// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2014 Daniele Panozzo <daniele.panozzo@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#ifndef IGL_VIEWER_VIEWER_CORE_H
#define IGL_VIEWER_VIEWER_CORE_H

#ifdef IGL_VIEWER_WITH_NANOGUI
#include <igl/viewer/TextRenderer.h>
#endif
#include <igl/viewer/ViewerData.h>
#include <igl/viewer/OpenGL_state.h>

#include <igl/igl_inline.h>
#include <Eigen/Geometry>
#include <Eigen/Core>

namespace igl
{
namespace viewer
{

// Basic class of the 3D mesh viewer
// TODO: write documentation

class ViewerCore
{
public:
  IGL_INLINE ViewerCore();

  // Initialization
  IGL_INLINE void init();

  // Shutdown
  IGL_INLINE void shut();

  // Serialization code
  IGL_INLINE void InitSerialization();


  // ------------------- Camera control functions

  // Adjust the view to see the entire model
  IGL_INLINE void align_camera_center(
    const Eigen::MatrixXd& V,
    const Eigen::MatrixXi& F);

  // Determines how much to zoom and shift such that the mesh fills the unit
  // box (centered at the origin)
  IGL_INLINE void get_scale_and_shift_to_fit_mesh(
    const Eigen::MatrixXd& V,
    const Eigen::MatrixXi& F,
    float & zoom,
    Eigen::Vector3f& shift);

    // Adjust the view to see the entire model
    IGL_INLINE void align_camera_center(
      const Eigen::MatrixXd& V);

    // Determines how much to zoom and shift such that the mesh fills the unit
    // box (centered at the origin)
    IGL_INLINE void get_scale_and_shift_to_fit_mesh(
      const Eigen::MatrixXd& V,
      float & zoom,
      Eigen::Vector3f& shift);

  // ------------------- Drawing functions

  // Clear the frame buffers
  IGL_INLINE void clear_framebuffers();

  // Draw everything
  IGL_INLINE void draw(ViewerData& data, OpenGL_state& opengl, bool update_matrices = true);
  IGL_INLINE void draw_buffer(
    ViewerData& data,
    OpenGL_state& opengl,
    bool update_matrices,
    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& R,
    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& G,
    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& B,
    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& A);

  // Trackball angle (quaternion)
  enum RotationType
  {
    ROTATION_TYPE_TRACKBALL = 0,
    ROTATION_TYPE_TWO_AXIS_VALUATOR_FIXED_UP = 1,
    NUM_ROTATION_TYPES = 2
  };
  IGL_INLINE void set_rotation_type(const RotationType & value);

  // ------------------- Properties

#ifdef IGL_VIEWER_WITH_NANOGUI
  // Text rendering helper
  TextRenderer textrenderer;
#endif

  // Shape material
  float shininess;

  // Colors
  Eigen::Vector4f background_color;
  Eigen::Vector4f line_color;

  // Lighting
  Eigen::Vector3f light_position;
  float lighting_factor;

  RotationType rotation_type;

  Eigen::Quaternionf trackball_angle;

  // Model viewing parameters
  float model_zoom;
  Eigen::Vector3f model_translation;

  // Model viewing paramters (uv coordinates)
  float model_zoom_uv;
  Eigen::Vector3f model_translation_uv;

  // Camera parameters
  float camera_zoom;
  bool orthographic;
  Eigen::Vector3f camera_eye;
  Eigen::Vector3f camera_up;
  Eigen::Vector3f camera_center;
  float camera_view_angle;
  float camera_dnear;
  float camera_dfar;

  // Visualization options
  bool show_overlay;
  bool show_overlay_depth;
  bool show_texture;
  bool show_faces;
  bool show_lines;
  bool show_vertid;
  bool show_faceid;
  bool invert_normals;
  bool depth_test;

  // Point size / line width
  float point_size;
  float line_width;

  // Animation
  bool is_animating;
  double animation_max_fps;

  // Caches the two-norm between the min/max point of the bounding box
  float object_scale;

  // Viewport size
  Eigen::Vector4f viewport;

  // Save the OpenGL transformation matrices used for the previous rendering pass
  Eigen::Matrix4f view;
  Eigen::Matrix4f model;
  Eigen::Matrix4f proj;
  public:
      EIGEN_MAKE_ALIGNED_OPERATOR_NEW
};

}
}

#ifndef IGL_STATIC_LIBRARY
#  include "ViewerCore.cpp"
#endif

#endif