1 // Created on: 1994-03-18
2 // Created by: Bruno DUMORTIER
3 // Copyright (c) 1994-1999 Matra Datavision
4 // Copyright (c) 1999-2014 OPEN CASCADE SAS
6 // This file is part of Open CASCADE Technology software library.
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.
14 // Alternatively, this file may be used under the terms of Open CASCADE
15 // commercial license or contractual agreement.
17 #ifndef _GeomAPI_ExtremaCurveCurve_HeaderFile
18 #define _GeomAPI_ExtremaCurveCurve_HeaderFile
20 #include <Standard.hxx>
21 #include <Standard_DefineAlloc.hxx>
22 #include <Standard_Handle.hxx>
24 #include <Standard_Integer.hxx>
25 #include <Extrema_ExtCC.hxx>
26 #include <GeomAdaptor_Curve.hxx>
31 //! Describes functions for computing all the extrema
32 //! between two 3D curves.
33 //! An ExtremaCurveCurve algorithm minimizes or
34 //! maximizes the distance between a point on the first
35 //! curve and a point on the second curve. Thus, it
36 //! computes start and end points of perpendiculars
37 //! common to the two curves (an intersection point is
38 //! not an extremum unless the two curves are tangential at this point).
39 //! Solutions consist of pairs of points, and an extremum
40 //! is considered to be a segment joining the two points of a solution.
41 //! An ExtremaCurveCurve object provides a framework for:
42 //! - defining the construction of the extrema,
43 //! - implementing the construction algorithm, and
44 //! - consulting the results.
46 //! In some cases, the nearest points between two
47 //! curves do not correspond to one of the computed
48 //! extrema. Instead, they may be given by:
49 //! - a limit point of one curve and one of the following:
50 //! - its orthogonal projection on the other curve,
51 //! - a limit point of the other curve; or
52 //! - an intersection point between the two curves.
53 class GeomAPI_ExtremaCurveCurve
60 //! Constructs an empty algorithm for computing
61 //! extrema between two curves. Use an Init function
62 //! to define the curves on which it is going to work.
63 Standard_EXPORT GeomAPI_ExtremaCurveCurve();
65 //! Computes the extrema between the curves C1 and C2.
66 Standard_EXPORT GeomAPI_ExtremaCurveCurve(const Handle(Geom_Curve)& C1, const Handle(Geom_Curve)& C2);
68 //! Computes the portion of the curve C1 limited by the two
69 //! points of parameter (U1min,U1max), and
70 //! - the portion of the curve C2 limited by the two
71 //! points of parameter (U2min,U2max).
73 //! Use the function NbExtrema to obtain the number
74 //! of solutions. If this algorithm fails, NbExtrema returns 0.
75 Standard_EXPORT GeomAPI_ExtremaCurveCurve(const Handle(Geom_Curve)& C1, const Handle(Geom_Curve)& C2, const Standard_Real U1min, const Standard_Real U1max, const Standard_Real U2min, const Standard_Real U2max);
77 //! Initializes this algorithm with the given arguments
78 //! and computes the extrema between the curves C1 and C2
79 Standard_EXPORT void Init (const Handle(Geom_Curve)& C1, const Handle(Geom_Curve)& C2);
81 //! Initializes this algorithm with the given arguments
82 //! and computes the extrema between :
83 //! - the portion of the curve C1 limited by the two
84 //! points of parameter (U1min,U1max), and
85 //! - the portion of the curve C2 limited by the two
86 //! points of parameter (U2min,U2max).
88 //! Use the function NbExtrema to obtain the number
89 //! of solutions. If this algorithm fails, NbExtrema returns 0.
90 Standard_EXPORT void Init (const Handle(Geom_Curve)& C1, const Handle(Geom_Curve)& C2, const Standard_Real U1min, const Standard_Real U1max, const Standard_Real U2min, const Standard_Real U2max);
92 //! Returns the number of extrema computed by this algorithm.
93 //! Note: if this algorithm fails, NbExtrema returns 0.
94 Standard_EXPORT Standard_Integer NbExtrema() const;
95 Standard_EXPORT operator Standard_Integer() const;
97 //! Returns the points P1 on the first curve and P2 on
98 //! the second curve, which are the ends of the
99 //! extremum of index Index computed by this algorithm.
101 //! Standard_OutOfRange if Index is not in the range [
102 //! 1,NbExtrema ], where NbExtrema is the
103 //! number of extrema computed by this algorithm.
104 Standard_EXPORT void Points (const Standard_Integer Index, gp_Pnt& P1, gp_Pnt& P2) const;
106 //! Returns the parameters U1 of the point on the first
107 //! curve and U2 of the point on the second curve, which
108 //! are the ends of the extremum of index Index computed by this algorithm.
110 //! Standard_OutOfRange if Index is not in the range [
111 //! 1,NbExtrema ], where NbExtrema is the
112 //! number of extrema computed by this algorithm.
113 Standard_EXPORT void Parameters (const Standard_Integer Index, Standard_Real& U1, Standard_Real& U2) const;
115 //! Computes the distance between the end points of the
116 //! extremum of index Index computed by this algorithm.
118 //! Standard_OutOfRange if Index is not in the range [
119 //! 1,NbExtrema ], where NbExtrema is the
120 //! number of extrema computed by this algorithm.
121 Standard_EXPORT Standard_Real Distance (const Standard_Integer Index) const;
123 //! Returns True if the two curves are parallel.
124 Standard_Boolean IsParallel() const
126 return myExtCC.IsParallel();
129 //! Returns the points P1 on the first curve and P2 on
130 //! the second curve, which are the ends of the shortest
131 //! extremum computed by this algorithm.
132 //! Exceptions StdFail_NotDone if this algorithm fails.
133 Standard_EXPORT void NearestPoints (gp_Pnt& P1, gp_Pnt& P2) const;
135 //! Returns the parameters U1 of the point on the first
136 //! curve and U2 of the point on the second curve, which
137 //! are the ends of the shortest extremum computed by this algorithm.
138 //! Exceptions StdFail_NotDone if this algorithm fails.
139 Standard_EXPORT void LowerDistanceParameters (Standard_Real& U1, Standard_Real& U2) const;
141 //! Computes the distance between the end points of the
142 //! shortest extremum computed by this algorithm.
143 //! Exceptions StdFail_NotDone if this algorithm fails.
144 Standard_EXPORT Standard_Real LowerDistance() const;
145 Standard_EXPORT operator Standard_Real() const;
147 //! return the algorithmic object from Extrema
148 const Extrema_ExtCC& Extrema() const;
150 //! set in <P1> and <P2> the couple solution points
151 //! such a the distance [P1,P2] is the minimum. taking in account
152 //! extremity points of curves.
153 Standard_EXPORT Standard_Boolean TotalNearestPoints (gp_Pnt& P1, gp_Pnt& P2);
155 //! set in <U1> and <U2> the parameters of the couple
156 //! solution points which represents the total nearest
158 Standard_EXPORT Standard_Boolean TotalLowerDistanceParameters (Standard_Real& U1, Standard_Real& U2);
160 //! return the distance of the total nearest couple solution
162 //! if <myExtCC> is not done
163 Standard_EXPORT Standard_Real TotalLowerDistance();
167 Standard_EXPORT void TotalPerform();
170 Standard_Boolean myIsDone;
171 Standard_Integer myIndex;
172 Extrema_ExtCC myExtCC;
173 GeomAdaptor_Curve myC1;
174 GeomAdaptor_Curve myC2;
175 Standard_Boolean myTotalExt;
176 Standard_Boolean myIsInfinite;
177 Standard_Real myTotalDist;
178 gp_Pnt myTotalPoints[2];
179 Standard_Real myTotalPars[2];
185 #include <GeomAPI_ExtremaCurveCurve.lxx>
191 #endif // _GeomAPI_ExtremaCurveCurve_HeaderFile