/*
 *  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 "cameras/std_camera.h"

namespace RAYPP {

extern HANDLE<WORLD> World;
extern HANDLE<RENDERER> Renderer;

STD_CAMERA::STD_CAMERA ()
  : Location (0,0,0), Sky (0,1,0), LookAt (0,0,1),
    u_fov (45), v_fov (34), Aspect_Ratio (4.0/3.0) {}

STD_CAMERA::STD_CAMERA (const VECTOR &Loc, const VECTOR &Look)
  : Location (Loc), Sky (0,1,0), LookAt (Look),
    u_fov (45), v_fov (34), Aspect_Ratio (4.0/3.0) {}

//virtual
void STD_CAMERA::Init ()
  {
  if (initialized) return;

  Direction = (LookAt - Location).Norm();
  Right = (Cross (Direction, Sky)).Norm();
  Up = Cross (Right, Direction);

  Right *= -tan (u_fov/2.0 * Pi/180.0)*2.0;
  Up *= tan (v_fov/2.0 * Pi/180.0)*2.0;

  World->Get_Surrounding_Volume (Location, MyVolume);

  initialized = true;
  }

//virtual
void STD_CAMERA::Transform (const TRANSFORM &trans)
  {
  cni();

  Location = trans.TransPoint (Location);
  LookAt = trans.TransPoint (LookAt);
  }

//virtual
COLOUR STD_CAMERA::Calc_Intensity (float8 u, float8 v) const
  {
  ci();
  VECTOR Dir = (Direction + Right*(u-0.5) + Up*(0.5-v)).Norm();
  RAY Ray (Location,
           Dir,
           0.0,
           Huge_float8,
           MyVolume,
           COLOUR (1,1,1));
  
  return Renderer->Trace_Ray (Ray);
  }

void STD_CAMERA::Set_Sky (const VECTOR &new_sky)
  {
  cni();
  Sky = new_sky;
  }

void STD_CAMERA::Set_Location (const VECTOR &new_loc)
  {
  cni();
  Location = new_loc;
  }

void STD_CAMERA::Set_LookAt (const VECTOR &new_look)
  {
  cni();
  LookAt = new_look;
  }

void STD_CAMERA::Set_Fov (float8 new_ufov, float8 new_vfov)
  {
  cni();
  u_fov = new_ufov;
  v_fov = new_vfov;
// a sanity check wouldn't be bad
  }

void STD_CAMERA::Set_Fov (float8 new_ufov)
  {
  cni();
  u_fov = new_ufov;
  v_fov = 180.0/Pi * 2 * atan (tan(Pi/180.0 * 0.5*u_fov)/Aspect_Ratio);
// a sanity check wouldn't be bad
  }

void STD_CAMERA::Set_Aspect_Ratio (float8 new_AR)
  {
  cni();
  Aspect_Ratio = new_AR;
  }

} // namespace RAYPP