#include <algorithm>
#include <cmath>

using namespace std;

#include "entity.h"

const vec3 cross (const vec3 &a, const vec3 &b)
{
  return vec3 (
            a.y * b.z - a.z * b.y,
            a.z * b.x - a.x * b.z,
            a.x * b.y - a.y * b.x
         );
}

GLfloat dot (const vec3 &a, const vec3 &b)
{
  return a.x * b.x + a.y * b.y + a.z * b.z;
}

void box::add (const box &o)
{
  a.x = min (a.x, o.a.x);
  a.y = min (a.y, o.a.y);
  a.z = min (a.z, o.a.z);
  b.x = max (b.x, o.b.x);
  b.y = max (b.y, o.b.y);
  b.z = max (b.z, o.b.z);
}

void entity_base::update_bbox ()
{
  if (parent)
    parent->update_bbox ();
}

void entity_base::hide ()
{
  for (vector<octant *>::iterator i = o.end (); i-- != o.begin (); )
    (*i)->remove (this);

  o.clear ();
}

void entity_filter::update_bbox ()
{
  bbox = e->bbox;
  entity_base::update_bbox ();
}

void entity_filter::show (const sector &sec)
{
  e->show (sec);
}

void entity_filter::draw ()
{
  e->draw ();
}

entity_filter::~entity_filter ()
{
  delete e;
}

void entity::show (const sector &sec)
{
  show ();
}

void entity::show ()
{
  e->show (this->sec);
}

void entity::draw ()
{
  glPushMatrix ();
  //TODO setup matrix etc.
  e->draw ();
  glPopMatrix ();
}

void entity_container::update_bbox ()
{
  bbox.reset ();

  for (iterator i = end (); i-- != begin (); )
    {
      (*i)->update_bbox ();
      bbox.add ((*i)->bbox);
    }
}

void entity_container::show (const sector &sec)
{
  for (iterator i = end (); i-- != begin (); )
    (*i)->show (sec);
}

void entity_container::draw ()
{
  for (iterator i = end (); i-- != begin (); )
    (*i)->draw ();
}

entity_container::~entity_container ()
{
  hide ();

  for (iterator i = end (); i-- != begin (); )
    delete *i;
 
  clear ();
}

template entity_opengl1d<GL_POINTS>;
template entity_opengl1d<GL_LINES>;
template entity_opengl1d<GL_LINE_STRIP>;
template entity_opengl1d<GL_LINE_LOOP>;
template entity_opengl2d<GL_TRIANGLES>;
template entity_opengl2d<GL_TRIANGLE_STRIP>;
template entity_opengl2d<GL_TRIANGLE_FAN>;
template entity_opengl2d<GL_QUADS>;
template entity_opengl2d<GL_QUAD_STRIP>;
template entity_opengl2d<GL_POLYGON>;

template<GLenum type>
void entity_opengl1d<type>::update_bbox ()
{
  entity_base::update_bbox ();
}

template<GLenum type>
void entity_opengl2d<type>::update_bbox ()
{
  entity_base::update_bbox ();
}

template<GLenum type>
void entity_opengl1d<type>::draw ()
{
  glBegin (type);

  for (iterator i = begin (); i < end (); ++i)
    {
      glColor3fv ((GLfloat *)&i->c);
      glVertex3fv ((GLfloat *)&i->p);
    }

  glEnd ();
}

template<GLenum type>
void entity_opengl2d<type>::draw ()
{
  glBegin (type);

  for (iterator i = begin (); i < end (); ++i)
    {
      glColor3fv ((GLfloat *)&i->c);
      glNormal3fv ((GLfloat *)&i->n);
      glTexCoord2fv ((GLfloat *)&i->t);
      glVertex3fv ((GLfloat *)&i->p);
    }

  glEnd ();
}

template<GLenum type>
void entity_opengl1d<type>::show (const sector &sec)
{
}

template<GLenum type>
void entity_opengl2d<type>::show (const sector &sec)
{
}

void view::draw (const draw_context &c)
{
  glViewport (0, 0, w, h);

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();

  double aspect = (double)w/h;
  double zNear = 5;
  double zFar = 1000.;

  {
    GLdouble xmin, xmax, ymin, ymax;

    ymax = zNear * tan (fov * (M_PI / 360.0));
    ymin = -ymax;
    xmin = ymin * aspect;
    xmax = ymax * aspect;

    glFrustum(xmin, xmax, ymin, ymax, zNear, zFar);
  }

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

  GLfloat m[4][4];
  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);

  glTranslatef (-p.x, -p.y, -p.z);

  glMatrixMode (GL_MODELVIEW);
  glLoadIdentity ();

  entity *e = new entity;
  e->sec.x = e->sec.y = e->sec.z = 0;

  entity_triangles *tri = new entity_triangles;
  tri->push_back (vertex2d (colour (1, 0, 0), point (-9, 0, -9), vec3 (0, 0, 1)));
  tri->push_back (vertex2d (colour (0, 1, 1), point ( 0, 9, -9), vec3 (0, 0, 1)));
  tri->push_back (vertex2d (colour (1, 0, 1), point ( 9, 0, -9), vec3 (0, 0, 1)));
  e->set (tri);

  e->show ();
  e->draw ();

  delete e;
}