/* See {PZGeo3.h} */
#include <PZGeo3.h>

/* Last edited on 2007-01-25 10:11:33 by stolfi */

#define PZGeo3_C_author \
  "Created by J. Stolfi and H. C. G. Leitão in 1999.\n" \
  "Adapted by L. A. P. Lozada, 1999-2000."

#include <r3.h>

#define _GNU_SOURCE
#include <stdio.h>
#include <math.h>

r3_t PZGeo3_LinearInterpolate(double t, double a, r3_t *pa, double b, r3_t *pb)
  { double Ca, Cb;
    if ((b - a) != 0.0)
      { Ca = (b - t)/(b - a);  Cb = 1 - Ca; }
    else
      { Ca = 0.5; Cb = 0.5; }
    return (r3_t) {{ 
        Ca*pa->c[0] + Cb*pb->c[0],
        Ca*pa->c[1] + Cb*pb->c[1],
        Ca*pa->c[2] + Cb*pb->c[2]
      }};
  }