-- File: Extrema_GenLocateExtPC.cdl -- Created: Tue Jul 18 17:40:06 1995 -- Author: Modelistation -- ---Copyright: Matra Datavision 1995 generic class GenLocateExtPC from Extrema (Curve as any; Tool as any; -- as ToolCurve(Curve); POnC as any; Pnt as any; Vec as any ) ---Purpose: It calculates the distance between a point and a -- curve with a close point. -- This distance can be a minimum or a maximum. raises DomainError from Standard, TypeMismatch from Standard, NotDone from StdFail private class PCLocF instantiates FuncExtPC (Curve, Tool, POnC, Pnt, Vec); is Create returns GenLocateExtPC; Create (P: Pnt; C: Curve; U0: Real; TolU: Real) returns GenLocateExtPC ---Purpose: Calculates the distance with a close point. -- The close point is defined by the parameter value -- U0. -- The function F(u)=distance(P,C(u)) has an extremum -- when g(u)=dF/du=0. The algorithm searchs a zero -- near the close point. -- TolU is used to decide to stop the iterations. -- At the nth iteration, the criteria is: -- abs(Un - Un-1) < TolU. raises DomainError; -- if U0 is outside the definition range of the curve. Create (P: Pnt; C: Curve; U0: Real; Umin, Usup: Real; TolU: Real) returns GenLocateExtPC ---Purpose: Calculates the distance with a close point. -- The close point is defined by the parameter value -- U0. -- The function F(u)=distance(P,C(u)) has an extremum -- when g(u)=dF/du=0. The algorithm searchs a zero -- near the close point. -- Zeros are searched between Umin et Usup. -- TolU is used to decide to stop the iterations. -- At the nth iteration, the criteria is: -- abs(Un - Un-1) < TolU. raises DomainError; -- if U0 is outside the definition range of the curve. Initialize(me: in out; C: Curve; Umin, Usup: Real; TolU: Real) ---Purpose: sets the fields of the algorithm. is static; Perform(me: in out; P: Pnt; U0: Real) ---Purpose: the algorithm is done with the point P. -- An exception is raised if the fields have not -- been initialized. raises TypeMismatch from Standard is static; IsDone (me) returns Boolean ---Purpose: Returns True if the distance is found. is static; SquareDistance (me) returns Real ---Purpose: Returns the value of the extremum square distance. raises NotDone from StdFail -- if IsDone(me)=False. is static; IsMin (me) returns Boolean ---Purpose: Returns True if the extremum distance is a minimum. raises NotDone from StdFail -- if IsDone(me)=False. is static; Point (me) returns POnC ---Purpose: Returns the point of the extremum distance. raises NotDone from StdFail -- if IsDone(me)=False. is static; fields myDone : Boolean; mytolU : Real; myumin: Real; myusup: Real; myF: PCLocF; end GenLocateExtPC;