/*
*
*  This software was developed by the Thermal Modeling and Analysis
*  Project(TMAP) of the National Oceanographic and Atmospheric
*  Administration's (NOAA) Pacific Marine Environmental Lab(PMEL),
*  hereafter referred to as NOAA/PMEL/TMAP.
*
*  Access and use of this software shall impose the following
*  obligations and understandings on the user. The user is granted the
*  right, without any fee or cost, to use, copy, modify, alter, enhance
*  and distribute this software, and any derivative works thereof, and
*  its supporting documentation for any purpose whatsoever, provided
*  that this entire notice appears in all copies of the software,
*  derivative works and supporting documentation.  Further, the user
*  agrees to credit NOAA/PMEL/TMAP in any publications that result from
*  the use of this software or in any product that includes this
*  software. The names TMAP, NOAA and/or PMEL, however, may not be used
*  in any advertising or publicity to endorse or promote any products
*  or commercial entity unless specific written permission is obtained
*  from NOAA/PMEL/TMAP. The user also understands that NOAA/PMEL/TMAP
*  is not obligated to provide the user with any support, consulting,
*  training or assistance of any kind with regard to the use, operation
*  and performance of this software nor to provide the user with any
*  updates, revisions, new versions or "bug fixes".
*
*  THIS SOFTWARE IS PROVIDED BY NOAA/PMEL/TMAP "AS IS" AND ANY EXPRESS
*  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
*  ARE DISCLAIMED. IN NO EVENT SHALL NOAA/PMEL/TMAP BE LIABLE FOR ANY SPECIAL,
*  INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
*  RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
*  CONTRACT, NEGLIGENCE OR OTHER TORTUOUS ACTION, ARISING OUT OF OR IN
*  CONNECTION WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.  
*
*/



/*      tm_world_recur - recursive C routine to locate the value of a
	coordinate from its index where the underlying axis is the child
	of some other axis

  See the FORTRAN routine
	DOUBLE PRECISION FUNCTION TM_WORLD
  as a reference

  TMAP interactive data analysis program

  programmer - steve hankin
  NOAA/PMEL, Seattle, WA - Tropical Modeling and Analysis Program

   revision history:
   10/95 - original
    5/99 *sh* - bug fix: modulo irregular axes get wrong memory subscript
    V510: 4/00 *sh* - the arrays line_parent and line_class are now indexed
                      from zero instead of from max_lines
    V541: 2/02 *sh* - added support for subspan modulo axes
                    - fixed bug in strides on modulo parent axis

    V542: 10/02 *sh* - serious bug fixes in non-modulo subspan modulo
    V698:  5/16 *acm*  ticket 513 - subspan modulo and strides

   compile this with
   cc -c -g tm_world_recur.c
   (and use -D_NO_PROTO for non-ANSI compilers)
*/ 

#include "fmtprotos.h"

/* local macro definitions */
#define PLINE_CLASS_BASIC   0
#define PLINE_CLASS_STRIDE  1
#define PLINE_CLASS_MIDPT   2
#define PLINE_CLASS_FOREIGN 3
#define PLINE_CLASS_FFT     4
#define BOX_LO_LIM          1
#define BOX_MIDDLE          2
#define BOX_HI_LIM          3

#define MIN(x, y) (( (x) < (y)) ? (x) : (y))
#define MAX(x, y) (( (x) < (y)) ? (y) : (x))

double FORTRAN(tm_world_recur)(int *isubscript, int *iaxis, int *where_in_box, int *max_lines, 
                               double line_mem[], int line_parent[], int line_class[], int line_dim[], 
                               double line_start[], double line_delta[], int line_subsc1[], 
                               int line_modulo[], double line_modulo_len[], int line_regular[])
{
  double tempwld, tm_world;
  int isub, rmod;
  int axis = *iaxis;   /* these FORTRAN arrs start at 0 like C */
  int line_len = line_dim[axis];
  int is_subspan;

/*
   if this is a child (e.g. every Nth point) of an irregularly-spaced
   axis then use a recursive C routine to find the answer
*/
  int recursive = axis > *max_lines;
  if ( recursive ) {
    recursive = line_parent[axis] != 0;    /* could use "&&" */
    if ( recursive ) {
      int new_ss, lo_ss, hi_ss, parent_len;
      int new_where;
      switch (line_class[axis]) {
      case PLINE_CLASS_STRIDE:
/* 5/99 - in irreg axis striding the box edges cannot simply be read from
          the box edge array (think about it) So we have xtra logic here.
*/
	new_ss = (int)line_start[axis]
	             +(*isubscript-1)*(int)line_delta[axis];
	
	if ( line_regular[axis] || *where_in_box==BOX_MIDDLE ) {

	  tm_world = FORTRAN(tm_world_recur)
	    (&new_ss,
	     &(line_parent[axis]),
	     where_in_box,
	     max_lines, line_mem, line_parent,
	     line_class, line_dim,
	     line_start, line_delta,
	     line_subsc1, line_modulo, line_modulo_len,
	     line_regular );

	} else {   /*  !!!! EXTRA LOGIC FOR IRREGULAR AXIS STRIDES */
	  /* cases to consider: interpolate to neighbor above or below
	                        use lower or upper limit of entire axis
	  */	  
	  if (*where_in_box ==  BOX_LO_LIM) {
	    lo_ss = (int)line_start[axis]
	             +(*isubscript-2)*(int)line_delta[axis];
	    hi_ss = new_ss;
	  } else {
	    lo_ss = new_ss;
	    hi_ss =  (int)line_start[axis]
	             +(*isubscript-0)*(int)line_delta[axis];
	  }

	  parent_len = line_dim[ line_parent[axis] ];

/* Handle subspan modulo axes, checking that if we are getting worldcoordinate 
   data from the cells at the defined axis edges the result doesn't stray into 
   the modulo void cell. Adaphed from logic for is_subspan in axis_intervals.F*/

	  is_subspan = ( FORTRAN(tm_its_subspan_modulo_int) (&line_parent[axis]) );
	  if (line_modulo[ line_parent[axis] ] && is_subspan)
	  {
		  if (lo_ss == 0 || lo_ss == -1)
		  { 
			  new_where = BOX_LO_LIM;
			  lo_ss = 1;
			  tm_world = (
			      FORTRAN(tm_world_recur)
			      (&lo_ss,
			       &(line_parent[axis]),
			       &new_where,
			       max_lines, line_mem, line_parent,
			       line_class, line_dim,
			       line_start, line_delta,
			       line_subsc1, line_modulo, line_modulo_len,
			       line_regular) );
			  return(tm_world);
		  }
		  if (hi_ss == parent_len+1)
		  {
			  new_where = BOX_HI_LIM;
			  hi_ss = parent_len;
			  tm_world = (
			      FORTRAN(tm_world_recur)
			      (&hi_ss,
			       &(line_parent[axis]),
			       &new_where,
			       max_lines, line_mem, line_parent,
			       line_class, line_dim,
			       line_start, line_delta,
			       line_subsc1, line_modulo, line_modulo_len,
			       line_regular) );
			  return(tm_world);
		  }
	  } 

	  if ( line_modulo[ line_parent[axis] ]   /* 2/02 bug fix */
	       || (lo_ss>=1 && hi_ss<=parent_len) ) {  /* interpolate */
	    new_where = BOX_MIDDLE;
	    tm_world = 0.5 * (
			      FORTRAN(tm_world_recur)
			      (&lo_ss,
			       &(line_parent[axis]),
			       &new_where,
			       max_lines, line_mem, line_parent,
			       line_class, line_dim,
			       line_start, line_delta,
			       line_subsc1, line_modulo, line_modulo_len,
			       line_regular)
	                  +   
			      FORTRAN(tm_world_recur)
			      (&hi_ss,
			       &(line_parent[axis]),
			       &new_where,
			       max_lines, line_mem, line_parent,
			       line_class, line_dim,
			       line_start, line_delta,
			       line_subsc1, line_modulo, line_modulo_len,
			       line_regular)
			      );
	  } else if (*where_in_box ==  BOX_LO_LIM) { /* lower axis edge */
	    new_ss = 1;
	    tm_world = FORTRAN(tm_world_recur)
	      (&new_ss,
	       &(line_parent[axis]),
	       where_in_box,
	       max_lines, line_mem, line_parent,
	       line_class, line_dim,
	       line_start, line_delta,
	       line_subsc1, line_modulo, line_modulo_len, line_regular);
	  } else {  /* upper axis edge */
	    new_ss = parent_len;
	    tm_world = FORTRAN(tm_world_recur)
	      (&new_ss,
	       &(line_parent[axis]),
	       where_in_box,
	       max_lines, line_mem, line_parent,
	       line_class, line_dim,
	       line_start, line_delta,
	       line_subsc1, line_modulo, line_modulo_len, line_regular);
	  }
	}
	break;

      case PLINE_CLASS_MIDPT:
	tm_world = FORTRAN(tm_world_recur)
	  (isubscript,iaxis,where_in_box,
	   max_lines, line_mem, line_parent,
	   line_class, line_dim,
	   line_start, line_delta,
	   line_subsc1, line_modulo, line_modulo_len, line_regular);
	break;
      default:
	tm_world = -999.;
      }
      return(tm_world);
    }
  }

/* 
   not a recursive access - return the same result that TM_WORLD would have.
   Force given subsc to data range as appropriate for modulo or non-modulo axes
*/
  if ( FORTRAN(tm_its_subspan_modulo_int) (&axis) ) line_len++;  /* 2/02 mod */
  if ( line_modulo[axis] ) {
    isub = ((*isubscript-1)%line_len) + 1 ;  /* inserted "+1" 5/99 */
    if (isub <= 0)
      isub += line_len;
  }
  else
      isub = MIN( line_len, MAX( 1, *isubscript ) );

/*
    the given index  falls in the "void" region of a subspan modulo axis
    ... get the box_hi_lim of the Nth point in the core region
*/
  if  ( FORTRAN(tm_its_subspan_modulo_int) (&axis)
	&& isub == line_len ) {
    double lo, hi;
    FORTRAN(tm_ww_axlims) (&axis,&lo, &hi);
/* ... now where within the grid box ? */
    if ( *where_in_box == BOX_LO_LIM )
      tempwld = hi;
    else if ( *where_in_box == BOX_MIDDLE )
      tempwld = ( hi + (lo+line_modulo_len[axis]) )/2.;
    else
      tempwld = lo + line_modulo_len[axis];
    
    if (*isubscript <= 0)
      rmod = *isubscript/line_len - 1;
    else
      rmod = (*isubscript-1)/line_len;
    tm_world = tempwld + rmod*line_modulo_len[axis];
	    

/*
   regularly spaced points
*/
    } else if ( line_regular[axis] ) {
/* ... calculate midpoint and box_size values */
    double midpoint = line_start[axis] + (isub-1)*line_delta[axis];
    double box_size = line_delta[axis];
/* ... now where within the grid box ? */
    if ( *where_in_box == BOX_LO_LIM )
      tempwld = midpoint - ( box_size / 2. );
    else if ( *where_in_box == BOX_MIDDLE )
      tempwld = midpoint;
    else
      tempwld = midpoint + ( box_size / 2. );
    
    if ( line_modulo[axis] ) {
      if (*isubscript <= 0)
	rmod = ( *isubscript/line_len - 1 );
      else
	rmod = ( (*isubscript-1)/line_len );
      tm_world = tempwld + rmod * FORTRAN(tm_modulo_axlen) (&axis);
    }
    else
      tm_world = tempwld;
  }
  else
    {
/*
  irregularly spaced points
*/
/* ... xlate subscript to location in line_mem array */
      isub  += line_subsc1[axis] - 1;
      isub--;      /* 5/99 switch to C-style zero-referenced indexing */
/* ... now, where within the grid box ? */
      if      ( *where_in_box == BOX_LO_LIM )
	tempwld = line_mem[isub+line_dim[axis]];
      else if ( *where_in_box == BOX_MIDDLE )
	tempwld = line_mem[isub];
      else
	tempwld = line_mem[isub+line_dim[axis]+1];
      
      if ( line_modulo[axis] ) {
	if (*isubscript <= 0)
	  rmod = *isubscript/line_len - 1;
	else
	  rmod = (*isubscript-1)/line_len;
	
	tm_world = tempwld + rmod * FORTRAN(tm_modulo_axlen) (&axis);
      }
      else
	tm_world = tempwld;
    }
  return(tm_world);
  
}

