OCCT

// Created on: 1991-10-11
// Created by: Remi GILET
// Copyright (c) 1991-1999 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.

//=========================================================================
//   CREATION of the BISSECTICE between a CIRCLE and a STRAIGHT LINE.     +
//=========================================================================

#include <GccAna_CircLin2dBisec.hxx>
#include <GccInt_BLine.hxx>
#include <GccInt_BParab.hxx>
#include <gp.hxx>
#include <gp_Ax2d.hxx>
#include <gp_Circ2d.hxx>
#include <gp_Dir2d.hxx>
#include <gp_Lin2d.hxx>
#include <gp_XY.hxx>
#include <Standard_OutOfRange.hxx>
#include <StdFail_NotDone.hxx>

//=========================================================================
GccAna_CircLin2dBisec::GccAna_CircLin2dBisec(const gp_Circ2d& Circle, const gp_Lin2d& Line)
    :

      circle(Circle),
      line(Line)
{

  //=========================================================================
  //  Initialization of fields :                                            +
  //            - circle                                                    +
  //            - line     (straight line.)                                 +
  //            - NbrSol   (number of solution.)                            +
  //            - WellDone (Boolean showing success or failure of algorithm)+
  //=========================================================================

  NbrSol   = 2;
  WellDone = true;
}

//=========================================================================
//  Processing.                                                           +
//  Return coordinates of origins of the straight line (xloc,yloc) and    +
//  the circle (xcencir, ycencir).                                        +
//  Also return the coordinates of the direction of the straight line     +
//  (xdir, ydir) and the radius of circle R1.                             +
//  Check at which side of the straight line is found the center of the   +
//  circle to orientate the parabola (sign).                              +
//  Create axis of each parabola (axeparab1, axeparb2), then              +
//  two parabolas (biscirlin1, biscirlin1).                               +
//=========================================================================

occ::handle<GccInt_Bisec> GccAna_CircLin2dBisec::ThisSolution(const int Index) const
{

  if (!WellDone)
  {
    throw StdFail_NotDone();
  }

  if ((Index <= 0) || (Index > NbrSol))
  {
    throw Standard_OutOfRange();
  }

  occ::handle<GccInt_Bisec> bissol;
  double                    xdir    = line.Direction().X();
  double                    ydir    = line.Direction().Y();
  double                    xloc    = line.Location().X();
  double                    yloc    = line.Location().Y();
  double                    xcencir = circle.Location().X();
  double                    ycencir = circle.Location().Y();
  double                    R1      = circle.Radius();
  double                    dist    = line.Distance(circle.Location());
  if ((std::abs(line.Distance(circle.Location()) - circle.Radius()) <= gp::Resolution())
      && (Index == 1))
  {
    gp_Lin2d biscirlin1(circle.Location(), gp_Dir2d(-ydir, xdir));
    bissol = new GccInt_BLine(biscirlin1);
    //       ==========================================================
  }
  else
  {
    int signe;
    if ((-ydir * (xcencir - xloc) + xdir * (ycencir - yloc)) > 0.0)
    {
      signe = 1;
    }
    else
    {
      signe = -1;
    }
    gp_Ax2d axeparab1;
    //    gp_Ax2d axeparab2;
    gp_Parab2d biscirlin;
    if (dist != R1)
    {
      if (Index == 1)
      {
        axeparab1 = gp_Ax2d(gp_Pnt2d(gp_XY(xcencir + signe * ydir * (dist + R1) / 2,
                                           ycencir - signe * xdir * (dist + R1) / 2.)),
                            gp_Dir2d(-signe * ydir, signe * xdir));
        biscirlin = gp_Parab2d(axeparab1, (dist + R1) / 2.0);
      }
      else
      {
        if (dist < R1)
        {
          axeparab1 = gp_Ax2d(gp_Pnt2d(gp_XY(xcencir + signe * ydir * (dist - R1) / 2,
                                             ycencir - signe * xdir * (dist - R1) / 2.)),
                              gp_Dir2d(signe * ydir, -signe * xdir));
        }
        else
        {
          axeparab1 = gp_Ax2d(gp_Pnt2d(gp_XY(xcencir + signe * ydir * (dist - R1) / 2,
                                             ycencir - signe * xdir * (dist - R1) / 2.)),
                              gp_Dir2d(-signe * ydir, signe * xdir));
        }
        biscirlin = gp_Parab2d(axeparab1, std::abs(dist - R1) / 2.0);
      }
      bissol = new GccInt_BParab(biscirlin);
      //         ==========================================================
    }
    else
    {
      axeparab1 = gp_Ax2d(gp_Pnt2d(gp_XY(xcencir + signe * ydir * (dist + R1) / 2.,
                                         ycencir - signe * xdir * (dist + R1) / 2.)),
                          gp_Dir2d(signe * (-ydir), signe * xdir));
      biscirlin = gp_Parab2d(axeparab1, R1);
      bissol    = new GccInt_BParab(biscirlin);
      //         ==========================================================
    }
  }

  return bissol;
}

//=========================================================================

bool GccAna_CircLin2dBisec::IsDone() const
{
  return WellDone;
}

int GccAna_CircLin2dBisec::NbSolutions() const
{
  return NbrSol;
}