#include <cmath>

#include "oct.h"
#include "view.h"

view::view ()
: gamma(1.0)
{
}

view::~view ()
{
}

bool view::may_draw (entity_base *e)
{
  if (drawn.find (e) != drawn.end ())
    return false;

  drawn.insert (e);
  return true;
}

void view::reset_projection ()
{
  renormalize (orig, p);

  glViewport (0, 0, w, h);

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();

  GLdouble aspect = (GLdouble)w/h;
  GLdouble zNear = 0.1;
  GLdouble zFar = 50.;

  GLdouble ymax = zNear * tan (fov * (M_PI / 360.0));
  glFrustum (-ymax * aspect, ymax * aspect, -ymax, ymax, zNear, zFar);

  d = normalize (d);//D
  u = normalize (u);//D
  vec3 rz = -d;
  vec3 rx = cross (u, rz);
  vec3 ry = cross (rz, rx);

  matrix &m = projection;
  m(0,0) = rx.x; m(0,1) = rx.y; m(0,2) = rx.z; m(0,3) = 0;
  m(1,0) = ry.x; m(1,1) = ry.y; m(1,2) = ry.z; m(1,3) = 0;
  m(2,0) = rz.x; m(2,1) = rz.y; m(2,2) = rz.z; m(2,3) = 0;
  m(3,0) =    0; m(3,1) =    0; m(3,2) =    0; m(3,3) = 1;

  glMultMatrixf ((GLfloat *)m.data);

  glGetFloatv (GL_PROJECTION_MATRIX, (GLfloat *)&m);

  frustum.l = plane ( m(3,0) + m(0,0), m(3,1) + m(0,1), m(3,2) + m(0,2), m(3,3) + m(0,3) );
  frustum.r = plane ( m(3,0) - m(0,0), m(3,1) - m(0,1), m(3,2) - m(0,2), m(3,3) - m(0,3) );
  frustum.b = plane ( m(3,0) + m(1,0), m(3,1) + m(1,1), m(3,2) + m(1,2), m(3,3) + m(1,3) );
  frustum.t = plane ( m(3,0) - m(1,0), m(3,1) - m(1,1), m(3,2) - m(1,2), m(3,3) - m(1,3) );
  frustum.n = plane ( m(3,0) + m(2,0), m(3,1) + m(2,1), m(3,2) + m(2,2), m(3,3) + m(2,3) );
  frustum.f = plane ( m(3,0) - m(2,0), m(3,1) - m(2,1), m(3,2) - m(2,2), m(3,3) - m(2,3) );

  glMatrixMode (GL_MODELVIEW);
  glLoadIdentity ();
  glTranslatef (-p.x, -p.y, -p.z);
}

void view::begin ()
{
  vismap.clear ();
  vislist.clear ();

  generation++;

  reset_projection ();

  // check occlusion queries here
  for (vector<octant *>::iterator i = checklist.begin (); i != checklist.end (); ++i)
    occ_query_result ((*i)->occ_query);

  checklist.clear ();

  world.detect_visibility (*this);
}

void view::end ()
{
  vismap.clear ();
}

void view::pass (enum mode m)
{
  mode = m;

  glDisable (GL_ALPHA_TEST);
  glDisable (GL_BLEND);

  if (mode == view::DEPTH)
    {
      glEnable (GL_POLYGON_OFFSET_FILL);
      glPolygonOffset (0, 1);
      glDepthFunc (GL_LESS);
      glDisable (GL_LIGHTING);
      glColorMask (0, 0, 0, 0);
      //cgGLDisableProfile (CG_PROFILE_ARBVP1);
      cgGLDisableProfile (CG_PROFILE_ARBFP1);
    }
  else
    {
#if 0
      glEnable (GL_MINMAX);
#endif
      glDisable (GL_POLYGON_OFFSET_FILL);
      glDepthFunc (GL_LESS);
      glDepthMask (0);
      cgGLEnableProfile (CG_PROFILE_ARBVP1);
      cgGLEnableProfile (CG_PROFILE_ARBFP1);
    }
  
  for (vector<octant *>::iterator i = vislist.begin (); i != vislist.end (); ++i)
    (*i)->display (*this);

  drawn.clear ();

  glColorMask (1, 1, 1, 0);
  glDepthMask (1);
}