#include <cmath>

#include <GL/gl.h>
#include <GL/glext.h>

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

      static GLenum gl_error;
view::view ()
: gamma(1.0)
{
}

view::~view ()
{
}

bool view::may_draw (const entity *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 ();

      gl_error = glGetError ();
  GLdouble aspect = (GLdouble)w/h;
  GLdouble zNear = 1.;
  GLdouble zFar = 500.;

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

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

  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;
      gl_error = glGetError ();

  glMultMatrixf ((GLfloat *)m.data);

      gl_error = glGetError ();
  glGetFloatv (GL_PROJECTION_MATRIX, (GLfloat *)&m);

      gl_error = glGetError ();
  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) );

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

void view::begin ()
{
  glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glDepthRange (0, 1. - (1. / pow (2., 16.)));

  vismap.clear ();
  vislist.clear ();

  generation++;

  reset_projection ();

  for (vector<octant *>::iterator i = farlist.begin (); i != farlist.end (); ++i)
    ;
  farlist.clear ();

  // check occlusion queries here
#if 0
  for (vector<octant *>::iterator i = checklist.begin (); i != checklist.end (); ++i)
    //printf ("%p %d\n", *i, occ_query_result ((*i)->occ_query));
    occ_query_result ((*i)->occ_query);

  checklist.clear ();
#endif

  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);
      cgGLEnableProfile (vsh_profile);// z-fighting??
      cgGLDisableProfile (fsh_profile);
    }
  else
    {
      glEnable (GL_MINMAX);
      glDisable (GL_POLYGON_OFFSET_FILL);
      glDepthFunc (GL_LESS);
      glDepthMask (0);
      cgGLEnableProfile (vsh_profile);
      cgGLEnableProfile (fsh_profile);
    }
  
  for (vector<octant *>::iterator i = vislist.begin (); i != vislist.end (); ++i)
    (*i)->display (*this);

  drawn.clear ();

  if (mode == view::DEPTH || 1)
    {
      glEnable (GL_DEPTH_CLAMP_NV);
      glDepthFunc (GL_LESS);
      glEnable (GL_COLOR_MATERIAL);
      glDisable (GL_LIGHTING);
#if 1
      cgGLDisableProfile (vsh_profile);
      cgGLDisableProfile (fsh_profile);
#endif
      glShadeModel (GL_FLAT);

#if 0
      static int count; count++;
      if (farlist.size ())
        printf ("%d: size %d\n", count, farlist.size ());
#endif

     for (vector<octant *>::iterator i = farlist.begin (); i != farlist.end (); ++i)
       {
        glColor3f (1,0,0);
        (*i)->draw_bbox (*this);
       }

      glEnable (GL_DEPTH_TEST);
      glDisable (GL_DEPTH_CLAMP_NV);
      glShadeModel (GL_SMOOTH);
    }

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

}