//individual cell in the environment
class env_cell{
  public:
  float top,left,bottom,right;
  int id;
  CheightMap heightMap; //height map
  env_map* map; //pointer to map handler object
  std::vector<env_cell*> visCells; //cells that can be seen from this cell
  std::vector<env_cell*>::iterator visCellsI; //visible cells iterator
  GLuint opaqueDraw, transDraw; //compiled static mesh and bsp display lists
  std::vector<entity*> entities; //pointers to entities within the cell
  prop_static staticProps[]; //static props linked to the cell
  bsp_detail detail[]; //bsp geometry linked to the cell cell
  std::vector<light*> lights; //pointers to lights in the cell
  float startHeight; //starting z height from z = 0
  int nextVisCellPos,nextStaticProp,nextBsp,nextLight;
  
  //constructor
  env_cell(int sId,float sTop,float sLeft,float sBottom,float sRight){
    id = sId;
    top = sTop;
    left = sLeft;
    bottom = sBottom;
    right = sRight;
    opaqueDraw = glGenLists(1);
    transDraw = glGenLists(1);
  }
  
  //set the height map and z start
  void setHeight(CheightMap sHeightMap,float sStartHeight){
    heightMap = sHeightMap;
    startHeight = sStartHeight;
  }
  
  //adds a cell pointer to the array of cells this cell can see
  void addVisCell(env_cell* visCell){
    visCells.push_back(visCell);
    nextVisCellPos ++;
  }
  
  //adds a static prop to the cell
  void addStaticProp(prop_static prop){
    staticProps[nextStaticProp] = prop;
    nextStaticProp ++;
  }
  
  //adds some bsp geometry to the cell
  void addBspDetail(bsp_detail bsp){
    detail[nextBsp] = bsp;
    nextBsp ++;
  }
  
  //renders the static props and bsp detail into display lists
  void compileDispLists(){
    //make opaque & transparent geometry into display lists
    
    //build opaque geometry
    glNewList(opaqueDraw,GL_COMPILE);
      //just draw a floor now (rather than combine static props and bsp)
    	glBegin(GL_QUADS);
    		//glNormal3f(0,1,0); //up
    		glVertex3f(left,0,bottom);
    		glVertex3f(right,0,bottom);
    		glVertex3f(right,0,top);
    		glVertex3f(left,0,top);
    	glEnd();
  	glEndList();
  }
  //what about light maps?
  
  //add a pointer to a light within the cell
  void addLight(light * thisLight){
    lights.push_back(thisLight);
    nextLight ++;
  }
  
  //returns the pointer of the cell a position is in
  env_cell* findCell(float x,float z){
    env_cell * foundCell;
    for(visCellsI = visCells.begin();visCellsI != visCells.end();visCellsI++){
      //if point is inside the cell
      if(x<=visCellsI->right && x>=visCellsI->left && z<=visCellsI->top && 
      z>=visCellsI->bottom){ //THIS LINE
        foundCell = &(*visCellsI);
        break;
      }
    }
    
    //if a cell was found
    if(foundCell){
      return foundCell; //return new cell
    } else {
      return this; //keep current cell assigned
    }
  }
};

if(x<=visCellsI->right && x>=visCellsI->left && z<=visCellsI->top && z>=visCellsI->bottom)