src/GccAna/GccAna_Circ2d2TanOn_4.cxx

   1 // File:        GccAna_Circ2d2TanOn_4.cxx
   2 // Created:     Thu Jan  2 15:54:38 1992
   3 // Author:      Remi GILET
   4 //              <reg@topsn3>
   5
   6 #include <GccAna_Circ2d2TanOn.jxx>
   7
   8 #include <ElCLib.hxx>
   9 #include <gp_Dir2d.hxx>
  10 #include <gp_Ax2d.hxx>
  11 #include <GccAna_LinPnt2dBisec.hxx>
  12 #include <IntAna2d_AnaIntersection.hxx>
  13 #include <IntAna2d_IntPoint.hxx>
  14 #include <GccInt_IType.hxx>
  15 #include <GccInt_Bisec.hxx>
  16 #include <GccInt_BCirc.hxx>
  17 #include <GccInt_BLine.hxx>
  18 #include <IntAna2d_Conic.hxx>
  19 #include <GccEnt_BadQualifier.hxx>
  20 #include <Precision.hxx>
  21 //=========================================================================
  22 //   Creation of a circle Tangent to : 1 straight line L1.                +
  23 //                        Passing by : 1 point Point2.                    +
  24 //                        Centered on  : 1 straight line OnLine.                  +
  25 //   with a Tolerance of precision  : Tolerance.                        +
  26 //                                                                        +
  27 //  We start by making difference with various boundary cases that will be +
  28 //  processed separately.                                            +
  29 //  For the general case:                                                  +
  30 //  ====================                                                  +
  31 //  We calculate bissectrices to L1 and Point2 that give us       +
  32 //  all possible locations of centers of all circles        +
  33 //  tangent to L1 and passing through Point2.                                  +
  34 //  We intersect these bissectrices with straight line OnLine which gives us +
  35 //  the points among which we'll choose the solutions.   +
  36 //  The choices are made basing on Qualifieurs of L1.        +
  37 //=========================================================================
  38
  39 GccAna_Circ2d2TanOn::
  40    GccAna_Circ2d2TanOn (const GccEnt_QualifiedLin&  Qualified1 ,
  41                         const gp_Pnt2d&             Point2     ,
  42                         const gp_Lin2d&             OnLine     ,
  43                         const Standard_Real         Tolerance  ):
  44    cirsol(1,4)     ,
  45    qualifier1(1,4) ,
  46    qualifier2(1,4),
  47    TheSame1(1,4) ,
  48    TheSame2(1,4) ,
  49    pnttg1sol(1,4)  ,
  50    pnttg2sol(1,4)  ,
  51    pntcen(1,4)     ,
  52    par1sol(1,4)    ,
  53    par2sol(1,4)    ,
  54    pararg1(1,4)    ,
  55    pararg2(1,4)    ,
  56    parcen3(1,4)
  57 {
  58   TheSame1.Init(0);
  59   TheSame2.Init(0);
  60   WellDone = Standard_False;
  61   NbrSol = 0;
  62   if (!(Qualified1.IsEnclosed() ||
  63         Qualified1.IsOutside() || Qualified1.IsUnqualified())) {
  64     GccEnt_BadQualifier::Raise();
  65     return;
  66   }
  67   Standard_Real Tol = Abs(Tolerance);
  68   gp_Dir2d dirx(1.,0.);
  69   gp_Lin2d L1 = Qualified1.Qualified();
  70   gp_Pnt2d originL1(L1.Location());
  71   gp_Dir2d dirL1(L1.Direction());
  72   gp_Dir2d normal(-dirL1.Y(),dirL1.X());
  73
  74 //=========================================================================
  75 //   Processing of boundary cases.                                          +
  76 //=========================================================================
  77
  78   if (dirL1.IsEqual(OnLine.Direction(),Precision::Confusion()) &&
  79       OnLine.Distance(originL1)<Precision::Confusion()) {
  80     // POP : l2s 2 straight line are identic : no Sol
  81     NbrSol = 0;
  82     return ;
  83   }
  84
  85
  86   Standard_Real dp2l = OnLine.Distance(Point2);
  87   gp_Dir2d donline(OnLine.Direction());
  88   gp_Pnt2d pinterm(Point2.XY()+dp2l*gp_XY(-donline.Y(),donline.X()));
  89   if (OnLine.Distance(pinterm) > Tol) {
  90     pinterm = gp_Pnt2d(Point2.XY()-dp2l*gp_XY(-donline.Y(),donline.X()));
  91   }
  92   Standard_Real dist = L1.Distance(pinterm);
  93   if (Abs(dist-dp2l) <= Tol) {
  94     gp_Dir2d dirbid(originL1.XY()-pinterm.XY());
  95     if (Qualified1.IsEnclosed() && dirbid.Dot(normal)<0.) {
  96       WellDone = Standard_True;
  97     }
  98     else if (Qualified1.IsOutside() && dirbid.Dot(normal) > 0.) {
  99       WellDone = Standard_True;
 100     }
 101     else if (Qualified1.IsUnqualified()) { WellDone = Standard_True; }
 102     if (WellDone) {
 103       NbrSol++;
 104       cirsol(NbrSol) = gp_Circ2d(gp_Ax2d(pinterm,dirx),dp2l);
 105 //    ======================================================
 106       qualifier2(NbrSol) = GccEnt_noqualifier;
 107       gp_Dir2d dc2(originL1.XY()-pinterm.XY());
 108       if (!Qualified1.IsUnqualified()) {
 109         qualifier1(NbrSol) = Qualified1.Qualifier();
 110       }
 111       else if (dc2.Dot(normal) > 0.0) {
 112         qualifier1(NbrSol) = GccEnt_outside;
 113       }
 114       else { qualifier1(NbrSol) = GccEnt_enclosed; }
 115       Standard_Real sign = dc2.Dot(gp_Dir2d(-dirL1.Y(),
 116                                             dirL1.X()));
 117       dc2 = gp_Dir2d(sign*gp_XY(-dirL1.Y(),dirL1.X()));
 118       pnttg1sol(NbrSol) = gp_Pnt2d(pinterm.XY()+dp2l*dc2.XY());
 119       pnttg2sol(NbrSol) = Point2;
 120       pntcen(NbrSol) = pinterm;
 121       par1sol(NbrSol)=ElCLib::Parameter(cirsol(NbrSol),pnttg1sol(NbrSol));
 122       pararg1(NbrSol)=ElCLib::Parameter(L1,pnttg1sol(NbrSol));
 123       par2sol(NbrSol)=ElCLib::Parameter(cirsol(NbrSol),pnttg2sol(NbrSol));
 124       pararg2(NbrSol) = 0.;
 125       parcen3(NbrSol)=ElCLib::Parameter(OnLine,pntcen(NbrSol));
 126       return;
 127     }
 128   }
 129
 130 //=========================================================================
 131 //   General case.                                                        +
 132 //=========================================================================
 133
 134   GccAna_LinPnt2dBisec Bis(L1,Point2);
 135   if (Bis.IsDone()) {
 136     Handle(GccInt_Bisec) Sol = Bis.ThisSolution();
 137     GccInt_IType type = Sol->ArcType();
 138     IntAna2d_AnaIntersection Intp;
 139     if (type == GccInt_Lin) {
 140       Intp.Perform(OnLine,Sol->Line());
 141     }
 142     if (type == GccInt_Par) {
 143       Intp.Perform(OnLine,IntAna2d_Conic(Sol->Parabola()));
 144     }
 145     if (Intp.IsDone()) {
 146       if (!Intp.IsEmpty()) {
 147         for (Standard_Integer j = 1 ; j <= Intp.NbPoints() ; j++) {
 148           gp_Pnt2d Center(Intp.Point(j).Value());
 149           Standard_Real Radius = L1.Distance(Center);
 150 //        Standard_Integer nbsol = 1;
 151           Standard_Boolean ok = Standard_False;
 152           if (Qualified1.IsEnclosed()) {
 153             if ((((originL1.X()-Center.X())*(-dirL1.Y()))+
 154                  ((originL1.Y()-Center.Y())*(dirL1.X())))<=0){
 155               ok = Standard_True;
 156             }
 157           }
 158           else if (Qualified1.IsOutside()) {
 159             if ((((originL1.X()-Center.X())*(-dirL1.Y()))+
 160                  ((originL1.Y()-Center.Y())*(dirL1.X())))>=0){
 161               ok = Standard_True;
 162             }
 163           }
 164           else if (Qualified1.IsUnqualified()) {
 165             ok = Standard_True;
 166           }
 167           if (ok) {
 168             NbrSol++;
 169             cirsol(NbrSol) = gp_Circ2d(gp_Ax2d(Center,dirx),Radius);
 170 //          =======================================================
 171             qualifier2(NbrSol) = GccEnt_noqualifier;
 172             gp_Dir2d dc2(originL1.XY()-Center.XY());
 173             if (!Qualified1.IsUnqualified()) {
 174               qualifier1(NbrSol) = Qualified1.Qualifier();
 175             }
 176             else if (dc2.Dot(normal) > 0.0) {
 177               qualifier1(NbrSol) = GccEnt_outside;
 178             }
 179             else { qualifier1(NbrSol) = GccEnt_enclosed; }
 180             TheSame1(NbrSol) = 0;
 181             TheSame2(NbrSol) = 0;
 182             gp_Dir2d dc1(originL1.XY()-Center.XY());
 183             Standard_Real sign = dc1.Dot(gp_Dir2d(normal));
 184             dc1=gp_Dir2d(sign*(normal.XY()));
 185             pnttg1sol(NbrSol) = gp_Pnt2d(Center.XY()+Radius*dc1.XY());
 186             pnttg2sol(NbrSol) = Point2;
 187             pntcen(NbrSol) = Center;
 188             par1sol(NbrSol)=ElCLib::Parameter(cirsol(NbrSol),
 189                                               pnttg1sol(NbrSol));
 190             pararg1(NbrSol)=ElCLib::Parameter(L1,pnttg1sol(NbrSol));
 191             par2sol(NbrSol)=ElCLib::Parameter(cirsol(NbrSol),
 192                                               pnttg2sol(NbrSol));
 193             pararg2(NbrSol) = 0.;
 194             parcen3(NbrSol)=ElCLib::Parameter(OnLine,pntcen(NbrSol));
 195           }
 196         }
 197       }
 198       WellDone = Standard_True;
 199     }
 200   }
 201 }
 202