//===========================================================================
// Copyright (C) 1998, 2000-2007, 2010, 2011, 2012 SINTEF ICT, Applied
// Mathematics, Norway.
//
// This file is part of GoTools
//
// This program is free software; you can redistribute it and/or          
// modify it under the terms of the GNU General Public License            
// as published by the Free Software Foundation version 2 of the License. 
//
// This program 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 General Public License for more details.                           
//
// You should have received a copy of the GNU General Public License      
// along with this program; if not, see <http://www.gnu.org/licenses>
//
// Contact information: E-mail: tor.dokken@sintef.no                      
// SINTEF ICT, Department of Applied Mathematics,                         
// P.O. Box 124 Blindern,                                                 
// 0314 Oslo, Norway.                                                     
//
// Other licenses are also available for this software, notably licenses
// for:
// - Building commercial software.                                        
// - Building software whose source code you wish to keep private.        
//===========================================================================

#include "sisl-copyright.h"

/*
 *
 * $Id: s1501.c,v 1.3 2001-03-19 15:58:49 afr Exp $
 *
 */


#define S1501

#include "sislP.h"

#if defined(SISLNEEDPROTOTYPES)
void
     s1501(SISLSurf *ps1,double *base,double *norm,double *axisA,double alpha,double ratio,int idim,
	   double aepsco,double aepsge,double amax,SISLIntcurve *pintcr,
	   int icur,int igraph,int *jstat)
#else
void s1501(ps1,base,norm,axisA,alpha,ratio,idim,aepsco,aepsge,amax,pintcr,
           icur,igraph,jstat)
     SISLSurf     *ps1;
     double   *base;
     double   *norm;
     double   *axisA;
     double   alpha;
     double   ratio;
     int      idim;
     double   aepsco;
     double   aepsge;
     double   amax;
     SISLIntcurve *pintcr;
     int      icur;
     int      igraph;
     int      *jstat;
#endif
/*
*********************************************************************
*
*********************************************************************
*
* PURPOSE    : To march an intersection curve desribed by parameter pairs
*              in an intersection curve object, a B-spline surface and
*              an elliptic cone.
*
*
* INPUT      : ps1    - Pointer to surface.
*              base   - Base point of cone
*              norm   - Direction of cone axis
*              axisA  - One of the two ellipse axis vectors
*              alpha  - The opening angle of the cone at axisA
*              ratio  - The ratio of axisA to axisB
*              idim   - Dimension of the space in which the plane lies.
*              aepsco - Computational resolution.
*              aepsge - Geometry resolution.
*              amax   - Maximal allowed step length. If amax <=aepsge
*                       amax is neglected.
*              icur   - Indicator telling if a 3-D curve is to be made
*                        0 - Don't make 3-D curve
*                        1 - Make 3-D curve
*                        2 - Make 3-D curve and curves in parameter plane
*              igraph - Indicator telling if the curve is to be output
*                       through function calls:
*                        0 - don't output curve through function call
*                        1 - output as straight line segments through
*                            s6move and s6line.
*
*
*
* INPUT/OUTPUT:pintcr - The intersection curve. When coming as input
*                       only parameter values in the parameter plane
*                       exist. When coming as output the 3-D geometry
*                       and possibly the curve in the parameter plane
*                       of the surface are added.
*
* OUTPUT:      jstat  - status messages
*                         = 3      : Iteration stopped due to singular
*                                    point or degenerate surface. A part
*                                    of intersection curve may have been
*                                    traced out. If no curve is traced out
*                                    the curve pointers in the Intcurve
*                                    object point to SISL_NULL.
*                         = 0      : ok
*                         < 0      : error
*                         = -185   : No points produced on intersection curve.
*
*
* METHOD     : An implicit description of the cone is made and then
*              a routine for intersecting implicit represented geometry
*              by a B-spline surface is used.
*
* REFERENCES :
*
*-
* CALLS      : s6err, s1313, s1500
* WRITTEN BY : Mike Floater, SI, Oslo, Norway, 22 Oct, 1988
*
*********************************************************************
*/
{
  int kpos=0;         /* Position of error                                  */
  int kdeg=2;         /* The degree of the implicit equation of the plane   */
  int knumb=1;        /* Number of implicit representations to be made      */
  int kstat;          /* Local status variable                              */
  double simpli[16];  /* Array containing the implicit description of sphere*/

  if (idim != 3) goto err104;

  /* Make description of cone */

  s1500(base,norm,axisA,alpha,ratio,idim,knumb,simpli,&kstat);
  if (kstat < 0) goto error;

  /* Make intersection of implicit surface and B-spline surface */

  s1313(ps1,simpli,kdeg,aepsco,aepsge,amax,pintcr,icur,igraph,&kstat);
  if (kstat == -185) goto err185;
  if (kstat < 0) goto error;

  *jstat = kstat;
  goto out;
  /* Dimension not 3 */

 err104:
  *jstat = -104;
  s6err("s1501",*jstat,kpos);
  goto out;

  /* Couldn't march */

 err185:
  *jstat = -185;
  goto out;

  /* Error in lower level routine.  */

  error:
  *jstat = kstat;
  s6err("s1501",*jstat,kpos);
  goto out;

 out:
  return;
}
