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 <Aspect_TypeOfLine.hxx>
  16 #include <Aspect_TypeOfMarker.hxx>
  17 #include <DsgPrs.hxx>
  18 #include <ElCLib.hxx>
  19 #include <gce_MakeLin.hxx>
  20 #include <Geom_Circle.hxx>
  21 #include <Geom_Curve.hxx>
  22 #include <Geom_Line.hxx>
  23 #include <Geom_Surface.hxx>
  24 #include <GeomAPI_ExtremaCurveCurve.hxx>
  25 #include <GeomAPI_ProjectPointOnCurve.hxx>
  26 #include <GeomAPI_ProjectPointOnSurf.hxx>
  27 #include <gp_Ax1.hxx>
  28 #include <gp_Circ.hxx>
  29 #include <gp_Dir.hxx>
  30 #include <gp_Elips.hxx>
  31 #include <gp_Pln.hxx>
  32 #include <gp_Pnt.hxx>
  33 #include <gp_Vec.hxx>
  34 #include <Graphic3d_ArrayOfPoints.hxx>
  35 #include <Graphic3d_AspectLine3d.hxx>
  36 #include <Graphic3d_AspectMarker3d.hxx>
  37 #include <Graphic3d_Group.hxx>
  38 #include <Graphic3d_Vertex.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   Prs3d_Root::CurrentGroup(aPresentation)->SetPrimitivesAspect(LA->LineAspect()->Aspect());
  60
  61   Quantity_Color aColor = LA->LineAspect()->Aspect()->Color();
  62   Handle(Graphic3d_AspectMarker3d) aMarkerAsp = new Graphic3d_AspectMarker3d (Aspect_TOM_O, aColor, 1.0);
  63   Prs3d_Root::CurrentGroup(aPresentation)->SetPrimitivesAspect (aMarkerAsp);
  64   Prs3d_Root::CurrentGroup(aPresentation)->SetPrimitivesAspect(LA->LineAspect()->Aspect());
  65
  66   switch(ArrowSide) {
  67   case DsgPrs_AS_NONE:
  68     {
  69       break;
  70     }
  71   case DsgPrs_AS_FIRSTAR:
  72     {
  73       Prs3d_Arrow::Draw(Prs3d_Root::CurrentGroup (aPresentation),
  74                     pt1,
  75                     dir1,
  76                     LA->ArrowAspect()->Angle(),
  77                     LA->ArrowAspect()->Length());
  78       break;
  79     }
  80   case DsgPrs_AS_LASTAR:
  81     {
  82
  83       Prs3d_Arrow::Draw (Prs3d_Root::CurrentGroup (aPresentation),
  84                     pt2,
  85                     dir2,
  86                     LA->ArrowAspect()->Angle(),
  87                     LA->ArrowAspect()->Length());
  88       break;
  89     }
  90
  91   case DsgPrs_AS_BOTHAR:
  92     {
  93       Prs3d_Arrow::Draw (Prs3d_Root::CurrentGroup (aPresentation),
  94                     pt1,
  95                     dir1,
  96                     LA->ArrowAspect()->Angle(),
  97                     LA->ArrowAspect()->Length());
  98       Prs3d_Arrow::Draw (Prs3d_Root::CurrentGroup (aPresentation),
  99                     pt2,
 100                     dir2,
 101                     LA->ArrowAspect()->Angle(),
 102                     LA->ArrowAspect()->Length());
 103
 104       break;
 105     }
 106
 107   case DsgPrs_AS_FIRSTPT:
 108     {
 109       if(drawFromCenter)
 110       {
 111         Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 112         anArrayOfPoints->AddVertex (pt1.X(), pt1.Y(), pt1.Z());
 113         Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints);
 114       }
 115       break;
 116     }
 117
 118   case DsgPrs_AS_LASTPT:
 119     {
 120       // On dessine un rond
 121       Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 122       anArrayOfPoints->AddVertex (pt2.X(), pt2.Y(), pt2.Z());
 123       Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints);
 124       break;
 125     }
 126
 127   case DsgPrs_AS_BOTHPT:
 128     {
 129       if(drawFromCenter)
 130       {
 131         Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints1 = new Graphic3d_ArrayOfPoints (1);
 132         anArrayOfPoints1->AddVertex (pt1.X(), pt1.Y(), pt1.Z());
 133         Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints1);
 134       }
 135       if(drawFromCenter)
 136       {
 137         Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints2 = new Graphic3d_ArrayOfPoints (1);
 138         anArrayOfPoints2->AddVertex (pt2.X(), pt2.Y(), pt2.Z());
 139         Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints2);
 140       }
 141       break;
 142     }
 143
 144   case DsgPrs_AS_FIRSTAR_LASTPT:
 145     {
 146       // an Arrow
 147       Prs3d_Arrow::Draw (Prs3d_Root::CurrentGroup (aPresentation),
 148                         pt1,
 149                         dir1,
 150                         LA->ArrowAspect()->Angle(),
 151                         LA->ArrowAspect()->Length());
 152       // a Round
 153       Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 154       anArrayOfPoints->AddVertex (pt2.X(), pt2.Y(), pt2.Z());
 155       Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints);
 156       break;
 157     }
 158
 159   case DsgPrs_AS_FIRSTPT_LASTAR:
 160     {
 161       // a Round
 162       if(drawFromCenter)
 163       {
 164         Handle(Graphic3d_ArrayOfPoints) anArrayOfPoints = new Graphic3d_ArrayOfPoints (1);
 165         anArrayOfPoints->AddVertex (pt1.X(), pt1.Y(), pt1.Z());
 166         Prs3d_Root::CurrentGroup(aPresentation)->AddPrimitiveArray (anArrayOfPoints);
 167       }
 168       // an Arrow
 169       Prs3d_Arrow::Draw (Prs3d_Root::CurrentGroup (aPresentation),
 170                         pt2,
 171                         dir2,
 172                         LA->ArrowAspect()->Angle(),
 173                         LA->ArrowAspect()->Length());
 174       break;
 175     }
 176   }
 177 }
 178
 179
 180 //=======================================================================
 181 //function : ComputePlanarFacesLengthPresentation
 182 //purpose  :
 183 //=======================================================================
 184
 185 void DsgPrs::ComputePlanarFacesLengthPresentation( const Standard_Real FirstArrowLength,
 186                                                    const Standard_Real SecondArrowLength,
 187                                                    const gp_Pnt& AttachmentPoint1,
 188                                                    const gp_Pnt& AttachmentPoint2,
 189                                                    const gp_Dir& DirAttach,
 190                                                    const gp_Pnt& OffsetPoint,
 191                                                    const gp_Pln& PlaneOfFaces,
 192                                                    gp_Pnt &        EndOfArrow1,
 193                                                    gp_Pnt &        EndOfArrow2,
 194                                                    gp_Dir &        DirOfArrow1 )
 195 {
 196   gp_Lin FirstLin( AttachmentPoint1, DirAttach );
 197   gp_Lin SecondLin( AttachmentPoint2, DirAttach );
 198
 199   EndOfArrow1 = ElCLib::Value( ElCLib::Parameter( FirstLin, OffsetPoint ), FirstLin );
 200   EndOfArrow2 = ElCLib::Value( ElCLib::Parameter( SecondLin, OffsetPoint ), SecondLin );
 201
 202   if (EndOfArrow1.SquareDistance( EndOfArrow2 ) > Precision::SquareConfusion()) // not null length
 203     {
 204       gp_Dir LengthDir( gp_Vec( EndOfArrow1, EndOfArrow2 ) );
 205       if ((FirstArrowLength + SecondArrowLength)*(FirstArrowLength + SecondArrowLength) <
 206           EndOfArrow1.SquareDistance( EndOfArrow2 ))
 207         DirOfArrow1 = -LengthDir;
 208       else
 209         DirOfArrow1 = LengthDir;
 210     }
 211   else // null length
 212     DirOfArrow1 = PlaneOfFaces.Axis().Direction();
 213 }
 214
 215 //=======================================================================
 216 //function : ComputeCurvilinearFacesLengthPresentation
 217 //purpose  :
 218 //=======================================================================
 219
 220 void DsgPrs::ComputeCurvilinearFacesLengthPresentation( const Standard_Real FirstArrowLength,
 221                                                         const Standard_Real SecondArrowLength,
 222                                                         const Handle( Geom_Surface )& SecondSurf,
 223                                                         const gp_Pnt& AttachmentPoint1,
 224                                                         const gp_Pnt& AttachmentPoint2,
 225                                                         const gp_Dir& DirAttach,
 226                                                         gp_Pnt &        EndOfArrow2,
 227                                                         gp_Dir &        DirOfArrow1,
 228                                                         Handle( Geom_Curve )& VCurve,
 229                                                         Handle( Geom_Curve )& UCurve,
 230                                                         Standard_Real & FirstU,
 231                                                         Standard_Real & deltaU,
 232                                                         Standard_Real & FirstV,
 233                                                         Standard_Real & deltaV )
 234 {
 235   GeomAPI_ProjectPointOnSurf ProjectorOnSurface;
 236   GeomAPI_ProjectPointOnCurve ProjectorOnCurve;
 237   Quantity_Parameter U1, V1, U2, V2;
 238   Standard_Real LastU, LastV;
 239   Standard_Real SquareTolerance = Precision::SquareConfusion();
 240
 241   ProjectorOnSurface.Init( AttachmentPoint1, SecondSurf );
 242   Standard_Integer Index(1);
 243   Quantity_Length MinDist = RealLast();
 244   Quantity_Parameter LocalU, LocalV;
 245   gp_Vec D1U, D1V;
 246   gp_Dir LocalDir;
 247   for (Standard_Integer i = 1; i <= ProjectorOnSurface.NbPoints(); i++)
 248     {
 249       ProjectorOnSurface.Parameters( i, LocalU, LocalV );
 250
 251       SecondSurf->D1( LocalU, LocalV, EndOfArrow2, D1U, D1V );
 252       if (D1U.SquareMagnitude() <= SquareTolerance || D1V.SquareMagnitude() <= SquareTolerance)
 253         LocalDir = gp_Dir( gp_Vec( AttachmentPoint1, ProjectorOnSurface.Point( i ) ) );
 254       else
 255         LocalDir = gp_Dir( D1U ^ D1V );
 256       if (DirAttach.IsParallel( LocalDir, Precision::Angular() ) && ProjectorOnSurface.Distance( i ) < MinDist)
 257         {
 258           Index = i;
 259           MinDist = ProjectorOnSurface.Distance( i );
 260         }
 261     }
 262   EndOfArrow2 = ProjectorOnSurface.Point( Index );
 263   ProjectorOnSurface.Parameters( Index, U1, V1 );
 264
 265   if ((FirstArrowLength + SecondArrowLength)*(FirstArrowLength + SecondArrowLength) <
 266       AttachmentPoint1.SquareDistance( EndOfArrow2 ))
 267     DirOfArrow1 = -DirAttach;
 268   else
 269     DirOfArrow1 = DirAttach;
 270
 271   if (EndOfArrow2.SquareDistance( AttachmentPoint2 ) > Precision::SquareConfusion())
 272     {
 273       VCurve = SecondSurf->VIso( V1 );
 274       ProjectorOnCurve.Init( EndOfArrow2, VCurve );
 275       FirstU = ProjectorOnCurve.LowerDistanceParameter();
 276
 277       ProjectorOnSurface.Init( AttachmentPoint2, SecondSurf );
 278       ProjectorOnSurface.LowerDistanceParameters( U2, V2 );
 279       UCurve = SecondSurf->UIso( U2 );
 280
 281       ProjectorOnCurve.Init( AttachmentPoint2, UCurve );
 282       LastV = ProjectorOnCurve.LowerDistanceParameter();
 283
 284       gp_Pnt Intersection = SecondSurf->Value( U2, V1 );
 285       ProjectorOnCurve.Init( Intersection, VCurve );
 286       LastU = ProjectorOnCurve.LowerDistanceParameter();
 287       ProjectorOnCurve.Init( Intersection, UCurve );
 288       FirstV = ProjectorOnCurve.LowerDistanceParameter();
 289
 290       deltaU = LastU - FirstU;
 291       deltaV = LastV - FirstV;
 292
 293       if (VCurve->IsPeriodic() && Abs( deltaU ) > VCurve->Period()/2)
 294         {
 295           Standard_Real Sign = (deltaU > 0.0)? -1.0 : 1.0;
 296           deltaU = VCurve->Period() - Abs( deltaU );
 297           deltaU *= Sign;
 298         }
 299       if (UCurve->IsPeriodic() && Abs( deltaV ) > UCurve->Period()/2)
 300         {
 301           Standard_Real Sign = (deltaV > 0.0)? -1.0 : 1.0;
 302           deltaV = UCurve->Period() - Abs( deltaV );
 303           deltaV *= Sign;
 304         }
 305     }
 306 }
 307
 308
 309 //=======================================================================
 310 //function : ComputeFacesAnglePresentation
 311 //purpose  :
 312 //=======================================================================
 313
 314 void DsgPrs::ComputeFacesAnglePresentation( const Standard_Real ArrowLength,
 315                                             const Standard_Real Value,
 316                                             const gp_Pnt& CenterPoint,
 317                                             const gp_Pnt& AttachmentPoint1,
 318                                             const gp_Pnt& AttachmentPoint2,
 319                                             const gp_Dir& dir1,
 320                                             const gp_Dir& dir2,
 321                                             const gp_Dir& axisdir,
 322                                             const Standard_Boolean isPlane,
 323                                             const gp_Ax1& AxisOfSurf,
 324                                             const gp_Pnt& OffsetPoint,
 325                                             gp_Circ &       AngleCirc,
 326                                             Standard_Real & FirstParAngleCirc,
 327                                             Standard_Real & LastParAngleCirc,
 328                                             gp_Pnt &        EndOfArrow1,
 329                                             gp_Pnt &        EndOfArrow2,
 330                                             gp_Dir &        DirOfArrow1,
 331                                             gp_Dir &        DirOfArrow2,
 332                                             gp_Pnt &        ProjAttachPoint2,
 333                                             gp_Circ &       AttachCirc,
 334                                             Standard_Real & FirstParAttachCirc,
 335                                             Standard_Real & LastParAttachCirc )
 336 {
 337   if (Value > Precision::Angular() && Abs( M_PI-Value ) > Precision::Angular())
 338     {
 339       // Computing presentation of angle's arc
 340       gp_Ax2 ax( CenterPoint, axisdir, dir1 );
 341       AngleCirc.SetPosition( ax );
 342       AngleCirc.SetRadius( CenterPoint.Distance( OffsetPoint ) );
 343       gp_Vec vec1( dir1 );
 344       vec1 *= AngleCirc.Radius();
 345       gp_Pnt p1 = CenterPoint.Translated( vec1 );
 346       gp_Vec vec2( dir2 );
 347       vec2 *= AngleCirc.Radius();
 348       gp_Pnt p2 = CenterPoint.Translated( vec2 );
 349
 350       Standard_Real Par1 = 0.;
 351       Standard_Real Par2 = ElCLib::Parameter( AngleCirc, p2 );
 352       Standard_Real Par0 = ElCLib::Parameter( AngleCirc, OffsetPoint );
 353
 354       gp_Vec PosVec( CenterPoint, OffsetPoint );
 355       gp_Vec NormalOfPlane = vec1 ^ vec2;
 356
 357       gp_Vec Normal1 = NormalOfPlane ^ vec1;
 358       gp_Vec Normal2 = NormalOfPlane ^ vec2;
 359       Standard_Integer Sign1 = (PosVec * Normal1 >= 0)? 1 : -1;
 360       Standard_Integer Sign2 = (PosVec * Normal2 >= 0)? 1 : -1;
 361       if (Sign1 == 1 && Sign2 == -1)
 362         {
 363           FirstParAngleCirc = Par1;
 364           LastParAngleCirc  = Par2;
 365         }
 366       else if (Sign1 == 1 && Sign2 == 1)
 367         {
 368           FirstParAngleCirc = Par1;
 369           LastParAngleCirc  = Par0;
 370         }
 371       else if (Sign1 == -1 && Sign2 == 1)
 372         {
 373           Par1 += M_PI;
 374           Par2 += M_PI;
 375           FirstParAngleCirc = Par1;
 376           LastParAngleCirc  = Par2;
 377         }
 378       else //Sign1 == -1 && Sign2 == -1
 379         {
 380           AngleCirc.SetPosition( gp_Ax2( CenterPoint, axisdir, gp_Dir( PosVec ) ) );
 381           Par0 = 0.;
 382           Par1 = ElCLib::Parameter( AngleCirc, p1 );
 383           Par2 = ElCLib::Parameter( AngleCirc, p2 );
 384           FirstParAngleCirc = Par0;
 385           LastParAngleCirc  = Par2;
 386         }
 387
 388       // Computing presentation of arrows
 389       EndOfArrow1 = ElCLib::Value( Par1, AngleCirc );
 390       EndOfArrow2  = ElCLib::Value( Par2, AngleCirc );
 391       Standard_Real beta = 0.;
 392       if (AngleCirc.Radius() > Precision::Confusion())
 393         beta = ArrowLength / AngleCirc.Radius();
 394       gp_Pnt OriginOfArrow1 = ElCLib::Value( Par1 + beta, AngleCirc );
 395       gp_Pnt OriginOfArrow2 = ElCLib::Value( Par2 - beta, AngleCirc );
 396       DirOfArrow1 = gp_Dir( gp_Vec( OriginOfArrow1, EndOfArrow1 ) );
 397       DirOfArrow2 = gp_Dir( gp_Vec( OriginOfArrow2, EndOfArrow2 ) );
 398       if (EndOfArrow1.SquareDistance( EndOfArrow2 ) <= (ArrowLength + ArrowLength)*(ArrowLength + ArrowLength))
 399         {
 400           DirOfArrow1.Reverse();
 401           DirOfArrow2.Reverse();
 402         }
 403     }
 404   else // dir1 and dir2 are parallel
 405     {
 406       gp_Dir ArrowDir = axisdir ^ dir1;
 407       DirOfArrow1 = ArrowDir;
 408       DirOfArrow2 = -ArrowDir;
 409       gp_Lin DirLine( AttachmentPoint1, dir1 );
 410       EndOfArrow1 = ElCLib::Value( ElCLib::Parameter( DirLine, OffsetPoint ), DirLine );
 411       EndOfArrow2 = EndOfArrow1;
 412     }
 413
 414   // Line or arc from AttachmentPoint2 to its "projection"
 415   gp_Lin SecondLin( CenterPoint, dir2 );
 416   if (SecondLin.Contains( AttachmentPoint2, Precision::Confusion() ))
 417     ProjAttachPoint2 = AttachmentPoint2;
 418   else
 419     {
 420       if (isPlane)
 421         ProjAttachPoint2 = ElCLib::Value( ElCLib::Parameter( SecondLin, AttachmentPoint2 ), SecondLin );
 422       else
 423         {
 424           gp_Lin LineOfAxis( AxisOfSurf );
 425           gp_Pnt CenterOfArc = ElCLib::Value( ElCLib::Parameter( LineOfAxis, AttachmentPoint2 ),
 426                                               LineOfAxis );
 427
 428           gp_Ax2 Ax2( CenterOfArc,
 429                       AxisOfSurf.Direction(),
 430                       gp_Dir( gp_Vec( CenterOfArc, AttachmentPoint2 ) ) );
 431           AttachCirc.SetPosition( Ax2 );
 432           AttachCirc.SetRadius( CenterOfArc.Distance( AttachmentPoint2 ) );
 433
 434           GeomAPI_ExtremaCurveCurve Intersection( new Geom_Circle( AttachCirc ),
 435                                                   new Geom_Line( SecondLin ) );
 436           Intersection.NearestPoints( ProjAttachPoint2, ProjAttachPoint2 );
 437
 438           Standard_Real U2 = ElCLib::Parameter( AttachCirc, ProjAttachPoint2 );
 439           if (U2 <= M_PI)
 440             {
 441               FirstParAttachCirc = 0;
 442               LastParAttachCirc  = U2;
 443             }
 444           else
 445             {
 446               FirstParAttachCirc = U2;
 447               LastParAttachCirc  = 2*M_PI;
 448             }
 449         }
 450     }
 451 }
 452
 453
 454
 455 void DsgPrs::ComputeFilletRadiusPresentation( const Standard_Real /*ArrowLength*/,
 456                                               const Standard_Real Value,
 457                                               const gp_Pnt &      Position,
 458                                               const gp_Dir &      NormalDir,
 459                                               const gp_Pnt &      FirstPoint,
 460                                               const gp_Pnt &      SecondPoint,
 461                                               const gp_Pnt &      Center,
 462                                               const gp_Pnt &      BasePnt,
 463                                               const Standard_Boolean drawRevers,
 464                                               Standard_Boolean &  SpecCase,
 465                                               gp_Circ &           FilletCirc,
 466                                               Standard_Real &     FirstParCirc,
 467                                               Standard_Real &     LastParCirc,
 468                                               gp_Pnt &            EndOfArrow,
 469                                               gp_Dir &            DirOfArrow,
 470                                               gp_Pnt &            DrawPosition)
 471 {
 472   gp_Dir dir1(gp_Vec(Center, FirstPoint));
 473   gp_Dir dir2(gp_Vec(Center, SecondPoint));
 474   Standard_Real Angle = dir1.Angle(dir2);
 475   if(Angle <= Precision::Angular() || ( M_PI - Angle ) <= Precision::Angular() ||
 476      Value <= Precision::Confusion()) SpecCase = Standard_True;
 477   else SpecCase = Standard_False;
 478   if ( !SpecCase )
 479     {
 480        // Computing presentation of fillet's arc
 481       gp_Ax2 ax( Center, NormalDir, dir1 );
 482       FilletCirc.SetPosition( ax );
 483       FilletCirc.SetRadius( Center.Distance( FirstPoint ) ); //***
 484       gp_Vec vec1( dir1 );
 485       vec1 *= FilletCirc.Radius();
 486       gp_Vec vec2( dir2 );
 487       vec2 *= FilletCirc.Radius();
 488       gp_Vec PosVec;
 489       if(! Center.IsEqual( Position, Precision::Confusion() ))
 490         PosVec.SetXYZ( gp_Vec(Center, Position).XYZ() );
 491       else
 492         PosVec.SetXYZ( (vec1.Added(vec2)).XYZ() );
 493       gp_Vec NormalOfPlane = vec1 ^ vec2;
 494       gp_Vec Normal1 = NormalOfPlane ^ vec1;
 495       gp_Vec Normal2 = NormalOfPlane ^ vec2;
 496       Standard_Integer Sign1 = (PosVec * Normal1 >= 0)? 1 : -1;
 497       Standard_Integer Sign2 = (PosVec * Normal2 >= 0)? 1 : -1;
 498       gp_Lin L1( Center, dir1 );
 499       gp_Lin L2( Center, dir2 );
 500       if ( Sign1 != Sign2 )
 501         {
 502           DrawPosition = Position; //***
 503           gp_Dir direction(PosVec) ;
 504           Standard_Real angle = dir1.Angle(direction) ;
 505           if (( dir1 ^ direction) * NormalDir < 0.0e0)   angle = -angle ;
 506           if(Sign1 == -1) angle += M_PI;
 507           EndOfArrow = ElCLib::Value(angle, FilletCirc); //***
 508
 509         }
 510       else
 511         {
 512           if(L1.Distance(Position) < L2.Distance(Position))
 513               {
 514                 EndOfArrow = FirstPoint; //***
 515                 DrawPosition =  ElCLib::Value(ElCLib::Parameter(L1, Position), L1);
 516               }
 517           else
 518             {
 519               EndOfArrow = SecondPoint; //***
 520               DrawPosition = ElCLib::Value(ElCLib::Parameter(L2, Position), L2);
 521             }
 522         }
 523       if((dir1^dir2).IsOpposite(NormalDir, Precision::Angular()))
 524         {
 525           gp_Dir newdir = NormalDir.Reversed() ;
 526           gp_Ax2 axnew( Center, newdir, dir1 );
 527           FilletCirc.SetPosition( axnew );
 528         }
 529       FirstParCirc = ElCLib::Parameter( FilletCirc, FirstPoint );
 530       LastParCirc  = ElCLib::Parameter( FilletCirc, SecondPoint );
 531     }
 532   else //Angle equal 0 or PI or R = 0
 533     {
 534       DrawPosition = Position;
 535       EndOfArrow   = BasePnt;
 536     }
 537
 538   if(drawRevers)
 539     {
 540       gp_Vec Vd(DrawPosition, EndOfArrow);
 541       DrawPosition.Translate(Vd *2);
 542     }
 543   DirOfArrow.SetXYZ(gp_Dir(gp_Vec(DrawPosition, EndOfArrow)).XYZ());
 544 }
 545
 546 //=======================================================================
 547 //function : ComputeRadiusLine
 548 //purpose  :
 549 //=======================================================================
 550
 551 void DsgPrs::ComputeRadiusLine(const gp_Pnt & aCenter,
 552                                const gp_Pnt & anEndOfArrow,
 553                                const gp_Pnt & aPosition,
 554                                const Standard_Boolean drawFromCenter,
 555                                      gp_Pnt & aRadLineOrign,
 556                                      gp_Pnt & aRadLineEnd)
 557 {
 558   if(drawFromCenter)
 559     {
 560       gp_Lin RadiusLine = gce_MakeLin( aCenter, anEndOfArrow );
 561       Standard_Real PosParOnLine = ElCLib::Parameter( RadiusLine, aPosition );
 562       Standard_Real EndOfArrowPar     = ElCLib::Parameter( RadiusLine, anEndOfArrow );
 563       if (PosParOnLine < 0.0)
 564         {
 565           aRadLineOrign = aPosition;
 566           aRadLineEnd   = anEndOfArrow;
 567         }
 568       else if (PosParOnLine > EndOfArrowPar)
 569         {
 570           aRadLineOrign = aPosition;
 571           aRadLineEnd   = aCenter;
 572         }
 573       else
 574         {
 575           aRadLineOrign = aCenter;
 576           aRadLineEnd   = anEndOfArrow;
 577         }
 578     }
 579   else
 580     {
 581       aRadLineOrign = aPosition;
 582       aRadLineEnd   = anEndOfArrow;
 583     }
 584 }
 585
 586
 587 //=======================================================================
 588 //function : DistanceFromApex
 589 //purpose  :
 590 //=======================================================================
 591
 592 Standard_Real DsgPrs::DistanceFromApex(const gp_Elips & elips,
 593                                        const gp_Pnt   & Apex,
 594                                        const Standard_Real par)
 595 {
 596   Standard_Real dist;
 597   Standard_Real parApex = ElCLib::Parameter ( elips, Apex );
 598   if(parApex == 0.0 || parApex == M_PI)
 599     {//Major case
 600       if(parApex == 0.0) //pos Apex
 601         dist = (par < M_PI) ? par : (2*M_PI - par);
 602       else //neg Apex
 603         dist = (par < M_PI) ? ( M_PI - par) : ( par - M_PI );
 604     }
 605   else
 606     {// Minor case
 607       if(parApex == M_PI / 2) //pos Apex
 608         {
 609           if(par <= parApex + M_PI && par > parApex )
 610             dist = par - parApex;
 611           else
 612             {
 613               if(par >  parApex + M_PI)
 614                 dist = 2*M_PI - par + parApex;
 615               else
 616                 dist = parApex - par; // 0 < par < M_PI/2
 617             }
 618         }
 619       else //neg Apex == 3/2 PI
 620         {
 621           if(par <= parApex && par >= M_PI/2)
 622             dist = parApex - par;
 623           else
 624             {
 625               if(par >  parApex)
 626                 dist = par - parApex;
 627               else
 628                 dist = par + M_PI/2; // 0 < par < PI/2
 629             }
 630         }
 631     }
 632   return dist;
 633 }