/*
Copyright (c) 2004-2005, Dirk Krause
All rights reserved.

Redistribution and use in source and binary forms,
with or without modification, are permitted provided
that the following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.
* Redistributions in binary form must reproduce the above 
  opyright notice, this list of conditions and the following
  disclaimer in the documentation and/or other materials
  provided with the distribution.
* Neither the name of the Dirk Krause nor the names of
  its contributors may be used to endorse or promote
  products derived from this software without specific
  prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.
*/

#ifndef DK_XSP_INC
#define DK_XSP_INC 1

#include <dk.h>

typedef struct {
  int    useA, useB, useC, useD;	/* use function from control point */
  int     ghA,  ghB,  ghC,  ghD;	/* use g-h-blend for function */
  double   sA,   sB,   sC,   sD;	/* the s_k */
  double   tA,   tB,   tC,   tD;	/* T_A^+, T_B^+, T_C^-, T_D^- */
  double   pA,   pB,   pC,   pD;	/* p and q for calculations */
  double   qA,   qB,   qC,   qD;
  double   xA,   xB,   xC,   xD;	/* x values */
  double   yA,   yB,   yC,   yD;	/* y values */
  double   dudtA, dudtB, dudtC, dudtD;
  double   dduA, dduB, dduC, dduD;
  double    t;				/* t for calculation */
  double    x, y, ddtx, ddty;
  double   fA,   fB,   fC,   fD;	/* function results */
  double   uA,   uB,   uC,   uD;
  double ddtA, ddtB, ddtC, ddtD;	/* control functions derived */
  size_t   current, max;		/* first/last spline */
  int      isclosed;			/* 0=open spline, 1=closed */
} dk_xspline_t;

#ifdef EXTERN
#undef EXTERN
#endif
#ifdef DK_XSP_C
#define EXTERN /* nix */
#else
#if DK_HAVE_PROTOTYPES
#define EXTERN /* nix */
#else
#define EXTERN extern
#endif
#endif

#ifdef __cplusplus
extern "C" {
#endif

EXTERN void
dkxsp_reset DK_PR((dk_xspline_t *s));
EXTERN void
dkxsp_setA DK_PR((dk_xspline_t *s, double sk, double x, double y));
EXTERN void
dkxsp_setB DK_PR((dk_xspline_t *s, double sk, double x, double y));
EXTERN void
dkxsp_setC DK_PR((dk_xspline_t *s, double sk, double x, double y));
EXTERN void
dkxsp_setD DK_PR((dk_xspline_t *s, double sk, double x, double y));
EXTERN void
dkxsp_step1 DK_PR((dk_xspline_t *s));
EXTERN int
dkxsp_step2 DK_PR((dk_xspline_t *s, double t));
EXTERN void
dkxsp_set_pos DK_PR((dk_xspline_t *s, size_t c, size_t m, int isc));
#ifdef __cplusplus
}
#endif

#endif