#ifndef PZGeo4_H
#define PZGeo4_H

/* Last edited on 2007-01-25 10:08:52 by stolfi */

#define PZGeo3_H_author \
  "Based on PZ_geo.h by H.C.G.Leitão and J.Stolfi, 1999-08." \
  "Adapted by L.A.P.Lozada, 1999-2000."

#include <r4.h>

r4_t PZGeo4_LinearInterpolate(double t, double a, r4_t *pa, double b, r4_t *pb);
  /* Interpolates linearly the position at time {t} between 
    points {pa} and {b}, assuming they have times {a} and {b}. */

void PZGeo4_HermiteInterpolate
  ( double t, 
    double a, r4_t *pa, r4_t *va, 
    double b, r4_t *pb, r4_t *vb,  
    r4_t *p, r4_t *v
  );
  /* Performs cubic Hermite interpolation for argument {t} given
    positions {pa} and {pb} and velocities {va} and {vb} at times {a}
    and {b}. Best used for {t} between {a} and {b}. */

r4_t PZGeo4_BSplineApproximation
  ( double t,
    double a, 
    double b, r4_t *Pabc,
    double c, r4_t *Pbcd,
    double d, r4_t *Pcde,
    double e, r4_t *Pdef,
    double f
  );
  /* Computes the position at time {t} of a cubic B-Spline curve
    with control points {Pabc}, {Pbcd}, {Pcde}, {Pdef},
    and knot times {a},... {f}.  Assumes {t} lies between {c}
    and {d}. */

r4_t PZGeo4_CubicBezier
  ( double t,  
    r4_t *Pabc,
    r4_t *Pbcd,
    r4_t *Pcde,
    r4_t *Pdef
  );
  /* Computes the position at time {t} of a cubic Bezier curve
    with control points {Pabc}, {Pbcd}, {Pcde}, {Pdef}. */

#endif