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0001 // Created on: 1993-03-10 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 _Geom_Ellipse_HeaderFile 0018 #define _Geom_Ellipse_HeaderFile 0019 0020 #include <Standard.hxx> 0021 #include <Standard_Type.hxx> 0022 0023 #include <Geom_Conic.hxx> 0024 #include <Standard_Integer.hxx> 0025 class gp_Elips; 0026 class gp_Ax2; 0027 class gp_Ax1; 0028 class gp_Pnt; 0029 class gp_Vec; 0030 class gp_Trsf; 0031 class Geom_Geometry; 0032 0033 0034 class Geom_Ellipse; 0035 DEFINE_STANDARD_HANDLE(Geom_Ellipse, Geom_Conic) 0036 0037 //! Describes an ellipse in 3D space. 0038 //! An ellipse is defined by its major and minor radii and, 0039 //! as with any conic curve, is positioned in space with a 0040 //! right-handed coordinate system (gp_Ax2 object) where: 0041 //! - the origin is the center of the ellipse, 0042 //! - the "X Direction" defines the major axis, and 0043 //! - the "Y Direction" defines the minor axis. 0044 //! The origin, "X Direction" and "Y Direction" of this 0045 //! coordinate system define the plane of the ellipse. The 0046 //! coordinate system is the local coordinate system of the ellipse. 0047 //! The "main Direction" of this coordinate system is the 0048 //! vector normal to the plane of the ellipse. The axis, of 0049 //! which the origin and unit vector are respectively the 0050 //! origin and "main Direction" of the local coordinate 0051 //! system, is termed the "Axis" or "main Axis" of the ellipse. 0052 //! The "main Direction" of the local coordinate system 0053 //! gives an explicit orientation to the ellipse (definition of 0054 //! the trigonometric sense), determining the direction in 0055 //! which the parameter increases along the ellipse. 0056 //! The Geom_Ellipse ellipse is parameterized by an angle: 0057 //! P(U) = O + MajorRad*Cos(U)*XDir + MinorRad*Sin(U)*YDir 0058 //! where: 0059 //! - P is the point of parameter U, 0060 //! - O, XDir and YDir are respectively the origin, "X 0061 //! Direction" and "Y Direction" of its local coordinate system, 0062 //! - MajorRad and MinorRad are the major and minor radii of the ellipse. 0063 //! The "X Axis" of the local coordinate system therefore 0064 //! defines the origin of the parameter of the ellipse. 0065 //! An ellipse is a closed and periodic curve. The period 0066 //! is 2.*Pi and the parameter range is [ 0, 2.*Pi [. 0067 class Geom_Ellipse : public Geom_Conic 0068 { 0069 0070 public: 0071 0072 0073 //! Constructs an ellipse by conversion of the gp_Elips ellipse E. 0074 Standard_EXPORT Geom_Ellipse(const gp_Elips& E); 0075 0076 //! Constructs an ellipse 0077 //! defined by its major and minor radii, MajorRadius 0078 //! and MinorRadius, where A2 locates the ellipse 0079 //! and defines its orientation in 3D space such that: 0080 //! - the center of the ellipse is the origin of A2, 0081 //! - the "X Direction" of A2 defines the major axis 0082 //! of the ellipse, i.e. the major radius 0083 //! MajorRadius is measured along this axis, 0084 //! - the "Y Direction" of A2 defines the minor axis 0085 //! of the ellipse, i.e. the minor radius 0086 //! MinorRadius is measured along this axis, 0087 //! - A2 is the local coordinate system of the ellipse. 0088 //! Exceptions 0089 //! Standard_ConstructionError if: 0090 //! - MajorRadius is less than MinorRadius, or 0091 //! - MinorRadius is less than 0. 0092 //! Warning The Geom package does not prevent the 0093 //! construction of an ellipse where MajorRadius and 0094 //! MinorRadius are equal. 0095 Standard_EXPORT Geom_Ellipse(const gp_Ax2& A2, const Standard_Real MajorRadius, const Standard_Real MinorRadius); 0096 0097 //! Converts the gp_Elips ellipse E into this ellipse. 0098 Standard_EXPORT void SetElips (const gp_Elips& E); 0099 0100 //! Assigns a value to the major radius of this ellipse. 0101 //! ConstructionError raised if MajorRadius < MinorRadius. 0102 Standard_EXPORT void SetMajorRadius (const Standard_Real MajorRadius); 0103 0104 //! Assigns a value to the minor radius of this ellipse. 0105 //! ConstructionError raised if MajorRadius < MinorRadius or if MinorRadius < 0. 0106 Standard_EXPORT void SetMinorRadius (const Standard_Real MinorRadius); 0107 0108 0109 //! returns the non transient ellipse from gp with the same 0110 Standard_EXPORT gp_Elips Elips() const; 0111 0112 //! Computes the parameter on the reversed ellipse for 0113 //! the point of parameter U on this ellipse. 0114 //! For an ellipse, the returned value is: 2.*Pi - U. 0115 Standard_EXPORT Standard_Real ReversedParameter (const Standard_Real U) const Standard_OVERRIDE; 0116 0117 0118 //! This directrix is the line normal to the XAxis of the ellipse 0119 //! in the local plane (Z = 0) at a distance d = MajorRadius / e 0120 //! from the center of the ellipse, where e is the eccentricity of 0121 //! the ellipse. 0122 //! This line is parallel to the "YAxis". The intersection point 0123 //! between directrix1 and the "XAxis" is the "Location" point 0124 //! of the directrix1. This point is on the positive side of 0125 //! the "XAxis". 0126 //! Raised if Eccentricity = 0.0. (The ellipse degenerates 0127 //! into a circle) 0128 Standard_EXPORT gp_Ax1 Directrix1() const; 0129 0130 0131 //! This line is obtained by the symmetrical transformation 0132 //! of "Directrix1" with respect to the "YAxis" of the ellipse. 0133 //! 0134 //! Raised if Eccentricity = 0.0. (The ellipse degenerates into a 0135 //! circle). 0136 Standard_EXPORT gp_Ax1 Directrix2() const; 0137 0138 0139 //! Returns the eccentricity of the ellipse between 0.0 and 1.0 0140 //! If f is the distance between the center of the ellipse and 0141 //! the Focus1 then the eccentricity e = f / MajorRadius. 0142 //! Returns 0 if MajorRadius = 0 0143 Standard_EXPORT Standard_Real Eccentricity() const Standard_OVERRIDE; 0144 0145 0146 //! Computes the focal distance. It is the distance between the 0147 //! the two focus of the ellipse. 0148 Standard_EXPORT Standard_Real Focal() const; 0149 0150 0151 //! Returns the first focus of the ellipse. This focus is on the 0152 //! positive side of the "XAxis" of the ellipse. 0153 Standard_EXPORT gp_Pnt Focus1() const; 0154 0155 0156 //! Returns the second focus of the ellipse. This focus is on 0157 //! the negative side of the "XAxis" of the ellipse. 0158 Standard_EXPORT gp_Pnt Focus2() const; 0159 0160 //! Returns the major radius of this ellipse. 0161 Standard_EXPORT Standard_Real MajorRadius() const; 0162 0163 //! Returns the minor radius of this ellipse. 0164 Standard_EXPORT Standard_Real MinorRadius() const; 0165 0166 0167 //! Returns p = (1 - e * e) * MajorRadius where e is the eccentricity 0168 //! of the ellipse. 0169 //! Returns 0 if MajorRadius = 0 0170 Standard_EXPORT Standard_Real Parameter() const; 0171 0172 //! Returns the value of the first parameter of this 0173 //! ellipse. This is respectively: 0174 //! - 0.0, which gives the start point of this ellipse, or 0175 //! The start point and end point of an ellipse are coincident. 0176 Standard_EXPORT Standard_Real FirstParameter() const Standard_OVERRIDE; 0177 0178 //! Returns the value of the last parameter of this 0179 //! ellipse. This is respectively: 0180 //! - 2.*Pi, which gives the end point of this ellipse. 0181 //! The start point and end point of an ellipse are coincident. 0182 Standard_EXPORT Standard_Real LastParameter() const Standard_OVERRIDE; 0183 0184 //! return True. 0185 Standard_EXPORT Standard_Boolean IsClosed() const Standard_OVERRIDE; 0186 0187 //! return True. 0188 Standard_EXPORT Standard_Boolean IsPeriodic() const Standard_OVERRIDE; 0189 0190 //! Returns in P the point of parameter U. 0191 //! P = C + MajorRadius * Cos (U) * XDir + MinorRadius * Sin (U) * YDir 0192 //! where C is the center of the ellipse , XDir the direction of 0193 //! the "XAxis" and "YDir" the "YAxis" of the ellipse. 0194 Standard_EXPORT void D0 (const Standard_Real U, gp_Pnt& P) const Standard_OVERRIDE; 0195 0196 Standard_EXPORT void D1 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1) const Standard_OVERRIDE; 0197 0198 0199 //! Returns the point P of parameter U. The vectors V1 and V2 0200 //! are the first and second derivatives at this point. 0201 Standard_EXPORT void D2 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1, gp_Vec& V2) const Standard_OVERRIDE; 0202 0203 0204 //! Returns the point P of parameter U, the first second and 0205 //! third derivatives V1 V2 and V3. 0206 Standard_EXPORT void D3 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1, gp_Vec& V2, gp_Vec& V3) const Standard_OVERRIDE; 0207 0208 //! For the point of parameter U of this ellipse, computes 0209 //! the vector corresponding to the Nth derivative. 0210 //! Exceptions Standard_RangeError if N is less than 1. 0211 Standard_EXPORT gp_Vec DN (const Standard_Real U, const Standard_Integer N) const Standard_OVERRIDE; 0212 0213 //! Applies the transformation T to this ellipse. 0214 Standard_EXPORT void Transform (const gp_Trsf& T) Standard_OVERRIDE; 0215 0216 //! Creates a new object which is a copy of this ellipse. 0217 Standard_EXPORT Handle(Geom_Geometry) Copy() const Standard_OVERRIDE; 0218 0219 //! Dumps the content of me into the stream 0220 Standard_EXPORT virtual void DumpJson (Standard_OStream& theOStream, Standard_Integer theDepth = -1) const Standard_OVERRIDE; 0221 0222 0223 0224 0225 DEFINE_STANDARD_RTTIEXT(Geom_Ellipse,Geom_Conic) 0226 0227 protected: 0228 0229 0230 0231 0232 private: 0233 0234 0235 Standard_Real majorRadius; 0236 Standard_Real minorRadius; 0237 0238 0239 }; 0240 0241 0242 0243 0244 0245 0246 0247 #endif // _Geom_Ellipse_HeaderFile
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