//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt 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 <vtkm/Math.h>
#include <vtkm/cont/DataSet.h>
#include <vtkm/cont/testing/MakeTestDataSet.h>

//Suppress warnings about glut being deprecated on OSX
#if (defined(VTKM_GCC) || defined(VTKM_CLANG))
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif

#include <vtkm/rendering/internal/OpenGLHeaders.h> //Required for compile....

#if defined(__APPLE__)
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <vtkm/cont/ColorTable.h>
#include <vtkm/rendering/CanvasGL.h>
#include <vtkm/rendering/MapperGL.h>
#include <vtkm/rendering/View3D.h>

vtkm::rendering::View3D* view = nullptr;

const vtkm::Int32 W = 512, H = 512;
int buttonStates[3] = { GLUT_UP, GLUT_UP, GLUT_UP };
bool shiftKey = false;
int lastx = -1, lasty = -1;

void reshape(int, int)
{
  //Don't allow resizing window.
  glutReshapeWindow(W, H);
}

// Render the output using simple OpenGL
void displayCall()
{
  view->Paint();
  glutSwapBuffers();
}

// Allow rotations of the camera
void mouseMove(int x, int y)
{
  const vtkm::Id width = view->GetCanvas().GetWidth();
  const vtkm::Id height = view->GetCanvas().GetHeight();

  //Map to XY
  y = static_cast<int>(height - y);

  if (lastx != -1 && lasty != -1)
  {
    vtkm::Float32 x1 = vtkm::Float32(lastx * 2) / vtkm::Float32(width) - 1.0f;
    vtkm::Float32 y1 = vtkm::Float32(lasty * 2) / vtkm::Float32(height) - 1.0f;
    vtkm::Float32 x2 = vtkm::Float32(x * 2) / vtkm::Float32(width) - 1.0f;
    vtkm::Float32 y2 = vtkm::Float32(y * 2) / vtkm::Float32(height) - 1.0f;

    if (buttonStates[0] == GLUT_DOWN)
    {
      if (shiftKey)
        view->GetCamera().Pan(x2 - x1, y2 - y1);
      else
        view->GetCamera().TrackballRotate(x1, y1, x2, y2);
    }
    else if (buttonStates[1] == GLUT_DOWN)
      view->GetCamera().Zoom(y2 - y1);
  }

  lastx = x;
  lasty = y;
  glutPostRedisplay();
}

// Respond to mouse button
void mouseCall(int button, int state, int vtkmNotUsed(x), int vtkmNotUsed(y))
{
  int modifiers = glutGetModifiers();
  shiftKey = modifiers & GLUT_ACTIVE_SHIFT;
  buttonStates[button] = state;

  //std::cout<<"Buttons: "<<buttonStates[0]<<" "<<buttonStates[1]<<" "<<buttonStates[2]<<" SHIFT= "<<shiftKey<<std::endl;

  //mouse down, reset.
  if (buttonStates[button] == GLUT_DOWN)
  {
    lastx = -1;
    lasty = -1;
  }
}

// Compute and render an isosurface for a uniform grid example
int main(int argc, char* argv[])
{
  auto opts =
    vtkm::cont::InitializeOptions::DefaultAnyDevice | vtkm::cont::InitializeOptions::Strict;
  vtkm::cont::Initialize(argc, argv, opts);

  vtkm::cont::testing::MakeTestDataSet maker;
  vtkm::cont::DataSet ds = maker.Make3DUniformDataSet0();

  lastx = lasty = -1;

  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
  glutInitWindowSize(W, H);
  glutCreateWindow("VTK-m Rendering");
  glutDisplayFunc(displayCall);
  glutMotionFunc(mouseMove);
  glutMouseFunc(mouseCall);
  glutReshapeFunc(reshape);

  vtkm::rendering::Color bg(0.2f, 0.2f, 0.2f, 1.0f);
  vtkm::rendering::CanvasGL canvas;
  vtkm::rendering::MapperGL mapper;

  vtkm::rendering::Scene scene;
  scene.AddActor(vtkm::rendering::Actor(ds.GetCellSet(),
                                        ds.GetCoordinateSystem(),
                                        ds.GetField("pointvar"),
                                        vtkm::cont::ColorTable("inferno")));

  //Create vtkm rendering stuff.
  view = new vtkm::rendering::View3D(scene, mapper, canvas, bg);
  view->Initialize();
  glutMainLoop();

  return 0;
}

#if (defined(VTKM_GCC) || defined(VTKM_CLANG))
#pragma GCC diagnostic pop
#endif
