/*
 *  Ray++ - Object-oriented ray tracing library
 *  Copyright (C) 1998-2001 Martin Reinecke and others.
 *  See the AUTHORS file for more information.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  See the README file for more information.
 */

#include "shapes/box.h"

namespace RAYPP {

const AXISBOX BOX::abox (VECTOR(0,0,0), VECTOR(1,1,1));

inline VECTOR BOX::Get_Normal (const VECTOR &Loc) const
  {
  VECTOR tmp = Trans.TransNormal (abox.Normal(Loc));
  tmp.Normalize();
  if (Inverted) tmp.Flip();
  return tmp;
  }

BOX::BOX (const VECTOR &lower, const VECTOR &higher)
  {
  Trans = Scaling_Transform (higher-lower);
  Trans.Add_Transform (Translation_Transform (lower));
  }

//virtual
void BOX::Init ()
  {
  if (initialized) return;
  initialized = true;
  }

//virtual
void BOX::Transform (const TRANSFORM &trans)
  {
  cni();
  Trans.Add_Transform (trans);
  }

//virtual
AXISBOX BOX::BBox () const
  {
  ci();

  AXISBOX Mybox (abox);
  Mybox.Transform (Trans);
  return Mybox;
  }

//virtual
bool BOX::Test (const GEOM_RAY &Ray, float8 &dist, bool &realhit) const
  {
  ci();

  float8 d1, d2;

  GEOM_RAY tmpray = Trans.InvTransRay (Ray);

  realhit = true;
  if (!abox.Ray_in_Bounds (tmpray, d1, d2))
    return false;
  if (d1>Ray.mindist)
    {
    dist=d1;
    return true;
    }
  if (d2<Ray.maxdist)
    {
    dist=d2;
    return true;
    }
  return false;
  }

//virtual
bool BOX::Inside (const VECTOR &Loc) const
  {
  ci();
  return (abox.Inside (Trans.InvTransPoint (Loc)) ^ Inverted);
  }

//virtual
bool BOX::Intersect (const GEOM_RAY &Ray, float8 &dist, VECTOR &Normal) const
  {
  ci();
  GEOM_RAY tmpray = Trans.InvTransRay (Ray);

  if (abox.Clip_Ray (tmpray))
    {
    if (tmpray.mindist>Ray.mindist)
      {
      dist = tmpray.mindist;
      Normal = Get_Normal (tmpray.eval(dist));
      return true;
      }
    if (tmpray.maxdist<Ray.maxdist)
      {
      dist = tmpray.maxdist;
      Normal = Get_Normal (tmpray.eval(dist));
      return true;
      }
    }
  return false;
  }

//virtual
void BOX::All_Intersections (const GEOM_RAY &Ray, vector<INTER> &Inter) const
  {
  ci();
  GEOM_RAY tmpray = Trans.InvTransRay (Ray);

  if (abox.Clip_Ray (tmpray))
    {
    if (tmpray.mindist>Ray.mindist)
      Inter.push_back (INTER (tmpray.mindist, Get_Normal (tmpray.evalmin())));
    if (tmpray.maxdist<Ray.maxdist)
      Inter.push_back (INTER (tmpray.maxdist, Get_Normal (tmpray.evalmax())));
    }
  }

} // namespace RAYPP