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/*
* Copyright (C) 1998, 2000-2007, 2010, 2011, 2012, 2013 SINTEF ICT,
* Applied Mathematics, Norway.
*
* Contact information: E-mail: tor.dokken@sintef.no
* SINTEF ICT, Department of Applied Mathematics,
* P.O. Box 124 Blindern,
* 0314 Oslo, Norway.
*
* This file is part of SISL.
*
* SISL is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* SISL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public
* License along with SISL. If not, see
* <http://www.gnu.org/licenses/>.
*
* In accordance with Section 7(b) of the GNU Affero General Public
* License, a covered work must retain the producer line in every data
* file that is created or manipulated using SISL.
*
* Other Usage
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial activities involving the SISL library without
* disclosing the source code of your own applications.
*
* This file may be used in accordance with the terms contained in a
* written agreement between you and SINTEF ICT.
*/
#include "sisl-copyright.h"
/*
*
* $Id: s1225.c,v 1.3 2001-03-19 15:58:42 afr Exp $
*
*/
#define S1225
#include "sislP.h"
#if defined(SISLNEEDPROTOTYPES)
void
s1225(SISLCurve *curve,int der,double parvalue,int *leftknot,
double derive[],double curvature[], double *radius_of_curvature,
int *jstat)
#else
void s1225(curve,der,parvalue,leftknot,derive,curvature,
radius_of_curvature,jstat)
SISLCurve *curve;
int der;
double parvalue;
int *leftknot;
double derive[];
double curvature[];
double *radius_of_curvature;
int *jstat;
#endif
/*
*********************************************************************
*
*********************************************************************
*
* PURPOSE : Evaluate position, first derivative, curvature and radius of
* curvature of a curve at a given parameter value, from the
* left hand side.
*
*
*
* INPUT : curve - Pointer to the curve for which position
* and derivatives are to be computed.
* der - The number of derivatives to compute.
* < 0 : Error.
* = 0 : Compute position.
* = 1 : Compute position and first derivative.
* etc.
* parvalue - The parameter value at which to compute
* position and derivatives.
*
*
*
* INPUT/OUTPUT : leftknot - Pointer to the interval in the knot vector
* where ax is located. If et is the knot vector,
* the relation
*
* et[ileft] < parvalue <= et[ileft+1]
*
* should hold. (If parvalue == et[ik-1] then ileft
* should be ik-1. Here in is the number of B-spline
* coefficients.)
* If ileft does not have the right value upon
* entry to the routine, its value will be changed
* to the value satisfying the above condition.
*
*
*
* OUTPUT : derive - Double array of dimension [(ider+1)*idim]
* containing the position and derivative vectors.
* (idim is the number of components of each B-spline
* coefficient, i.e. the dimension of the Euclidean
* space in which the curve lies.)
* These vectors are stored in the following order:
* First the idim components of the position vector,
* then the idim components of the tangent vector,
* then the idim components of the second derivative
* vector, and so on.
* (The C declaration of eder as a two dimensional array
* would therefore be eder[ider+1,idim].)
* curvature - Array of dimension idim
* radius_of_curvature - A radius of curvature =-1, indicates
* that the radius of curvature is infinit.
* jstat - Status messages
* > 0 : Warning.
* = 0 : Ok.
* < 0 : Error.
*
*
* METHOD : The derivatives are evaluated from the left hand
* side by s1227
* The curvature and the radius of curvature are evaluated
* by s1307
*
* REFERENCES :
*
*-
* CALLS : s1227, s1307
*
* WRITTEN BY : Cathrine Tegnander
* MODIFIED BY :
* REVISED BY :
*
*********************************************************************
*/
{
int ider=2; /* minimum number of derivatives needed to
calculated the curvature */
int kdim = curve -> idim; /* copy curve attribute to local parameter */
int kstat=0; /* local status variable */
int kpos = 0; /* local error position */
int iknot = 0; /* local version of leftknot */
double *iderive = SISL_NULL; /* pointer to array used to store the position
and the first and second derivatives */
double *egeo = SISL_NULL; /* pointer to store curvature and radius of
curvature */
iderive= newarray(3*kdim,DOUBLE);
if (iderive == SISL_NULL)
goto err101;
egeo= newarray(3*kdim+1,DOUBLE);
if (egeo == SISL_NULL)
goto err101;
/* Evaluate the derivatives */
if (der<2)
{
s1227(curve,ider,parvalue,&iknot,iderive,&kstat);
if (kstat<0) goto error;
/* Copy position */
memcopy(derive,iderive,(der+1)*kdim,DOUBLE);
}
else
{
s1227(curve,der,parvalue,&iknot,derive,&kstat);
if (kstat<0) goto error;
/* Copy position */
memcopy(iderive,derive,3*kdim,DOUBLE);
}
*leftknot = iknot;
/* Evaluate the curvature and the radius_of_curvature */
s1307(iderive,kdim,egeo,&kstat);
if (kstat<0) goto error;
/* Copy position */
memcopy(curvature,egeo+kdim*2,kdim,DOUBLE);
*radius_of_curvature = egeo[kdim*3];
/* Free memory */
freearray(iderive);
freearray(egeo);
/* Successful computations. */
*jstat = 0;
goto out;
/* Error in scratch allocation */
err101:
*jstat = -101;
s6err("s1226",*jstat,kpos);
/* Error in lower level routine. */
error: *jstat = kstat;
s6err("S1227",*jstat,kpos);
goto out;
out: return;
}
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