|
||||
File indexing completed on 2025-01-18 10:03:36
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_Parabola_HeaderFile 0018 #define _Geom_Parabola_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_Parab; 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_Parabola; 0035 DEFINE_STANDARD_HANDLE(Geom_Parabola, Geom_Conic) 0036 0037 //! Describes a parabola in 3D space. 0038 //! A parabola is defined by its focal length (i.e. the 0039 //! distance between its focus and its apex) and is 0040 //! positioned in space with a coordinate system 0041 //! (gp_Ax2 object) where: 0042 //! - the origin is the apex of the parabola, 0043 //! - the "X Axis" defines the axis of symmetry; the 0044 //! parabola is on the positive side of this axis, 0045 //! - the origin, "X Direction" and "Y Direction" define the 0046 //! plane of the parabola. 0047 //! This coordinate system is the local coordinate 0048 //! system of the parabola. 0049 //! The "main Direction" of this coordinate system is a 0050 //! vector normal to the plane of the parabola. The axis, 0051 //! of which the origin and unit vector are respectively the 0052 //! origin and "main Direction" of the local coordinate 0053 //! system, is termed the "Axis" or "main Axis" of the parabola. 0054 //! The "main Direction" of the local coordinate system 0055 //! gives an explicit orientation to the parabola, 0056 //! determining the direction in which the parameter 0057 //! increases along the parabola. 0058 //! The Geom_Parabola parabola is parameterized as follows: 0059 //! P(U) = O + U*U/(4.*F)*XDir + U*YDir 0060 //! where: 0061 //! - P is the point of parameter U, 0062 //! - O, XDir and YDir are respectively the origin, "X 0063 //! Direction" and "Y Direction" of its local coordinate system, 0064 //! - F is the focal length of the parabola. 0065 //! The parameter of the parabola is therefore its Y 0066 //! coordinate in the local coordinate system, with the "X 0067 //! Axis" of the local coordinate system defining the origin 0068 //! of the parameter. 0069 //! The parameter range is ] -infinite, +infinite [. 0070 class Geom_Parabola : public Geom_Conic 0071 { 0072 0073 public: 0074 0075 0076 //! Creates a parabola from a non transient one. 0077 Standard_EXPORT Geom_Parabola(const gp_Parab& Prb); 0078 0079 0080 //! Creates a parabola with its local coordinate system "A2" 0081 //! and it's focal length "Focal". 0082 //! The XDirection of A2 defines the axis of symmetry of the 0083 //! parabola. The YDirection of A2 is parallel to the directrix 0084 //! of the parabola. The Location point of A2 is the vertex of 0085 //! the parabola 0086 //! Raised if Focal < 0.0 0087 Standard_EXPORT Geom_Parabola(const gp_Ax2& A2, const Standard_Real Focal); 0088 0089 0090 //! D is the directrix of the parabola and F the focus point. 0091 //! The symmetry axis (XAxis) of the parabola is normal to the 0092 //! directrix and pass through the focus point F, but its 0093 //! location point is the vertex of the parabola. 0094 //! The YAxis of the parabola is parallel to D and its location 0095 //! point is the vertex of the parabola. The normal to the plane 0096 //! of the parabola is the cross product between the XAxis and the 0097 //! YAxis. 0098 Standard_EXPORT Geom_Parabola(const gp_Ax1& D, const gp_Pnt& F); 0099 0100 //! Assigns the value Focal to the focal distance of this parabola. 0101 //! Exceptions Standard_ConstructionError if Focal is negative. 0102 Standard_EXPORT void SetFocal (const Standard_Real Focal); 0103 0104 //! Converts the gp_Parab parabola Prb into this parabola. 0105 Standard_EXPORT void SetParab (const gp_Parab& Prb); 0106 0107 0108 //! Returns the non transient parabola from gp with the same 0109 //! geometric properties as <me>. 0110 Standard_EXPORT gp_Parab Parab() const; 0111 0112 //! Computes the parameter on the reversed parabola, 0113 //! for the point of parameter U on this parabola. 0114 //! For a parabola, the returned value is: -U. 0115 Standard_EXPORT Standard_Real ReversedParameter (const Standard_Real U) const Standard_OVERRIDE; 0116 0117 //! Returns the value of the first or last parameter of this 0118 //! parabola. This is, respectively: 0119 //! - Standard_Real::RealFirst(), or 0120 //! - Standard_Real::RealLast(). 0121 Standard_EXPORT Standard_Real FirstParameter() const Standard_OVERRIDE; 0122 0123 //! Returns the value of the first or last parameter of this 0124 //! parabola. This is, respectively: 0125 //! - Standard_Real::RealFirst(), or 0126 //! - Standard_Real::RealLast(). 0127 Standard_EXPORT Standard_Real LastParameter() const Standard_OVERRIDE; 0128 0129 //! Returns False 0130 Standard_EXPORT Standard_Boolean IsClosed() const Standard_OVERRIDE; 0131 0132 //! Returns False 0133 Standard_EXPORT Standard_Boolean IsPeriodic() const Standard_OVERRIDE; 0134 0135 //! Computes the directrix of this parabola. 0136 //! This is a line normal to the axis of symmetry, in the 0137 //! plane of this parabola, located on the negative side 0138 //! of its axis of symmetry, at a distance from the apex 0139 //! equal to the focal length. 0140 //! The directrix is returned as an axis (gp_Ax1 object), 0141 //! where the origin is located on the "X Axis" of this parabola. 0142 Standard_EXPORT gp_Ax1 Directrix() const; 0143 0144 //! Returns 1. (which is the eccentricity of any parabola). 0145 Standard_EXPORT Standard_Real Eccentricity() const Standard_OVERRIDE; 0146 0147 //! Computes the focus of this parabola. The focus is on the 0148 //! positive side of the "X Axis" of the local coordinate 0149 //! system of the parabola. 0150 Standard_EXPORT gp_Pnt Focus() const; 0151 0152 //! Computes the focal distance of this parabola 0153 //! The focal distance is the distance between the apex 0154 //! and the focus of the parabola. 0155 Standard_EXPORT Standard_Real Focal() const; 0156 0157 //! Computes the parameter of this parabola which is the 0158 //! distance between its focus and its directrix. This 0159 //! distance is twice the focal length. 0160 //! If P is the parameter of the parabola, the equation of 0161 //! the parabola in its local coordinate system is: Y**2 = 2.*P*X. 0162 Standard_EXPORT Standard_Real Parameter() const; 0163 0164 //! Returns in P the point of parameter U. 0165 //! If U = 0 the returned point is the origin of the XAxis and 0166 //! the YAxis of the parabola and it is the vertex of the parabola. 0167 //! P = S + F * (U * U * XDir + * U * YDir) 0168 //! where S is the vertex of the parabola, XDir the XDirection and 0169 //! YDir the YDirection of the parabola's local coordinate system. 0170 Standard_EXPORT void D0 (const Standard_Real U, gp_Pnt& P) const Standard_OVERRIDE; 0171 0172 0173 //! Returns the point P of parameter U and the first derivative V1. 0174 Standard_EXPORT void D1 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1) const Standard_OVERRIDE; 0175 0176 0177 //! Returns the point P of parameter U, the first and second 0178 //! derivatives V1 and V2. 0179 Standard_EXPORT void D2 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1, gp_Vec& V2) const Standard_OVERRIDE; 0180 0181 0182 //! Returns the point P of parameter U, the first second and third 0183 //! derivatives V1 V2 and V3. 0184 Standard_EXPORT void D3 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1, gp_Vec& V2, gp_Vec& V3) const Standard_OVERRIDE; 0185 0186 //! For the point of parameter U of this parabola, 0187 //! computes the vector corresponding to the Nth derivative. 0188 //! Exceptions Standard_RangeError if N is less than 1. 0189 Standard_EXPORT gp_Vec DN (const Standard_Real U, const Standard_Integer N) const Standard_OVERRIDE; 0190 0191 //! Applies the transformation T to this parabola. 0192 Standard_EXPORT void Transform (const gp_Trsf& T) Standard_OVERRIDE; 0193 0194 //! Returns the parameter on the transformed curve for 0195 //! the transform of the point of parameter U on <me>. 0196 //! 0197 //! me->Transformed(T)->Value(me->TransformedParameter(U,T)) 0198 //! 0199 //! is the same point as 0200 //! 0201 //! me->Value(U).Transformed(T) 0202 //! 0203 //! This methods returns <U> * T.ScaleFactor() 0204 Standard_EXPORT Standard_Real TransformedParameter (const Standard_Real U, const gp_Trsf& T) const Standard_OVERRIDE; 0205 0206 //! Returns a coefficient to compute the parameter on 0207 //! the transformed curve for the transform of the 0208 //! point on <me>. 0209 //! 0210 //! Transformed(T)->Value(U * ParametricTransformation(T)) 0211 //! 0212 //! is the same point as 0213 //! 0214 //! Value(U).Transformed(T) 0215 //! 0216 //! This methods returns T.ScaleFactor() 0217 Standard_EXPORT Standard_Real ParametricTransformation (const gp_Trsf& T) const Standard_OVERRIDE; 0218 0219 //! Creates a new object which is a copy of this parabola. 0220 Standard_EXPORT Handle(Geom_Geometry) Copy() const Standard_OVERRIDE; 0221 0222 //! Dumps the content of me into the stream 0223 Standard_EXPORT virtual void DumpJson (Standard_OStream& theOStream, Standard_Integer theDepth = -1) const Standard_OVERRIDE; 0224 0225 0226 0227 0228 DEFINE_STANDARD_RTTIEXT(Geom_Parabola,Geom_Conic) 0229 0230 protected: 0231 0232 0233 0234 0235 private: 0236 0237 0238 Standard_Real focalLength; 0239 0240 0241 }; 0242 0243 0244 0245 0246 0247 0248 0249 #endif // _Geom_Parabola_HeaderFile
[ Source navigation ] | [ Diff markup ] | [ Identifier search ] | [ general search ] |
This page was automatically generated by the 2.3.7 LXR engine. The LXR team |