/***************************************************************************
   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>


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

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

  // OpenGL texture state parameters
  std::vector<GLenum> _paramNames;
  std::vector<GLuint> _paramValues; 
};
typedef std::vector<Tri>          TriBucket;
typedef std::vector<TriBucket>    TriBucketArray;
typedef std::vector<RenderState*> RenderStateArray;


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,
                  int renderState);

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

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

  void CompileRenderStates();

  void SetRenderState(int renderState);

  
  /*---------------------------------------------------------------------------
      Setting Lighting and Camera Parameters
  ----------------------------------------------------------------------------*/
  void SetLightPosition(float lightPosition[4]);
  void SetCameraPosition(float cameraPosition[3]);


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

private:
  // stylized rendering
  RenderStateArray _pRenderStates;
  int              _numRenderStates;

  // triangle buckets for sorting by render state
  TriBucketArray   _triangles;
  
  /*---------------------------------------------------------------------------
      Lights and Camera
  ----------------------------------------------------------------------------*/
  float _lightPosition[4];
  float _cameraPosition[3];

  /*---------------------------------------------------------------------------
      Render State Decision Function
  ----------------------------------------------------------------------------*/
  int _lastState;
  int _SelectRenderState(Tri Tri){return _lastState++ % _numRenderStates;}

};