// Created on: 1993-08-24
// Created by: Bruno DUMORTIER
// Copyright (c) 1993-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.


#include <ElSLib.hxx>
#include <gp.hxx>
#include <gp_Circ.hxx>
#include <gp_Cone.hxx>
#include <gp_Elips.hxx>
#include <gp_Hypr.hxx>
#include <gp_Lin.hxx>
#include <gp_Parab.hxx>
#include <gp_Trsf.hxx>
#include <gp_Vec.hxx>
#include <gp_Vec2d.hxx>
#include <Precision.hxx>
#include <ProjLib_Cone.hxx>
#include <Standard_NoSuchObject.hxx>

//=======================================================================
//function : ProjLib_Cone
//purpose  : 
//=======================================================================
ProjLib_Cone::ProjLib_Cone()
{
}


//=======================================================================
//function : ProjLib_Cone
//purpose  : 
//=======================================================================

ProjLib_Cone::ProjLib_Cone(const gp_Cone& Co)
{
  Init(Co);
}


//=======================================================================
//function : ProjLib_Cone
//purpose  : 
//=======================================================================

ProjLib_Cone::ProjLib_Cone(const gp_Cone& Co, const gp_Lin& L)
{
  Init(Co);
  Project(L);
}


//=======================================================================
//function : ProjLib_Cone
//purpose  : 
//=======================================================================

ProjLib_Cone::ProjLib_Cone(const gp_Cone& Co, const gp_Circ& C)
{
  Init(Co);
  Project(C);
}


//=======================================================================
//function : Init
//purpose  : 
//=======================================================================

void  ProjLib_Cone::Init(const gp_Cone& Co)
{
  myType = GeomAbs_OtherCurve;
  myCone = Co;
  myIsPeriodic = Standard_False;
  isDone = Standard_False;
}

//=======================================================================
//function : Project
//purpose  : 
//=======================================================================

void  ProjLib_Cone::Project(const gp_Lin& L)
{
  gp_Pnt aPnt = L.Location(), anApex = myCone.Apex();

  Standard_Real aDeltaV = 0.0;

  Standard_Real U,V;
  if (aPnt.IsEqual(anApex, Precision::Confusion()))
  {
    //Take another point in the line L, which does not coincide with the cone apex.
    aPnt.Translate(L.Direction().XYZ());
    aDeltaV = 1.0; // == ||L.Direction()|| == 1.0
  }
 
  ElSLib::ConeParameters(myCone.Position(), myCone.RefRadius(), myCone.SemiAngle(), aPnt,
			                   U, V);
  //
  gp_Pnt P;
  gp_Vec Vu, Vv;

  ElSLib::ConeD1(U, V, myCone.Position(), myCone.RefRadius(), myCone.SemiAngle(),
		 P, Vu, Vv);

  gp_Dir Dv(Vv);
  if(Dv.IsParallel(L.Direction(), Precision::Angular()))
  {
    // L is parallel to U-isoline of the cone.
    myType = GeomAbs_Line;
  
    const Standard_Real aSign = Sign(1.0, L.Direction().Dot(Dv));
    gp_Pnt2d P2d(U, V - aDeltaV*aSign);
    gp_Dir2d D2d(0., aSign);
  
    myLin = gp_Lin2d( P2d, D2d);

    isDone = Standard_True;
  }    
}


//=======================================================================
//function : Project
//purpose  : 
//=======================================================================

void  ProjLib_Cone::Project(const gp_Circ& C)
{
  myType = GeomAbs_Line;

  gp_Ax3 ConePos = myCone.Position();
  gp_Ax3 CircPos = C.Position();
  //
  if (!ConePos.Direction().IsParallel(CircPos.Direction(), Precision::Angular())) {
    isDone = Standard_False;
    return;
  }
  //
  gp_Dir ZCone = ConePos.XDirection().Crossed(ConePos.YDirection());
  gp_Dir ZCir =  CircPos.XDirection().Crossed(CircPos.YDirection());

  Standard_Real U, V;
  Standard_Real x = ConePos.XDirection().Dot(CircPos.XDirection());
  Standard_Real y = ConePos.YDirection().Dot(CircPos.XDirection());
  Standard_Real z 
    = gp_Vec(myCone.Location(),C.Location()).Dot(ConePos.Direction());
  
  // pour trouver le point U V, on reprend le code de ElSLib
  // sans appliquer la Trsf au point ( aller retour inutile).
  if ( x == 0.0 && y == 0.0 ) {
    U = 0.;
  }
  else if ( -myCone.RefRadius() > z * Tan(myCone.SemiAngle())) {
    U = ATan2(-y, -x);
  }
  else {
    U = ATan2( y, x);
  }
  if ( U < 0.) U += 2*M_PI;

  V = z / Cos(myCone.SemiAngle());

  gp_Pnt2d P2d1 (U, V);
  gp_Dir2d D2d;
  if ( ZCone.Dot(ZCir) > 0.) 
    D2d.SetCoord(1., 0.);
  else
    D2d.SetCoord(-1., 0.);

  myLin = gp_Lin2d(P2d1, D2d);
  isDone = Standard_True;
}

void  ProjLib_Cone::Project(const gp_Elips& E)
{
  ProjLib_Projector::Project(E);
}

void  ProjLib_Cone::Project(const gp_Parab& P)
{
 ProjLib_Projector::Project(P);
}

void  ProjLib_Cone::Project(const gp_Hypr& H)
{
 ProjLib_Projector::Project(H);
}