src/DsgPrs/DsgPrs.cxx

   1 // Copyright (c) 1998-1999 Matra Datavision
   2 // Copyright (c) 1999-2014 OPEN CASCADE SAS
   3 //
   4 // This file is part of Open CASCADE Technology software library.
   5 //
   6 // This library is free software; you can redistribute it and/or modify it under
   7 // the terms of the GNU Lesser General Public License version 2.1 as published
   8 // by the Free Software Foundation, with special exception defined in the file
   9 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
  10 // distribution for complete text of the license and disclaimer of any warranty.
  11 //
  12 // Alternatively, this file may be used under the terms of Open CASCADE
  13 // commercial license or contractual agreement.
  14
  15 #include <DsgPrs.hxx>
  16
  17 #include <Aspect_TypeOfLine.hxx>
  18 #include <Aspect_TypeOfMarker.hxx>
  19 #include <ElCLib.hxx>
  20 #include <gce_MakeLin.hxx>
  21 #include <Geom_Circle.hxx>
  22 #include <Geom_Curve.hxx>
  23 #include <Geom_Line.hxx>
  24 #include <Geom_Surface.hxx>
  25 #include <GeomAPI_ExtremaCurveCurve.hxx>
  26 #include <GeomAPI_ProjectPointOnCurve.hxx>
  27 #include <GeomAPI_ProjectPointOnSurf.hxx>
  28 #include <gp_Ax1.hxx>
  29 #include <gp_Circ.hxx>
  30 #include <gp_Dir.hxx>
  31 #include <gp_Elips.hxx>
  32 #include <gp_Pln.hxx>
  33 #include <gp_Pnt.hxx>
  34 #include <gp_Vec.hxx>
  35 #include <Graphic3d_ArrayOfPoints.hxx>
  36 #include <Graphic3d_AspectLine3d.hxx>
  37 #include <Graphic3d_AspectMarker3d.hxx>
  38 #include <Graphic3d_Group.hxx>
  39 #include <Precision.hxx>
  40 #include <Prs3d_Arrow.hxx>
  41 #include <Prs3d_ArrowAspect.hxx>
  42 #include <Prs3d_DimensionAspect.hxx>
  43 #include <Prs3d_LineAspect.hxx>
  44 #include <Prs3d_Presentation.hxx>
  45 #include <Prs3d_Root.hxx>
  46 #include <Quantity_Color.hxx>
  47 #include <TCollection_AsciiString.hxx>
  48 #include <TCollection_ExtendedString.hxx>
  49
  50 void DsgPrs::ComputeSymbol (const Handle(Prs3d_Presentation)& aPresentation,
  51                             const Handle(Prs3d_DimensionAspect)& LA,
  52                             const gp_Pnt& pt1,
  53                             const gp_Pnt& pt2,
  54                             const gp_Dir& dir1,
  55                             const gp_Dir& dir2,
  56                             const DsgPrs_ArrowSide ArrowSide,
  57                             const Standard_Boolean drawFromCenter)
  58 {
  59   Handle(Graphic3d_Group) aGroup = aPresentation->NewGroup();
  60
  61   Quantity_Color aColor = LA->LineAspect()->Aspect()->Color();
  62   Handle(Graphic3d_AspectMarker3d) aMarkerAsp = new Graphic3d_AspectMarker3d (Aspect_TOM_O, aColor, 1.0);
  63   aGroup->SetGroupPrimitivesAspect (LA->LineAspect()->Aspect());
  64
  65   switch(ArrowSide) {
  66   case DsgPrs_AS_NONE:
  67     {
  68       break;
  69     }
  70   case DsgPrs_AS_FIRSTAR:
  71     {
  72       Prs3d_Arrow::Draw (aGroup,
  73                     pt1,
  74                     dir1,
  75                     LA->ArrowAspect()->Angle(),
  76                     LA->ArrowAspect()->Length());
  77       break;
  78     }
  79   case DsgPrs_AS_LASTAR:
  80     {
  81
  82       Prs3d_Arrow::Draw (aGroup,
  83                     pt2,
  84                     dir2,
  85                     LA->ArrowAspect()->Angle(),
  86                     LA->ArrowAspect()->Length());
  87       break;
  88     }
  89
  90   case DsgPrs_AS_BOTHAR:
  91     {
  92       Prs3d_Arrow::Draw (aGroup,
  93                     pt1,
  94                     dir1,
  95                     LA->ArrowAspect()->Angle(),
  96                     LA->ArrowAspect()->Length());
  97       Prs3d_Arrow::Draw (aGroup,
  98                     pt2,
  99                     dir2,
 100                     LA->ArrowAspect()->Angle(),
 101                     LA->ArrowAspect()->Length());
 102
 103       break;
 104     }
 105
 106   case DsgPrs_AS_FIRSTPT:
 107     {
 108       if(drawFromCenter)
 109       {
 110         Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 111         anArrayOfPoints->AddVertex (pt1.X(), pt1.Y(), pt1.Z());
 112         Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints);
 113       }
 114       break;
 115     }
 116
 117   case DsgPrs_AS_LASTPT:
 118     {
 119       // On dessine un rond
 120       Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 121       anArrayOfPoints->AddVertex (pt2.X(), pt2.Y(), pt2.Z());
 122       Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints);
 123       break;
 124     }
 125
 126   case DsgPrs_AS_BOTHPT:
 127     {
 128       if(drawFromCenter)
 129       {
 130         Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints1 = new Graphic3d_ArrayOfPoints (2);
 131         anArrayOfPoints1->AddVertex (pt1.X(), pt1.Y(), pt1.Z());
 132         anArrayOfPoints1->AddVertex (pt2.X(), pt2.Y(), pt2.Z());
 133         aGroup->SetGroupPrimitivesAspect (aMarkerAsp);
 134         aGroup->AddPrimitiveArray (anArrayOfPoints1);
 135       }
 136       break;
 137     }
 138
 139   case DsgPrs_AS_FIRSTAR_LASTPT:
 140     {
 141       // an Arrow
 142       Prs3d_Arrow::Draw (aGroup,
 143                         pt1,
 144                         dir1,
 145                         LA->ArrowAspect()->Angle(),
 146                         LA->ArrowAspect()->Length());
 147       // a Round
 148       Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 149       anArrayOfPoints->AddVertex (pt2.X(), pt2.Y(), pt2.Z());
 150       aGroup->SetPrimitivesAspect (aMarkerAsp);
 151       aGroup->AddPrimitiveArray (anArrayOfPoints);
 152       break;
 153     }
 154
 155   case DsgPrs_AS_FIRSTPT_LASTAR:
 156     {
 157       // an Arrow
 158       Prs3d_Arrow::Draw (aGroup,
 159                         pt2,
 160                         dir2,
 161                         LA->ArrowAspect()->Angle(),
 162                         LA->ArrowAspect()->Length());
 163
 164       // a Round
 165       if (drawFromCenter)
 166       {
 167         Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 168         anArrayOfPoints->AddVertex (pt1.X(), pt1.Y(), pt1.Z());
 169         aGroup->SetPrimitivesAspect (aMarkerAsp);
 170         aGroup->AddPrimitiveArray (anArrayOfPoints);
 171       }
 172       break;
 173     }
 174   }
 175 }
 176
 177
 178 //=======================================================================
 179 //function : ComputePlanarFacesLengthPresentation
 180 //purpose  :
 181 //=======================================================================
 182
 183 void DsgPrs::ComputePlanarFacesLengthPresentation( const Standard_Real FirstArrowLength,
 184                                                    const Standard_Real SecondArrowLength,
 185                                                    const gp_Pnt& AttachmentPoint1,
 186                                                    const gp_Pnt& AttachmentPoint2,
 187                                                    const gp_Dir& DirAttach,
 188                                                    const gp_Pnt& OffsetPoint,
 189                                                    const gp_Pln& PlaneOfFaces,
 190                                                    gp_Pnt &        EndOfArrow1,
 191                                                    gp_Pnt &        EndOfArrow2,
 192                                                    gp_Dir &        DirOfArrow1 )
 193 {
 194   gp_Lin FirstLin( AttachmentPoint1, DirAttach );
 195   gp_Lin SecondLin( AttachmentPoint2, DirAttach );
 196
 197   EndOfArrow1 = ElCLib::Value( ElCLib::Parameter( FirstLin, OffsetPoint ), FirstLin );
 198   EndOfArrow2 = ElCLib::Value( ElCLib::Parameter( SecondLin, OffsetPoint ), SecondLin );
 199
 200   if (EndOfArrow1.SquareDistance( EndOfArrow2 ) > Precision::SquareConfusion()) // not null length
 201     {
 202       gp_Dir LengthDir( gp_Vec( EndOfArrow1, EndOfArrow2 ) );
 203       if ((FirstArrowLength + SecondArrowLength)*(FirstArrowLength + SecondArrowLength) <
 204           EndOfArrow1.SquareDistance( EndOfArrow2 ))
 205         DirOfArrow1 = -LengthDir;
 206       else
 207         DirOfArrow1 = LengthDir;
 208     }
 209   else // null length
 210     DirOfArrow1 = PlaneOfFaces.Axis().Direction();
 211 }
 212
 213 //=======================================================================
 214 //function : ComputeCurvilinearFacesLengthPresentation
 215 //purpose  :
 216 //=======================================================================
 217
 218 void DsgPrs::ComputeCurvilinearFacesLengthPresentation( const Standard_Real FirstArrowLength,
 219                                                         const Standard_Real SecondArrowLength,
 220                                                         const Handle( Geom_Surface )& SecondSurf,
 221                                                         const gp_Pnt& AttachmentPoint1,
 222                                                         const gp_Pnt& AttachmentPoint2,
 223                                                         const gp_Dir& DirAttach,
 224                                                         gp_Pnt &        EndOfArrow2,
 225                                                         gp_Dir &        DirOfArrow1,
 226                                                         Handle( Geom_Curve )& VCurve,
 227                                                         Handle( Geom_Curve )& UCurve,
 228                                                         Standard_Real & FirstU,
 229                                                         Standard_Real & deltaU,
 230                                                         Standard_Real & FirstV,
 231                                                         Standard_Real & deltaV )
 232 {
 233   GeomAPI_ProjectPointOnSurf ProjectorOnSurface;
 234   GeomAPI_ProjectPointOnCurve ProjectorOnCurve;
 235   Standard_Real U1, V1, U2, V2;
 236   Standard_Real LastU, LastV;
 237   Standard_Real SquareTolerance = Precision::SquareConfusion();
 238
 239   ProjectorOnSurface.Init( AttachmentPoint1, SecondSurf );
 240   Standard_Integer Index(1);
 241   Standard_Real MinDist = RealLast();
 242   Standard_Real LocalU, LocalV;
 243   gp_Vec D1U, D1V;
 244   gp_Dir LocalDir;
 245   for (Standard_Integer i = 1; i <= ProjectorOnSurface.NbPoints(); i++)
 246     {
 247       ProjectorOnSurface.Parameters( i, LocalU, LocalV );
 248
 249       SecondSurf->D1( LocalU, LocalV, EndOfArrow2, D1U, D1V );
 250       if (D1U.SquareMagnitude() <= SquareTolerance || D1V.SquareMagnitude() <= SquareTolerance)
 251         LocalDir = gp_Dir( gp_Vec( AttachmentPoint1, ProjectorOnSurface.Point( i ) ) );
 252       else
 253         LocalDir = gp_Dir( D1U ^ D1V );
 254       if (DirAttach.IsParallel( LocalDir, Precision::Angular() ) && ProjectorOnSurface.Distance( i ) < MinDist)
 255         {
 256           Index = i;
 257           MinDist = ProjectorOnSurface.Distance( i );
 258         }
 259     }
 260   EndOfArrow2 = ProjectorOnSurface.Point( Index );
 261   ProjectorOnSurface.Parameters( Index, U1, V1 );
 262
 263   if ((FirstArrowLength + SecondArrowLength)*(FirstArrowLength + SecondArrowLength) <
 264       AttachmentPoint1.SquareDistance( EndOfArrow2 ))
 265     DirOfArrow1 = -DirAttach;
 266   else
 267     DirOfArrow1 = DirAttach;
 268
 269   if (EndOfArrow2.SquareDistance( AttachmentPoint2 ) > Precision::SquareConfusion())
 270     {
 271       VCurve = SecondSurf->VIso( V1 );
 272       ProjectorOnCurve.Init( EndOfArrow2, VCurve );
 273       FirstU = ProjectorOnCurve.LowerDistanceParameter();
 274
 275       ProjectorOnSurface.Init( AttachmentPoint2, SecondSurf );
 276       ProjectorOnSurface.LowerDistanceParameters( U2, V2 );
 277       UCurve = SecondSurf->UIso( U2 );
 278
 279       ProjectorOnCurve.Init( AttachmentPoint2, UCurve );
 280       LastV = ProjectorOnCurve.LowerDistanceParameter();
 281
 282       gp_Pnt Intersection = SecondSurf->Value( U2, V1 );
 283       ProjectorOnCurve.Init( Intersection, VCurve );
 284       LastU = ProjectorOnCurve.LowerDistanceParameter();
 285       ProjectorOnCurve.Init( Intersection, UCurve );
 286       FirstV = ProjectorOnCurve.LowerDistanceParameter();
 287
 288       deltaU = LastU - FirstU;
 289       deltaV = LastV - FirstV;
 290
 291       if (VCurve->IsPeriodic() && Abs( deltaU ) > VCurve->Period()/2)
 292         {
 293           Standard_Real Sign = (deltaU > 0.0)? -1.0 : 1.0;
 294           deltaU = VCurve->Period() - Abs( deltaU );
 295           deltaU *= Sign;
 296         }
 297       if (UCurve->IsPeriodic() && Abs( deltaV ) > UCurve->Period()/2)
 298         {
 299           Standard_Real Sign = (deltaV > 0.0)? -1.0 : 1.0;
 300           deltaV = UCurve->Period() - Abs( deltaV );
 301           deltaV *= Sign;
 302         }
 303     }
 304 }
 305
 306
 307 //=======================================================================
 308 //function : ComputeFacesAnglePresentation
 309 //purpose  :
 310 //=======================================================================
 311
 312 void DsgPrs::ComputeFacesAnglePresentation( const Standard_Real ArrowLength,
 313                                             const Standard_Real Value,
 314                                             const gp_Pnt& CenterPoint,
 315                                             const gp_Pnt& AttachmentPoint1,
 316                                             const gp_Pnt& AttachmentPoint2,
 317                                             const gp_Dir& dir1,
 318                                             const gp_Dir& dir2,
 319                                             const gp_Dir& axisdir,
 320                                             const Standard_Boolean isPlane,
 321                                             const gp_Ax1& AxisOfSurf,
 322                                             const gp_Pnt& OffsetPoint,
 323                                             gp_Circ &       AngleCirc,
 324                                             Standard_Real & FirstParAngleCirc,
 325                                             Standard_Real & LastParAngleCirc,
 326                                             gp_Pnt &        EndOfArrow1,
 327                                             gp_Pnt &        EndOfArrow2,
 328                                             gp_Dir &        DirOfArrow1,
 329                                             gp_Dir &        DirOfArrow2,
 330                                             gp_Pnt &        ProjAttachPoint2,
 331                                             gp_Circ &       AttachCirc,
 332                                             Standard_Real & FirstParAttachCirc,
 333                                             Standard_Real & LastParAttachCirc )
 334 {
 335   if (Value > Precision::Angular() && Abs( M_PI-Value ) > Precision::Angular())
 336     {
 337       // Computing presentation of angle's arc
 338       gp_Ax2 ax( CenterPoint, axisdir, dir1 );
 339       AngleCirc.SetPosition( ax );
 340       AngleCirc.SetRadius( CenterPoint.Distance( OffsetPoint ) );
 341       gp_Vec vec1( dir1 );
 342       vec1 *= AngleCirc.Radius();
 343       gp_Pnt p1 = CenterPoint.Translated( vec1 );
 344       gp_Vec vec2( dir2 );
 345       vec2 *= AngleCirc.Radius();
 346       gp_Pnt p2 = CenterPoint.Translated( vec2 );
 347
 348       Standard_Real Par1 = 0.;
 349       Standard_Real Par2 = ElCLib::Parameter( AngleCirc, p2 );
 350       Standard_Real Par0 = ElCLib::Parameter( AngleCirc, OffsetPoint );
 351
 352       gp_Vec PosVec( CenterPoint, OffsetPoint );
 353       gp_Vec NormalOfPlane = vec1 ^ vec2;
 354
 355       gp_Vec Normal1 = NormalOfPlane ^ vec1;
 356       gp_Vec Normal2 = NormalOfPlane ^ vec2;
 357       Standard_Integer Sign1 = (PosVec * Normal1 >= 0)? 1 : -1;
 358       Standard_Integer Sign2 = (PosVec * Normal2 >= 0)? 1 : -1;
 359       if (Sign1 == 1 && Sign2 == -1)
 360         {
 361           FirstParAngleCirc = Par1;
 362           LastParAngleCirc  = Par2;
 363         }
 364       else if (Sign1 == 1 && Sign2 == 1)
 365         {
 366           FirstParAngleCirc = Par1;
 367           LastParAngleCirc  = Par0;
 368         }
 369       else if (Sign1 == -1 && Sign2 == 1)
 370         {
 371           Par1 += M_PI;
 372           Par2 += M_PI;
 373           FirstParAngleCirc = Par1;
 374           LastParAngleCirc  = Par2;
 375         }
 376       else //Sign1 == -1 && Sign2 == -1
 377         {
 378           AngleCirc.SetPosition( gp_Ax2( CenterPoint, axisdir, gp_Dir( PosVec ) ) );
 379           Par0 = 0.;
 380           Par1 = ElCLib::Parameter( AngleCirc, p1 );
 381           Par2 = ElCLib::Parameter( AngleCirc, p2 );
 382           FirstParAngleCirc = Par0;
 383           LastParAngleCirc  = Par2;
 384         }
 385
 386       // Computing presentation of arrows
 387       EndOfArrow1 = ElCLib::Value( Par1, AngleCirc );
 388       EndOfArrow2  = ElCLib::Value( Par2, AngleCirc );
 389       Standard_Real beta = 0.;
 390       if (AngleCirc.Radius() > Precision::Confusion())
 391         beta = ArrowLength / AngleCirc.Radius();
 392       gp_Pnt OriginOfArrow1 = ElCLib::Value( Par1 + beta, AngleCirc );
 393       gp_Pnt OriginOfArrow2 = ElCLib::Value( Par2 - beta, AngleCirc );
 394       DirOfArrow1 = gp_Dir( gp_Vec( OriginOfArrow1, EndOfArrow1 ) );
 395       DirOfArrow2 = gp_Dir( gp_Vec( OriginOfArrow2, EndOfArrow2 ) );
 396       if (EndOfArrow1.SquareDistance( EndOfArrow2 ) <= (ArrowLength + ArrowLength)*(ArrowLength + ArrowLength))
 397         {
 398           DirOfArrow1.Reverse();
 399           DirOfArrow2.Reverse();
 400         }
 401     }
 402   else // dir1 and dir2 are parallel
 403     {
 404       gp_Dir ArrowDir = axisdir ^ dir1;
 405       DirOfArrow1 = ArrowDir;
 406       DirOfArrow2 = -ArrowDir;
 407       gp_Lin DirLine( AttachmentPoint1, dir1 );
 408       EndOfArrow1 = ElCLib::Value( ElCLib::Parameter( DirLine, OffsetPoint ), DirLine );
 409       EndOfArrow2 = EndOfArrow1;
 410     }
 411
 412   // Line or arc from AttachmentPoint2 to its "projection"
 413   gp_Lin SecondLin( CenterPoint, dir2 );
 414   if (SecondLin.Contains( AttachmentPoint2, Precision::Confusion() ))
 415     ProjAttachPoint2 = AttachmentPoint2;
 416   else
 417     {
 418       if (isPlane)
 419         ProjAttachPoint2 = ElCLib::Value( ElCLib::Parameter( SecondLin, AttachmentPoint2 ), SecondLin );
 420       else
 421         {
 422           gp_Lin LineOfAxis( AxisOfSurf );
 423           gp_Pnt CenterOfArc = ElCLib::Value( ElCLib::Parameter( LineOfAxis, AttachmentPoint2 ),
 424                                               LineOfAxis );
 425
 426           gp_Ax2 Ax2( CenterOfArc,
 427                       AxisOfSurf.Direction(),
 428                       gp_Dir( gp_Vec( CenterOfArc, AttachmentPoint2 ) ) );
 429           AttachCirc.SetPosition( Ax2 );
 430           AttachCirc.SetRadius( CenterOfArc.Distance( AttachmentPoint2 ) );
 431
 432           GeomAPI_ExtremaCurveCurve Intersection( new Geom_Circle( AttachCirc ),
 433                                                   new Geom_Line( SecondLin ) );
 434           Intersection.NearestPoints( ProjAttachPoint2, ProjAttachPoint2 );
 435
 436           Standard_Real U2 = ElCLib::Parameter( AttachCirc, ProjAttachPoint2 );
 437           if (U2 <= M_PI)
 438             {
 439               FirstParAttachCirc = 0;
 440               LastParAttachCirc  = U2;
 441             }
 442           else
 443             {
 444               FirstParAttachCirc = U2;
 445               LastParAttachCirc  = 2*M_PI;
 446             }
 447         }
 448     }
 449 }
 450
 451
 452
 453 void DsgPrs::ComputeFilletRadiusPresentation( const Standard_Real /*ArrowLength*/,
 454                                               const Standard_Real Value,
 455                                               const gp_Pnt &      Position,
 456                                               const gp_Dir &      NormalDir,
 457                                               const gp_Pnt &      FirstPoint,
 458                                               const gp_Pnt &      SecondPoint,
 459                                               const gp_Pnt &      Center,
 460                                               const gp_Pnt &      BasePnt,
 461                                               const Standard_Boolean drawRevers,
 462                                               Standard_Boolean &  SpecCase,
 463                                               gp_Circ &           FilletCirc,
 464                                               Standard_Real &     FirstParCirc,
 465                                               Standard_Real &     LastParCirc,
 466                                               gp_Pnt &            EndOfArrow,
 467                                               gp_Dir &            DirOfArrow,
 468                                               gp_Pnt &            DrawPosition)
 469 {
 470   gp_Dir dir1(gp_Vec(Center, FirstPoint));
 471   gp_Dir dir2(gp_Vec(Center, SecondPoint));
 472   Standard_Real Angle = dir1.Angle(dir2);
 473   if(Angle <= Precision::Angular() || ( M_PI - Angle ) <= Precision::Angular() ||
 474      Value <= Precision::Confusion()) SpecCase = Standard_True;
 475   else SpecCase = Standard_False;
 476   if ( !SpecCase )
 477     {
 478        // Computing presentation of fillet's arc
 479       gp_Ax2 ax( Center, NormalDir, dir1 );
 480       FilletCirc.SetPosition( ax );
 481       FilletCirc.SetRadius( Center.Distance( FirstPoint ) ); //***
 482       gp_Vec vec1( dir1 );
 483       vec1 *= FilletCirc.Radius();
 484       gp_Vec vec2( dir2 );
 485       vec2 *= FilletCirc.Radius();
 486       gp_Vec PosVec;
 487       if(! Center.IsEqual( Position, Precision::Confusion() ))
 488         PosVec.SetXYZ( gp_Vec(Center, Position).XYZ() );
 489       else
 490         PosVec.SetXYZ( (vec1.Added(vec2)).XYZ() );
 491       gp_Vec NormalOfPlane = vec1 ^ vec2;
 492       gp_Vec Normal1 = NormalOfPlane ^ vec1;
 493       gp_Vec Normal2 = NormalOfPlane ^ vec2;
 494       Standard_Integer Sign1 = (PosVec * Normal1 >= 0)? 1 : -1;
 495       Standard_Integer Sign2 = (PosVec * Normal2 >= 0)? 1 : -1;
 496       gp_Lin L1( Center, dir1 );
 497       gp_Lin L2( Center, dir2 );
 498       if ( Sign1 != Sign2 )
 499         {
 500           DrawPosition = Position; //***
 501           gp_Dir direction(PosVec) ;
 502           Standard_Real angle = dir1.Angle(direction) ;
 503           if (( dir1 ^ direction) * NormalDir < 0.0e0)   angle = -angle ;
 504           if(Sign1 == -1) angle += M_PI;
 505           EndOfArrow = ElCLib::Value(angle, FilletCirc); //***
 506
 507         }
 508       else
 509         {
 510           if(L1.Distance(Position) < L2.Distance(Position))
 511               {
 512                 EndOfArrow = FirstPoint; //***
 513                 DrawPosition =  ElCLib::Value(ElCLib::Parameter(L1, Position), L1);
 514               }
 515           else
 516             {
 517               EndOfArrow = SecondPoint; //***
 518               DrawPosition = ElCLib::Value(ElCLib::Parameter(L2, Position), L2);
 519             }
 520         }
 521       if((dir1^dir2).IsOpposite(NormalDir, Precision::Angular()))
 522         {
 523           gp_Dir newdir = NormalDir.Reversed() ;
 524           gp_Ax2 axnew( Center, newdir, dir1 );
 525           FilletCirc.SetPosition( axnew );
 526         }
 527       FirstParCirc = ElCLib::Parameter( FilletCirc, FirstPoint );
 528       LastParCirc  = ElCLib::Parameter( FilletCirc, SecondPoint );
 529     }
 530   else //Angle equal 0 or PI or R = 0
 531     {
 532       DrawPosition = Position;
 533       EndOfArrow   = BasePnt;
 534     }
 535
 536   if(drawRevers)
 537     {
 538       gp_Vec Vd(DrawPosition, EndOfArrow);
 539       DrawPosition.Translate(Vd *2);
 540     }
 541   DirOfArrow.SetXYZ(gp_Dir(gp_Vec(DrawPosition, EndOfArrow)).XYZ());
 542 }
 543
 544 //=======================================================================
 545 //function : ComputeRadiusLine
 546 //purpose  :
 547 //=======================================================================
 548
 549 void DsgPrs::ComputeRadiusLine(const gp_Pnt & aCenter,
 550                                const gp_Pnt & anEndOfArrow,
 551                                const gp_Pnt & aPosition,
 552                                const Standard_Boolean drawFromCenter,
 553                                      gp_Pnt & aRadLineOrign,
 554                                      gp_Pnt & aRadLineEnd)
 555 {
 556   if(drawFromCenter)
 557     {
 558       gp_Lin RadiusLine = gce_MakeLin( aCenter, anEndOfArrow );
 559       Standard_Real PosParOnLine = ElCLib::Parameter( RadiusLine, aPosition );
 560       Standard_Real EndOfArrowPar     = ElCLib::Parameter( RadiusLine, anEndOfArrow );
 561       if (PosParOnLine < 0.0)
 562         {
 563           aRadLineOrign = aPosition;
 564           aRadLineEnd   = anEndOfArrow;
 565         }
 566       else if (PosParOnLine > EndOfArrowPar)
 567         {
 568           aRadLineOrign = aPosition;
 569           aRadLineEnd   = aCenter;
 570         }
 571       else
 572         {
 573           aRadLineOrign = aCenter;
 574           aRadLineEnd   = anEndOfArrow;
 575         }
 576     }
 577   else
 578     {
 579       aRadLineOrign = aPosition;
 580       aRadLineEnd   = anEndOfArrow;
 581     }
 582 }
 583
 584
 585 //=======================================================================
 586 //function : DistanceFromApex
 587 //purpose  :
 588 //=======================================================================
 589
 590 Standard_Real DsgPrs::DistanceFromApex(const gp_Elips & elips,
 591                                        const gp_Pnt   & Apex,
 592                                        const Standard_Real par)
 593 {
 594   Standard_Real dist;
 595   Standard_Real parApex = ElCLib::Parameter ( elips, Apex );
 596   if(parApex == 0.0 || parApex == M_PI)
 597     {//Major case
 598       if(parApex == 0.0) //pos Apex
 599         dist = (par < M_PI) ? par : (2*M_PI - par);
 600       else //neg Apex
 601         dist = (par < M_PI) ? ( M_PI - par) : ( par - M_PI );
 602     }
 603   else
 604     {// Minor case
 605       if(parApex == M_PI / 2) //pos Apex
 606         {
 607           if(par <= parApex + M_PI && par > parApex )
 608             dist = par - parApex;
 609           else
 610             {
 611               if(par >  parApex + M_PI)
 612                 dist = 2*M_PI - par + parApex;
 613               else
 614                 dist = parApex - par; // 0 < par < M_PI/2
 615             }
 616         }
 617       else //neg Apex == 3/2 PI
 618         {
 619           if(par <= parApex && par >= M_PI/2)
 620             dist = parApex - par;
 621           else
 622             {
 623               if(par >  parApex)
 624                 dist = par - parApex;
 625               else
 626                 dist = par + M_PI/2; // 0 < par < PI/2
 627             }
 628         }
 629     }
 630   return dist;
 631 }