/* See box.h. */
/* Last edited on 2002-11-09 03:58:47 by stolfi */

#include <box.h>
#include <math.h>
#include <ia.h>
#include <flt.h>
#include <js.h>

void box_corner(box_Dim d, box_Interval *b, box_Corner c, Float *x)
{
  int i;
  for (i = 0; i < d; i ++)
    { x[i] = (c & 1 ? b[i].hi : b[i].lo);
      c <<= 1;
    }
}

void box_center(box_Dim d, box_Interval *b, Float *x)
{
  int i;
  for (i = 0; i < d; i ++) { x[i] = ia_mid(b[i]); }
}

box_Axis box_max_axis(box_Dim d, box_Interval *b)
{
  int i, imax;
  Float dmax = MinusInfinity;
  for (i = 0; i < d; i ++) 
    { Float ri = ia_rad(b[i]); 
      if (ri > dmax) { dmax = ri; imax = i; }
    }
  return imax;
}

Float box_max_rad(box_Dim d, box_Interval *b)
{
  int i;
  Float dmax = MinusInfinity;
  for (i = 0; i < d; i ++) 
    { Float ri = ia_rad(b[i]); 
      if (ri > dmax) { dmax = ri; }
    }
  return dmax;
}

double box_radius(box_Dim d, box_Interval *b)
{
  int i;
  double r, r2 = Zero;
  ROUND_UP;
  for (i = 0; i < d; i ++) 
    { double ri = (double)(ia_rad(b[i])); 
      r2 += ri*ri;
    }
  r = sqrt(r2);
  ROUND_NEAR;
  return r;
}

void box_from_corners(box_Dim d, Float *x, Float *y, box_Interval *b)
{
  int i;
  for (i = 0; i < d; i ++) 
    { Float xi = x[i];
      Float yi = y[i];
      if (xi <= yi) 
        { b[i].lo = xi; b[i].hi = yi; }
      else
        { b[i].lo = yi; b[i].hi = xi; }
    }
}

void box_split(box_Dim d, box_Axis k, box_Dir dir, box_Interval *b, box_Interval *h)
{
  int i;
  for (i = 0; i < d; i ++) 
    { box_Interval *hp = &(h[i]);
      *hp = b[i];
      if (i == k)
        { Float md = ia_mid(*hp);
          if (dir != HI) { hp->hi = md; }
          if (dir != LO) { hp->lo = md; }
        }
    }
}