/* See {pz_windo.h} */
/* Last edited on 2008-02-08 13:36:14 by stolfi */

#include <pz_window.h>
#include <pz_types.h>
#include <pz_proc.h>

#include <nget.h>
#include <fget.h>
#include <filefmt.h>

bool_t pz_window_is_empty(pz_window_t *w)
  { return 
      (w->r[0].end[0] >= w->r[0].end[1]) ||
      (w->r[1].end[0] >= w->r[1].end[1]);
  }
  
pz_window_t pz_window_join(pz_window_t *w1, pz_window_t *w2)
  { pz_window_t wr;
    int ax;
    for (ax = 0; ax < 2; ax++)
      { wr.r[ax].end[0] = fmin(w1->r[ax].end[0], w2->r[ax].end[0]);
        wr.r[ax].end[1] = fmax(w1->r[ax].end[1], w2->r[ax].end[1]);
      }
    return wr;
  }

pz_window_t pz_window_expand(pz_window_t *w, double rel)
  { pz_window_t wr;
    int ax;
    for (ax = 0; ax < 2; ax++)
      { double extra = rel*fmax(1.0e-100, w->r[ax].end[1] - w->r[ax].end[0]);
        wr.r[ax].end[0] = w->r[ax].end[0] - extra;
        wr.r[ax].end[1] = w->r[ax].end[1] + extra;
      }
    return wr;
  }

#define pz_window_FILE_TYPE "pz_window_t"
#define pz_window_FILE_VERSION "2004-04-30"

pz_window_t pz_window_read(FILE *rd)
  {
    pz_window_t w;
    filefmt_read_header(rd, pz_window_FILE_TYPE, pz_window_FILE_VERSION);
    w.r[0].end[0] = nget_double(rd, "XMin"); fget_eol(rd); 
    w.r[0].end[1] = nget_double(rd, "XMax"); fget_eol(rd); 
    w.r[1].end[0] = nget_double(rd, "YMin"); fget_eol(rd); 
    w.r[1].end[1] = nget_double(rd, "YMax"); fget_eol(rd); 
    filefmt_read_footer(rd, pz_window_FILE_TYPE);
    return w;
  }