src/Geom2dGcc/Geom2dGcc_FunctionTanCirCu.cxx

   1 // Created on: 1992-01-20
   2 // Created by: Remi GILET
   3 // Copyright (c) 1992-1999 Matra Datavision
   4 // Copyright (c) 1999-2014 OPEN CASCADE SAS
   5 //
   6 // This file is part of Open CASCADE Technology software library.
   7 //
   8 // This library is free software; you can redistribute it and/or modify it under
   9 // the terms of the GNU Lesser General Public License version 2.1 as published
  10 // by the Free Software Foundation, with special exception defined in the file
  11 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
  12 // distribution for complete text of the license and disclaimer of any warranty.
  13 //
  14 // Alternatively, this file may be used under the terms of Open CASCADE
  15 // commercial license or contractual agreement.
  16
  17
  18 #include <Geom2dAdaptor_Curve.hxx>
  19 #include <Geom2dGcc_CurveTool.hxx>
  20 #include <Geom2dGcc_FunctionTanCirCu.hxx>
  21 #include <gp_Circ2d.hxx>
  22 #include <gp_Pnt.hxx>
  23 #include <gp_Pnt2d.hxx>
  24 #include <gp_Vec.hxx>
  25 #include <gp_Vec2d.hxx>
  26
  27 //=========================================================================
  28 //  soit P1 le point sur la courbe Geom2dAdaptor_Curve d abscisse u.      +
  29 //  soit C  le centre du cercle TheCirc.                                  +
  30 //  Nous recherchons un point P2 appartenant au cercle tel que :          +
  31 //           --->   -->                                                   +
  32 //        *  P1P2 . CP2 = 0                                               +
  33 //                                                                        +
  34 //        *    -->  2    2                                                +
  35 //           ||CP2||  = R                                                 +
  36 //  Nous cherchons donc les zeros de la fonction suivante:                +
  37 //                         -->  --> 2                                     +
  38 //             -->  2    ( CP1 . T )      2                               +
  39 //           ||CP1||  -  -----------  -  R   =  F(u)                      +
  40 //                          --> 2                                         +
  41 //                         ||T||                                          +
  42 //                                                                        +
  43 //  La derivee de cette fonction est :                                    +
  44 //                                                                        +
  45 //             2*(CP1.T)(CP1.N)     2*(CP1.T)*(CP1.T)*T.N                 +
  46 //  f(u) =  -  ----------------  +  ---------------------                 +
  47 //                  T.T                  (T.T)*(T.T)                      +
  48 //=========================================================================
  49 //                                                                        +
  50 // skv: Small addition: The function and the derivative are normalized    +
  51 //                      by an average square distance between the circle  +
  52 //                      and the curve.                                    +
  53 //=========================================================================
  54 Geom2dGcc_FunctionTanCirCu::
  55 Geom2dGcc_FunctionTanCirCu(const gp_Circ2d& Circ   ,
  56                            const Geom2dAdaptor_Curve&  Curv   ) {
  57                              Curve = Curv;
  58                              TheCirc = Circ;
  59
  60                              //  Modified by Sergey KHROMOV - Thu Apr  5 09:51:21 2001 Begin
  61                              Standard_Integer aNbSamp = Geom2dGcc_CurveTool::NbSamples(Curve);
  62                              Standard_Real    aFirst  = Geom2dGcc_CurveTool::FirstParameter(Curve);
  63                              Standard_Real    aLast   = Geom2dGcc_CurveTool::LastParameter(Curve);
  64                              Standard_Real    aStep   = (aLast - aFirst)/aNbSamp;
  65                              Standard_Real    anX     = aFirst + aStep/2.;
  66                              Standard_Integer aNbP    = 0;
  67                              gp_XY            aLoc(0., 0.);
  68
  69                              while (anX <= aLast) {
  70                                aLoc += (Geom2dGcc_CurveTool::Value(Curve, anX)).XY();
  71                                anX  += aStep;
  72                                aNbP++;
  73                              }
  74                              myWeight = Max((aLoc - TheCirc.Location().XY()).SquareModulus(), TheCirc.Radius());
  75                              //  Modified by Sergey KHROMOV - Thu Apr  5 09:51:25 2001 End
  76 }
  77
  78
  79 Standard_Boolean Geom2dGcc_FunctionTanCirCu::
  80 Value (const Standard_Real  X    ,
  81        Standard_Real& Fval ) {
  82          gp_Pnt2d Point;
  83          gp_Vec2d Vect1;
  84          Geom2dGcc_CurveTool::D1(Curve,X,Point,Vect1);
  85          Standard_Real NormeD1 = Vect1.Magnitude();
  86          gp_Vec2d TheDirection(TheCirc.Location(),Point);
  87          Standard_Real squaredir = TheDirection.Dot(TheDirection);
  88          Standard_Real R = TheCirc.Radius();
  89          Fval = squaredir-R*R-
  90            (TheDirection.Dot(Vect1))*(TheDirection.Dot(Vect1))/(NormeD1*NormeD1);
  91          //  Modified by Sergey KHROMOV - Thu Apr  5 17:38:05 2001 Begin
  92          Fval /= myWeight;
  93          //  Modified by Sergey KHROMOV - Thu Apr  5 17:38:06 2001 End
  94          return Standard_True;
  95 }
  96
  97 Standard_Boolean Geom2dGcc_FunctionTanCirCu::
  98 Derivative (const Standard_Real  X     ,
  99             Standard_Real& Deriv ) {
 100               gp_Pnt2d Point;
 101               gp_Vec2d Vect1,Vect2;
 102               Geom2dGcc_CurveTool::D2(Curve,X,Point,Vect1,Vect2);
 103               Standard_Real NormeD1 = Vect1.SquareMagnitude();
 104               gp_Vec2d TheDirection(TheCirc.Location(),Point);
 105               Standard_Real cp1dott = TheDirection.Dot(Vect1);
 106               Deriv = -2.*(cp1dott/NormeD1)*
 107                 ((TheDirection.Dot(Vect2))-cp1dott*Vect1.Dot(Vect2)/NormeD1);
 108               //  Modified by Sergey KHROMOV - Thu Apr  5 17:38:15 2001 Begin
 109               Deriv /= myWeight;
 110               //  Modified by Sergey KHROMOV - Thu Apr  5 17:38:15 2001 End
 111               return Standard_True;
 112 }
 113
 114 Standard_Boolean Geom2dGcc_FunctionTanCirCu::
 115 Values (const Standard_Real  X     ,
 116         Standard_Real& Fval  ,
 117         Standard_Real& Deriv ) {
 118           gp_Pnt2d Point;
 119           gp_Vec2d Vect1,Vect2;
 120           Geom2dGcc_CurveTool::D2(Curve,X,Point,Vect1,Vect2);
 121           Standard_Real NormeD1 = Vect1.SquareMagnitude();
 122           gp_Vec2d TheDirection(TheCirc.Location(),Point);
 123           Standard_Real squaredir = TheDirection.SquareMagnitude();
 124           Standard_Real cp1dott = TheDirection.Dot(Vect1);
 125           Standard_Real R = TheCirc.Radius();
 126
 127           Fval = squaredir-R*R-cp1dott*cp1dott/NormeD1;
 128           //  Modified by Sergey KHROMOV - Thu Apr  5 17:38:28 2001 Begin
 129           Fval /= myWeight;
 130           //  Modified by Sergey KHROMOV - Thu Apr  5 17:38:28 2001 End
 131
 132           Deriv = -2.*(cp1dott/NormeD1)*
 133             ((TheDirection.Dot(Vect2))-cp1dott*Vect1.Dot(Vect2)/NormeD1);
 134           //  Modified by Sergey KHROMOV - Thu Apr  5 17:37:36 2001 Begin
 135           Deriv /= myWeight;
 136           //  Modified by Sergey KHROMOV - Thu Apr  5 17:37:37 2001 End
 137           return Standard_True;
 138 }