/***************************************************************************
   File:        Renderer.cpp                                                            
   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 "Renderer.hpp"

void Renderer::
Initialize(const char* renderFile){
  ifstream rsrc;
  rsrc.open( renderFile );
  rsrc >> _numRenderStates;

  for(int i = 0; i < _numRenderStates; i++){
    // initialize triangle bucket
    TriBucket TB;
    _triangles.push_back(TB);
  
    // initialize render state
    RenderState* state = new RenderState;
    _pRenderStates.push_back(state);
    
    // load render state texture
    char textureFile[FILE_NAME_LENGTH];
    rsrc >> textureFile;
    AddTexture(textureFile, i);

     // set some default parameters
    SetParameter(GL_TEXTURE_WRAP_S, GL_REPEAT, i);
    SetParameter(GL_TEXTURE_WRAP_T, GL_REPEAT, i);
    SetParameter(GL_TEXTURE_MAG_FILTER, GL_NEAREST, i);
    SetParameter(GL_TEXTURE_MIN_FILTER, GL_NEAREST, i);
  }
  CompileRenderStates();
}

void Renderer::
AddTexture(GLubyte* texture, 
               GLuint Width, GLuint Height, GLuint Channels,
               int renderState)
{
  _pRenderStates[renderState]->_texture      = texture;
  _pRenderStates[renderState]->_texWidth     = Width;
  _pRenderStates[renderState]->_texHeight    = Height;
  _pRenderStates[renderState]->_texChannels = Channels;
}

void Renderer::
AddTexture(const char* textureFile, 
                    int renderState)
{
  _pRenderStates[renderState]->_texture = NULL;
   LoadTGA(textureFile, _pRenderStates[renderState]->_texture, 
           _pRenderStates[renderState]->_texWidth, 
           _pRenderStates[renderState]->_texHeight,
           _pRenderStates[renderState]->_texChannels);
}



void Renderer::
SetParameter(GLenum paramName, GLuint paramValue, int renderState)
{
  _pRenderStates[renderState]->_paramNames.push_back(paramName);
  _pRenderStates[renderState]->_paramValues.push_back(paramValue);

}

void Renderer::
CompileRenderStates()
{
  // initialize GLstate
  glClearColor (0.0, 0.0, 0.0, 0.0);
  glShadeModel (GL_FLAT);
  glEnable     (GL_DEPTH_TEST);

  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

  for(int i = 0; i < _numRenderStates; i++)
  {
    // generate name;
    static GLuint texName;
    glGenTextures(1, &texName);
    
    // bind the texture
    glBindTexture(GL_TEXTURE_2D, texName);
    _pRenderStates[i]->_texName = texName;

    // set texture state parameters
    for(int j = 0; j < _pRenderStates[i]->_paramNames.size(); j++)
    {
      glTexParameteri(GL_TEXTURE_2D,
                    _pRenderStates[i]->_paramNames[j],
                    _pRenderStates[i]->_paramValues[j]);
    }

    // load texture image
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 
                _pRenderStates[i]->_texWidth, 
                _pRenderStates[i]->_texHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, 
                _pRenderStates[i]->_texture);
  }
  //delete(texNames);
}


void Renderer::
SetRenderState(int renderState)
{
   glBindTexture(GL_TEXTURE_2D, _pRenderStates[renderState]->_texName);
}


/*---------------------------------------------------------------------------
    Lights and Camera
----------------------------------------------------------------------------*/
void Renderer::
SetLightPosition(float lightPosition[4])
{ 
  for(int i = 0; i < 4; i++) _lightPosition[i] = lightPosition[i];
}

void Renderer::
SetCameraPosition(float cameraPosition[3])
{
  for(int i = 0; i < 3; i++) _cameraPosition[i] = cameraPosition[i];
}

/*---------------------------------------------------------------------------
    Rendering
----------------------------------------------------------------------------*/
void Renderer::
Begin()
{
    for(int i = 0; i < _numRenderStates; i++)
      _triangles[i].clear();
}

void Renderer::
RenderTriangle(Tri tri)
{
  int renderState = _SelectRenderState(tri);
  _triangles[renderState].push_back(tri);
}

void Renderer::
End()
{
  glEnable(GL_TEXTURE_2D);
  glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);

  for(int i = 0; i < _numRenderStates; i++)
  {
    SetRenderState(i);
    glBegin(GL_TRIANGLES);
    int k = _triangles[i].size();
    for(int t = 0; t < _triangles[i].size(); t++)
    {
        glColor3ubv(_triangles[i][t].Color);
        glNormal3fv(_triangles[i][t].N);
        glTexCoord2f(0.0, 0.0); glVertex3fv(_triangles[i][t].A);
        glTexCoord2f(0.0, 1.0); glVertex3fv(_triangles[i][t].B);
        glTexCoord2f(1.0, 1.0); glVertex3fv(_triangles[i][t].C);
    }
    glEnd();
  }
    glDisable(GL_TEXTURE_2D);
}