1 // Created on: 2013-05-20
2 // Created by: Mikhail PONIKAROV
3 // Copyright (c) 2003-2014 OPEN CASCADE SAS
5 // This file is part of Open CASCADE Technology software library.
7 // This library is free software; you can redistribute it and / or modify it
8 // under the terms of the GNU Lesser General Public version 2.1 as published
9 // by the Free Software Foundation, with special exception defined in the file
10 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
11 // distribution for complete text of the license and disclaimer of any warranty.
13 // Alternatively, this file may be used under the terms of Open CASCADE
14 // commercial license or contractual agreement.
16 #ifndef _FILLETALGO_H_
17 #define _FILLETALGO_H_
19 #include <TopoDS_Edge.hxx>
20 #include <TopoDS_Wire.hxx>
22 #include <Geom2d_Curve.hxx>
23 #include <Geom_Plane.hxx>
24 #include <TColStd_ListOfReal.hxx>
25 #include <TColStd_SequenceOfReal.hxx>
26 #include <TColStd_SequenceOfInteger.hxx>
30 //! Algorithm that creates fillet edge: arc tangent to two edges in the start
31 //! and in the end vertices. Initial edges must be located on the plane and
32 //! must be connected by the end or start points (shared vertices are not
33 //! obligatory). Created fillet arc is created with the given radius, that is
34 //! useful in sketcher applications.
36 //! The algorithm is iterative that allows to create fillet on any curves
37 //! of initial edges, that supports projection of point and C2 continuous.
38 //! Principles of algorithm can de reduced to the Newton method:
39 //! 1. Splitting initial edge into N segments where probably only 1 root can be
40 //! found. N depends on the complexity of the underlying curve.
41 //! 2. On each segment compute value and derivative of the function:
42 //! - argument of the function is the parameter on the curve
43 //! - take point on the curve by the parameter: point of tangency
44 //! - make center of fillet: perpendicular vector from the point of tagency
45 //! - make projection from the center to the second curve
46 //! - length of the projection minus radius of the fillet is result of the
48 //! - derivative of this function in the point is computed by value in
49 //! point with small shift
50 //! 3. Using Newton search method take the point on the segment where function
51 //! value is most close to zero. If it is not enough close, step 2 and 3 are
52 //! repeated taking as start or end point the found point.
53 //! 4. If solution is found, result is created on point on root of the function
54 //! (as a start point), point of the projection onto second curve (as an end
55 //! point) and center of arc in found center. Initial edges are cutted by
56 //! the start and end point of tangency.
57 class ChFi2d_FilletAlgo
61 //! An empty constructor of the fillet algorithm.
62 //! Call a method Init() to initialize the algorithm
63 //! before calling of a Perform() method.
64 Standard_EXPORT ChFi2d_FilletAlgo();
66 //! A constructor of a fillet algorithm: accepts a wire consisting of two edges in a plane.
67 Standard_EXPORT ChFi2d_FilletAlgo(const TopoDS_Wire& theWire,
68 const gp_Pln& thePlane);
70 //! A constructor of a fillet algorithm: accepts two edges in a plane.
71 Standard_EXPORT ChFi2d_FilletAlgo(const TopoDS_Edge& theEdge1,
72 const TopoDS_Edge& theEdge2,
73 const gp_Pln& thePlane);
75 //! Initializes a fillet algorithm: accepts a wire consisting of two edges in a plane.
76 Standard_EXPORT void Init(const TopoDS_Wire& theWire,
77 const gp_Pln& thePlane);
79 //! Initializes a fillet algorithm: accepts two edges in a plane.
80 Standard_EXPORT void Init(const TopoDS_Edge& theEdge1,
81 const TopoDS_Edge& theEdge2,
82 const gp_Pln& thePlane);
84 //! Constructs a fillet edge.
85 //! Returns true, if at least one result was found
86 Standard_EXPORT Standard_Boolean Perform(const Standard_Real theRadius);
88 //! Returns number of possible solutions.
89 //! <thePoint> chooses a particular fillet in case of several fillets
90 //! may be constructed (for example, a circle intersecting a segment in 2 points).
91 //! Put the intersecting (or common) point of the edges.
92 Standard_EXPORT Standard_Integer NbResults(const gp_Pnt& thePoint);
94 //! Returns result (fillet edge, modified edge1, modified edge2),
95 //! neares to the given point <thePoint> if iSolution == -1.
96 //! <thePoint> chooses a particular fillet in case of several fillets
97 //! may be constructed (for example, a circle intersecting a segment in 2 points).
98 //! Put the intersecting (or common) point of the edges.
99 Standard_EXPORT TopoDS_Edge Result(const gp_Pnt& thePoint,
100 TopoDS_Edge& theEdge1, TopoDS_Edge& theEdge2,
101 const Standard_Integer iSolution = -1);
104 //! Computes the value the function in the current point.
105 //! <theLimit> is end parameter of the segment
106 void FillPoint(FilletPoint*, const Standard_Real theLimit);
107 //! Computes the derivative value of the function in the current point.
108 //! <theDiffStep> is small step for approximate derivative computation
109 //! <theFront> is direction of the step: from or reverced
110 void FillDiff(FilletPoint*, Standard_Real theDiffStep, Standard_Boolean theFront);
111 //! Using Newton methods computes optimal point, that can be root of the
112 //! function taking into account two input points, functions value and derivatives.
113 //! Performs iteration until root is found or failed to find root.
114 //! Stores roots in myResultParams.
115 void PerformNewton(FilletPoint*, FilletPoint*);
116 //! Splits segment by the parameter and calls Newton method for both segments.
117 //! It supplies recursive iterations of the Newthon methods calls
118 //! (PerformNewton calls this function and this calls Netwton two times).
119 Standard_Boolean ProcessPoint(FilletPoint*, FilletPoint*, Standard_Real);
121 //! Initial edges where the fillet must be computed.
122 TopoDS_Edge myEdge1, myEdge2;
123 //! Plane where fillet arc must be created.
124 Handle(Geom_Plane) myPlane;
125 //! Underlying curves of the initial edges
126 Handle(Geom2d_Curve) myCurve1, myCurve2;
127 //! Start and end parameters of curves of initial edges.
128 Standard_Real myStart1, myEnd1, myStart2, myEnd2, myRadius;
129 //! List of params where roots were found.
130 TColStd_ListOfReal myResultParams;
131 //! sequence of 0 or 1: position of the fillet relatively to the first curve
132 TColStd_SequenceOfInteger myResultOrientation;
133 //! position of the fillet relatively to the first curve
134 Standard_Boolean myStartSide;
135 //! are initial edges where exchanged in the beginning: to make first edge
136 //! more simple and minimize number of iterations
137 Standard_Boolean myEdgesExchnged;
138 //! Number to avoid infinity recursion: indicates how deep the recursion is performed.
139 Standard_Integer myDegreeOfRecursion;
142 //! Private class. Corresponds to the point on the first curve, computed
143 //! fillet function and derivative on it.
147 //! Creates a point on a first curve by parameter on this curve.
148 FilletPoint(Standard_Real theParam) : myParam2(0.)
149 {myParam = theParam;}
151 //! Changes the point position by changing point parameter on the first curve.
152 void setParam(Standard_Real theParam) {myParam = theParam;}
153 //! Returns the point parameter on the first curve.
154 Standard_Real getParam() const {return myParam;}
156 //! Returns number of found values of function in this point.
157 Standard_Integer getNBValues() {return myV.Length();}
158 //! Returns value of function in this point.
159 Standard_Real getValue(int theIndex) {return myV.Value(theIndex);}
160 //! Returns derivatives of function in this point.
161 Standard_Real getDiff(int theIndex) {return myD.Value(theIndex);}
162 //! Returns true if function is valid (rediuses vectors of fillet do not intersect any curve).
163 Standard_Boolean isValid(int theIndex) {return (Standard_Boolean)myValid.Value(theIndex);}
164 //! Returns the index of the nearest value
165 int getNear(int theIndex) {return myNear.Value(theIndex);}
167 //! Defines the parameter of the projected point on the second curve.
168 void setParam2(const Standard_Real theParam2) {myParam2 = theParam2;}
169 //! Returns the parameter of the projected point on the second curve.
170 Standard_Real getParam2() { return myParam2 ; }
172 //! Center of the fillet.
173 void setCenter(const gp_Pnt2d thePoint) {myCenter = thePoint;}
174 //! Center of the fillet.
175 const gp_Pnt2d getCenter() {return myCenter;}
177 //! Appends value of the function.
178 void appendValue(Standard_Real theValue, Standard_Boolean theValid);
180 //! Computes difference between this point and the given. Stores difference in myD.
181 Standard_Boolean calculateDiff(FilletPoint*);
182 //! Filters out the values and leaves the most optimal one.
183 void FilterPoints(FilletPoint*);
185 //! Returns a pointer to created copy of the point
186 //! warning: this is not the full copy! Copies only: myParam, myV, myD, myValid
188 //! Returns the index of the solution or zero if there is no solution
189 Standard_Integer hasSolution(Standard_Real theRadius);
191 Standard_Real LowerValue()
193 Standard_Integer a, aResultIndex = 0;
194 Standard_Real aValue;
195 for(a = myV.Length(); a > 0; a--)
197 if (aResultIndex == 0 || Abs(aValue) > Abs(myV.Value(a)))
200 aValue = myV.Value(a);
205 //! Removes the found value by the given index.
206 void remove(Standard_Integer theIndex);
209 //! Parameter on the first curve (start fillet point).
210 Standard_Real myParam;
211 //! Parameter on the second curve (end fillet point).
212 Standard_Real myParam2;
213 //! Values and derivative values of the fillet function.
214 //! May be several if there are many projections on the second curve.
215 TColStd_SequenceOfReal myV, myD;
216 //! Center of the fillet arc.
218 //! Flags for storage the validity of solutions. Indexes corresponds to indexes
219 //! in sequences myV, myD.
220 TColStd_SequenceOfInteger myValid, myNear;
223 #endif // _FILLETALGO_H_