/* See r3.h */
/* Last edited on 2021-06-09 20:43:42 by jstolfi */

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

#include <r3.h>

#include <jsrandom.h>
#include <affirm.h>
#include <rn.h>
#include <vec.h>

#define N 3

void r3_zero (r3_t *r)
  { r->c[0] = 0.0;
    r->c[1] = 0.0;
    r->c[2] = 0.0;
  }

void r3_all (double x, r3_t *r)
  { r->c[0] = x;
    r->c[1] = x;
    r->c[2] = x;
  }

void r3_axis (int32_t i, r3_t *r)
  { affirm((i >= 0) && (i < N), "r3_axis: bad index");
    r->c[0] = 0.0;
    r->c[1] = 0.0;
    r->c[2] = 0.0;

    r->c[i] = 1.0;
  }

void r3_add (r3_t *a, r3_t *b, r3_t *r)
  { r->c[0] = a->c[0] + b->c[0];
    r->c[1] = a->c[1] + b->c[1];
    r->c[2] = a->c[2] + b->c[2];
  }

void r3_sub (r3_t *a, r3_t *b, r3_t *r)
  { r->c[0] = a->c[0] - b->c[0];
    r->c[1] = a->c[1] - b->c[1];
    r->c[2] = a->c[2] - b->c[2];
  }

void r3_neg (r3_t *a, r3_t *r)
  { r->c[0] = - a->c[0];
    r->c[1] = - a->c[1];
    r->c[2] = - a->c[2];
  }

void r3_scale (double s, r3_t *a, r3_t *r)
  { r->c[0] = s * a->c[0];
    r->c[1] = s * a->c[1];
    r->c[2] = s * a->c[2];
  }

void r3_mix (double s, r3_t *a, double t, r3_t *b, r3_t *r)
  { r->c[0] = s * a->c[0] + t * b->c[0];
    r->c[1] = s * a->c[1] + t * b->c[1];
    r->c[2] = s * a->c[2] + t * b->c[2];
  }

void r3_mix_in (double s, r3_t *a, r3_t *r)
  { r->c[0] += s * a->c[0];
    r->c[1] += s * a->c[1];
    r->c[2] += s * a->c[2];
  }

void r3_weigh (r3_t *a, r3_t *w, r3_t *r)
  { r->c[0] = a->c[0] * w->c[0];
    r->c[1] = a->c[1] * w->c[1];
    r->c[2] = a->c[2] * w->c[2];
  }

double r3_norm (r3_t *a)
  { double a0 = a->c[0];
    double a1 = a->c[1];
    double a2 = a->c[2];
    return sqrt(a0*a0 + a1*a1 + a2*a2);
  }

double r3_norm_sqr (r3_t *a)
  { double a0 = a->c[0];
    double a1 = a->c[1];
    double a2 = a->c[2];
    return a0*a0 + a1*a1 + a2*a2;
  }

double r3_L_inf_norm (r3_t *a)
  { double d = 0.0;
    double a0 = fabs(a->c[0]);
    double a1 = fabs(a->c[1]);
    double a2 = fabs(a->c[2]);
    if (a0 > d) d = a0;
    if (a1 > d) d = a1;
    if (a2 > d) d = a2;
    return (d);
  }

double r3_dist (r3_t *a, r3_t *b)
  { double d0 = (a->c[0] - b->c[0]);
    double d1 = (a->c[1] - b->c[1]);
    double d2 = (a->c[2] - b->c[2]);
    double d = sqrt(d0*d0 + d1*d1 + d2*d2);
    return (d);
  }

double r3_dist_sqr (r3_t *a, r3_t *b)
  { double d0 = (a->c[0] - b->c[0]);
    double d1 = (a->c[1] - b->c[1]);
    double d2 = (a->c[2] - b->c[2]);
    return d0*d0 + d1*d1 + d2*d2;
  }

double r3_L_inf_dist (r3_t *a, r3_t *b)
  { double d = 0.0;
    double d0 = fabs(a->c[0] - b->c[0]);
    double d1 = fabs(a->c[1] - b->c[1]);
    double d2 = fabs(a->c[2] - b->c[2]);
    if (d0 > d) d = d0;
    if (d1 > d) d = d1;
    if (d2 > d) d = d2;
    return (d);
  }

double r3_dir (r3_t *a, r3_t *r)
  { double d = sqrt(a->c[0]*a->c[0] + a->c[1]*a->c[1] + a->c[2]*a->c[2]);
    r->c[0] = a->c[0]/d;
    r->c[1] = a->c[1]/d;
    r->c[2] = a->c[2]/d;
    return (d);
  }

double r3_L_inf_dir (r3_t *a, r3_t *r)
  { double d = 0.0;
    double a0 = fabs(a->c[0]);
    double a1 = fabs(a->c[1]);
    double a2 = fabs(a->c[2]);
    if (a0 > d) d = a0;
    if (a1 > d) d = a1;
    if (a2 > d) d = a2;
    r->c[0] = a->c[0]/d;
    r->c[1] = a->c[1]/d;
    r->c[2] = a->c[2]/d;
    return (d);
  }

double r3_dot (r3_t *a, r3_t *b)
  { return a->c[0]*b->c[0] + a->c[1]*b->c[1] + a->c[2]*b->c[2]; }

double r3_cos (r3_t *a, r3_t *b)
  { double a0 = a->c[0];
    double a1 = a->c[1];
    double a2 = a->c[2];

    double b0 = b->c[0];
    double b1 = b->c[1];
    double b2 = b->c[2];

    double ab = a0*b0 + a1*b1 + a2*b2;
    double aa = a0*a0 + a1*a1 + a2*a2;
    double bb = b0*b0 + b1*b1 + b2*b2;
    return ab/(sqrt(aa)*sqrt(bb));
  }

double r3_sin (r3_t *a, r3_t *b)
  { return rn_sin(N, &(a->c[0]), &(b->c[0])); }

double r3_angle (r3_t *a, r3_t *b)
  { return rn_angle(N, &(a->c[0]), &(b->c[0])); }

void r3_cross (r3_t *a, r3_t *b, r3_t *r)
  { double a0 = a->c[0];
    double a1 = a->c[1];
    double a2 = a->c[2];

    double b0 = b->c[0];
    double b1 = b->c[1];
    double b2 = b->c[2];

    r->c[0] = (a1 * b2) - (a2 * b1);
    r->c[1] = (a2 * b0) - (a0 * b2);
    r->c[2] = (a0 * b1) - (a1 * b0);
  }

double r3_det (r3_t *a, r3_t *b, r3_t *c)
  { r3_t p;
    r3_cross(a, b, &p);
    return p.c[0]*c->c[0] + p.c[1]*c->c[1] + p.c[2]*c->c[2];
  }

double r3_decomp (r3_t *a, r3_t *u, r3_t *para, r3_t *perp)
  { double u0 = u->c[0];
    double u1 = u->c[1];
    double u2 = u->c[2];

    double sau = a->c[0]*u0 + a->c[1]*u1 + a->c[2]*u2;
    if (sau == 0.0) 
      { if (para != NULL)
          { para->c[0] = 0.0; 
            para->c[1] = 0.0;
            para->c[2] = 0.0; 
          }

        if (perp != NULL)
          { perp->c[0] = a->c[0]; 
            perp->c[1] = a->c[1];
            perp->c[2] = a->c[2]; 
          } 
        return 0.0;
      }
    else
      { double suu = u0*u0 + u1*u1 + u2*u2;
        double c = sau / suu;
        double p0 = c * u0; 
        double p1 = c * u1; 
        double p2 = c * u2; 

        if (para != NULL)
          { para->c[0] = p0;
            para->c[1] = p1;
            para->c[2] = p2;
          }

        if (perp != NULL)
          { perp->c[0] = a->c[0] - p0; 
            perp->c[1] = a->c[1] - p1;
            perp->c[2] = a->c[2] - p2; 
          }
        return c;
      }
  }

int32_t r3_is_finite(r3_t *p)
  { if (fabs(p->c[0]) == INF) return FALSE;
    if (fabs(p->c[1]) == INF) return FALSE;
    if (fabs(p->c[2]) == INF) return FALSE;
    return TRUE;
  }

bool_t r3_eq(r3_t *p, r3_t *q)
  { if (p->c[0] != q->c[0]) return FALSE;
    if (p->c[1] != q->c[1]) return FALSE;
    if (p->c[2] != q->c[2]) return FALSE;
    return TRUE;
  }

void r3_throw_cube (r3_t *r)
  { r->c[0] = 2.0 * drandom() - 1.0;
    r->c[1] = 2.0 * drandom() - 1.0;
    r->c[2] = 2.0 * drandom() - 1.0;
  }

void r3_throw_dir (r3_t *r)
  { double z = 2.0 * drandom() - 1.0;
    double m = sqrt(1 - z*z);
    double theta = 2*M_PI*drandom();
    r->c[0] = m*cos(theta);
    r->c[1] = m*sin(theta);
    r->c[2] = z;
  }

void r3_throw_ball (r3_t *r)
  { double x, y, z;
    do
      { x = 2.0 * drandom() - 1.0; r->c[0] = x;
        y = 2.0 * drandom() - 1.0; r->c[1] = y;
        z = 2.0 * drandom() - 1.0; r->c[2] = z;
      }
    while (x*x + y*y + z*z >= 1.0);
  }

void r3_throw_normal (r3_t *r)
  { r->c[0] = dgaussrand();
    r->c[1] = dgaussrand();
    r->c[2] = dgaussrand();
  }

void r3_print (FILE *f, r3_t *a)
  { r3_gen_print(f, a, NULL, NULL, NULL, NULL); }

void r3_gen_print (FILE *f, r3_t *a, char *fmt, char *lp, char *sep, char *rp)
  { rn_gen_print(f, N, &(a->c[0]), fmt, lp, sep, rp); }

vec_typeimpl(r3_vec_t,r3_vec,r3_t);