Rhino C++ API  6.17
Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
ON_Curve Class Referenceabstract

#include <opennurbs_curve.h>

Inheritance diagram for ON_Curve:
ON_Geometry ON_Object ON_ArcCurve ON_CurveOnSurface ON_CurveProxy ON_LineCurve ON_NurbsCurve ON_PolyCurve ON_PolylineCurve CRhinoPolyEdgeSegment ON_BrepEdge ON_BrepTrim ON_HLDCurve ON_PolyEdgeSegment CRhinoPolyEdge ON_PolyEdgeCurve

Public Member Functions

 ON_Curve () ON_NOEXCEPT
 
 ON_Curve (const ON_Curve &)
 
virtual ~ON_Curve ()
 
bool AreaMassProperties (ON_3dPoint base_point, ON_3dVector plane_normal, ON_MassProperties &mp, bool bArea=true, bool bFirstMoments=true, bool bSecondMoments=true, bool bProductMoments=true, double rel_tol=1.0e-6, double abs_tol=1.0e-6) const
 
bool ChangeClosedCurveSeam (double t, double min_dist)
 
virtual bool ChangeClosedCurveSeam (double t)
 
virtual bool ChangeDimension (int desired_dimension)
 
virtual class ON_CurveTreeCreateCurveTree () const
 
ON_3dVector CurvatureAt (double t) const
 
const class ON_CurveTreeCurveTree () const
 
virtual int Degree () const =0
 
ON_3dVector DerivativeAt (double t) const
 
void DestroyCurveTree ()
 
void DestroyRuntimeCache (bool bDelete=true) override
 virtual ON_Object::DestroyRuntimeCache override More...
 
virtual ON_Interval Domain () const =0
 
virtual ON_CurveDuplicateCurve () const
 
bool Ev1Der (double t, ON_3dPoint &point, ON_3dVector &first_derivative, int side=0, int *hint=0) const
 
bool Ev2Der (double t, ON_3dPoint &point, ON_3dVector &first_derivative, ON_3dVector &second_derivative, int side=0, int *hint=0) const
 
virtual bool Evaluate (double t, int der_count, int v_stride, double *v, int side=0, int *hint=0) const =0
 
bool EvaluatePoint (const class ON_ObjRef &objref, ON_3dPoint &P) const override
 virtual ON_Geometry override More...
 
bool EvCurvature (double t, ON_3dPoint &point, ON_3dVector &tangent, ON_3dVector &kappa, int side=0, int *hint=0) const
 
bool EvPoint (double t, ON_3dPoint &point, int side=0, int *hint=0) const
 
bool EvTangent (double t, ON_3dPoint &point, ON_3dVector &tangent, int side=0, int *hint=0) const
 
virtual bool Extend (const ON_Interval &domain)
 
bool FirstSpanIsLinear (double min_length, double tolerance) const
 
bool FirstSpanIsLinear (double min_length, double tolerance, ON_Line *span_line) const
 
bool FrameAt (double t, ON_Plane &plane) const
 
virtual bool GetClosestPoint (const ON_3dPoint &, double *t, double maximum_distance=0.0, const ON_Interval *sub_domain=nullptr) const
 
virtual bool GetCurveParameterFromNurbFormParameter (double nurbs_t, double *curve_t) const
 
bool GetDomain (double *t0, double *t1) const
 curve interface More...
 
virtual bool GetLength (double *length, double fractional_tolerance=1.0e-8, const ON_Interval *sub_domain=nullptr) const
 
virtual bool GetLocalClosestPoint (const ON_3dPoint &test_point, double seed_parameter, double *t, const ON_Interval *sub_domain=0) const
 
virtual bool GetNextDiscontinuity (ON::continuity c, double t0, double t1, double *t, int *hint=nullptr, int *dtype=nullptr, double cos_angle_tolerance=ON_DEFAULT_ANGLE_TOLERANCE_COSINE, double curvature_tolerance=ON_SQRT_EPSILON) const
 
virtual bool GetNormalizedArcLengthPoint (double s, double *t, double fractional_tolerance=1.0e-8, const ON_Interval *sub_domain=nullptr) const
 
virtual bool GetNormalizedArcLengthPoints (int count, const double *s, double *t, double absolute_tolerance=0.0, double fractional_tolerance=1.0e-8, const ON_Interval *sub_domain=nullptr) const
 
virtual int GetNurbForm (ON_NurbsCurve &nurbs_curve, double tolerance=0.0, const ON_Interval *subdomain=nullptr) const
 
virtual bool GetNurbFormParameterFromCurveParameter (double curve_t, double *nurbs_t) const
 
virtual bool GetParameterTolerance (double t, double *tminus, double *tplus) const
 
virtual bool GetSpanVector (double *knots) const =0
 
virtual bool GetSpanVectorIndex (double t, int side, int *span_vector_index, ON_Interval *span_domain) const
 
bool GetTightBoundingBox (class ON_BoundingBox &tight_bbox, bool bGrowBox=false, const class ON_Xform *xform=nullptr) const override
 virtual ON_Geometry GetTightBoundingBox override More...
 
virtual int HasNurbForm () const
 
int IntersectCurve (const ON_Curve *curveB, ON_SimpleArray< ON_X_EVENT > &x, double intersection_tolerance=0.0, double overlap_tolerance=0.0, const ON_Interval *curveA_domain=0, const ON_Interval *curveB_domain=0) const
 
int IntersectPlane (ON_PlaneEquation plane_equation, ON_SimpleArray< ON_X_EVENT > &x, double intersection_tolerance=0.0, double overlap_tolerance=0.0, const ON_Interval *curve_domain=0) const
 
virtual int IntersectSelf (ON_SimpleArray< ON_X_EVENT > &x, double intersection_tolerance=0.0, const ON_Interval *curve_domain=0) const
 
int IntersectSurface (const ON_Surface *surfaceB, ON_SimpleArray< ON_X_EVENT > &x, double intersection_tolerance=0.0, double overlap_tolerance=0.0, const ON_Interval *curveA_domain=0, const ON_Interval *surfaceB_udomain=0, const ON_Interval *surfaceB_vdomain=0) const
 
virtual bool IsArc (const ON_Plane *plane=nullptr, ON_Arc *arc=nullptr, double tolerance=ON_ZERO_TOLERANCE) const
 
bool IsArcAt (double t, const ON_Plane *plane=0, ON_Arc *arc=0, double tolerance=ON_ZERO_TOLERANCE, double *t0=0, double *t1=0) const
 
bool IsClosable (double tolerance, double min_abs_size=0.0, double min_rel_size=10.0) const
 
virtual bool IsClosed () const
 
virtual bool IsContinuous (ON::continuity c, double t, int *hint=nullptr, double point_tolerance=ON_ZERO_TOLERANCE, double d1_tolerance=ON_ZERO_TOLERANCE, double d2_tolerance=ON_ZERO_TOLERANCE, double cos_angle_tolerance=ON_DEFAULT_ANGLE_TOLERANCE_COSINE, double curvature_tolerance=ON_SQRT_EPSILON) const
 
virtual bool IsEllipse (const ON_Plane *plane=nullptr, ON_Ellipse *ellipse=nullptr, double tolerance=ON_ZERO_TOLERANCE) const
 
virtual bool IsInPlane (const ON_Plane &test_plane, double tolerance=ON_ZERO_TOLERANCE) const =0
 
virtual bool IsLinear (double tolerance=ON_ZERO_TOLERANCE) const
 
virtual bool IsPeriodic () const
 
virtual bool IsPlanar (ON_Plane *plane=nullptr, double tolerance=ON_ZERO_TOLERANCE) const
 
virtual int IsPolyline (ON_SimpleArray< ON_3dPoint > *pline_points=nullptr, ON_SimpleArray< double > *pline_t=nullptr) const
 
virtual bool IsShort (double tolerance, const ON_Interval *sub_domain=0, double *length_estimate=0) const
 
bool LastSpanIsLinear (double min_length, double tolerance) const
 
bool LastSpanIsLinear (double min_length, double tolerance, ON_Line *span_line) const
 
bool LengthMassProperties (class ON_MassProperties &mp, bool bLength=true, bool bFirstMoments=true, bool bSecondMoments=true, bool bProductMoments=true, double rel_tol=1.0e-6, double abs_tol=1.0e-6) const
 
class ON_PolylineCurveMeshCurve (ON_MeshCurveParameters &mp, ON_PolylineCurve *polyline, bool bSkipFirstPoint, const ON_Interval *domain) const
 
ON_NurbsCurveNurbsCurve (ON_NurbsCurve *pNurbsCurve=nullptr, double tolerance=0.0, const ON_Interval *subdomain=nullptr) const
 
ON::object_type ObjectType () const override
 
ON_Curveoperator= (const ON_Curve &)
 
ON_3dPoint PointAt (double t) const
 
ON_3dPoint PointAtEnd () const
 
ON_3dPoint PointAtStart () const
 
virtual bool RemoveShortSegments (double tolerance, bool bRemoveShortSegments=true)
 
virtual bool Reverse ()=0
 
bool SetDomain (ON_Interval domain)
 
virtual bool SetDomain (double t0, double t1)
 
virtual bool SetEndPoint (ON_3dPoint end_point)
 
virtual bool SetStartPoint (ON_3dPoint start_point)
 
unsigned int SizeOf () const override
 virtual ON_Object::SizeOf override More...
 
virtual int SpanCount () const =0
 
virtual bool Split (double t, ON_Curve *&left_side, ON_Curve *&right_side) const
 
ON_3dVector TangentAt (double t) const
 
bool Transform (const ON_Xform &xform) override
 
virtual bool Trim (const ON_Interval &domain)
 
- Public Member Functions inherited from ON_Geometry
 ON_Geometry ()=default
 
 ON_Geometry (const ON_Geometry &)=default
 
 ~ON_Geometry ()=default
 
ON_BoundingBox BoundingBox () const
 
virtual class ON_BrepBrepForm (class ON_Brep *brep=nullptr) const
 
virtual void ClearBoundingBox ()
 
virtual ON_COMPONENT_INDEX ComponentIndex () const
 
virtual int Dimension () const
 
virtual bool GetBBox (double *boxmin, double *boxmax, bool bGrowBox=false) const
 
bool GetBoundingBox (ON_BoundingBox &bbox, bool bGrowBox=false) const
 
bool GetBoundingBox (ON_3dPoint &bbox_min, ON_3dPoint &bbox_max, bool bGrowBox=false) const
 
virtual bool HasBrepForm () const
 
virtual bool IsDeformable () const
 
virtual bool IsMorphable () const
 
bool IsValid (class ON_TextLog *text_log=nullptr) const override
 
virtual bool MakeDeformable ()
 
virtual bool Morph (const class ON_SpaceMorph &morph)
 
ON_Geometryoperator= (const ON_Geometry &)=default
 
bool Rotate (double sin_angle, double cos_angle, const ON_3dVector &rotation_axis, const ON_3dPoint &rotation_center)
 
bool Rotate (double rotation_angle, const ON_3dVector &rotation_axis, const ON_3dPoint &rotation_center)
 
bool Scale (double scale_factor)
 
virtual bool SwapCoordinates (int i, int j)
 
bool Translate (const ON_3dVector &translation_vector)
 
- Public Member Functions inherited from ON_Object
 ON_Object () ON_NOEXCEPT
 
 ON_Object (const ON_Object &)
 
virtual ~ON_Object ()
 
virtual ON_AggregateComponentStatus AggregateComponentStatus () const
 
bool AttachUserData (class ON_UserData *pUserData)
 
unsigned int ClearAllComponentStates () const
 
virtual unsigned int ClearComponentStates (ON_ComponentStatus states_to_clear) const
 
virtual unsigned int ClearComponentStates (ON_COMPONENT_INDEX component_index, ON_ComponentStatus states_to_clear) const
 
unsigned int CopyUserData (const ON_Object &source_object, ON_UUID source_userdata_item_id, ON_Object::UserDataConflictResolution userdata_conflict_resolution)
 
void CopyUserData (const ON_Object &source_object)
 
virtual ON__UINT32 DataCRC (ON__UINT32 current_remainder) const
 
virtual bool DeleteComponents (const ON_COMPONENT_INDEX *ci_list, size_t ci_count)
 
bool DetachUserData (class ON_UserData *pUserData)
 
virtual void Dump (ON_TextLog &) const
 
void EmergencyDestroy ()
 
class ON_UserDataFirstUserData () const
 
virtual unsigned int GetComponentsWithSetStates (ON_ComponentStatus states_filter, bool bAllEqualStates, ON_SimpleArray< ON_COMPONENT_INDEX > &components) const
 
class ON_UserDataGetUserData (const ON_UUID &userdata_uuid) const
 
bool GetUserString (const wchar_t *key, ON_wString &string_value) const
 
int GetUserStringKeys (ON_ClassArray< ON_wString > &user_string_keys) const
 
int GetUserStrings (ON_ClassArray< ON_UserString > &user_strings) const
 
bool IsCorrupt (bool bRepair, bool bSilentError, class ON_TextLog *text_log) const
 
bool IsKindOf (const ON_ClassId *pClassId) const
 
virtual void MarkAggregateComponentStatusAsNotCurrent () const
 
virtual void MemoryRelocate ()
 
virtual ON_UUID ModelObjectId () const
 
unsigned int MoveUserData (ON_Object &source_object, ON_UUID source_userdata_item_id, ON_Object::UserDataConflictResolution userdata_conflict_resolution, bool bDeleteAllSourceItems)
 
void MoveUserData (ON_Object &source_object)
 
ON_Objectoperator= (const ON_Object &)
 
void PurgeUserData ()
 
virtual bool Read (ON_BinaryArchive &binary_archive)
 
virtual unsigned int SetComponentStates (ON_COMPONENT_INDEX component_index, ON_ComponentStatus states_to_set) const
 
virtual unsigned int SetComponentStatus (ON_COMPONENT_INDEX component_index, ON_ComponentStatus status_to_copy) const
 
bool SetUserString (const wchar_t *key, const wchar_t *string_value)
 
int SetUserStrings (int count, const ON_UserString *user_strings, bool bReplace)
 
bool ThisIsNullptr (bool bSilentError) const
 
void TransformUserData (const class ON_Xform &xform)
 
virtual bool UpdateReferencedComponents (const class ON_ComponentManifest &source_manifest, const class ON_ComponentManifest &destination_manifest, const class ON_ManifestMap &manifest_map)
 
int UserStringCount () const
 
virtual bool Write (ON_BinaryArchive &binary_archive) const
 

Static Public Member Functions

static class ON_NurbsCurveCreateCubicLoft (int point_count, int point_dim, int point_stride, const double *point_list, double k, int is_closed=0, ON::cubic_loft_end_condition start_shape=ON::cubic_loft_ec_quadratic, ON::cubic_loft_end_condition end_shape=ON::cubic_loft_ec_quadratic, class ON_NurbsCurve *nurbs_curve=0)
 

Protected Member Functions

bool ParameterSearch (double t, int &index, bool bEnableSnap, const ON_SimpleArray< double > &m_t, double RelTol=ON_SQRT_EPSILON) const
 

Additional Inherited Members

- Public Types inherited from ON_Object
enum  UserDataConflictResolution : unsigned char {
  UserDataConflictResolution::destination_object = 0, UserDataConflictResolution::source_object = 1, UserDataConflictResolution::source_copycount_gt = 2, UserDataConflictResolution::source_copycount_ge = 3,
  UserDataConflictResolution::destination_copycount_gt = 4, UserDataConflictResolution::destination_copycount_ge = 5, UserDataConflictResolution::delete_item = 6
}
 
- Static Public Attributes inherited from ON_Geometry
static const ON_Geometry Unset
 

Detailed Description

Description: ON_Curve is a pure virtual class for curve objects

Constructor & Destructor Documentation

◆ ON_Curve() [1/2]

ON_Curve::ON_Curve ( )

◆ ~ON_Curve()

virtual ON_Curve::~ON_Curve ( )
virtual

◆ ON_Curve() [2/2]

ON_Curve::ON_Curve ( const ON_Curve )

Member Function Documentation

◆ AreaMassProperties()

bool ON_Curve::AreaMassProperties ( ON_3dPoint  base_point,
ON_3dVector  plane_normal,
ON_MassProperties mp,
bool  bArea = true,
bool  bFirstMoments = true,
bool  bSecondMoments = true,
bool  bProductMoments = true,
double  rel_tol = 1.0e-6,
double  abs_tol = 1.0e-6 
) const

Description: Calculate area mass properties of a curve. The curve should be planar. Parameters: base_point - [in] A point on the plane that contians the curve. To get the best results, the point should be in the near the curve's centroid.

When computing the area, area centroid, or area first moments of a planar area whose boundary is defined by several curves, pass the same base_point and plane_normal to each call to AreaMassProperties. The base_point must be in the plane of the curves.

When computing the area second moments or area product moments of a planar area whose boundary is defined by several curves, you MUST pass the entire area's centroid as the base_point and the input mp parameter must contain the results of a previous call to AreaMassProperties(mp,true,true,false,false,base_point). In particular, in this case, you need to make two sets of calls; use first set to calculate the area centroid and the second set calculate the second moments and product moments. plane_normal - [in] nonzero unit normal to the plane of integration. If a closed curve has counter clock-wise orientation with respect to this normal, the area will be positive. If the a closed curve has clock-wise orientation with respect to this normal, the area will be negative. mp - [out] bArea - [in] true to calculate volume bFirstMoments - [in] true to calculate area first moments, area, and area centroid. bSecondMoments - [in] true to calculate area second moments. bProductMoments - [in] true to calculate area product moments. Notes: Here is an example of using a curve to compute the mass properies of the planar area bounded by the curve.

ON_Curve& crv = ...; ON_Plane plane; double tol = .001; ON_MassProperties mp; if( crv.IsClosed() && crv.IsPlanar( plane, tol)) ///< ensure curve is closed and planar { if( ON_ClosedCurveOrientation( crv, plane)<0) ///< get correct orientation of plane plane.Flip(); ON_BoundingBox bbox = crv.BoundingBox(); ///< choose a reasonable base_point ON_3dPoint base_point = plane.ClosestPointTo(bbox.Center()); } if( crv.AreaMassProperties( base_point, plane.Normal(), mp)) { / mp contains area mass properties of planar region bounded crv. } Returns: True if successful.

◆ ChangeClosedCurveSeam() [1/2]

bool ON_Curve::ChangeClosedCurveSeam ( double  t,
double  min_dist 
)

Description: If this curve is closed, then modify it so that the start/end point is at curve parameter t. Parameters: t - [in] curve parameter of new start/end point. The returned curves domain will start at t. min_dist - [in] Do not change if Crv(t) is within min_dist of the original seam Returns: true if successful, and seam was moved.

◆ ChangeClosedCurveSeam() [2/2]

virtual bool ON_Curve::ChangeClosedCurveSeam ( double  t)
virtual

Description: If this curve is closed, then modify it so that the start/end point is at curve parameter t. Parameters: t - [in] curve parameter of new start/end point. The returned curves domain will start at t. Returns: true if successful.

Reimplemented in ON_NurbsCurve, CRhinoPolyEdge, ON_PolyEdgeCurve, ON_PolyCurve, ON_PolylineCurve, and ON_ArcCurve.

◆ ChangeDimension()

virtual bool ON_Curve::ChangeDimension ( int  desired_dimension)
virtual

Description: Change the dimension of a curve. Parameters: desired_dimension - [in] Returns: true if the curve's dimension was already desired_dimension or if the curve's dimension was successfully changed to desired_dimension.

Reimplemented in ON_NurbsCurve, ON_PolyCurve, ON_PolylineCurve, ON_ArcCurve, and ON_LineCurve.

◆ CreateCubicLoft()

static class ON_NurbsCurve* ON_Curve::CreateCubicLoft ( int  point_count,
int  point_dim,
int  point_stride,
const double *  point_list,
double  k,
int  is_closed = 0,
ON::cubic_loft_end_condition  start_shape = ON::cubic_loft_ec_quadratic,
ON::cubic_loft_end_condition  end_shape = ON::cubic_loft_ec_quadratic,
class ON_NurbsCurve nurbs_curve = 0 
)
static

Description: Create a cubic nurbs surface that interpolates a list of curves.

Parameters: point_count - [in] >= 2 number of points point_dim - [in] >= 1 dimension of points point_stride - [in] >= point_dim The first coordinate of the i-th point is point_list[i*point_stride]. point_list - [in] array of point coordinates

k - in or k = ON_UNSET_VALUE k determines how the curve's m_knot[0] values are calculated. Most frequently, 0.0, 0.5, or 1.0 should be used. 0.0: uniform 0.5: sqrt(chord length) 1.0: chord length In general, when k >= 0.0, then spacing is pow(d,k), where d is the average distance between the curves defining the span. ON_UNSET_VALUE: the intepolation knot vector is explicity specified. The knots in the interpolated direction are specified. You must understand the mathematics of NURBS surfaces to use this option. To specify an explicit knot vector for the interpolation, the nurbs_curve parameter must be non-null, nurbs_curve->m_order must be 4. The value of nurbs_curve->m_cv_count must be set as describe in the is_closed parameter section. The array nurbs_curve->m_knot[0][] must have length nurbs_curve->m_cv_count[0]+2, and the values in nurbs_curve->m_knot[0][2, ..., nurbs_curve->m_cv_count[0]-1] must be strictly increasing. is_closed - [in] 0: open curve_count must be at least 2. The resulting nurbs_curve will have m_cv_count = point_count+2. 1: closed curve_count must be at least 3. Do not include a duplicate of the start point as the last point in the list. The resulting nurbs_curve will have m_cv_count = point_count+3. 2: periodic curve_count must be at least 3. The resulting nurbs_curve will have m_cv_count = point_count+3.

start_shape - [in] end_shape - [in] The start_shape and end_shape paramters determine the starting and ending shape of the lofted surface.

Simple shapes: The simple end conditions calculate the rows of free control points based on the locations of the input curves and do not require additional input information. ON::cubic_loft_ec_quadratic: quadratic ON::cubic_loft_ec_linear: linear ON::cubic_loft_ec_cubic: cubic ON::cubic_loft_ec_natural: natrual (zero 2nd derivative)

Explicit shapes: ON::cubic_loft_ec_unit_tangent: unit tangent is specified ON::cubic_loft_ec_1st_derivative: first derivative is specified ON::cubic_loft_ec_2nd_derivative: second derivative is specified ON::cubic_loft_ec_free_cv: free control vertex is specified

In order to specify explicit end conditions, point_count must be at least 3, is_closed must be 0 or 1, the nurbs_curve parameter must be non-null, the nurbs_curve control points must be allocated, and nurbs_curve->m_cv_count must set as described in the is_closed parameter section. If the start_shape is explicit, then nurbs_curve->CV(1) must be set to the desired value. If the end_shape is explicit, then nurbs_curve->CV(nurbs_curve->m_cv_count-2) must be set to the desired value. A good way to specify explicit shapes is to call CreateCubicLoft() with ON::cubic_loft_ec_quadratic as the condition paramters, modify the returned curves's end condition CVs as desired, and then call CreateCubicLoft() with the explicit end condition option. This way you will be sure to have a properly initialized nurbs_curve.

nurbs_curve - [in] If not null, the result will returned in this ON_NurbsCurve. Typically, this parameter is used when you want to store the result in an ON_NurbsCurve that is on the stack. This parameter is also used when you want to specify the interpolation knots or end conditions.

Returns: If successful, a pointer to the surface is returned. If the input nurbs_surface parameter was null, then this surface is on the heap and will need to be deleted to avoid memory leaks. If the input is not valid, null is returned, even when nurbs_surface is not null.

Example:

/ EXAMPLE: Loft a curve through a list of points ON_SimpleArray< ON_3dPoint > point_list = ....; ON_NurbsCurve* srf = ON_Curve::CreateCubicLoft( point_list.Count(), ///< number of points 3, ///< dimension 3, ///< stride &point_list[0].x, 0.5 ///< sqrt(chord length) spacing );

◆ CreateCurveTree()

virtual class ON_CurveTree* ON_Curve::CreateCurveTree ( ) const
virtual

◆ CurvatureAt()

ON_3dVector ON_Curve::CurvatureAt ( double  t) const

Description: Evaluate the curvature vector at a parameter. Parameters: t - [in] evaluation parameter Returns: curvature vector of the curve at the parameter t. Remarks: No error handling. See Also: ON_Curve::EvCurvature

◆ CurveTree()

const class ON_CurveTree* ON_Curve::CurveTree ( ) const

Description: Get the runtime curve tree used to speed closest point and intersection calcuations. Returns: Pointer to the curve tree.

◆ Degree()

virtual int ON_Curve::Degree ( ) const
pure virtual

Description: Returns maximum algebraic degree of any span or a good estimate if curve spans are not algebraic. Returns: degree

Implemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ DerivativeAt()

ON_3dVector ON_Curve::DerivativeAt ( double  t) const

Description: Evaluate first derivative at a parameter. Parameters: t - [in] evaluation parameter Returns: First derivative of the curve at the parameter t. Remarks: No error handling. See Also: ON_Curve::Ev1Der

◆ DestroyCurveTree()

void ON_Curve::DestroyCurveTree ( )

Description: Destroys the runtime curve tree used to speed closest point and intersection calcuations. Remarks: If the geometry of the curve is modified in any way, then call DestroyCurveTree(); The curve tree is created as needed.

◆ DestroyRuntimeCache()

void ON_Curve::DestroyRuntimeCache ( bool  bDelete = true)
overridevirtual

◆ Domain()

virtual ON_Interval ON_Curve::Domain ( ) const
pure virtual

Returns: domain of the curve.

Implemented in ON_NurbsCurve, ON_CurveProxy, ON_PolyCurve, ON_ArcCurve, ON_PolylineCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ DuplicateCurve()

virtual ON_Curve* ON_Curve::DuplicateCurve ( ) const
virtual

Description: Get a duplicate of the curve. Returns: A duplicate of the curve. Remarks: The caller must delete the returned curve. For non-ON_CurveProxy objects, this simply duplicates the curve using ON_Object::Duplicate. For ON_CurveProxy objects, this duplicates the actual proxy curve geometry and, if necessary, trims and reverse the result to that the returned curve's parameterization and locus match the proxy curve's.

Reimplemented in CRhinoPolyEdgeSegment, ON_PolyEdgeSegment, ON_CurveProxy, ON_PolyCurve, ON_PolyEdgeCurve, and CRhinoPolyEdge.

◆ Ev1Der()

bool ON_Curve::Ev1Der ( double  t,
ON_3dPoint point,
ON_3dVector first_derivative,
int  side = 0,
int *  hint = 0 
) const

Description: Evaluate first derivative at a parameter with error checking. Parameters: t - [in] evaluation parameter point - [out] value of curve at t first_derivative - [out] value of first derivative at t side - [in] optional - determines which side to evaluate from =0 default <0 to evaluate from below, >0 to evaluate from above hint - [in/out] optional evaluation hint used to speed repeated evaluations Returns: false if unable to evaluate. See Also: ON_Curve::EvPoint ON_Curve::Ev2Der ON_Curve::EvTangent ON_Curve::Evaluate

◆ Ev2Der()

bool ON_Curve::Ev2Der ( double  t,
ON_3dPoint point,
ON_3dVector first_derivative,
ON_3dVector second_derivative,
int  side = 0,
int *  hint = 0 
) const

Description: Evaluate second derivative at a parameter with error checking. Parameters: t - [in] evaluation parameter point - [out] value of curve at t first_derivative - [out] value of first derivative at t second_derivative - [out] value of second derivative at t side - [in] optional - determines which side to evaluate from =0 default <0 to evaluate from below, >0 to evaluate from above hint - [in/out] optional evaluation hint used to speed repeated evaluations Returns: false if unable to evaluate. See Also: ON_Curve::Ev1Der ON_Curve::EvCurvature ON_Curve::Evaluate

◆ Evaluate()

virtual bool ON_Curve::Evaluate ( double  t,
int  der_count,
int  v_stride,
double *  v,
int  side = 0,
int *  hint = 0 
) const
pure virtual

Description: This evaluator actually does all the work. The other ON_Curve evaluation tools call this virtual function. Parameters: t - [in] evaluation parameter ( usually in Domain() ). der_count - [in] (>=0) number of derivatives to evaluate v_stride - [in] (>=Dimension()) stride to use for the v[] array v - [out] array of length (der_count+1)*v_stride curve(t) is returned in (v[0],...,v[m_dim-1]), curve'(t) is retuned in (v[v_stride],...,v[v_stride+m_dim-1]), curve"(t) is retuned in (v[2*v_stride],...,v[2*v_stride+m_dim-1]), etc. side - [in] optional - determines which side to evaluate from =0 default <0 to evaluate from below, >0 to evaluate from above hint - [in/out] optional evaluation hint used to speed repeated evaluations Returns: false if unable to evaluate. See Also: ON_Curve::EvPoint ON_Curve::Ev1Der ON_Curve::Ev2Der

Implemented in ON_NurbsCurve, ON_PolylineCurve, ON_CurveProxy, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ EvaluatePoint()

bool ON_Curve::EvaluatePoint ( const class ON_ObjRef objref,
ON_3dPoint P 
) const
overridevirtual

virtual ON_Geometry override

Reimplemented from ON_Geometry.

Reimplemented in ON_PolyCurve.

◆ EvCurvature()

bool ON_Curve::EvCurvature ( double  t,
ON_3dPoint point,
ON_3dVector tangent,
ON_3dVector kappa,
int  side = 0,
int *  hint = 0 
) const

Description: Evaluate unit tangent and curvature at a parameter with error checking. Parameters: t - [in] evaluation parameter point - [out] value of curve at t tangent - [out] value of unit tangent kappa - [out] value of curvature vector side - [in] optional - determines which side to evaluate from =0 default <0 to evaluate from below, >0 to evaluate from above hint - [in/out] optional evaluation hint used to speed repeated evaluations Returns: false if unable to evaluate. See Also: ON_Curve::CurvatureAt ON_Curve::Ev2Der ON_EvCurvature

◆ EvPoint()

bool ON_Curve::EvPoint ( double  t,
ON_3dPoint point,
int  side = 0,
int *  hint = 0 
) const

Description: Evaluate point at a parameter with error checking. Parameters: t - [in] evaluation parameter point - [out] value of curve at t side - [in] optional - determines which side to evaluate from =0 default <0 to evaluate from below, >0 to evaluate from above hint - [in/out] optional evaluation hint used to speed repeated evaluations Returns: false if unable to evaluate. See Also: ON_Curve::PointAt ON_Curve::EvTangent ON_Curve::Evaluate

◆ EvTangent()

bool ON_Curve::EvTangent ( double  t,
ON_3dPoint point,
ON_3dVector tangent,
int  side = 0,
int *  hint = 0 
) const

Description: Evaluate unit tangent at a parameter with error checking. Parameters: t - [in] evaluation parameter point - [out] value of curve at t tangent - [out] value of unit tangent side - [in] optional - determines which side to evaluate from =0 default <0 to evaluate from below, >0 to evaluate from above hint - [in/out] optional evaluation hint used to speed repeated evaluations Returns: false if unable to evaluate. See Also: ON_Curve::TangentAt ON_Curve::Ev1Der

◆ Extend()

virtual bool ON_Curve::Extend ( const ON_Interval domain)
virtual

Description: Pure virtual function. Default returns false. Where possible, analytically extends curve to include domain. Parameters: domain - [in] if domain is not included in curve domain, curve will be extended so that its domain includes domain. Will not work if curve is closed. Original curve is identical to the restriction of the resulting curve to the original curve domain, Returns: true if successful.

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, ON_LineCurve, and ON_ArcCurve.

◆ FirstSpanIsLinear() [1/2]

bool ON_Curve::FirstSpanIsLinear ( double  min_length,
double  tolerance 
) const

Parameters: min_length -[in] minimum length of a linear span tolerance -[in] distance tolerance to use when checking linearity. Returns true if the span is a non-degenrate line. This means:

  • dimension = 2 or 3
  • The length of the the line segment from the span's initial point to the span's control point is >= min_length.
  • The maximum distance from the line segment to the span is <= tolerance and the span increases monotonically in the direction of the line segment.

◆ FirstSpanIsLinear() [2/2]

bool ON_Curve::FirstSpanIsLinear ( double  min_length,
double  tolerance,
ON_Line span_line 
) const

◆ FrameAt()

bool ON_Curve::FrameAt ( double  t,
ON_Plane plane 
) const

Description: Return a 3d frame at a parameter. Parameters: t - [in] evaluation parameter plane - [out] the frame is returned here Returns: true if successful See Also: ON_Curve::PointAt, ON_Curve::TangentAt, ON_Curve::Ev1Der, Ev2Der

◆ GetClosestPoint()

virtual bool ON_Curve::GetClosestPoint ( const ON_3dPoint ,
double *  t,
double  maximum_distance = 0.0,
const ON_Interval sub_domain = nullptr 
) const
virtual

Find parameter of the point on a curve that is closest to test_point. If the maximum_distance parameter is > 0, then only points whose distance to the given point is <= maximum_distance will be returned. Using a positive value of maximum_distance can substantially speed up the search. If the sub_domain parameter is not nullptr, then the search is restricted to the specified portion of the curve.

true if returned if the search is successful. false is returned if the search fails.

Parameters
tparameter of local closest point returned here
maximum_distancemaximum_distance
sub_domainsub_domain

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_CurveProxy, ON_PolyCurve, ON_ArcCurve, and ON_LineCurve.

◆ GetCurveParameterFromNurbFormParameter()

virtual bool ON_Curve::GetCurveParameterFromNurbFormParameter ( double  nurbs_t,
double *  curve_t 
) const
virtual

Description: Convert a NURBS curve parameter to a curve parameter

Parameters: nurbs_t - [in] nurbs form parameter curve_t - [out] curve parameter

Remarks: If GetNurbForm returns 2, this function converts the curve parameter to the NURBS curve parameter.

See Also: ON_Curve::GetNurbForm, ON_Curve::GetNurbFormParameterFromCurveParameter

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, ON_LineCurve, and ON_ArcCurve.

◆ GetDomain()

bool ON_Curve::GetDomain ( double *  t0,
double *  t1 
) const

curve interface

Description: Gets domain of the curve Parameters: t0 - [out] t1 - [out] domain is [*t0, *t1] Returns: true if successful.

◆ GetLength()

virtual bool ON_Curve::GetLength ( double *  length,
double  fractional_tolerance = 1.0e-8,
const ON_Interval sub_domain = nullptr 
) const
virtual

Description: Get the length of the curve. Parameters: length - [out] length returned here. fractional_tolerance - [in] desired fractional precision. fabs(("exact" length from start to t) - arc_length)/arc_length <= fractional_tolerance sub_domain - [in] If not nullptr, the calculation is performed on the specified sub-domain of the curve (must be non-decreasing) Returns: true if returned if the length calculation is successful. false is returned if the length is not calculated. Remarks: The arc length will be computed so that (returned length - real length)/(real length) <= fractional_tolerance More simply, if you want N significant figures in the answer, set the fractional_tolerance to 1.0e-N. For "nice" curves, 1.0e-8 works fine. For very high degree NURBS and NURBS with bad parameterizations, use larger values of fractional_tolerance.

Reimplemented in ON_PolylineCurve, ON_CurveProxy, ON_PolyCurve, ON_ArcCurve, and ON_LineCurve.

◆ GetLocalClosestPoint()

virtual bool ON_Curve::GetLocalClosestPoint ( const ON_3dPoint test_point,
double  seed_parameter,
double *  t,
const ON_Interval sub_domain = 0 
) const
virtual

Find parameter of the point on a curve that is locally closest to the test_point. The search for a local close point starts at seed_parameter. If the sub_domain parameter is not nullptr, then the search is restricted to the specified portion of the curve.

true if returned if the search is successful. false is returned if the search fails.

Reimplemented in ON_PolylineCurve, ON_CurveProxy, ON_PolyCurve, ON_ArcCurve, and ON_LineCurve.

◆ GetNextDiscontinuity()

virtual bool ON_Curve::GetNextDiscontinuity ( ON::continuity  c,
double  t0,
double  t1,
double *  t,
int *  hint = nullptr,
int *  dtype = nullptr,
double  cos_angle_tolerance = ON_DEFAULT_ANGLE_TOLERANCE_COSINE,
double  curvature_tolerance = ON_SQRT_EPSILON 
) const
virtual

Description: Search for a derivatitive, tangent, or curvature discontinuity. Parameters: c - [in] type of continity to test for. t0 - [in] Search begins at t0. If there is a discontinuity at t0, it will be ignored. This makes it possible to repeatedly call GetNextDiscontinuity and step through the discontinuities. t1 - [in] (t0 != t1) If there is a discontinuity at t1 is will be ingored unless c is a locus discontinuity type and t1 is at the start or end of the curve. t - [out] if a discontinuity is found, then *t reports the parameter at the discontinuity. hint - [in/out] if GetNextDiscontinuity will be called repeatedly, passing a "hint" with initial value *hint=0 will increase the speed of the search. dtype - [out] if not nullptr, *dtype reports the kind of discontinuity found at *t. A value of 1 means the first derivative or unit tangent was discontinuous. A value of 2 means the second derivative or curvature was discontinuous. A value of 0 means teh curve is not closed, a locus discontinuity test was applied, and t1 is at the start of end of the curve. If 'c', the type of continuity to test for is ON::continuity::Gsmooth_continuous and the curvature changes from curved to 0 or 0 to curved and there is no tangency kink dtype is returns 3 cos_angle_tolerance - [in] default = cos(1 degree) Used only when c is ON::continuity::G1_continuous or ON::continuity::G2_continuous. If the cosine of the angle between two tangent vectors is <= cos_angle_tolerance, then a G1 discontinuity is reported. curvature_tolerance - [in] (default = ON_SQRT_EPSILON) Used only when c is ON::continuity::G2_continuous. If K0 and K1 are curvatures evaluated from above and below and |K0 - K1| > curvature_tolerance, then a curvature discontinuity is reported. Returns: Parametric continuity tests c = (C0_continuous, ..., G2_continuous):

true if a parametric discontinuity was found strictly between t0 and t1. Note well that all curves are parametrically continuous at the ends of their domains.

Locus continuity tests c = (C0_locus_continuous, ...,G2_locus_continuous):

true if a locus discontinuity was found strictly between t0 and t1 or at t1 is the at the end of a curve. Note well that all open curves (IsClosed()=false) are locus discontinuous at the ends of their domains. All closed curves (IsClosed()=true) are at least C0_locus_continuous at the ends of their domains.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, and ON_PolyCurve.

◆ GetNormalizedArcLengthPoint()

virtual bool ON_Curve::GetNormalizedArcLengthPoint ( double  s,
double *  t,
double  fractional_tolerance = 1.0e-8,
const ON_Interval sub_domain = nullptr 
) const
virtual

Description: Get the parameter of the point on the curve that is a prescribed arc length from the start of the curve. Parameters: s - [in] normalized arc length parameter. E.g., 0 = start of curve, 1/2 = midpoint of curve, 1 = end of curve. t - [out] parameter such that the length of the curve from its start to t is arc_length. fractional_tolerance - [in] desired fractional precision. fabs(("exact" length from start to t) - arc_length)/arc_length <= fractional_tolerance sub_domain - [in] If not nullptr, the calculation is performed on the specified sub-domain of the curve. Returns: true if successful

Reimplemented in ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, ON_ArcCurve, and ON_LineCurve.

◆ GetNormalizedArcLengthPoints()

virtual bool ON_Curve::GetNormalizedArcLengthPoints ( int  count,
const double *  s,
double *  t,
double  absolute_tolerance = 0.0,
double  fractional_tolerance = 1.0e-8,
const ON_Interval sub_domain = nullptr 
) const
virtual

Description: Get the parameter of the point on the curve that is a prescribed arc length from the start of the curve. Parameters: count - [in] number of parameters in s. s - [in] array of normalized arc length parameters. E.g., 0 = start of curve, 1/2 = midpoint of curve, 1 = end of curve. t - [out] array of curve parameters such that the length of the curve from its start to t[i] is s[i]*curve_length. absolute_tolerance - [in] if absolute_tolerance > 0, then the difference between (s[i+1]-s[i])*curve_length and the length of the curve segment from t[i] to t[i+1] will be <= absolute_tolerance. fractional_tolerance - [in] desired fractional precision for each segment. fabs("true" length - actual length)/(actual length) <= fractional_tolerance sub_domain - [in] If not nullptr, the calculation is performed on the specified sub-domain of the curve. A 0.0 s value corresponds to sub_domain->Min() and a 1.0 s value corresponds to sub_domain->Max(). Returns: true if successful

Reimplemented in ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, ON_ArcCurve, and ON_LineCurve.

◆ GetNurbForm()

virtual int ON_Curve::GetNurbForm ( ON_NurbsCurve nurbs_curve,
double  tolerance = 0.0,
const ON_Interval subdomain = nullptr 
) const
virtual

Description: Get a NURBS curve representation of this curve. Parameters: nurbs_curve - [out] NURBS representation returned here tolerance - [in] tolerance to use when creating NURBS representation. subdomain - [in] if not nullptr, then the NURBS representation for this portion of the curve is returned. Returns: 0 unable to create NURBS representation with desired accuracy. 1 success - returned NURBS parameterization matches the curve's to wthe desired accuracy 2 success - returned NURBS point locus matches the curve's to the desired accuracy and the domain of the NURBS curve is correct. On However, This curve's parameterization and the NURBS curve parameterization may not match to the desired accuracy. This situation happens when getting NURBS representations of curves that have a transendental parameterization like circles Remarks: This is a low-level virtual function. If you do not need the parameterization information provided by the return code, then ON_Curve::NurbsCurve may be easier to use. See Also: ON_Curve::NurbsCurve

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, ON_LineCurve, ON_ArcCurve, and ON_CurveOnSurface.

◆ GetNurbFormParameterFromCurveParameter()

virtual bool ON_Curve::GetNurbFormParameterFromCurveParameter ( double  curve_t,
double *  nurbs_t 
) const
virtual

Description: Convert a curve parameter to a NURBS curve parameter.

Parameters: curve_t - [in] curve parameter nurbs_t - [out] nurbs form parameter

Remarks: If GetNurbForm returns 2, this function converts the curve parameter to the NURBS curve parameter.

See Also: ON_Curve::GetNurbForm, ON_Curve::GetCurveParameterFromNurbFormParameter

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, ON_LineCurve, and ON_ArcCurve.

◆ GetParameterTolerance()

virtual bool ON_Curve::GetParameterTolerance ( double  t,
double *  tminus,
double *  tplus 
) const
virtual

Description: Returns maximum algebraic degree of any span or a good estimate if curve spans are not algebraic. Returns: degree

Parameters
treturns tminus < tplus: parameters tminus <= s <= tplus [IN] t = parameter in domain
[out]tminustminus
[out]tplustplus

Reimplemented in ON_NurbsCurve, ON_CurveProxy, and ON_CurveOnSurface.

◆ GetSpanVector()

virtual bool ON_Curve::GetSpanVector ( double *  knots) const
pure virtual

Description: Get number of parameters of "knots". Parameters: knots - [out] an array of length SpanCount()+1 is filled in with the parameters where the curve is not smooth (C-infinity). Returns: true if successful

Implemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ GetSpanVectorIndex()

virtual bool ON_Curve::GetSpanVectorIndex ( double  t,
int  side,
int *  span_vector_index,
ON_Interval span_domain 
) const
virtual

If t is in the domain of the curve, GetSpanVectorIndex() returns the span vector index "i" such that span_vector[i] <= t <= span_vector[i+1]. The "side" parameter determines which span is selected when t is at the end of a span.

Parameters
[in]tt = evaluation parameter
[in]sideside 0 = default, -1 = from below, +1 = from above
[out]span_vector_indexspan vector index
[out]span_domaindomain of the span containing "t"

◆ GetTightBoundingBox()

bool ON_Curve::GetTightBoundingBox ( class ON_BoundingBox tight_bbox,
bool  bGrowBox = false,
const class ON_Xform xform = nullptr 
) const
overridevirtual

virtual ON_Geometry GetTightBoundingBox override

Reimplemented from ON_Geometry.

Reimplemented in ON_PolyCurve, ON_PolylineCurve, and ON_LineCurve.

◆ HasNurbForm()

virtual int ON_Curve::HasNurbForm ( ) const
virtual

Description: Does a NURBS curve representation of this curve. Parameters: Returns: 0 unable to create NURBS representation with desired accuracy. 1 success - NURBS parameterization matches the curve's to wthe desired accuracy 2 success - NURBS point locus matches the curve's and the domain of the NURBS curve is correct. However, This curve's parameterization and the NURBS curve parameterization may not match. This situation happens when getting NURBS representations of curves that have a transendental parameterization like circles Remarks: This is a low-level virtual function. See Also: ON_Curve::GetNurbForm ON_Curve::NurbsCurve

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, ON_LineCurve, and ON_ArcCurve.

◆ IntersectCurve()

int ON_Curve::IntersectCurve ( const ON_Curve curveB,
ON_SimpleArray< ON_X_EVENT > &  x,
double  intersection_tolerance = 0.0,
double  overlap_tolerance = 0.0,
const ON_Interval curveA_domain = 0,
const ON_Interval curveB_domain = 0 
) const

Description: Intersect this curve with curveB. Parameters: curveB - [in] x - [out] Intersection events are appended to this array. intersection_tolerance - [in] If the distance from a point on this curve to curveB is <= intersection tolerance, then the point will be part of an intersection event. If the input intersection_tolerance <= 0.0, then 0.001 is used. overlap_tolerance - [in] If t1 and t2 are parameters of this curve's intersection events and the distance from curve(t) to curveB is <= overlap_tolerance for every t1 <= t <= t2, then the event will be returened as an overlap event. If the input overlap_tolerance <= 0.0, then intersection_tolerance*2.0 is used. curveA_domain - [in] optional restriction on this curve's domain curveB_domain - [in] optional restriction on curveB domain Returns: Number of intersection events appended to x.

◆ IntersectPlane()

int ON_Curve::IntersectPlane ( ON_PlaneEquation  plane_equation,
ON_SimpleArray< ON_X_EVENT > &  x,
double  intersection_tolerance = 0.0,
double  overlap_tolerance = 0.0,
const ON_Interval curve_domain = 0 
) const

Description: Intersect this curve with an infinite plane.

Parameters: plane_equation - [in]

x - [out] Intersection events are appended to this array. intersection_tolerance - [in] If the distance from a point on this curve to the surface is <= intersection tolerance, then the point will be part of an intersection event, or there is an intersection event the point leads to. If the input intersection_tolerance <= 0.0, then 0.001 is used.

overlap_tolerance - [in] If the input overlap_tolerance <= 0.0, then 2.0*intersection_tolerance is used. Otherwise, overlap tolerance must be >= intersection_tolerance. In all cases, the intersection calculation is performed with an overlap_tolerance that is >= intersection_tolerance. If t1 and t2 are curve parameters of intersection events and the distance from curve(t) to the surface is <= overlap_tolerance for every t1 <= t <= t2, then the event will be returned as an overlap event.

curve_domain - [in] optional restriction on this curve's domain

Returns: Number of intersection events appended to x.

NOTE: The surface parameters, m_b, of x are not useful. If you got the plane equation from an ON_Plane, the m_b will most likely not be correct with respect to the original plane.

◆ IntersectSelf()

virtual int ON_Curve::IntersectSelf ( ON_SimpleArray< ON_X_EVENT > &  x,
double  intersection_tolerance = 0.0,
const ON_Interval curve_domain = 0 
) const
virtual

Description: Find curve's self intersection points. Parameters: x - [out] Intersection events are appended to this array. Only intersection points are reported. Overlaps are not reported. intersection_tolerance - [in] curve_domain - [in] optional restriction Returns: Number of intersection events appended to x. Remarks: Overlaps are not reported.

Reimplemented in ON_ArcCurve, and ON_LineCurve.

◆ IntersectSurface()

int ON_Curve::IntersectSurface ( const ON_Surface surfaceB,
ON_SimpleArray< ON_X_EVENT > &  x,
double  intersection_tolerance = 0.0,
double  overlap_tolerance = 0.0,
const ON_Interval curveA_domain = 0,
const ON_Interval surfaceB_udomain = 0,
const ON_Interval surfaceB_vdomain = 0 
) const

Description: Intersect this curve with surfaceB.

Parameters: surfaceB - [in]

x - [out] Intersection events are appended to this array. intersection_tolerance - [in] If the distance from a point on this curve to the surface is <= intersection tolerance, then the point will be part of an intersection event, or there is an intersection event the point leads to. If the input intersection_tolerance <= 0.0, then 0.001 is used.

overlap_tolerance - [in] If the input overlap_tolerance <= 0.0, then 2.0*intersection_tolerance is used. Otherwise, overlap tolerance must be >= intersection_tolerance. In all cases, the intersection calculation is performed with an overlap_tolerance that is >= intersection_tolerance. If t1 and t2 are curve parameters of intersection events and the distance from curve(t) to the surface is <= overlap_tolerance for every t1 <= t <= t2, then the event will be returned as an overlap event.

curveA_domain - [in] optional restriction on this curve's domain

surfaceB_udomain - [in] optional restriction on surfaceB u domain

surfaceB_vdomain - [in] optional restriction on surfaceB v domain

Returns: Number of intersection events appended to x.

◆ IsArc()

virtual bool ON_Curve::IsArc ( const ON_Plane plane = nullptr,
ON_Arc arc = nullptr,
double  tolerance = ON_ZERO_TOLERANCE 
) const
virtual

Description: Test a curve to see if the locus if its points is an arc or circle. Parameters: plane - [in] if not nullptr, test is performed in this plane arc - [out] if not nullptr and true is returned, then arc parameters are filled in tolerance - [in] tolerance to use when checking Returns: ON_Arc.m_angle > 0 if curve locus is an arc between specified points. If ON_Arc.m_angle is 2.0*ON_PI, then the curve is a circle.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ IsArcAt()

bool ON_Curve::IsArcAt ( double  t,
const ON_Plane plane = 0,
ON_Arc arc = 0,
double  tolerance = ON_ZERO_TOLERANCE,
double *  t0 = 0,
double *  t1 = 0 
) const

Description: Parameters: t - [in] curve parameter plane - [in] if not nullptr, test is performed in this plane arc - [out] if not nullptr and true is returned, then arc parameters are filled in tolerance - [in] tolerance to use when checking t0 - [out] if not nullptr, and then *t0 is set to the parameter at the start of the G2 curve segment that was tested. t1 - [out] if not nullptr, and then *t0 is set to the parameter at the start of the G2 curve segment that was tested. Returns: True if the paramter t is on a arc segment of the curve.

◆ IsClosable()

bool ON_Curve::IsClosable ( double  tolerance,
double  min_abs_size = 0.0,
double  min_rel_size = 10.0 
) const

Description: Decide if it makes sense to close off this curve by moving the endpoint to the start based on start-end gap size and length of curve as approximated by chord defined by 6 points. Parameters: tolerance - [in] maximum allowable distance between start and end. if start - end gap is greater than tolerance, returns false min_abs_size - [in] if greater than 0.0 and none of the interior sampled points are at least min_abs_size from start, returns false. min_rel_size - [in] if greater than 1.0 and chord length is less than min_rel_size*gap, returns false. Returns: true if start and end points are close enough based on above conditions.

◆ IsClosed()

virtual bool ON_Curve::IsClosed ( ) const
virtual

Description: Test a curve to see if it is closed. Returns: true if the curve is closed.

Reimplemented in ON_NurbsCurve, CRhinoPolyEdgeSegment, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_PolyEdgeSegment, ON_BrepEdge, ON_ArcCurve, ON_LineCurve, ON_CurveOnSurface, ON_PolyEdgeCurve, and CRhinoPolyEdge.

◆ IsContinuous()

virtual bool ON_Curve::IsContinuous ( ON::continuity  c,
double  t,
int *  hint = nullptr,
double  point_tolerance = ON_ZERO_TOLERANCE,
double  d1_tolerance = ON_ZERO_TOLERANCE,
double  d2_tolerance = ON_ZERO_TOLERANCE,
double  cos_angle_tolerance = ON_DEFAULT_ANGLE_TOLERANCE_COSINE,
double  curvature_tolerance = ON_SQRT_EPSILON 
) const
virtual

Description: Test continuity at a curve parameter value. Parameters: c - [in] type of continuity to test for. Read ON::continuity comments for details. t - [in] parameter to test hint - [in] evaluation hint point_tolerance - [in] if the distance between two points is greater than point_tolerance, then the curve is not C0. d1_tolerance - [in] if the difference between two first derivatives is greater than d1_tolerance, then the curve is not C1. d2_tolerance - [in] if the difference between two second derivatives is greater than d2_tolerance, then the curve is not C2. cos_angle_tolerance - [in] default = cos(1 degree) Used only when c is ON::continuity::G1_continuous or ON::continuity::G2_continuous. If the cosine of the angle between two tangent vectors is <= cos_angle_tolerance, then a G1 discontinuity is reported. curvature_tolerance - [in] (default = ON_SQRT_EPSILON) Used only when c is ON::continuity::G2_continuous or ON::continuity::Gsmooth_continuous. ON::continuity::G2_continuous: If K0 and K1 are curvatures evaluated from above and below and |K0 - K1| > curvature_tolerance, then a curvature discontinuity is reported. ON::continuity::Gsmooth_continuous: If K0 and K1 are curvatures evaluated from above and below and the angle between K0 and K1 is at least twice angle tolerance or ||K0| - |K1|| > (max(|K0|,|K1|) > curvature_tolerance, then a curvature discontinuity is reported. Returns: true if the curve has at least the c type continuity at the parameter t.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, and ON_ArcCurve.

◆ IsEllipse()

virtual bool ON_Curve::IsEllipse ( const ON_Plane plane = nullptr,
ON_Ellipse ellipse = nullptr,
double  tolerance = ON_ZERO_TOLERANCE 
) const
virtual

◆ IsInPlane()

virtual bool ON_Curve::IsInPlane ( const ON_Plane test_plane,
double  tolerance = ON_ZERO_TOLERANCE 
) const
pure virtual

Description: Test a curve to see if it lies in a specific plane. Parameters: test_plane - [in] tolerance - [in] tolerance to use when checking Returns: true if the maximum distance from the curve to the test_plane is <= tolerance.

Implemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ IsLinear()

virtual bool ON_Curve::IsLinear ( double  tolerance = ON_ZERO_TOLERANCE) const
virtual

Description: Test a curve to see if the locus if its points is a line segment. Parameters: tolerance - [in] ///< tolerance to use when checking linearity Returns: true if the ends of the curve are farther than tolerance apart and the maximum distance from any point on the curve to the line segment connecting the curve's ends is <= tolerance.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ IsPeriodic()

virtual bool ON_Curve::IsPeriodic ( ) const
virtual

Description: Test a curve to see if it is periodic. Returns: true if the curve is closed and at least C2 at the start/end.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ IsPlanar()

virtual bool ON_Curve::IsPlanar ( ON_Plane plane = nullptr,
double  tolerance = ON_ZERO_TOLERANCE 
) const
virtual

Description: Test a curve to see if it is planar. Parameters: plane - [out] if not nullptr and true is returned, the plane parameters are filled in. tolerance - [in] tolerance to use when checking Returns: true if there is a plane such that the maximum distance from the curve to the plane is <= tolerance.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ IsPolyline()

virtual int ON_Curve::IsPolyline ( ON_SimpleArray< ON_3dPoint > *  pline_points = nullptr,
ON_SimpleArray< double > *  pline_t = nullptr 
) const
virtual

Description: Several types of ON_Curve can have the form of a polyline including a degree 1 ON_NurbsCurve, an ON_PolylineCurve, and an ON_PolyCurve all of whose segments are some form of polyline. IsPolyline tests a curve to see if it can be represented as a polyline. Parameters: pline_points - [out] if not nullptr and true is returned, then the points of the polyline form are returned here. t - [out] if not nullptr and true is returned, then the parameters of the polyline points are returned here. Returns: table 0 curve is not some form of a polyline >=2 number of points in polyline form

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, and ON_LineCurve.

◆ IsShort()

virtual bool ON_Curve::IsShort ( double  tolerance,
const ON_Interval sub_domain = 0,
double *  length_estimate = 0 
) const
virtual

Description: Used to quickly find short curves. Parameters: tolerance - [in] (>=0) sub_domain - [in] If not nullptr, the test is performed on the interval that is the intersection of sub_domain with Domain(). Returns: True if the length of the curve is <= tolerance. Remarks: Faster than calling Length() and testing the result.

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_CurveProxy, ON_PolyCurve, ON_ArcCurve, and ON_LineCurve.

◆ LastSpanIsLinear() [1/2]

bool ON_Curve::LastSpanIsLinear ( double  min_length,
double  tolerance 
) const

◆ LastSpanIsLinear() [2/2]

bool ON_Curve::LastSpanIsLinear ( double  min_length,
double  tolerance,
ON_Line span_line 
) const

◆ LengthMassProperties()

bool ON_Curve::LengthMassProperties ( class ON_MassProperties mp,
bool  bLength = true,
bool  bFirstMoments = true,
bool  bSecondMoments = true,
bool  bProductMoments = true,
double  rel_tol = 1.0e-6,
double  abs_tol = 1.0e-6 
) const

Description: Calculate length mass properties of the curve. Parameters: mp - [out] bLength - [in] true to calculate length bFirstMoments - [in] true to calculate volume first moments, length, and length centroid. bSecondMoments - [in] true to calculate length second moments. bProductMoments - [in] true to calculate length product moments. Returns: True if successful.

◆ MeshCurve()

class ON_PolylineCurve* ON_Curve::MeshCurve ( ON_MeshCurveParameters mp,
ON_PolylineCurve polyline,
bool  bSkipFirstPoint,
const ON_Interval domain 
) const

Description: Mesh a curve into line segments. Parameters: mp - [in] Parameters that determine how the curve will be approximated by a polyline. polyline - [in] If not nullptr, the polyline approximation will be appended to this polyline. bSkipFirstPoint - [in] If true, the starting point of the approximation will not be added to the returned polyline. This parameter is useful when getting a polyline approximation of a sequence of contiguous curves. domain - [in] If not nullptr, the polyline approximation will be restricted to this domain. Returns: A pointer to the polyline approximation.

◆ NurbsCurve()

ON_NurbsCurve* ON_Curve::NurbsCurve ( ON_NurbsCurve pNurbsCurve = nullptr,
double  tolerance = 0.0,
const ON_Interval subdomain = nullptr 
) const

Description: Get a NURBS curve representation of this curve. Parameters: pNurbsCurve - [in/out] if not nullptr, this ON_NurbsCurve will be used to store the NURBS representation of the curve will be returned. tolerance - [in] tolerance to use when creating NURBS representation. subdomain - [in] if not nullptr, then the NURBS representation for this portion of the curve is returned. Returns: nullptr or a NURBS representation of the curve. Remarks: See ON_Surface::GetNurbForm for important details about the NURBS surface parameterization. See Also: ON_Curve::GetNurbForm

◆ ObjectType()

ON::object_type ON_Curve::ObjectType ( ) const
overridevirtual

Description: overrides virtual ON_Object::ObjectType. Returns: ON::curve_object

Reimplemented from ON_Object.

◆ operator=()

ON_Curve& ON_Curve::operator= ( const ON_Curve )

◆ ParameterSearch()

bool ON_Curve::ParameterSearch ( double  t,
int &  index,
bool  bEnableSnap,
const ON_SimpleArray< double > &  m_t,
double  RelTol = ON_SQRT_EPSILON 
) const
protected

Description: Lookup a parameter in the m_t array, optionally using a built in snap tolerance to snap a parameter value to an element of m_t. This function is used by some types derived from ON_Curve to snap parameter values Parameters: t - [in] parameter index -[out] index into m_t such that if function returns false then

 @table  
 value                  condition
-1                                   t<m_t[0] or m_t is empty               
    0<=i<=m_t.Count()-2     m_t[i] < t < m_t[i+1]           
    m_t.Count()-1                   t>m_t[ m_t.Count()-1]            

if the function returns true then t is equal to, or is closest to and 
within  tolerance of m_t[index]. 

bEnableSnap-[in] enable snapping m_t -[in] Array of parameter values to snap to RelTol -[in] tolerance used in snapping

Returns: true if the t is exactly equal to (bEnableSnap==false), or within tolerance of (bEnableSnap==true) m_t[index].

◆ PointAt()

ON_3dPoint ON_Curve::PointAt ( double  t) const

Description: Evaluate point at a parameter. Parameters: t - [in] evaluation parameter Returns: Point (location of curve at the parameter t). Remarks: No error handling. See Also: ON_Curve::EvPoint ON_Curve::PointAtStart ON_Curve::PointAtEnd

◆ PointAtEnd()

ON_3dPoint ON_Curve::PointAtEnd ( ) const

Description: Evaluate point at the end of the curve. Parameters: t - [in] evaluation parameter Returns: Point (location of the end of the curve.) Remarks: No error handling. See Also: ON_Curve::PointAt

◆ PointAtStart()

ON_3dPoint ON_Curve::PointAtStart ( ) const

Description: Evaluate point at the start of the curve. Parameters: t - [in] evaluation parameter Returns: Point (location of the start of the curve.) Remarks: No error handling. See Also: ON_Curve::PointAt

◆ RemoveShortSegments()

virtual bool ON_Curve::RemoveShortSegments ( double  tolerance,
bool  bRemoveShortSegments = true 
)
virtual

Description: Looks for segments that are shorter than tolerance that can be removed. If bRemoveShortSegments is true, then the short segments are removed. Does not change the domain, but it will change the relative parameterization. Parameters: tolerance - [in] bRemoveShortSegments - [in] If true, then short segments are removed. Returns: True if removable short segments can were found. False if no removable short segments can were found.

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, and ON_PolyCurve.

◆ Reverse()

virtual bool ON_Curve::Reverse ( )
pure virtual

Description: Reverse the direction of the curve. Returns: true if curve was reversed. Remarks: If reveresed, the domain changes from [a,b] to [-b,-a]

Implemented in ON_BrepTrim, ON_NurbsCurve, ON_CurveProxy, ON_PolylineCurve, ON_PolyCurve, ON_BrepEdge, ON_LineCurve, ON_ArcCurve, and ON_CurveOnSurface.

◆ SetDomain() [1/2]

bool ON_Curve::SetDomain ( ON_Interval  domain)

Description: Set the domain of the curve. Parameters: domain - [in] increasing interval Returns: true if successful.

◆ SetDomain() [2/2]

virtual bool ON_Curve::SetDomain ( double  t0,
double  t1 
)
virtual

Description: Set the domain of the curve Parameters: t0 - [in] t1 - [in] new domain will be [t0,t1] Returns: true if successful.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolyCurve, ON_PolylineCurve, ON_ArcCurve, and ON_LineCurve.

◆ SetEndPoint()

virtual bool ON_Curve::SetEndPoint ( ON_3dPoint  end_point)
virtual

Description: Force the curve to end at a specified point. Parameters: end_point - [in] Returns: true if successful. Remarks: Some end points cannot be moved. Be sure to check return code. ON_Curve::SetEndPoint() returns true if end_point is the same as the end of the curve, false otherwise. See Also: ON_Curve::SetStartPoint ON_Curve::PointAtStart ON_Curve::PointAtEnd

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, CRhinoPolyEdge, ON_ArcCurve, ON_LineCurve, and ON_PolyEdgeCurve.

◆ SetStartPoint()

virtual bool ON_Curve::SetStartPoint ( ON_3dPoint  start_point)
virtual

Description: Force the curve to start at a specified point. Parameters: start_point - [in] Returns: true if successful. Remarks: Some end points cannot be moved. Be sure to check return code. ON_Curve::SetStartPoint() returns true if start_point is the same as the start of the curve, false otherwise. See Also: ON_Curve::SetEndPoint ON_Curve::PointAtStart ON_Curve::PointAtEnd

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, CRhinoPolyEdge, ON_ArcCurve, ON_LineCurve, and ON_PolyEdgeCurve.

◆ SizeOf()

unsigned int ON_Curve::SizeOf ( ) const
overridevirtual

virtual ON_Object::SizeOf override

Reimplemented from ON_Object.

Reimplemented in ON_NurbsCurve, ON_PolyCurve, ON_CurveProxy, ON_CurveOnSurface, ON_LineCurve, and ON_PolylineCurve.

◆ SpanCount()

virtual int ON_Curve::SpanCount ( ) const
pure virtual

Description: Get number of nonempty smooth (c-infinity) spans in curve Returns: Number of nonempty smooth (c-infinity) spans.

Implemented in ON_NurbsCurve, ON_CurveProxy, ON_PolyCurve, ON_PolylineCurve, ON_ArcCurve, ON_LineCurve, and ON_CurveOnSurface.

◆ Split()

virtual bool ON_Curve::Split ( double  t,
ON_Curve *&  left_side,
ON_Curve *&  right_side 
) const
virtual

Description: Splits (divides) the curve at the specified parameter. The parameter must be in the interior of the curve's domain. The pointers passed to Split must either be nullptr or point to an ON_Curve object of the same type. If the pointer is nullptr, then a curve will be created in Split(). You may pass "this" as left_side or right_side. Parameters: t - [in] parameter to split the curve at in the interval returned by Domain(). left_side - [out] left portion of curve returned here right_side - [out] right portion of curve returned here Returns: true - The curve was split into two pieces. false - The curve could not be split. For example if the parameter is too close to an endpoint.

Example: For example, if crv were an ON_NurbsCurve, then

  ON_NurbsCurve right_side;
  crv.Split( crv.Domain().Mid() &crv, &right_side );

would split crv at the parametric midpoint, put the left side in crv, and return the right side in right_side.

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, CRhinoPolyEdgeSegment, ON_LineCurve, ON_PolyEdgeSegment, and ON_ArcCurve.

◆ TangentAt()

ON_3dVector ON_Curve::TangentAt ( double  t) const

Description: Evaluate unit tangent vector at a parameter. Parameters: t - [in] evaluation parameter Returns: Unit tangent vector of the curve at the parameter t. Remarks: No error handling. See Also: ON_Curve::EvTangent

◆ Transform()

bool ON_Curve::Transform ( const ON_Xform xform)
overridevirtual

Description: overrides virtual ON_Geometry::Transform(). ON_Curve::Transform() calls ON_Geometry::Transform(xform), which calls ON_Object::TransformUserData(xform), and then calls this->DestroyCurveTree(). Parameters: xform - [in] transformation to apply to object. Remarks: Classes derived from ON_Curve should call ON_Curve::Transform() to handle user data transformations and curve tree destruction and then transform their definition.

Reimplemented from ON_Geometry.

Reimplemented in ON_NurbsCurve, ON_CurveProxy, ON_PolyCurve, ON_PolylineCurve, ON_CurveOnSurface, and ON_LineCurve.

◆ Trim()

virtual bool ON_Curve::Trim ( const ON_Interval domain)
virtual

Description: Removes portions of the curve outside the specified interval. Parameters: domain - [in] interval of the curve to keep. Portions of the curve before curve(domain[0]) and after curve(domain[1]) are removed. Returns: true if successful.

Reimplemented in ON_NurbsCurve, ON_PolylineCurve, ON_PolyCurve, ON_CurveProxy, CRhinoPolyEdgeSegment, ON_LineCurve, ON_PolyEdgeSegment, and ON_ArcCurve.