/* Last edited on 2007-12-26 17:34:02 by stolfi */

void bb2_initialize_plot
  ( char *outName,
    bool_t epsfmt, 
    Interval xr, 
    Interval yr,
    FILE **psfP, 
    double *xsc, 
    double *ysc,
    char *title
  );
  /* Opens the output plot file and initializes scales, captions, etc.
    If {epsfmt} is true the file is encapsulated Postscript
    ("{outname}.eps") otherwise it is a plain Postscripr
    ("{outname}.ps"). The file is returned in {*psfP}.
    
    The procedure also computes factors {xsc} and {ysc} to be applied
    to the X and Y coordinates before plotting. The client plot window
    will contain the rectangle {{xsc*xr} × (ysc*yr)}. */

void bb2_finalize_plot(FILE **psfP, bool_t epsfmt);
   /* Finalizes the plot and closes the plot file {*psfP}, whose
     type is indicated by {epsf}. */

void bb2_initialize_plot
  ( char *outName,
    bool_t epsfmt, 
    Interval xr, 
    Interval yr,
    FILE **psfP, 
    double *xsc, 
    double *ysc,
    char *title
  )
  {
    PSStream *ps = NULL;
  
    /* Compute widths of {xr} and {yr}: */
    double xw = xr.hi - xr.lo;
    double yw = yr.hi - yr.lo;
    
    /* Add a safety margin around {xr,yr}: */
    xr.lo -= 0.01*xw; xr.hi += 0.01*xw; xw = xr.hi - xr.lo;
    yr.lo -= 0.01*yw; yr.hi += 0.01*yw; yw = yr.hi - yr.lo;

    /* Actual figure dimensions: */
    double hw = 420.0, vw = 420.0;   /* In pt. */
    
    /* Compute {xscale,yscale} so that {(xscale*xw)/(yscale*yw) = hw/vw}: */
    double xscale, yscale;
    { double hyq = hw*yw;
      double vxq = vw*xw;
      if (hyq < vxq)
        { xscale = hyq/vxq; yscale = 1.0; }
      else
        { xscale = 1.0; yscale = vxq/hyq; }
    }

    double mrg = 4.0;
    ps = pswr_new_stream(epsfmt, outName, NULL, "letter", hw + 2*mrg, vw + 2*mrg);
    pswr_begin_picture(ps, xr.lo, xr.hi, yscale*yr.lo, yscale*yr.hi);
    pswr_set_pen(ps, 0.0,0.0,0.0, 0.10, 0.0,0.0);
        
    if (! epsfmt) { pswr_add_caption(psfile, title, 0.5); }
    *psfP = psfile;
    *xsc = xscale;
    *ysc = yscale;
  }

void bb2_finalize_plot(PSStream **psfP, bool_t epsfmt)  
  { PSStream *ps = *psfP;
    pswr_close_stream(ps);
    (*psfP) = NULL;
  }