option
  // turns on directional lighting, which will usually enhance the
  // appearance of the volume and make it look more "3D".  However,
  // the quality of the shading depends on how accurately the gradient
  // of the volume can be calculated, and for noisy data the gradient
  // estimation will be very poor.  The impact of the shading can be
  // decreased by increasing the Ambient coefficient while decreasing
  // the Diffuse and Specular coefficient.  To increase the impact
  // of shading, decrease the Ambient and increase the Diffuse and Specular.
  volumeProperty = vtkSmartPointer<vtkVolumeProperty>::New();
  volumeProperty->SetColor(volumeColor);
  volumeProperty->SetScalarOpacity(volumeScalarOpacity);
//  volumeProperty->SetGradientOpacity(volumeGradientOpacity);
  volumeProperty->SetInterpolationTypeToLinear();
  volumeProperty->ShadeOn();
  volumeProperty->SetAmbient(0.4);
  volumeProperty->SetDiffuse(0.6);
  volumeProperty->SetSpecular(0.2);

  // The vtkVolume is a vtkProp3D (like a vtkActor) and controls the position
  // and orientation of the volume in world coordinates.
  vtkSmartPointer<vtkVolume> volume =
    vtkSmartPointer<vtkVolume>::New();
  volume->SetMapper(volumeMapper);
  volume->SetProperty(volumeProperty);

  // Finally, add the volume to the renderer
  ren->AddViewProp(volume);

  // Set up an initial view of the volume.  The focal point will be the
  // center of the volume, and the camera position will be 400mm to the
  // patient's left (which is our right).
  vtkCamera *camera = ren->GetActiveCamera();
  double *c = volume->GetCenter();
  camera->SetViewUp (0, 0, -1);
  camera->SetPosition (c[0], c[1] - 400, c[2]);
  camera->SetFocalPoint (c[0], c[1], c[2]);
  camera->Azimuth(30.0);
  camera->Elevation(30.0);

  // Set a background color for the renderer
  ren->SetBackground(colors->GetColor3d("BkgColor").GetData());

  // Increase the size of the render window
  renWin->SetSize(640, 480);

  // Interact with the data.
  iren->Start();

  return EXIT_SUCCESS;
}

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);

	std::cout << "Pressed: " << iren->GetKeySym() << std::endl;
	std::string key = iren->GetKeySym();

	if (key == "Up") {
	//	volumeColor->RemoveAllPoints();
	//	volumeScalarOpacity->RemoveAllPoints();

		step++;
		int isoValue_ = 0;
		double stepValue = (double)1 / step;

		for (int i = 0; i < step; i++) {
			double r = stepValue * 2 * i;
			double b = stepValue / 2 * i;
			if (r > 1.0) r = 1.0;
			volumeScalarOpacity->AddPoint(isoValue_, stepValue * i);
		//	volumeGradientOpacity->AddPoint(isoValue_, stepValue * i);
			volumeColor->AddRGBPoint(isoValue_, r, stepValue * i, b);
			isoValue_ += 50;
		}
		volumeProperty->SetColor(volumeColor);
		volumeProperty->SetScalarOpacity(volumeScalarOpacity);
		volumeProperty->ShadeOn();
		volumeProperty->SetInterpolationTypeToLinear();
	//	volumeProperty->SetGradientOpacity(volumeGradientOpacity);
		renWin->Render();
	}
	else if (key == "Down") {
//		volumeColor->RemoveAllPoints();
//		volumeScalarOpacity->RemoveAllPoints();
//		volumeGradientOpacity->RemoveAllPoints();

		if (step > 0) {
			step--;
//			volumeScalarOpacity->RemoveAllPoints();
//			volumeGradientOpacity->RemoveAllPoints();
//			volumeColor->RemoveAllPoints();
			int isoValue_ = 0;
			double stepValue = (double)1 / step;

			for (int i = 0; i < step; i++) {
				double r = stepValue * 2 * i;
				double b = stepValue / 2 * i;
				if (r > 1.0) r = 1.0;
				volumeScalarOpacity->AddPoint(isoValue_, stepValue * i);
			//	volumeGradientOpacity->AddPoint(isoValue_, stepValue * i);
				volumeColor->AddRGBPoint(isoValue_, r, stepValue * i, b);
				isoValue_ += 50;
			}
			volumeProperty->SetColor(volumeColor);
			volumeProperty->SetScalarOpacity(volumeScalarOpacity);
			volumeProperty->ShadeOn();
			volumeProperty->SetInterpolationTypeToLinear();
		//	volumeProperty->SetGradientOpacity(volumeGradientOpacity);
			renWin->Render();
		}
	}
}