// Copyright (c) 1991-1999 Matra Datavision // Copyright (c) 1999-2014 OPEN CASCADE SAS // // This file is part of Open CASCADE Technology software library. // // This library is free software; you can redistribute it and/or modify it under // the terms of the GNU Lesser General Public License version 2.1 as published // by the Free Software Foundation, with special exception defined in the file // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT // distribution for complete text of the license and disclaimer of any warranty. // // Alternatively, this file may be used under the terms of Open CASCADE // commercial license or contractual agreement. #ifndef _gp_Circ_HeaderFile #define _gp_Circ_HeaderFile #include #include #include #include #include #include //! Describes a circle in 3D space. //! A circle is defined by its radius and positioned in space //! with a coordinate system (a gp_Ax2 object) as follows: //! - the origin of the coordinate system is the center of the circle, and //! - the origin, "X Direction" and "Y Direction" of the //! coordinate system define the plane of the circle. //! This positioning coordinate system is the "local //! coordinate system" of the circle. Its "main Direction" //! gives the normal vector to the plane of the circle. The //! "main Axis" of the coordinate system is referred to as //! the "Axis" of the circle. //! Note: when a gp_Circ circle is converted into a //! Geom_Circle circle, some implicit properties of the //! circle are used explicitly: //! - the "main Direction" of the local coordinate system //! gives an implicit orientation to the circle (and defines //! its trigonometric sense), //! - this orientation corresponds to the direction in //! which parameter values increase, //! - the starting point for parameterization is that of the //! "X Axis" of the local coordinate system (i.e. the "X Axis" of the circle). //! See Also //! gce_MakeCirc which provides functions for more complex circle constructions //! Geom_Circle which provides additional functions for //! constructing circles and works, in particular, with the //! parametric equations of circles class gp_Circ { public: DEFINE_STANDARD_ALLOC //! Creates an indefinite circle. gp_Circ() : radius (RealLast()) {} //! A2 locates the circle and gives its orientation in 3D space. //! Warnings : //! It is not forbidden to create a circle with theRadius = 0.0 Raises ConstructionError if theRadius < 0.0 gp_Circ (const gp_Ax2& theA2, const Standard_Real theRadius) : pos (theA2), radius(theRadius) { Standard_ConstructionError_Raise_if (theRadius < 0.0, "gp_Circ() - radius should be positive number"); } //! Changes the main axis of the circle. It is the axis //! perpendicular to the plane of the circle. //! Raises ConstructionError if the direction of theA1 //! is parallel to the "XAxis" of the circle. void SetAxis (const gp_Ax1& theA1) { pos.SetAxis (theA1); } //! Changes the "Location" point (center) of the circle. void SetLocation (const gp_Pnt& theP) { pos.SetLocation (theP); } //! Changes the position of the circle. void SetPosition (const gp_Ax2& theA2) { pos = theA2; } //! Modifies the radius of this circle. //! Warning. This class does not prevent the creation of a circle where theRadius is null. //! Exceptions //! Standard_ConstructionError if theRadius is negative. void SetRadius (const Standard_Real theRadius) { Standard_ConstructionError_Raise_if (theRadius < 0.0, "gp_Circ::SetRadius() - radius should be positive number"); radius = theRadius; } //! Computes the area of the circle. Standard_Real Area() const { return M_PI * radius * radius; } //! Returns the main axis of the circle. //! It is the axis perpendicular to the plane of the circle, //! passing through the "Location" point (center) of the circle. const gp_Ax1& Axis() const { return pos.Axis(); } //! Computes the circumference of the circle. Standard_Real Length() const { return 2. * M_PI * radius; } //! Returns the center of the circle. It is the //! "Location" point of the local coordinate system //! of the circle const gp_Pnt& Location() const { return pos.Location(); } //! Returns the position of the circle. //! It is the local coordinate system of the circle. const gp_Ax2& Position() const { return pos; } //! Returns the radius of this circle. Standard_Real Radius() const { return radius; } //! Returns the "XAxis" of the circle. //! This axis is perpendicular to the axis of the conic. //! This axis and the "Yaxis" define the plane of the conic. gp_Ax1 XAxis() const { return gp_Ax1 (pos.Location(), pos.XDirection()); } //! Returns the "YAxis" of the circle. //! This axis and the "Xaxis" define the plane of the conic. //! The "YAxis" is perpendicular to the "Xaxis". gp_Ax1 YAxis() const { return gp_Ax1 (pos.Location(), pos.YDirection()); } //! Computes the minimum of distance between the point theP and //! any point on the circumference of the circle. Standard_Real Distance (const gp_Pnt& theP) const { return sqrt (SquareDistance (theP)); } //! Computes the square distance between and the point theP. Standard_Real SquareDistance (const gp_Pnt& theP) const { gp_Vec aV (Location(), theP); Standard_Real aX = aV.Dot (pos.XDirection()); Standard_Real anY = aV.Dot (pos.YDirection()); Standard_Real aZ = aV.Dot (pos.Direction()); Standard_Real aT = sqrt (aX * aX + anY * anY) - radius; return (aT * aT + aZ * aZ); } //! Returns True if the point theP is on the circumference. //! The distance between and must be lower or //! equal to theLinearTolerance. Standard_Boolean Contains (const gp_Pnt& theP, const Standard_Real theLinearTolerance) const { return Distance (theP) <= theLinearTolerance; } Standard_EXPORT void Mirror (const gp_Pnt& theP); //! Performs the symmetrical transformation of a circle //! with respect to the point theP which is the center of the //! symmetry. Standard_NODISCARD Standard_EXPORT gp_Circ Mirrored (const gp_Pnt& theP) const; Standard_EXPORT void Mirror (const gp_Ax1& theA1); //! Performs the symmetrical transformation of a circle with //! respect to an axis placement which is the axis of the //! symmetry. Standard_NODISCARD Standard_EXPORT gp_Circ Mirrored (const gp_Ax1& theA1) const; Standard_EXPORT void Mirror (const gp_Ax2& theA2); //! Performs the symmetrical transformation of a circle with respect //! to a plane. The axis placement theA2 locates the plane of the //! of the symmetry : (Location, XDirection, YDirection). Standard_NODISCARD Standard_EXPORT gp_Circ Mirrored (const gp_Ax2& theA2) const; void Rotate (const gp_Ax1& theA1, const Standard_Real theAng) { pos.Rotate (theA1, theAng); } //! Rotates a circle. theA1 is the axis of the rotation. //! theAng is the angular value of the rotation in radians. Standard_NODISCARD gp_Circ Rotated (const gp_Ax1& theA1, const Standard_Real theAng) const { gp_Circ aC = *this; aC.pos.Rotate (theA1, theAng); return aC; } void Scale (const gp_Pnt& theP, const Standard_Real theS); //! Scales a circle. theS is the scaling value. //! Warnings : //! If theS is negative the radius stay positive but //! the "XAxis" and the "YAxis" are reversed as for //! an ellipse. Standard_NODISCARD gp_Circ Scaled (const gp_Pnt& theP, const Standard_Real theS) const; void Transform (const gp_Trsf& theT); //! Transforms a circle with the transformation theT from class Trsf. Standard_NODISCARD gp_Circ Transformed (const gp_Trsf& theT) const; void Translate (const gp_Vec& theV) { pos.Translate (theV); } //! Translates a circle in the direction of the vector theV. //! The magnitude of the translation is the vector's magnitude. Standard_NODISCARD gp_Circ Translated (const gp_Vec& theV) const { gp_Circ aC = *this; aC.pos.Translate (theV); return aC; } void Translate (const gp_Pnt& theP1, const gp_Pnt& theP2) { pos.Translate (theP1, theP2); } //! Translates a circle from the point theP1 to the point theP2. Standard_NODISCARD gp_Circ Translated (const gp_Pnt& theP1, const gp_Pnt& theP2) const { gp_Circ aC = *this; aC.pos.Translate (theP1, theP2); return aC; } private: gp_Ax2 pos; Standard_Real radius; }; // ======================================================================= // function : Scale // purpose : // ======================================================================= inline void gp_Circ::Scale (const gp_Pnt& theP, const Standard_Real theS) { radius *= theS; if (radius < 0) { radius = -radius; } pos.Scale (theP, theS); } // ======================================================================= // function : Scaled // purpose : // ======================================================================= inline gp_Circ gp_Circ::Scaled (const gp_Pnt& theP, const Standard_Real theS) const { gp_Circ aC = *this; aC.radius *= theS; if (aC.radius < 0) { aC.radius = -aC.radius; } aC.pos.Scale (theP, theS); return aC; } // ======================================================================= // function : Transform // purpose : // ======================================================================= inline void gp_Circ::Transform (const gp_Trsf& theT) { radius *= theT.ScaleFactor(); if (radius < 0) { radius = -radius; } pos.Transform (theT); } // ======================================================================= // function : Transformed // purpose : // ======================================================================= inline gp_Circ gp_Circ::Transformed (const gp_Trsf& theT) const { gp_Circ aC = *this; aC.radius *= theT.ScaleFactor(); if (aC.radius < 0) { aC.radius = -aC.radius; } aC.pos.Transform (theT); return aC; } #endif // _gp_Circ_HeaderFile