-- File: GeomAPI_ExtremaCurveCurve.cdl -- Created: Fri Mar 18 10:09:20 1994 -- Author: Bruno DUMORTIER -- ---Copyright: Matra Datavision 1994 class ExtremaCurveCurve from GeomAPI ---Purpose: Describes functions for computing all the extrema -- between two 3D curves. -- An ExtremaCurveCurve algorithm minimizes or -- maximizes the distance between a point on the first -- curve and a point on the second curve. Thus, it -- computes start and end points of perpendiculars -- common to the two curves (an intersection point is -- not an extremum unless the two curves are tangential at this point). -- Solutions consist of pairs of points, and an extremum -- is considered to be a segment joining the two points of a solution. -- An ExtremaCurveCurve object provides a framework for: -- - defining the construction of the extrema, -- - implementing the construction algorithm, and -- - consulting the results. -- Warning -- In some cases, the nearest points between two -- curves do not correspond to one of the computed -- extrema. Instead, they may be given by: -- - a limit point of one curve and one of the following: -- - its orthogonal projection on the other curve, -- - a limit point of the other curve; or -- - an intersection point between the two curves. uses Curve from Geom, Curve from GeomAdaptor, ExtCC from Extrema, Pnt from gp, Length from Quantity, Parameter from Quantity raises OutOfRange from Standard, NotDone from StdFail is Create ---Purpose: Constructs an empty algorithm for computing -- extrema between two curves. Use an Init function -- to define the curves on which it is going to work. returns ExtremaCurveCurve from GeomAPI; Create(C1 , C2 : Curve from Geom) ---Purpose: Computes the extrema between the curves C1 and C2. returns ExtremaCurveCurve from GeomAPI; Create(C1 , C2 : Curve from Geom; U1min, U1max : Parameter from Quantity; U2min, U2max : Parameter from Quantity) ---Purpose: Computes the portion of the curve C1 limited by the two -- points of parameter (U1min,U1max), and -- - the portion of the curve C2 limited by the two -- points of parameter (U2min,U2max). -- Warning -- Use the function NbExtrema to obtain the number -- of solutions. If this algorithm fails, NbExtrema returns 0. returns ExtremaCurveCurve from GeomAPI; Init(me : in out; C1 , C2 : Curve from Geom) ---Purpose: Initializes this algorithm with the given arguments -- and computes the extrema between the curves C1 and C2 is static; Init(me : in out; C1 , C2 : Curve from Geom; U1min, U1max : Parameter from Quantity; U2min, U2max : Parameter from Quantity) ---Purpose: Initializes this algorithm with the given arguments -- and computes the extrema between : -- - the portion of the curve C1 limited by the two -- points of parameter (U1min,U1max), and -- - the portion of the curve C2 limited by the two -- points of parameter (U2min,U2max). -- Warning -- Use the function NbExtrema to obtain the number -- of solutions. If this algorithm fails, NbExtrema returns 0. is static; NbExtrema(me) ---Purpose: Returns the number of extrema computed by this algorithm. -- Note: if this algorithm fails, NbExtrema returns 0. returns Integer from Standard ---C++: alias "Standard_EXPORT operator Standard_Integer() const;" is static; Points(me; Index : Integer from Standard; P1, P2 : out Pnt from gp ) ---Purpose: Returns the points P1 on the first curve and P2 on -- the second curve, which are the ends of the -- extremum of index Index computed by this algorithm. -- Exceptions -- Standard_OutOfRange if Index is not in the range [ -- 1,NbExtrema ], where NbExtrema is the -- number of extrema computed by this algorithm. raises OutOfRange from Standard is static; Parameters(me; Index : Integer from Standard; U1, U2 : out Parameter from Quantity) ---Purpose: Returns the parameters U1 of the point on the first -- curve and U2 of the point on the second curve, which -- are the ends of the extremum of index Index computed by this algorithm. -- Exceptions -- Standard_OutOfRange if Index is not in the range [ -- 1,NbExtrema ], where NbExtrema is the -- number of extrema computed by this algorithm. raises OutOfRange from Standard is static; Distance(me; Index : Integer from Standard) returns Length from Quantity ---Purpose: Computes the distance between the end points of the -- extremum of index Index computed by this algorithm. -- Exceptions -- Standard_OutOfRange if Index is not in the range [ -- 1,NbExtrema ], where NbExtrema is the -- number of extrema computed by this algorithm. raises OutOfRange from Standard is static; NearestPoints(me; P1, P2 : out Pnt from gp) ---Purpose: Returns the points P1 on the first curve and P2 on -- the second curve, which are the ends of the shortest -- extremum computed by this algorithm. -- Exceptions StdFail_NotDone if this algorithm fails. raises NotDone from StdFail is static; LowerDistanceParameters(me; U1, U2 : out Parameter from Quantity) ---Purpose: Returns the parameters U1 of the point on the first -- curve and U2 of the point on the second curve, which -- are the ends of the shortest extremum computed by this algorithm. -- Exceptions StdFail_NotDone if this algorithm fails. raises NotDone from StdFail is static; LowerDistance(me) ---Purpose: Computes the distance between the end points of the -- shortest extremum computed by this algorithm. -- Exceptions StdFail_NotDone if this algorithm fails. ---C++: alias "Standard_EXPORT operator Standard_Real() const;" returns Length from Quantity raises NotDone from StdFail is static; Extrema(me) ---Purpose: return the algorithmic object from Extrema ---Level: Advanced ---C++: return const& ---C++: inline returns ExtCC from Extrema is static; TotalNearestPoints(me : in out; P1, P2 : out Pnt from gp ) ---Purpose: set in and the couple solution points -- such a the distance [P1,P2] is the minimum. taking in account -- extremity points of curves. ---Level: Public returns Boolean from Standard -- returns "true" if it is possible to compute points and "false" -- if such points do not exist, for ex. - infinite parallel lines is static; TotalLowerDistanceParameters(me : in out; U1, U2 : out Parameter from Quantity) ---Purpose: set in and the parameters of the couple -- solution points which represents the total nearest -- solution. ---Level: Public returns Boolean from Standard -- returns "true" if it is possible to compute points and "false" -- if such points do not exist, for ex. - infinite parallel lines is static; TotalLowerDistance(me : in out) ---Purpose: return the distance of the total nearest couple solution -- point. ---Level: Public returns Length from Quantity raises NotDone from StdFail ---Purpose: if is not done is static; TotalPerform(me : in out) is static private; fields myIsDone: Boolean from Standard; myIndex : Integer from Standard; -- index of the nearest solution myExtCC : ExtCC from Extrema; myC1 : Curve from GeomAdaptor; myC2 : Curve from GeomAdaptor; -- Fields to compute total min. dist with extremities of curves myTotalExt : Boolean from Standard; -- indicate that total extr. -- has been computed myIsInfinite : Boolean from Standard; -- infinite extremity points myTotalDist : Real from Standard; -- total min. dist myTotalPoints : Pnt[2]; myTotalPars : Real[2]; end ExtremaCurveCurve;