#ifndef VIEW_H
#define VIEW_H

#include <set>
#include <map>
#include <utility>

using namespace std;

#include "util.h"
#include "event.h"

struct visibility_base
{
  unsigned int generation; // freshness check
};

struct visible {
  visibility_base *get_visibility (view &ctx);
  virtual visibility_base *new_visibility () = 0;
  virtual void clear_visibility (visibility_base *vs) = 0;
};

struct occ_query
{
  struct view &ctx;
  void *id;
  GLuint count;

  occ_query (view &ctx, void *id, GLuint count) : ctx(ctx), id(id), count(count) { };
};

typedef event_receiver<void, occ_query> recv_occ_query;

struct view
{
  sector orig;
  point p;
  vec3 d, u;
  GLfloat fov;
  GLfloat z_near, z_far, c_far;
  int w, h;
  GLfloat pixfact; // how many pixels on screen are drawn by a unit length line, *roughly*

  GLfloat gamma;

  // only to be used by friends: TODO

  GLfloat nz_far, nc_far;
  GLfloat diagfact; // bounding box border to depth factor
  GLfloat perspfact; // perspfact * (1/depth)=> pixels

  gl::matrix projection;

  struct {
    plane l, r, t, b, n, f;
    cone c;
    sphere s;
  } frustum;

  // the passes
  enum pass {
    DEPTH,	// mandatory, render depth only
    POSTDEPTH,	// mandatory, occ tests or ignored
    LIGHTED,    // optional, render faces in full glory
  } pass;

  struct light *l;
  set<const entity *> drawn; // TODO: put drawn info and octant+entity visibility info into vismap!

  unsigned int generation;
  typedef map<visible *, visibility_base *> visibility_map;
  visibility_map vismap;

  vector<octant *> vislist; // octants that want to be drawn

  struct oq_data {
    recv_occ_query *recv;
    GLint id;
    void *data;

    oq_data (recv_occ_query *recv, GLint id, void *data) : recv(recv), id(id), data(data) { };
  };
  vector<oq_data> occ_queries;
  void begin_occ_query (recv_occ_query &recv, void *id = 0);
  void end_occ_query ();

  void reset_projection ();

  // public
  
  void begin ();
  void render (enum pass p);
  void end ();

  bool may_draw (const entity *e);

  view ();
  ~view ();
};

#endif