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Warning, file /include/opencascade/Geom2d_Ellipse.hxx was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).
0001 // Created on: 1993-03-24 0002 // Created by: JCV 0003 // Copyright (c) 1993-1999 Matra Datavision 0004 // Copyright (c) 1999-2014 OPEN CASCADE SAS 0005 // 0006 // This file is part of Open CASCADE Technology software library. 0007 // 0008 // This library is free software; you can redistribute it and/or modify it under 0009 // the terms of the GNU Lesser General Public License version 2.1 as published 0010 // by the Free Software Foundation, with special exception defined in the file 0011 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT 0012 // distribution for complete text of the license and disclaimer of any warranty. 0013 // 0014 // Alternatively, this file may be used under the terms of Open CASCADE 0015 // commercial license or contractual agreement. 0016 0017 #ifndef _Geom2d_Ellipse_HeaderFile 0018 #define _Geom2d_Ellipse_HeaderFile 0019 0020 #include <Standard.hxx> 0021 #include <Standard_Type.hxx> 0022 0023 #include <Geom2d_Conic.hxx> 0024 #include <Standard_Integer.hxx> 0025 class gp_Elips2d; 0026 class gp_Ax2d; 0027 class gp_Ax22d; 0028 class gp_Pnt2d; 0029 class gp_Vec2d; 0030 class gp_Trsf2d; 0031 class Geom2d_Geometry; 0032 0033 class Geom2d_Ellipse; 0034 DEFINE_STANDARD_HANDLE(Geom2d_Ellipse, Geom2d_Conic) 0035 0036 //! Describes an ellipse in the plane (2D space). 0037 //! An ellipse is defined by its major and minor radii and, 0038 //! as with any conic curve, is positioned in the plane 0039 //! with a coordinate system (gp_Ax22d object) where: 0040 //! - the origin is the center of the ellipse, 0041 //! - the "X Direction" defines the major axis, and 0042 //! - the "Y Direction" defines the minor axis. 0043 //! This coordinate system is the local coordinate system of the ellipse. 0044 //! The orientation (direct or indirect) of the local 0045 //! coordinate system gives an explicit orientation to the 0046 //! ellipse, determining the direction in which the 0047 //! parameter increases along the ellipse. 0048 //! The Geom2d_Ellipse ellipse is parameterized by an angle: 0049 //! P(U) = O + MajorRad*Cos(U)*XDir + MinorRad*Sin(U)*YDir 0050 //! where: 0051 //! - P is the point of parameter U, 0052 //! - O, XDir and YDir are respectively the origin, "X 0053 //! Direction" and "Y Direction" of its local coordinate system, 0054 //! - MajorRad and MinorRad are the major and 0055 //! minor radii of the ellipse. 0056 //! The "X Axis" of the local coordinate system therefore 0057 //! defines the origin of the parameter of the ellipse. 0058 //! An ellipse is a closed and periodic curve. The period 0059 //! is 2.*Pi and the parameter range is [ 0,2.*Pi [. 0060 //! See Also 0061 //! GCE2d_MakeEllipse which provides functions for 0062 //! more complex ellipse constructions 0063 //! gp_Ax22d 0064 //! gp_Elips2d for an equivalent, non-parameterized data structure 0065 class Geom2d_Ellipse : public Geom2d_Conic 0066 { 0067 0068 public: 0069 //! Creates an ellipse by conversion of the gp_Elips2d ellipse E. 0070 Standard_EXPORT Geom2d_Ellipse(const gp_Elips2d& E); 0071 0072 //! Creates an ellipse defined by its major and minor radii, 0073 //! MajorRadius and MinorRadius, and positioned 0074 //! in the plane by its major axis MajorAxis; the 0075 //! center of the ellipse is the origin of MajorAxis 0076 //! and the unit vector of MajorAxis is the "X 0077 //! Direction" of the local coordinate system of the 0078 //! ellipse; this coordinate system is direct if Sense 0079 //! is true (default value) or indirect if Sense is false. 0080 //! Warnings : 0081 //! It is not forbidden to create an ellipse with MajorRadius = 0082 //! MinorRadius. 0083 //! Exceptions 0084 //! Standard_ConstructionError if: 0085 //! - MajorRadius is less than MinorRadius, or 0086 //! - MinorRadius is less than 0. 0087 Standard_EXPORT Geom2d_Ellipse(const gp_Ax2d& MajorAxis, 0088 const Standard_Real MajorRadius, 0089 const Standard_Real MinorRadius, 0090 const Standard_Boolean Sense = Standard_True); 0091 0092 //! Creates an ellipse defined by its major and minor radii, 0093 //! MajorRadius and MinorRadius, where the 0094 //! coordinate system Axis locates the ellipse and 0095 //! defines its orientation in the plane such that: 0096 //! - the center of the ellipse is the origin of Axis, 0097 //! - the "X Direction" of Axis defines the major 0098 //! axis of the ellipse, 0099 //! - the "Y Direction" of Axis defines the minor 0100 //! axis of the ellipse, 0101 //! - the orientation of Axis (direct or indirect) 0102 //! gives the orientation of the ellipse. 0103 //! Warnings : 0104 //! It is not forbidden to create an ellipse with MajorRadius = 0105 //! MinorRadius. 0106 //! Exceptions 0107 //! Standard_ConstructionError if: 0108 //! - MajorRadius is less than MinorRadius, or 0109 //! - MinorRadius is less than 0. 0110 Standard_EXPORT Geom2d_Ellipse(const gp_Ax22d& Axis, 0111 const Standard_Real MajorRadius, 0112 const Standard_Real MinorRadius); 0113 0114 //! Converts the gp_Elips2d ellipse E into this ellipse. 0115 Standard_EXPORT void SetElips2d(const gp_Elips2d& E); 0116 0117 //! Assigns a value to the major radius of this ellipse. 0118 //! Exceptions 0119 //! Standard_ConstructionError if: 0120 //! - the major radius of this ellipse becomes less than 0121 //! the minor radius, or 0122 //! - MinorRadius is less than 0. 0123 Standard_EXPORT void SetMajorRadius(const Standard_Real MajorRadius); 0124 0125 //! Assigns a value to the minor radius of this ellipse. 0126 //! Exceptions 0127 //! Standard_ConstructionError if: 0128 //! - the major radius of this ellipse becomes less than 0129 //! the minor radius, or 0130 //! - MinorRadius is less than 0. 0131 Standard_EXPORT void SetMinorRadius(const Standard_Real MinorRadius); 0132 0133 //! Converts this ellipse into a gp_Elips2d ellipse. 0134 Standard_EXPORT gp_Elips2d Elips2d() const; 0135 0136 //! Computes the parameter on the reversed ellipse for 0137 //! the point of parameter U on this ellipse. 0138 //! For an ellipse, the returned value is: 2.*Pi - U. 0139 Standard_EXPORT Standard_Real ReversedParameter(const Standard_Real U) const Standard_OVERRIDE; 0140 0141 //! Computes the directrices of this ellipse. 0142 //! This directrix is the line normal to the XAxis of the ellipse 0143 //! in the local plane (Z = 0) at a distance d = MajorRadius / e 0144 //! from the center of the ellipse, where e is the eccentricity of 0145 //! the ellipse. 0146 //! This line is parallel to the "YAxis". The intersection point 0147 //! between directrix1 and the "XAxis" is the "Location" point 0148 //! of the directrix1. This point is on the positive side of 0149 //! the "XAxis". 0150 //! Raises ConstructionError if Eccentricity = 0.0. (The ellipse degenerates 0151 //! into a circle) 0152 Standard_EXPORT gp_Ax2d Directrix1() const; 0153 0154 //! This line is obtained by the symmetrical transformation 0155 //! of "Directrix1" with respect to the "YAxis" of the ellipse. 0156 //! Raises ConstructionError if Eccentricity = 0.0. (The ellipse degenerates into a 0157 //! circle). 0158 Standard_EXPORT gp_Ax2d Directrix2() const; 0159 0160 //! Returns the eccentricity of the ellipse between 0.0 and 1.0 0161 //! If f is the distance between the center of the ellipse and 0162 //! the Focus1 then the eccentricity e = f / MajorRadius. 0163 //! Returns 0 if MajorRadius = 0 0164 Standard_EXPORT Standard_Real Eccentricity() const Standard_OVERRIDE; 0165 0166 //! Computes the focal distance. The focal distance is the distance between the center 0167 //! and a focus of the ellipse. 0168 Standard_EXPORT Standard_Real Focal() const; 0169 0170 //! Returns the first focus of the ellipse. This focus is on the 0171 //! positive side of the "XAxis" of the ellipse. 0172 Standard_EXPORT gp_Pnt2d Focus1() const; 0173 0174 //! Returns the second focus of the ellipse. This focus is on 0175 //! the negative side of the "XAxis" of the ellipse. 0176 Standard_EXPORT gp_Pnt2d Focus2() const; 0177 0178 //! Returns the major radius of this ellipse. 0179 Standard_EXPORT Standard_Real MajorRadius() const; 0180 0181 //! Returns the minor radius of this ellipse. 0182 Standard_EXPORT Standard_Real MinorRadius() const; 0183 0184 //! Computes the parameter of this ellipse. This value is 0185 //! given by the formula p = (1 - e * e) * MajorRadius where e is the eccentricity 0186 //! of the ellipse. 0187 //! Returns 0 if MajorRadius = 0 0188 Standard_EXPORT Standard_Real Parameter() const; 0189 0190 //! Returns the value of the first parameter of this 0191 //! ellipse. This is 0.0, which gives the start point of this ellipse. 0192 //! The start point and end point of an ellipse are coincident. 0193 Standard_EXPORT Standard_Real FirstParameter() const Standard_OVERRIDE; 0194 0195 //! Returns the value of the last parameter of this 0196 //! ellipse. This is 2.*Pi, which gives the end point of this ellipse. 0197 //! The start point and end point of an ellipse are coincident. 0198 Standard_EXPORT Standard_Real LastParameter() const Standard_OVERRIDE; 0199 0200 //! return True. 0201 Standard_EXPORT Standard_Boolean IsClosed() const Standard_OVERRIDE; 0202 0203 //! return True. 0204 Standard_EXPORT Standard_Boolean IsPeriodic() const Standard_OVERRIDE; 0205 0206 //! Returns in P the point of parameter U. 0207 //! P = C + MajorRadius * Cos (U) * XDir + MinorRadius * Sin (U) * YDir 0208 //! where C is the center of the ellipse , XDir the direction of 0209 //! the "XAxis" and "YDir" the "YAxis" of the ellipse. 0210 Standard_EXPORT void D0(const Standard_Real U, gp_Pnt2d& P) const Standard_OVERRIDE; 0211 0212 Standard_EXPORT void D1(const Standard_Real U, gp_Pnt2d& P, gp_Vec2d& V1) const Standard_OVERRIDE; 0213 0214 //! Returns the point P of parameter U. The vectors V1 and V2 0215 //! are the first and second derivatives at this point. 0216 Standard_EXPORT void D2(const Standard_Real U, 0217 gp_Pnt2d& P, 0218 gp_Vec2d& V1, 0219 gp_Vec2d& V2) const Standard_OVERRIDE; 0220 0221 //! Returns the point P of parameter U, the first second and 0222 //! third derivatives V1 V2 and V3. 0223 Standard_EXPORT void D3(const Standard_Real U, 0224 gp_Pnt2d& P, 0225 gp_Vec2d& V1, 0226 gp_Vec2d& V2, 0227 gp_Vec2d& V3) const Standard_OVERRIDE; 0228 0229 //! For the point of parameter U of this ellipse, 0230 //! computes the vector corresponding to the Nth derivative. 0231 //! Exceptions Standard_RangeError if N is less than 1. 0232 Standard_EXPORT gp_Vec2d DN(const Standard_Real U, 0233 const Standard_Integer N) const Standard_OVERRIDE; 0234 0235 //! Applies the transformation T to this ellipse. 0236 Standard_EXPORT void Transform(const gp_Trsf2d& T) Standard_OVERRIDE; 0237 0238 //! Creates a new object which is a copy of this ellipse. 0239 Standard_EXPORT Handle(Geom2d_Geometry) Copy() const Standard_OVERRIDE; 0240 0241 //! Dumps the content of me into the stream 0242 Standard_EXPORT virtual void DumpJson(Standard_OStream& theOStream, 0243 Standard_Integer theDepth = -1) const Standard_OVERRIDE; 0244 0245 DEFINE_STANDARD_RTTIEXT(Geom2d_Ellipse, Geom2d_Conic) 0246 0247 protected: 0248 private: 0249 Standard_Real majorRadius; 0250 Standard_Real minorRadius; 0251 }; 0252 0253 #endif // _Geom2d_Ellipse_HeaderFile
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