/***************************************************************************
   File:        Renderer.hpp                                                             
   Created:     03/01/2001                                                            
   Author:      Maxim Garber                                                
                Computer Science Department                                 
                University of North Carolina - Chapel Hill                  
                garber@cs.unc.edu                                           
                                                                            
   Description:                                                             
                                                                            
----------------------------------------------------------------------------.
   Copyright 2001 Maxim Garber                                              
   UNC Motion Planning Research Group                                       
                                                                            
                                                                            
*****************************************************************************/
#include <GL/glut.h>
#include <GL/glu.h>
#include <fstream.h>
#include "tga.hpp"
#include "trimodel.hpp"
#include <vector>
#include "Renderer_constants.hpp"


/*---------------------------------------------------------------------------
    Constants
----------------------------------------------------------------------------*/
#define FILE_NAME_LENGTH  20
#define MAX_NUM_LIGHTS    8

/*---------------------------------------------------------------------------
    Types
----------------------------------------------------------------------------*/
struct RenderState{
   // texture
  int       _texHeight;
  int       _texWidth;
  int       _texChannels;
  GLuint    _texName;
  GLubyte*  _texture;
  float     _texScaleFactor;

  // OpenGL texture state parameters
  std::vector<GLenum> _paramNames;
  std::vector<GLuint> _paramValues; 
};

struct LightParams
{
  float Ambient[4], Diffuse[4], Specular[4], Position[4], 
        SpotDirection[3], SpotExponent, SpotCutoff,
        ConstantAttenuation, LinearAttenuation, QuadraticAttenuation;
  int IsEnabled;
};

struct MaterialParams
{
  float Ambient[4], Diffuse[4], Specular[4], Shininess, Emission[4];
};

typedef std::vector<Tri>          TriBucket;
typedef std::vector<TriBucket>    TriBucketArray;
typedef std::vector<RenderState*> RenderStateArray;

enum RenderMode
{ 
  TEXTURE_MODE_STANDARD,
  TEXTURE_MODE_FLAT,
  COMPUTED_COLOR_MODE
};

class Renderer{
public:
  /*---------------------------------------------------------------------------
      Constructors
  ----------------------------------------------------------------------------*/
  
  Renderer();
  ~Renderer(){};

  void Initialize(const char* renderFile);

  
  /*---------------------------------------------------------------------------
      Setting Render State Parameters
  ----------------------------------------------------------------------------*/
  void AddTexture(GLubyte* texture, 
                  GLuint Width, GLuint Height, GLuint Channels,
                  float textureScale, int renderState);

  void AddTexture(const char* textureFile, float textureScale,
                  int renderState);

  void SetParameter(GLenum paramName, GLuint paramValue, 
                  int renderState);

  void CompileRenderStates();

  void SetRenderState(int renderState);

  void SetRenderMode(RenderMode mode){_mode = mode;}

  
  /*---------------------------------------------------------------------------
      Setting Lighting and Camera Parameters
  ----------------------------------------------------------------------------*/
  void Lightf(int LightID, int ParamName, float Value);
  void Lightfv(int LightID, int ParamName, float *Value);
  void LightModelfv(int ParamName, float *Value);
  void LightModeli(int ParamName, int Value);

  void Materialf(int Face, int ParamName, float Value);
  void Materialfv(int Face, int ParamName, float *Value);
  void ColorMaterial(int Face, int Mode);

  void SetCameraPosition(float cameraPosition[3]);
  void SetDefaultLightingState();
  void SetDefaultMaterialState();
  
  void SetEnableState(int i, int value);
  void Enable(int i) { SetEnableState(i,1); }
  void Disable(int i) { SetEnableState(i,0); };

  /*---------------------------------------------------------------------------
      View Matrix for texture calculations
  ----------------------------------------------------------------------------*/
  void  SetModelViewMatrix(float *modelview);
  void  SetProjectionMatrix(float *_projection);

  /*---------------------------------------------------------------------------
      Screen Dimensions
  ----------------------------------------------------------------------------*/
  void SetWindowDimensions(int screenWidth, int screenHeight)
  {_screenHeight = screenHeight; _screenWidth = screenWidth;}

  /*---------------------------------------------------------------------------
      Rendering
  ----------------------------------------------------------------------------*/
  void Begin();
  void RenderTriangle(Tri tri);
  void End();
  
protected:

private:
  RenderMode _mode;            // if true is non-photorealistic

  // stylized rendering
  RenderStateArray _pRenderStates;
  int              _numRenderStates;

  // triangle buckets for sorting by render state
  TriBucketArray   _triangles;
  
  /*---------------------------------------------------------------------------
      Lights and Material
  ----------------------------------------------------------------------------*/
  LightParams Lights[MAX_NUM_LIGHTS];
  int LightingEnabled;               // Enable(LIGHTING)
  float LightModelAmbient[4];        // LightModelfv
  int LightModelLocalViewer;         // LightModelf
  int LightModelTwoSide;             // LightModelf

  MaterialParams ColorMaterials[2];  // Materialfv: MATERIAL PROPERTIES FOR FRONT (0) AND BACK (1)
  int ColorMaterialEnabled;          // Enable(COLOR_MATERIAL)
  int ColorMaterialFace;             // ColorMaterial: FRONT, BACK, FRONT_AND_BACK
  int ColorMaterialMode;             // ColorMaterial: AMBIENT, DIFFUSE, AMBIENT_AND_DIFFUSE, SPECULAR, EMISSION
    
  /*---------------------------------------------------------------------------
      Camera
  ----------------------------------------------------------------------------*/
  float _cameraPosition[3];

  /*---------------------------------------------------------------------------
      Viewport DimensionsCamera
  ----------------------------------------------------------------------------*/
  int _screenWidth;
  int _screenHeight;

  /*---------------------------------------------------------------------------
      OpenGL Matrices
  -- used for view dependent texture coords
  ----------------------------------------------------------------------------*/
  float _modelviewMatrix[16];
  float _projectionMatrix[16];

  /*---------------------------------------------------------------------------
      Render State Decision Function
  ----------------------------------------------------------------------------*/
 int _SelectRenderState(Tri Tri);

 void _CalcLighting(float FinalVertexColor[4], const float p[4], const float n[3], 
                    MaterialParams ColorMaterials[2], const int IsBackfacing);


 void _CalcTextureCoords(float point[3], RenderState* renderState, float texCoords[2]); 
};