#include <cmath>

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

draw_context::draw_context (view &v)
: v(v), l(0), mode(LIGHTED)
{
}

draw_context::~draw_context ()
{
}

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

  drawn.insert (e);
  return true;
}

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

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();

  GLdouble aspect = (GLdouble)w/h;
  GLdouble zNear = 0.0001;
  GLdouble zFar = 1000.;

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

  world.draw (ctx);
}