/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF.  The full HDF copyright notice, including       *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://support.hdfgroup.org/ftp/HDF/releases/.  *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/* $Id$ */

/*
FILE
    mfgr.c

PURPOSE
    Multi-file access to "generic" raster images

REMARKS
    These functions perform manipulate "generic" raster images.  These
    raster images are composed of "pixels" which can have multiple
    components of data-types other than 8-bit unsigned integers.  Each
    image can have multiple palettes associated with it and other 'attributes'
    in the same "name=value" style as the SD*() routines have.

DESIGN
        These routines are modeled loosely after the previous single-file
    DFGR*() routines and the current SD*() routines.  There is a table of
    pointers to sets of raster images stored in the files which have been
    initialized, similar to the current Vgroup/Vdata implementation.  The table
    contains entries for each file which contain pointers to set of information
    about the "global" attributes (for this interface) and to the set of raster
    images in the file.
        Each set of information for each file is stored in memory using
    the tbbt*() routines.
        Each raster image (RI) in the file will be stored in one Vgroup which
    will contain all the RIs created as well as the "global" raster attributes.
        Each RI in the file will be stored as a Vgroup containing the image data
    for each RI as well as the palettes and dataset attributes for that image.
    Also, each RI Vgroup will have a corresponding RIG created with it and
    maintained in parallel, for backward compatibility.

BUGS/LIMITATIONS
   Currently the following design limitations are still in place:
   1 - Cannot have pixels or palette entries which contain mixed variable
        types, ie. all the pixel/palette components must be of the same
        number type.
   2 - Currently all the components must be of valid HDF number types,
        fractional bytes (ie. 6-bit components) or 'plain' multiple byte values
        are not handled, although they can be packed into the next larger
        sized number type in order to hold them.

EXPORTED ROUTINES

File/Interface Functions:
int32 GRstart(int32 hdf_file_id)
    - Initializes the GR interface for a particular file. Returns a 'grid' to
        specify the GR group to operate on.
intn GRfileinfo(int32 grid, int32 *n_datasets, int32 *n_attrs)
    - Returns information about the datasets and "global" attributes for the
        GR interface.
intn GRend(int32 grid)
    - Terminates multi-file GR access for a file.

Image I/O Functions:
int32 GRcreate(int32 grid,char *name,int32 ncomp,int32 nt,int32 il,int32 dimsizes[2])
    - Defines a raster image in a file.  Returns a 'riid' to work with the new
        raster image.
int32 GRselect(int32 grid,int32 index)
    - Selects an existing RI to operate on.
int32 GRnametoindex(int32 grid,char *name)
    - Maps a RI name to an index which is returned.
intn GRgetiminfo(int32 riid,char *name,int32 *ncomp,int32 *nt,int32 *il,int32 dimsizes[2],int32 *n_attr)
    - Gets information about an RI which has been selected/created.
intn GRgetnluts(int32 riid)
    - Get the number of palettes (LUTs) for an image
intn GRwriteimage(int32 riid,int32 start[2],int32 stride[2],int32 count[2],void * data)
    - Writes image data to an RI.  Partial dataset writing and subsampling is
        allowed, but only with the dimensions of the dataset (ie. no UNLIMITED
        dimension support)
intn GRreadimage(int32 riid,int32 start[2],int32 stride[2],int32 count[2],void * data)
    - Read image data from an RI.  Partial reads and subsampling are allowed.
intn GRendaccess(int32 riid)
    - End access to an RI.

Dimension Functions:
int32 GRgetdimid(int32 riid,int32 index)
    - Get a dimension id ('dimid') for an RI to assign atrributes to. [Later]
intn GRsetdimname(int32 dimid,char *name)
    - Set the name of a dimension. [Later]
int32 GRdiminfo(int32 dimid,char *name,int32 *size,int32 *n_attr)
    - Get information about the dimensions attributes and size. [Later]

ID/Ref/Index Functions:
uint16 GRidtoref(int32 riid)
    - Maps an riid to a reference # for annotating or including in a Vgroup.
int32 GRreftoindex(int32 hdf_file_id,uint16 ref)
    - Maps the reference # of an RI into an index which can be used with
        GRselect.

Interlace Request Functions:
intn GRreqlutil(int32 riid,intn il)
    - Request that the next LUT read from an RI have a particular interlace.
intn GRreqimageil(int32 riid,intn il)
    - Request that the image read from an RI have a particular interlace.

LUT/Palette I/O Functions:
int32 GRgetlutid(int32 riid,int32 index)
    - Get a palette id ('palid') for an RI.
uint16 GRluttoref(int32 lutid)
    - Maps a lutid to a reference # for annotating of including in a Vgroup.
intn GRgetlutinfo(int32 lutid,int32 *ncomp,int32 *nt,int32 *il,int32 *nentries)
    - Gets information about a palette.
intn GRwritelut(int32 lutid,int32 ncomps,int32 nt,int32 il,int32 nentries,void * data)
    - Writes out a palette for an RI.
intn GRreadlut(int32 palid,void * data)
    - Reads a palette from an RI.

Special Element Functions:
int32 GRsetexternalfile(int32 riid,char *filename,int32 offset)
    - Makes the image data of an RI into an external element special element.
intn GRsetaccesstype(int32 riid,uintn accesstype)
    - Sets the access for an RI to be either serial or parallel I/O.
intn GRsetcompress(int32 riid,comp_coder_t comp_type,comp_info *cinfo)
    - Makes the image data of an RI into a compressed special element.
intn GRgetcompress(int32 riid,comp_coder_t* comp_type,comp_info *cinfo)
    - Retrieves the compression information of a raster image's data.
intn GRgetcompinfo(int32 riid,comp_coder_t* comp_type,comp_info *cinfo)
    - Retrieves the compression information of a raster image's data.
      Will replace GRgetcompress in the future.

Attribute Functions:
intn GRsetattr(int32 dimid|riid|grid,char *name,int32 attr_nt,int32 count,void * data)
    - Write an attribute for an object.
int32 GRattrinfo(int32 dimid|riid|grid,int32 index,char *name,int32 *attr_nt,int32 *count)
    - Get attribute information for an object.
intn GRgetattr(int32 dimid|riid|grid,int32 index,void * data)
    - Read an attribute for an object.
int32 GRfindattr(int32 dimid|riid|grid,char *name)
    - Get the index of an attribute with a given name for an object.

Chunking Functions:
     GRsetchunk     -- make GR a chunked GR
     GRgetchunkinfo -- get Info on GR
     GRwritechunk   -- write the specified chunk to the GR
     GRreadchunk    -- read the specified chunk to the GR
     GRsetchunkcache -- maximum number of chunks to cache 

LOCAL ROUTINES
intn GRIil_convert(const void * inbuf,gr_interlace_t inil,void * outbuf,
        gr_interlace_t outil,int32 dims[2],int32 ncomp,int32 nt);
    - Copy a pixel buffer from one interlace to another.

AUTHOR
   Quincey Koziol

MODIFICATION HISTORY
   10/20/95  - Starting writing specs & coding prototype
    3/ 8/96  - Modifications to remove compiled limits on the # of files
 */

#define MFGR_MASTER
#include "hdf.h"
#include "hlimits.h"

#ifdef H4_HAVE_LIBSZ          /* we have the library */
#include "szlib.h"
#endif

/* Local pre-processor macros */
#define XDIM    0
#define YDIM    1

/*
   * --------------------------------------------------------------------
   * PRIVATE  data structure and routines.
   * --------------------------------------------------------------------
 */
static TBBT_TREE *gr_tree=NULL;

/* Whether we've installed the library termination function yet for this interface */
PRIVATE intn library_terminate = FALSE;

typedef struct image_info_struct {
    uint16 grp_tag,grp_ref;         /* tag/ref of the group the image is in */
    uint16 img_tag,img_ref;         /* tag/ref of the image itself */
    uint16 aux_ref;                 /* ref of aux. info about an image */
    int32 offset;                   /* offset of the image data */
} imginfo_t;

PRIVATE intn GRIupdatemeta(int32 hdf_file_id,ri_info_t *img_ptr);

PRIVATE intn GRIupdateRIG(int32 hdf_file_id,ri_info_t *img_ptr);

PRIVATE intn GRIupdateRI(int32 hdf_file_id,ri_info_t *img_ptr);

PRIVATE intn GRIup_attr_data(int32 hdf_file_id,at_info_t *attr_ptr);

PRIVATE intn GRIstart(void);

PRIVATE intn GRIgetaid(ri_info_t *img_ptr, intn acc_perm);

PRIVATE intn GRIisspecial_type(int32 file_id, uint16 tag, uint16 ref);

/*--------------------------------------------------------------------------
 NAME
    rigcompare
 PURPOSE
    Compare two B-tree keys for equality.
 USAGE
    intn rigcompare(k1, k2, cmparg)
        void * k1, k2;               IN: ptrs to the keys for the tree elements
        intn cmparg;                IN/OUT: unused
 RETURNS
    Returns negative for k2>k1, positive for k2<k1 and 0 for k2=k1
 DESCRIPTION
    Similar to memcmp function, this routine just compares tree keys for
    greater/equal/lesser status.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS

  *** Only called by B-tree routines, should _not_ be called externally ***

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn rigcompare(void * k1, void * k2, intn cmparg)
{
    /* shut compiler up */
    cmparg = cmparg;

    return ((intn) ((*(int32 *) k1) - (*(int32 *) k2)));    /* valid for integer keys */
}   /* rigcompare */

/* ---------------------------- GRIgrdestroynode ------------------------- */
/*
   Frees B-Tree gr_info_t nodes

   *** Only called by B-tree routines, should _not_ be called externally ***
 */
VOID
GRIgrdestroynode(void * n)
{
    gr_info_t      *gr_ptr=(gr_info_t *)n;

    /* clear out the tbbt's */
    tbbtdfree(gr_ptr->grtree, GRIridestroynode, NULL);
    tbbtdfree(gr_ptr->gattree, GRIattrdestroynode, NULL);

    HDfree(gr_ptr);
}   /* GRIgrdestroynode */

/*--------------------------------------------------------------------------
 NAME
    GRIattrdestroynode
 PURPOSE
    Frees B-Tree attribute nodes.
 USAGE
    VOID GRIattrdestroynode(n)
        void * n;               IN: ptr to the attr node to delete
 RETURNS
    none
 DESCRIPTION
    Called internally by the tbbt*() routines, this routine is used when
    deleting trees.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS

  *** Only called by B-tree routines, should _not_ be called externally ***

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
VOID GRIattrdestroynode(void * n)
{
    at_info_t *at_ptr=(at_info_t *)n;

    if(at_ptr->name!=NULL)
        HDfree(at_ptr->name);
    if(at_ptr->data!=NULL)
        HDfree(at_ptr->data);

    HDfree(at_ptr);
}   /* GRIattrdestroynode */
       
/*--------------------------------------------------------------------------
 NAME
    GRIridestroynode
 PURPOSE
    Frees B-Tree raster-image nodes.
 USAGE
    VOID GRIridestroynode(n)
        void * n;               IN: ptr to the attr node to delete
 RETURNS
    none
 DESCRIPTION
    Called internally by the tbbt*() routines, this routine is used when
    deleting trees.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS

  *** Only called by B-tree routines, should _not_ be called externally ***

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
VOID GRIridestroynode(void * n)
{
    ri_info_t *ri_ptr=(ri_info_t *)n;

    if(ri_ptr->name!=NULL)
        HDfree(ri_ptr->name);
    if(ri_ptr->ext_name!=NULL)
        HDfree(ri_ptr->ext_name);
    tbbtdfree(ri_ptr->lattree, GRIattrdestroynode, NULL);
    if(ri_ptr->fill_value!=NULL)
        HDfree(ri_ptr->fill_value);

    HDfree(ri_ptr);
}   /* GRIridestroynode */
       
/* -------------------------- Get_grfile ------------------------ */
/*
   Looks in the TBBT gr_tree for the file ID of a file.
   Returns a pointer to the gr_info_t for that file on success, otherwise NULL.
 */
PRIVATE gr_info_t *
Get_grfile(HFILEID f)
{
    void * *t;       /* vfile_t pointer from tree */
    int32 key=(int32)f;

    t = (void **)tbbtdfind(gr_tree, &key, NULL);
    return((gr_info_t *)(t==NULL ? NULL : *t));
} /* end Get_grfile() */

/*--------------------------------------------------------------------------
 NAME
    GRIisspecial_type
 PURPOSE
    Returns the special type if the given element is special.
 USAGE
    intn GRIisspecial_type(file_id, tag, ref)
        int32 file_id;    IN: file id
        uint16 tag;    IN: tag of the element
        uint16 ref;    IN: ref of the element
 RETURNS
    Special type:
  SPECIAL_LINKED
  SPECIAL_EXT
  SPECIAL_COMP
  SPECIAL_VLINKED
  SPECIAL_CHUNKED
  SPECIAL_BUFFERED
  SPECIAL_COMPRAS
    or 0 if the element is not special element.
 DESCRIPTION
    Called internally by the GRIget_image_list to allow a chunked or 
    linked-block element to proceed eventhough its offset is 0.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS

  *** Only called by library routines, should _not_ be called externally ***

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
PRIVATE intn
GRIisspecial_type(int32 file_id, uint16 tag, uint16 ref)
{
    CONSTR(FUNC, "GRIisspecial_type");
    accrec_t* access_rec=NULL;/* access element record */
    int32     aid;
    intn      ret_value=0;

    /* clear error stack */
    HEclear();

    /* start read access on the access record of the data element, which
       is being inquired for its special information */
    aid = Hstartread(file_id, tag, ref);

    /* get the access_rec pointer */
    access_rec = HAatom_object(aid);
    if (access_rec == NULL) HGOTO_ERROR(DFE_ARGS, FAIL);

    /* only return the valid special code, anything else return 0 */
    switch (access_rec->special)
    {
  case SPECIAL_LINKED:
  case SPECIAL_EXT:
  case SPECIAL_COMP:
  case SPECIAL_VLINKED:
  case SPECIAL_CHUNKED:
  case SPECIAL_BUFFERED:
  case SPECIAL_COMPRAS:
      ret_value = access_rec->special;
      break;
  default:
      ret_value = 0;
    } /* switch */

    if (Hendaccess(aid)== FAIL)
        HERROR(DFE_CANTENDACCESS);
done:
  if(ret_value == FAIL)
    { /* Error condition cleanup */
  /* end access to the aid if it's been accessed */
  if (aid != 0)
      if (Hendaccess(aid)== FAIL)
    HERROR(DFE_CANTENDACCESS);
    } /* end if */

  /* Normal function cleanup */
  return ret_value;
}   /* GRIisspecial_type */

/* -------------------------- New_grfile ------------------------ */
/*
   Creates gr_info_t structure and adds it to the tree
   Returns a pointer to the gr_info_t for that file on success, otherwise NULL.
 */
PRIVATE gr_info_t *
New_grfile(HFILEID f)
{
    gr_info_t *g;
    
    /* Allocate the gr_info_t structure */
    if (NULL == (g = (gr_info_t *) HDcalloc(1,sizeof(gr_info_t))))
      return(NULL);

    /* Assign the file ID & insert into the tree */
    g->hdf_file_id=f;
    tbbtdins(gr_tree, g, NULL);    /* insert the vg instance in B-tree */

    return(g);
} /* end New_grfile() */

/* -------------------------- Store_imginfo ------------------------ */
/*
   Stores information into the image_info_struct.

   Added to refactor repeated code. -BMR, Jun 7, 2015
 */
PRIVATE void
Store_imginfo(
        imginfo_t *imginfo,
        uint16 grp_tag,
        uint16 grp_ref,
        uint16 img_tag,
        uint16 img_ref)
{
    imginfo->grp_tag=(uint16)grp_tag;
    imginfo->grp_ref=(uint16)grp_ref;
    imginfo->img_tag=(uint16)img_tag;
    imginfo->img_ref=(uint16)img_ref;
} /* end Store_imginfo() */

/* -------------------------- Get_oldimgs ------------------------ */
/*
   Find all images of tag searched_tag in the file and store their
   information in the list of image_info_structs.  The stored information
   include the image's tag/ref, DFTAG_NULL/DFREF_WILDCARD for the group's
   tag/ref, and the image's offset in the file.

   Returns the number of images on success, or NULL, otherwise.

   Added to refactor repeated code. -BMR, Jul 13, 2015
 */
PRIVATE intn
Get_oldimgs(int32 file_id, imginfo_t *img_info, uint16 searched_tag)
{
    uint16 find_tag, find_ref;
    int32 find_off, find_len;
    intn num_imgs = 0;
    imginfo_t *ptr = img_info;

    find_tag = find_ref = 0;
    find_off = find_len = 0;

    while (Hfind(file_id, searched_tag, DFREF_WILDCARD, &find_tag, &find_ref, &find_off, &find_len, DF_FORWARD) == SUCCEED)
    {
        /* DFTAG_NULL is passed in for parent group because old images don't
           have group structure. */
        Store_imginfo(ptr, DFTAG_NULL, DFREF_WILDCARD, find_tag, find_ref);
        ptr->offset = find_off;   /* store offset */
        num_imgs++;
        ptr++;
    }   /* end while */
    return num_imgs;
} /* end Get_oldimgs() */

/* -------------------------- Init_diminfo ------------------------ */
/*
   Initializes the dimension information.

   Added to refactor repeated code. -BMR, Apr 23, 2015
 */
PRIVATE void
Init_diminfo(dim_info_t *dim_info)
{ /* Init_diminfo */
    dim_info->dim_ref = DFREF_WILDCARD;
    dim_info->xdim = 256;
    dim_info->ydim = 1;
    dim_info->ncomps = 3;
    dim_info->nt = DFNT_UINT8;
    dim_info->file_nt_subclass = DFNTF_HDFDEFAULT;
    dim_info->il = MFGR_INTERLACE_PIXEL;
    dim_info->nt_tag = DFTAG_NULL;
    dim_info->nt_ref = DFREF_WILDCARD;
    dim_info->comp_tag = DFTAG_NULL;
    dim_info->comp_ref = DFREF_WILDCARD;
} /* end Init_diminfo */

/* -------------------------- Decode_diminfo ------------------------ */
/*
   Decodes dimension information.

   The parameter *p points to a buffer containing the data read from the
   file.  The data is the previously encoded dimension information.

   Added to refactor repeated code. -BMR, Apr 23, 2015
 */
PRIVATE void
Decode_diminfo(uint8 *p, dim_info_t *dim_info)
{
    int16 int16var;  /* temp var */

    INT32DECODE(p, dim_info->xdim);
    INT32DECODE(p, dim_info->ydim);
    UINT16DECODE(p, dim_info->nt_tag);
    UINT16DECODE(p, dim_info->nt_ref);
    INT16DECODE(p, int16var);
    dim_info->ncomps = (int32)int16var;
    INT16DECODE(p, dim_info->il);
    UINT16DECODE(p, dim_info->comp_tag);
    UINT16DECODE(p, dim_info->comp_ref);
} /* Decode_diminfo */

/*--------------------------------------------------------------------------
 NAME
    GRIget_image_list
 PURPOSE
    Find all the unique raster images in the file
 USAGE
    intn GRIget_image_list(hdf_file_id,gr_info)
        int32 hdf_file_id;          IN: file ID from Hopen
        gr_info_t *gr_info;         IN: # of unique images found
 RETURNS
    Return SUCCEED/FAIL
 DESCRIPTION
    Sifts through all the images in a file and compiles a list of all the
    unique ones.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
   o Count the maximum number of possible raster images in the file
   o Search through the file for raster images
      - Look for RI8s
      - Look for RIGs
      - Look for an RI Vgroup, then read in RIs & "global" attributes.
   o Eliminate duplicate images
   o Throw all the remaining RI8s, RIGs, and RIs into an internal table with
      appropriate information about each of them
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static intn GRIget_image_list(int32 file_id,gr_info_t *gr_ptr)
{
    CONSTR(FUNC, "GRIget_image_list");
    uint16      gr_ref;         /* ref # of the Vgroup containing new-style RIs */
    intn        curr_image;     /* current image gathering information about */
    intn        nimages;        /* total number of potential images */
    intn        noldimages;     /* count of old imgs returned by Get_oldimgs */
    int32       nri, nci, nri8, nci8, nii8, nvg;   /* number of RIs, CIs, RI8s, CI8s & II8s & Vgroups */
    uint16      find_tag, find_ref;     /* storage for tag/ref pairs found */
    int32       find_off, find_len;     /* storage for offset/lengths of tag/refs found */
    imginfo_t *img_info;        /* image info list */
    intn        i, j;           /* local counting variable */
    intn        ret_value = SUCCEED;

    HEclear();

    /* In a completely psychotic file, there could be RIGs with no corresponding
       RI8s and also RI8s with no corresponding RIGs, so assume the worst
       case and then run through them all to eliminate matched pairs */
    nri = Hnumber(file_id, DFTAG_RI);     /* count the number of RI and CIs */
    if (nri == FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);
    nci = Hnumber(file_id, DFTAG_CI);     /* count the number of RI and CIs */
    if (nci == FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);
    nri8 = Hnumber(file_id, DFTAG_RI8);     /* add the number of RI8, CI8s and II8s */
    if (nri8 == FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);
    nci8 = Hnumber(file_id, DFTAG_CI8);
    if (nci8 == FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);
    nii8 = Hnumber(file_id, DFTAG_II8);
    if (nii8 == FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);
    nvg = Hnumber(file_id, RI_TAG);
    if (nvg == FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);
    nimages = (intn) (nri + nci + nri8 + nci8 + nii8 + nvg);

    /* if there are no images just close the file and get out */
    if (nimages == 0)
      {
        ret_value = (SUCCEED);
        goto done;
      }

    /* Get space to store the image offsets */
    if ((img_info = (imginfo_t *) HDmalloc(nimages * sizeof(imginfo_t))) == NULL)
        HGOTO_ERROR(DFE_NOSPACE, FAIL);
    HDmemset(img_info, 0, (size_t)nimages * sizeof(imginfo_t));

    /* search through the GR group for raster images & global attributes */
    curr_image = 0;
    if((gr_ref=(uint16)Vfind(file_id,GR_NAME))!=0)
    {
        int32       gr_key;         /* Vgroup key of the GR Vgroup */

        gr_ptr->gr_ref=gr_ref; /* squirrel this away for later use */
        if((gr_key=Vattach(file_id,(int32)gr_ref,"r"))!=FAIL)
        {
            int32 nobjs=Vntagrefs(gr_key); /* The number of objects in the Vgroup */
            int32 img_key;  /* Vgroup key of an image */
            int32 grp_tag,grp_ref;  /* a tag/ref in the Vgroup */
            int32 img_tag,img_ref;  /* image tag/ref in the Vgroup */
            char textbuf[VGNAMELENMAX + 1];    /* buffer to store the name in */
                
            for(i=0; i<nobjs; i++)
            {
                if(Vgettagref(gr_key,i,&grp_tag,&grp_ref)==FAIL)
                    continue;
                      
                switch(grp_tag)
                {
                    case DFTAG_VG:  /* should be an image */
                        if((img_key=Vattach(file_id,grp_ref,"r"))!=FAIL)
                        {
                            if(Vgetclass(img_key,textbuf)!=FAIL)
                            {
                                if(!HDstrcmp(textbuf,RI_NAME))
                                { /* it is an image, get the image's tag/ref */
                                    for(j=0; j<Vntagrefs(img_key); j++)
                                    {
                                        if(Vgettagref(img_key,j,&img_tag,&img_ref)==FAIL)
                                            continue;
                                        /* Make sure the tag is correct, then
                                           store the image's info and the
                                           tag/ref of the vgroup that represents
                                           the image into image_info_struct and
                                           increment image count */
                                        if(img_tag==DFTAG_RI || img_tag==DFTAG_CI)
                                        {
                                            Store_imginfo(&img_info[curr_image], grp_tag, grp_ref, img_tag, img_ref);
                                            img_info[curr_image].offset = Hoffset(file_id, (uint16)img_tag, (uint16)img_ref);     /* store offset */
                                            curr_image++;
                                            break;
                                        } /* end if */
                                    } /* end for */
                                } /* end if */
                            } /* end if */
                            Vdetach(img_key);
                        } /* end if */
                        break; /* case DFTAG_VG, an image */

                    case DFTAG_VH:  /* must be a "global" attribute */
                    {
                        at_info_t *new_attr;  /* attr to add to the set of global attrs */
                        int32 at_key;         /* VData key for the attribute */

                        if((new_attr=(at_info_t *)HDmalloc(sizeof(at_info_t)))==NULL)
                            HGOTO_ERROR(DFE_NOSPACE,FAIL);
                        new_attr->ref=(uint16)grp_ref;
                        new_attr->index=gr_ptr->gattr_count;
                        new_attr->data_modified=FALSE;
                        new_attr->new_at=FALSE;
                        new_attr->data=NULL;

                        /* Open the vdata to read the attr's info */
                        if((at_key=VSattach(file_id,(int32)grp_ref,"r"))!=FAIL)
                        {
                            char *fname;

                            /* Make certain the attribute only has one field */
                            if(VFnfields(at_key)!=1)
                            {
                                VSdetach(at_key);
                                HDfree(new_attr);
                                break;
                            } /* end if */
                            new_attr->nt=VFfieldtype(at_key,0);
                            new_attr->len=VFfieldorder(at_key,0);
                            if(new_attr->len==1)
                                new_attr->len=VSelts(at_key);

                            /* Get the name of the attribute */
                            if((fname=VFfieldname(at_key,0))==NULL)
                            {
                                sprintf(textbuf,"Attribute #%d",(int)new_attr->index);
                                if((new_attr->name=(char *)HDmalloc(HDstrlen(textbuf)+1))==NULL)
                                {
                                    VSdetach(at_key);
                                    HDfree(new_attr);
                                    HGOTO_ERROR(DFE_NOSPACE,FAIL);
                                } /* end if */
                                HDstrcpy(new_attr->name,textbuf);
                            } /* end if */
                            else
                            {
                                if((new_attr->name=(char *)HDmalloc(HDstrlen(fname)+1))==NULL)
                                {
                                    VSdetach(at_key);
                                    HDfree(new_attr);
                                    HGOTO_ERROR(DFE_NOSPACE,FAIL);
                                } /* end if */
                                HDstrcpy(new_attr->name,fname);
                            } /* end else */
                                                
                            /* insert the attr instance in B-tree */ 
                            tbbtdins(gr_ptr->gattree, new_attr, NULL);

                            VSdetach(at_key);
                        } /* end if */

                        /* increment the number of GR global attributes */
                        gr_ptr->gattr_count++;
                    } /* end case DFTAG_VH, a global attribute */
                    break;

                    default:
                        break;
                } /* end switch */
            } /* end for */
            Vdetach(gr_key);
        } /* end if */
    } /* end if */

    /* Get information about the RIGs in the file */
    find_tag = find_ref = 0;
    while (Hfind(file_id, DFTAG_RIG, DFREF_WILDCARD, &find_tag, &find_ref, &find_off, &find_len, DF_FORWARD) == SUCCEED)
      {
          uint16      elt_tag, elt_ref;   /* tag/ref of items in a RIG */
          int32       group_id;       /* group ID for looking at RIG's */

          /* read RIG into memory */
          if ((group_id = DFdiread(file_id, DFTAG_RIG, find_ref)) == FAIL)
              HGOTO_ERROR(DFE_INTERNAL, FAIL);
          elt_tag = elt_ref = 0;    /* initialize bogus tag/ref */
          while (DFdiget(group_id, &elt_tag, &elt_ref)!=FAIL)
            {   /* get next tag/ref */
                if (elt_tag == DFTAG_CI || elt_tag == DFTAG_RI)
                  {   
                      if (elt_tag != DFTAG_NULL && elt_ref != DFREF_NONE) /* make certain we found an image */
                        {     /* store the information about the image */
                            Store_imginfo(&img_info[curr_image], DFTAG_RIG, find_ref, elt_tag, elt_ref);
                            img_info[curr_image].offset = Hoffset(file_id, elt_tag, elt_ref);     /* store offset */
                            curr_image++;
                        }     /* end if */
                  } /* end if */
            } /* end while */
      } /* end while */

    /* go through the RI8s */
    noldimages = Get_oldimgs(file_id, &img_info[curr_image], DFTAG_RI8);
    curr_image = curr_image + noldimages;

    /* go through the CI8s */
    noldimages = Get_oldimgs(file_id, &img_info[curr_image], DFTAG_CI8);
    curr_image = curr_image + noldimages;

    /* go through the II8s */
    noldimages = Get_oldimgs(file_id, &img_info[curr_image], DFTAG_II8);
    curr_image = curr_image + noldimages;

    /* Eliminate duplicate images by using the offset of the image data */
    /* Here's a table for how the images will be eliminated: */
    /*
                                    img_info[i].grp_tag
                                    VG              RIG             NULL(RI8)
                               +-----------------+-----------------+--------+
                            VG | j=NULL          | i=NULL          | i=NULL |
                               |                 | j.aux=i.grp_ref |        |
                               +-----------------+-----------------+--------+
    img_info[j].grp_tag     RIG| j=NULL          | j=NULL          | i=NULL |
                               | i.aux=j.grp_ref |                 |        |
                               +-----------------+-----------------+--------+
                      NULL(RI8)| j=NULL          | j=NULL          | j=NULL |
                               +-----------------+-----------------+--------+
    */

    for (i = 0; i < curr_image; i++)
    {     /* go through the images looking for duplicates */
        if(img_info[i].img_tag!=DFTAG_NULL)
            for (j = i+1; j < curr_image; j++)
            {
                /* if their refs are different, they're not duplicate, skip */
                if(img_info[i].img_ref == img_info[j].img_ref)
                    if(img_info[j].img_tag!=DFTAG_NULL)
                    {
                        /* If the element is special, get its type, to allow
                           linked block or chunked images to go into the if
                           statement below in order for the duplicate image be
                           eliminated - bug #814, BMR Feb, 2005 */
                        intn special_type = GRIisspecial_type(file_id,img_info[i].img_tag,img_info[i].img_ref);

                        if (((img_info[i].offset!= INVALID_OFFSET && img_info[i].offset!=0)
                                && img_info[i].offset == img_info[j].offset) ||
                             (img_info[i].offset==0
                                && (special_type == SPECIAL_LINKED ||
                                    special_type == SPECIAL_CHUNKED)))
                        {
                            /* eliminate the oldest tag from the match */
                            switch(img_info[i].img_tag)
                            {
                              case DFTAG_RI:
                              case DFTAG_CI: /* Newer style raster image, found in RIG & Vgroup */
                                  if(img_info[j].grp_tag==DFTAG_RIG)
                                  {
                                      img_info[j].img_tag=DFTAG_NULL;
                                      if(img_info[i].grp_tag==DFTAG_VG)
                                          img_info[i].aux_ref=img_info[j].grp_ref;
                                  } /* end if */
                                  else
                                  {
                                      if(img_info[i].grp_tag==DFTAG_VG)
                                          img_info[j].img_tag=DFTAG_NULL;
                                      else
                                      {
                                          img_info[j].img_tag=DFTAG_NULL;
                                          if(img_info[i].grp_tag==DFTAG_RIG)
                                              img_info[j].aux_ref=img_info[i].grp_ref;
                                      } /* end else */
                                  } /* end else */
                                  break;

                              case DFTAG_RI8:
                              case DFTAG_CI8:
                              case DFTAG_II8: /* Eldest style raster image, no grouping */
                                  if(img_info[j].img_tag!=DFTAG_RI8 && img_info[j].img_tag!=DFTAG_CI8 && img_info[j].img_tag!=DFTAG_II8)
                                      img_info[i].img_tag=DFTAG_NULL;
                                  else
                                      img_info[j].img_tag=DFTAG_NULL;
                                  break;

                              default:
                                  /* an image which was eliminated from the list of images */
                                  break;
                            } /* end switch */
                        } /* end if */
                    } /* end if */
            } /* end for */
    } /* end for go through the images looking for duplicates */

    /* Ok, now sort through the file for information about each image found */
    for(i=0; i<curr_image; i++)
    {
        if(img_info[i].img_tag!=DFTAG_NULL)
        {
            switch(img_info[i].grp_tag)
            {
              case DFTAG_VG: /* New style raster image, found in a Vgroup */
              {
                  ri_info_t *new_image; /* ptr to the image to read in */
                  int32 img_key;            /* Vgroup key of an image */
                  int32 img_tag,img_ref;    /* image tag/ref in the Vgroup */
                  char textbuf[VGNAMELENMAX + 1];    /* buffer to store the name in */
                  uint8 ntstring[4];        /* buffer to store NT info */
                  uint8 GRtbuf[64];         /* local buffer for reading RIG info */

                  if((img_key=Vattach(file_id,(int32)img_info[i].grp_ref,"r"))!=FAIL)
                  {
                      uint16 name_len;
                      if((new_image=(ri_info_t *)HDmalloc(sizeof(ri_info_t)))==NULL)
                      {
                          HDfree(img_info);   /* free offsets */
                          Hclose(file_id);
                          HGOTO_ERROR(DFE_NOSPACE,FAIL);
                      } /* end if */

                      /* Initialize all the fields in the image structure to zeros */
                      HDmemset(new_image,0,sizeof(ri_info_t));

                      /* Get the name of the image */
                      if(Vgetnamelen(img_key,&name_len)==FAIL)
                          name_len = 20; /* for "Raster Image #%d" */
                      if((new_image->name=(char *)HDmalloc(name_len+1))==NULL)
                          HGOTO_ERROR(DFE_NOSPACE,FAIL);
                      if(Vgetname(img_key,new_image->name)==FAIL)
                          sprintf(new_image->name,"Raster Image #%d",(int)i);

                      /* Initialize the local attribute tree */
                      new_image->lattr_count = 0;
                      new_image->lattree = tbbtdmake(rigcompare, sizeof(int32), TBBT_FAST_INT32_COMPARE);
                      if (new_image->lattree == NULL)
                          HGOTO_ERROR(DFE_NOSPACE, FAIL);
                      new_image->ri_ref=img_info[i].grp_ref;
                      if(img_info[i].aux_ref!=0)
                          new_image->rig_ref=img_info[i].aux_ref;
                      else
                          new_image->rig_ref=DFREF_WILDCARD;

                      for(j=0; j<Vntagrefs(img_key); j++)
                      {
                          if(Vgettagref(img_key,j,&img_tag,&img_ref)==FAIL)
                              continue;

                          /* parse this tag/ref pair */
                          switch(img_tag)
                          {
                            case DFTAG_RI:    /* Regular image data */
                                new_image->img_tag=(uint16)img_tag;
                                new_image->img_ref=(uint16)img_ref;
                                if(SPECIALTAG(new_image->img_tag)==TRUE)
                                {
                                    new_image->use_buf_drvr=1;
                                }
                                break;

                            case DFTAG_CI:    /* Compressed image data */
                                new_image->img_tag=(uint16)img_tag;
                                new_image->img_ref=(uint16)img_ref;
                                new_image->use_buf_drvr=1;
                                new_image->use_cr_drvr=1;
                                break;

                            case DFTAG_LUT:   /* Palette */
                                new_image->lut_tag=(uint16)img_tag;
                                new_image->lut_ref=(uint16)img_ref;

                                /* Fill in some default palette dimension info, in case there isn't a DFTAG_LD for this palette */
                                if(new_image->lut_dim.dim_ref==0)
				    Init_diminfo(&(new_image->lut_dim));
                                break;

                            case DFTAG_LD:    /* Palette dimensions */
{
                                uint8 *p = GRtbuf;
                                if (Hgetelement(file_id, (uint16)img_tag, (uint16)img_ref, GRtbuf) != FAIL)
				    Decode_diminfo(p, &(new_image->lut_dim));
                                else
                                    HGOTO_ERROR(DFE_READERROR, FAIL);

                                /* read NT */
                                if (Hgetelement(file_id, new_image->lut_dim.nt_tag, new_image->lut_dim.nt_ref, ntstring) == FAIL)
                                    HGOTO_ERROR(DFE_READERROR, FAIL);

                                /* check for any valid NT */
                                if (ntstring[1] == DFNT_NONE)
                                    break;

                                /* set NT info */
                                new_image->lut_dim.dim_ref = (uint16)img_ref;
                                new_image->lut_dim.nt = (int32)ntstring[1];
                                new_image->lut_dim.file_nt_subclass = (int32)ntstring[3];
                                if ((new_image->lut_dim.file_nt_subclass != DFNTF_HDFDEFAULT)
                                    && (new_image->lut_dim.file_nt_subclass!= DFNTF_PC)
                                    && (new_image->lut_dim.file_nt_subclass!= DFKgetPNSC(new_image->lut_dim.nt, DF_MT)))
                                    break; /* unknown subclass */
                                if (new_image->lut_dim.file_nt_subclass!= DFNTF_HDFDEFAULT)
                                {     /* if native or little endian */
                                    if (new_image->lut_dim.file_nt_subclass!= DFNTF_PC)   /* native */
                                        new_image->lut_dim.nt |= DFNT_NATIVE;
                                    else  /* little endian */
                                        new_image->lut_dim.nt |= DFNT_LITEND;
                                }     /* end if */
}
                                break;

                            case DFTAG_ID:    /* Image description info */
                            {
                                uint8 *p = GRtbuf;
                                at_info_t *new_attr;  /* attr to add to the local attr set */
                                if (Hgetelement(file_id, (uint16)img_tag, (uint16)img_ref, GRtbuf) != FAIL)
				    Decode_diminfo(p, &(new_image->img_dim));
                                else
                                    HGOTO_ERROR(DFE_READERROR, FAIL);

                                /* read NT */
                                if (Hgetelement(file_id, new_image->img_dim.nt_tag, new_image->img_dim.nt_ref, ntstring) == FAIL)
                                    HGOTO_ERROR(DFE_READERROR, FAIL);

                                /* check for any valid NT */
                                if (ntstring[1] == DFNT_NONE)
                                    break;

                                /* set NT info */
                                new_image->img_dim.dim_ref=(uint16)img_ref;
                                new_image->img_dim.nt = (int32)ntstring[1];
                                new_image->img_dim.file_nt_subclass = (int32)ntstring[3];
                                if ((new_image->img_dim.file_nt_subclass != DFNTF_HDFDEFAULT)
                                    && (new_image->img_dim.file_nt_subclass!= DFNTF_PC)
                                    && (new_image->img_dim.file_nt_subclass!= DFKgetPNSC(new_image->img_dim.nt, DF_MT)))
                                    break; /* unknown subclass */
                                if (new_image->img_dim.file_nt_subclass!= DFNTF_HDFDEFAULT)
                                {     /* if native or little endian */
                                    if (new_image->img_dim.file_nt_subclass!= DFNTF_PC)   /* native */
                                        new_image->img_dim.nt |= DFNT_NATIVE;
                                    else  /* little endian */
                                        new_image->img_dim.nt |= DFNT_LITEND;
                                }     /* end if */
                            } /* end case DFTAG_ID */

                            case DFTAG_VH:    /* Attribute information */
                            {
                                at_info_t *new_attr;  /* attr to add to the local attr set */
                                int32 at_key;         /* VData key for the attribute */

                                if((new_attr=(at_info_t *)HDmalloc(sizeof(at_info_t)))==NULL)
                                    HGOTO_ERROR(DFE_NOSPACE,FAIL);
                                new_attr->ref=(uint16)img_ref;
                                new_attr->index=new_image->lattr_count;
                                new_attr->data_modified=FALSE;
                                new_attr->new_at=FALSE;
                                new_attr->data=NULL;
                                if((at_key=VSattach(file_id,(int32)img_ref,"r"))!=FAIL)
                                {
                                    char *fname;

                                    /* Make certain the attribute only has one field */
                                    if(VFnfields(at_key)!=1)
                                    {
                                        VSdetach(at_key);
                                        HDfree(new_attr);
                                        break;
                                    } /* end if */
                                    new_attr->nt=VFfieldtype(at_key,0);
                                    new_attr->len=VFfieldorder(at_key,0);
                                    if(new_attr->len==1)
                                        new_attr->len=VSelts(at_key);

                                    /* Get the name of the attribute */
                                    if((fname=VFfieldname(at_key,0))==NULL)
                                    {
                                        sprintf(textbuf,"Attribute #%d",(int)new_attr->index);
                                        if((new_attr->name=(char *)HDmalloc(HDstrlen(textbuf)+1))==NULL)
                                        {
                                            VSdetach(at_key);
                                            HDfree(new_attr);
                                            HGOTO_ERROR(DFE_NOSPACE,FAIL);
                                        } /* end if */
                                        HDstrcpy(new_attr->name,textbuf);
                                    } /* end if */
                                    else
                                    {
                                        if((new_attr->name=(char *)HDmalloc(HDstrlen(fname)+1))==NULL)
                                        {
                                            VSdetach(at_key);
                                            HDfree(new_attr);
                                            HGOTO_ERROR(DFE_NOSPACE,FAIL);
                                        } /* end if */
                                        HDstrcpy(new_attr->name,fname);
                                    } /* end else */
                                                
                                    tbbtdins(new_image->lattree, new_attr, NULL);    /* insert the attr instance in B-tree */ 

                                    VSdetach(at_key);
                                } /* end if */

                                new_image->lattr_count++;

                                break;
                            } /* end case DFTAG_VH */

                            default:          /* Unknown tag */
                                break;
                          } /* end switch */
                      } /* end for */

                      new_image->index=gr_ptr->gr_count;
                      new_image->gr_ptr=gr_ptr; /* point up the tree */
                      tbbtdins(gr_ptr->grtree, new_image, NULL);    /* insert the new image into B-tree */ 
                      gr_ptr->gr_count++;
                      Vdetach(img_key);
                  } /* end if */
              } /* end case DFTAG_VG */
              break;

              case DFTAG_RIG:   /* Older style raster image, found in RIG */
              {
                  int32       GroupID;
                  uint16      elt_tag, elt_ref;
                  ri_info_t *new_image; /* ptr to the image to read in */
                  char textbuf[VGNAMELENMAX + 1];    /* buffer to store the name in */
                  uint8 ntstring[4];        /* buffer to store NT info */
                  uint8 GRtbuf[64];         /* local buffer for reading RIG info */

                  /* read RIG into memory */
                  if ((GroupID = DFdiread(file_id, DFTAG_RIG, img_info[i].grp_ref)) == FAIL)
                      HGOTO_ERROR(DFE_READERROR, FAIL);

                  if((new_image=(ri_info_t *)HDmalloc(sizeof(ri_info_t)))==NULL)
                  {
                      HDfree(img_info);   /* free offsets */
                      Hclose(file_id);
                      HGOTO_ERROR(DFE_NOSPACE,FAIL);
                  } /* end if */

                  /* Initialize all the fields in the image structure to zeros */
                  HDmemset(new_image,0,sizeof(ri_info_t));

                  /* Get the name of the image */
                  sprintf(textbuf,"Raster Image #%d",(int)i);
                  if((new_image->name=(char *)HDmalloc(HDstrlen(textbuf)+1))==NULL)
                      HGOTO_ERROR(DFE_NOSPACE,FAIL);
                  HDstrcpy(new_image->name,textbuf);
                  new_image->name_generated = TRUE;

                  /* Initialize the local attribute tree */
                  new_image->lattree = tbbtdmake(rigcompare, sizeof(int32), TBBT_FAST_INT32_COMPARE);
                  if (new_image->lattree == NULL)
                      HGOTO_ERROR(DFE_NOSPACE, FAIL);
                  new_image->ri_ref=DFREF_WILDCARD;
                  new_image->rig_ref=img_info[i].grp_ref;

                  while (DFdiget(GroupID, &elt_tag, &elt_ref)!=FAIL)
                  {     /* get next tag/ref */
                      switch (elt_tag)
                      {   /* process tag/ref */
                        case DFTAG_RI:    /* regular image data */
                            new_image->img_tag=elt_tag;
                            new_image->img_ref=elt_ref;
                            if(SPECIALTAG(new_image->img_tag)==TRUE)
                            {
                                new_image->use_buf_drvr=1;
                            } /* end if */
                            break;

                        case DFTAG_CI:    /* compressed image data */
                            new_image->img_tag=elt_tag;
                            new_image->img_ref=elt_ref;
                            new_image->use_buf_drvr=1;
                            new_image->use_cr_drvr=1;
                            break;

                        case DFTAG_LUT:   /* Palette */
                            new_image->lut_tag=elt_tag;
                            new_image->lut_ref=elt_ref;

                            /* Fill in some default palette dimension info, in
			       case there isn't a DFTAG_LD for this palette */
                            if(new_image->lut_dim.dim_ref==0)
                            {
				    Init_diminfo(&(new_image->lut_dim));
                            } /* end if */
                            break;

                        case DFTAG_LD:    /* Palette dimensions */
{
                            uint8 *p = GRtbuf;
                            if (Hgetelement(file_id, elt_tag, elt_ref, GRtbuf) != FAIL)
				Decode_diminfo(p, &(new_image->lut_dim));
                            else
                            {
                                DFdifree(GroupID);
                                HGOTO_ERROR(DFE_READERROR, FAIL);
                            }

                            /* read NT */
                            if (Hgetelement(file_id, new_image->lut_dim.nt_tag, new_image->lut_dim.nt_ref, ntstring) == FAIL)
                            {
                                DFdifree( GroupID );
                                HGOTO_ERROR(DFE_READERROR, FAIL);
                            }

                            /* check for any valid NT */
                            if (ntstring[1] == DFNT_NONE)
                                break;
                                              
                            /* set NT info */
                            new_image->lut_dim.dim_ref = elt_ref;
                            new_image->lut_dim.nt = (int32)ntstring[1];
                            new_image->lut_dim.file_nt_subclass = (int32)ntstring[3];
                            if ((new_image->lut_dim.file_nt_subclass != DFNTF_HDFDEFAULT)
                                && (new_image->lut_dim.file_nt_subclass!= DFNTF_PC)
                                && (new_image->lut_dim.file_nt_subclass!= DFKgetPNSC(new_image->lut_dim.nt, DF_MT)))
                                break; /* unknown subclass */
                            if (new_image->lut_dim.file_nt_subclass!= DFNTF_HDFDEFAULT)
                            {     /* if native or little endian */
                                if (new_image->lut_dim.file_nt_subclass!= DFNTF_PC)   /* native */
                                    new_image->lut_dim.nt |= DFNT_NATIVE;
                                else  /* little endian */
                                    new_image->lut_dim.nt |= DFNT_LITEND;
                            }     /* end if */
                            break;
}
                        case DFTAG_ID:    /* Image description info */
                          {
                            uint8 *p = GRtbuf;
                            if (Hgetelement(file_id, elt_tag, elt_ref, GRtbuf) != FAIL)
				Decode_diminfo(p, &(new_image->img_dim));
                            else
                            {
                                DFdifree( GroupID );
                                HGOTO_ERROR(DFE_GETELEM, FAIL);
                            }

                            /* read NT */
                            if (Hgetelement(file_id, new_image->img_dim.nt_tag, new_image->img_dim.nt_ref, ntstring) == FAIL)
                            {
                                DFdifree( GroupID );
                                HGOTO_ERROR(DFE_GETELEM, FAIL);
                            }

                            /* check for any valid NT */
                            if (ntstring[1] == DFNT_NONE)
                                break;

                            /* set NT info */
                            new_image->img_dim.dim_ref=elt_ref;
                            new_image->img_dim.nt = (int32)ntstring[1];
                            new_image->img_dim.file_nt_subclass = (int32)ntstring[3];
                            if ((new_image->img_dim.file_nt_subclass != DFNTF_HDFDEFAULT)
                                && (new_image->img_dim.file_nt_subclass!= DFNTF_PC)
                                && (new_image->img_dim.file_nt_subclass!= DFKgetPNSC(new_image->img_dim.nt, DF_MT)))
                                break; /* unknown subclass */
                            if (new_image->img_dim.file_nt_subclass!= DFNTF_HDFDEFAULT)
                            {     /* if native or little endian */
                                if (new_image->img_dim.file_nt_subclass!= DFNTF_PC)   /* native */
                                    new_image->img_dim.nt |= DFNT_NATIVE;
                                else  /* little endian */
                                    new_image->img_dim.nt |= DFNT_LITEND;
                            }     /* end if */
                            break;
                          }
                        default:    /* ignore unknown tags */
                            break;
                      } /* end switch */
                  } /* end while */
                  new_image->index=gr_ptr->gr_count;
                  new_image->gr_ptr=gr_ptr; /* point up the tree */
                  tbbtdins(gr_ptr->grtree, new_image, NULL);    /* insert the new image into B-tree */ 
                  gr_ptr->gr_count++;
              } /* end case DFTAG_RIG */
              break;

              case DFTAG_NULL:  /* Eldest style raster image, no grouping */
              {
                  ri_info_t *new_image; /* ptr to the image to read in */
                  char textbuf[VGNAMELENMAX + 1];    /* buffer to store the name in */
                  uint8 GRtbuf[64];         /* local buffer for reading RIG info */

                  if((new_image=(ri_info_t *)HDmalloc(sizeof(ri_info_t)))==NULL)
                  {
                      HDfree(img_info);   /* free offsets */
                      Hclose(file_id);
                      HGOTO_ERROR(DFE_NOSPACE,FAIL);
                  } /* end if */

                  /* Initialize all the fields in the image structure to zeros */
                  HDmemset(new_image,0,sizeof(ri_info_t));

                  /* Get the name of the image */
                  sprintf(textbuf,"Raster Image #%d",(int)i);
                  if((new_image->name=(char *)HDmalloc(HDstrlen(textbuf)+1))==NULL)
                      HGOTO_ERROR(DFE_NOSPACE,FAIL);
                  HDstrcpy(new_image->name,textbuf);
                  new_image->name_generated = TRUE;

                  /* Initialize the local attribute tree */
                  new_image->lattree = tbbtdmake(rigcompare, sizeof(int32), TBBT_FAST_INT32_COMPARE);
                  if (new_image->lattree == NULL)
                      HGOTO_ERROR(DFE_NOSPACE, FAIL);
                  new_image->ri_ref=DFREF_WILDCARD;
                  new_image->rig_ref=DFREF_WILDCARD;

                  /* Get tag/ref for image */
                  new_image->img_tag=img_info[i].img_tag;
                  new_image->img_ref=img_info[i].img_ref;

                  /* Get dimension information for this 8-bit image */

		  /* Initialize dim info to default */
		  Init_diminfo(&(new_image->img_dim));

		  /* Reassign valid values */
                  if (Hgetelement(file_id, DFTAG_ID8, new_image->img_ref, GRtbuf) != FAIL)
                  {
                      uint8      *p;
                      uint16      u;

                      p = GRtbuf;
                      UINT16DECODE(p, u);
                      new_image->img_dim.xdim=(int32)u;
                      UINT16DECODE(p, u);
                      new_image->img_dim.ydim=(int32)u;
                      new_image->img_dim.ncomps=1;
                  }   /* end if */
                  else
                      HGOTO_ERROR(DFE_GETELEM, FAIL);

                  /* Get palette information */
                  if(Hexist(file_id, DFTAG_IP8, new_image->img_ref)==SUCCEED)
                  {
                      new_image->lut_tag=DFTAG_IP8;
                      new_image->lut_ref=new_image->img_ref;

                      /* set palette dimensions too */
		      Init_diminfo(&(new_image->lut_dim));
                  } /* end if */
                  else
                      new_image->lut_tag=new_image->lut_ref=DFREF_WILDCARD;

                  new_image->index=gr_ptr->gr_count;
                  new_image->gr_ptr=gr_ptr; /* point up the tree */
                  tbbtdins(gr_ptr->grtree, new_image, NULL);    /* insert the new image into B-tree */ 
                  gr_ptr->gr_count++;
              } /* end case DFTAG_NULL */
              break;

              default: /* an image which was eliminated from the list of images */
                  break;
            } /* end switch */
        } /* end if */
    } /* end for */

    HDfree(img_info);   /* free image info structures */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */

  return ret_value;
} /* end GRIget_image_list() */

/*--------------------------------------------------------------------------
 NAME
    GRIil_convert
 PURPOSE
    Convert a buffer from one interlace to another.
 USAGE
    intn GRIil_convert(inbuf,inil,outbuf,outil,dims,ncomp,nt)
        const void * inbuf;          IN: input buffer
        gr_interlace_t inil;        IN: input buffer's interlace scheme
        void * outbuf;               IN: output buffer
        gr_interlace_t outil;       IN: output buffer's requested interlace scheme
        int32 dims[2];              IN: dimensions of the buffers
        int32 ncomp;                IN: both buffer's number of components per pixel
        int32 nt;                   IN: both buffer's pixel number-type
 RETURNS
    Returns SUCCEED/FAIL
 DESCRIPTION
    This routine converts between PIXEL, LINE & COMPONENT interlacing schemes.
    All data written to the disk is written in PIXEL interlacing and converted
    to/from the user's buffers.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    This routine does no parameter checking, it's assumed to be done at a
    higher layer.

    This routine also does not handle the case where the inbuf==outbuf, i.e.
    switching the interlace 'in-place'.  More work would be required to enable
    this to be done.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRIil_convert(const void * inbuf,gr_interlace_t inil,void * outbuf,
        gr_interlace_t outil,int32 dims[2],int32 ncomp,int32 nt)
{
    CONSTR(FUNC, "GRIil_convert");    /* for HERROR */
    intn ret_value=SUCCEED;
    uintn pixel_size=(uintn)DFKNTsize((nt|DFNT_NATIVE)&(~DFNT_LITEND))*(uintn)ncomp;
    uintn comp_size=(uintn)DFKNTsize((nt|DFNT_NATIVE)&(~DFNT_LITEND));
    const void * *in_comp_ptr=NULL;    /* an array of pointers to each input component */
    void * *out_comp_ptr=NULL;   /* an array of pointers to each output component */
    int32 *in_pixel_add=NULL;   /* an array of increments for each input pixel moved */
    int32 *out_pixel_add=NULL;  /* an array of increments for each output pixel moved */
    int32 *in_line_add=NULL;    /* an array of increments for each input line moved */
    int32 *out_line_add=NULL;   /* an array of increments for each output line moved */
    intn i,j,k;       /* local counting variables */

    if(inil==outil)     /* check for trivial input=output 'conversion' */
        HDmemcpy(outbuf,inbuf,(size_t)dims[XDIM]*(size_t)dims[YDIM]*(size_t)pixel_size);
    else
      {
          /* allocate pixel pointer arrays */
          if((in_comp_ptr=HDmalloc(sizeof(void *)*(size_t)ncomp))==NULL)
              HGOTO_ERROR(DFE_NOSPACE, FAIL);
          if((out_comp_ptr=HDmalloc(sizeof(void *)*(size_t)ncomp))==NULL)
              HGOTO_ERROR(DFE_NOSPACE, FAIL);

          /* allocate pixel increment arrays */
          if((in_pixel_add=HDmalloc(sizeof(int32)*(size_t)ncomp))==NULL)
              HGOTO_ERROR(DFE_NOSPACE, FAIL);
          if((out_pixel_add=HDmalloc(sizeof(int32)*(size_t)ncomp))==NULL)
              HGOTO_ERROR(DFE_NOSPACE, FAIL);

          /* allocate line increment arrays */
          if((in_line_add=HDmalloc(sizeof(int32)*(size_t)ncomp))==NULL)
              HGOTO_ERROR(DFE_NOSPACE, FAIL);
          if((out_line_add=HDmalloc(sizeof(int32)*(size_t)ncomp))==NULL)
              HGOTO_ERROR(DFE_NOSPACE, FAIL);

          /* Set up the input buffer pointers and adders */
          switch(inil)
            {
                case MFGR_INTERLACE_PIXEL:
                    for(i=0; i<ncomp; i++)
                      {
                        in_comp_ptr[i]=((const uint8 *)inbuf)+(size_t)i*comp_size;
                        in_pixel_add[i]=(int32)pixel_size;
                        in_line_add[i]=0;
                      } /* end for */
                    break;

                case MFGR_INTERLACE_LINE:
                    for(i=0; i<ncomp; i++)
                      {
                        in_comp_ptr[i]=((const uint8 *)inbuf)+(size_t)i*(size_t)dims[XDIM]*comp_size;
                        in_pixel_add[i]=(int32)comp_size;
                        in_line_add[i]=(int32)((size_t)(ncomp-1)*(size_t)dims[XDIM]*comp_size);
                      } /* end for */
                    break;

                case MFGR_INTERLACE_COMPONENT:
                    for(i=0; i<ncomp; i++)
                      {
                        in_comp_ptr[i]=((const uint8 *)inbuf)+(size_t)i*(size_t)dims[YDIM]*(size_t)dims[XDIM]*comp_size;
                        in_pixel_add[i]=(int32)comp_size;
                        in_line_add[i]=0;
                      } /* end for */
                    break;

                default:
                    HGOTO_ERROR(DFE_ARGS, FAIL);
            } /* end switch */

          /* Set up the output buffer pointers and adders */
          switch(outil)
            {
                case MFGR_INTERLACE_PIXEL:
                    for(i=0; i<ncomp; i++)
                      {
                        out_comp_ptr[i]=((uint8 *)outbuf)+(size_t)i*comp_size;
                        out_pixel_add[i]=(int32)pixel_size;
                        out_line_add[i]=0;
                      } /* end for */
                    break;

                case MFGR_INTERLACE_LINE:
                    for(i=0; i<ncomp; i++)
                      {
                        out_comp_ptr[i]=((uint8 *)outbuf)+(size_t)i*(size_t)dims[XDIM]*comp_size;
                        out_pixel_add[i]=(int32)comp_size;
                        out_line_add[i]=(int32)((size_t)(ncomp-1)*(size_t)dims[XDIM]*comp_size);
                      } /* end for */
                    break;

                case MFGR_INTERLACE_COMPONENT:
                    for(i=0; i<ncomp; i++)
                      {
                        out_comp_ptr[i]=((uint8 *)outbuf)+(size_t)i*(size_t)dims[YDIM]*(size_t)dims[XDIM]*comp_size;
                        out_pixel_add[i]=(int32)comp_size;
                        out_line_add[i]=0;
                      } /* end for */
                    break;

                default:
                    HGOTO_ERROR(DFE_ARGS, FAIL);
            } /* end switch */

        /* now just push pixels from one buffer to another */
        for(i=0; i<dims[YDIM]; i++)
          {
              for(j=0; j<dims[XDIM]; j++)
                {
                    for(k=0; k<ncomp; k++)
                      {
                          HDmemcpy(out_comp_ptr[k],in_comp_ptr[k],comp_size);
                          out_comp_ptr[k]=((uint8 *)out_comp_ptr[k])+out_pixel_add[k];
                          in_comp_ptr[k]=((const uint8 *)in_comp_ptr[k])+in_pixel_add[k];
                      } /* end for */
                } /* end for */

              /* wrap around the end of the line of pixels */
              /* (only necessary if one of the buffers is in 'line' interlace) */
              if(inil==MFGR_INTERLACE_LINE || outil==MFGR_INTERLACE_LINE)
                  for(k=0; k<ncomp; k++)
                    {
                        out_comp_ptr[k]=((uint8 *)out_comp_ptr[k])+out_line_add[k];
                        in_comp_ptr[k]=((const uint8 *)in_comp_ptr[k])+in_line_add[k];
                    } /* end for */
          } /* end for */
      } /* end else */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */

    /* Free arrays allocated during this routine */
    /* (common for both error and normal returns) */
    if(in_comp_ptr!=NULL)
        HDfree((void*)in_comp_ptr);
    if(out_comp_ptr!=NULL)
        HDfree(out_comp_ptr);
    if(in_pixel_add!=NULL)
        HDfree(in_pixel_add);
    if(out_pixel_add!=NULL)
        HDfree(out_pixel_add);
    if(in_line_add!=NULL)
        HDfree(in_line_add);
    if(out_line_add!=NULL)
        HDfree(out_line_add);

  return ret_value;
} /* end GRIil_convert() */

/*--------------------------------------------------------------------------
 NAME
    GRstart
 PURPOSE
    Initialize the GR*() interface for a given HDF file.
 USAGE
    int32 GRstart(hdf_file_id)
        int32 hdf_file_id;          IN: file ID from Hopen
 RETURNS
    Return grid on success or FAIL
 DESCRIPTION
    Initializes the GR*() interface to operate on the HDF file which was
    specified by hdf_file_id.  This routine must be called before any further
    GR*() routines are called for a file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int32 GRstart(int32 hdf_file_id)
{
    CONSTR(FUNC, "GRstart");    /* for HERROR */
    gr_info_t *gr_ptr;          /* ptr to the new GR information for a file */
    int32  ret_value = SUCCEED;

    /* clear error stack and check validity of file id */
    HEclear();

    /* Perform global, one-time initialization */
    if (library_terminate == FALSE)
        if(GRIstart()==FAIL)
            HGOTO_ERROR(DFE_CANTINIT, FAIL);

    /* check the validity of the file ID */
    if(!HDvalidfid(hdf_file_id))
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Check if GR file tree has been allocated */
    if (gr_tree == NULL)
      {
          if ((gr_tree = tbbtdmake(rigcompare, sizeof(int32), TBBT_FAST_INT32_COMPARE)) == NULL)
              HGOTO_ERROR(DFE_NOSPACE, FAIL);

          /* Initialize the atom groups for GRs and RIs */
          HAinit_group(GRIDGROUP,GRATOM_HASH_SIZE);
          HAinit_group(RIIDGROUP,GRATOM_HASH_SIZE);
      } /* end if */

    /* Grab the existing gr_info_t structure first, otherwise create a new one */
    if ((gr_ptr = Get_grfile(hdf_file_id)) == NULL)
        if ((gr_ptr = New_grfile(hdf_file_id)) == NULL)
            HGOTO_ERROR(DFE_FNF, FAIL);

    if (gr_ptr->access==0)
      {
        /* Fire up the Vset interface */
        if(Vstart(hdf_file_id)==FAIL)
            HGOTO_ERROR(DFE_CANTINIT,FAIL);

        /* Initialize the starting information for the interface */
        gr_ptr->hdf_file_id=hdf_file_id;
        gr_ptr->gr_ref=DFREF_WILDCARD;
        gr_ptr->gr_count=0;
        gr_ptr->grtree = tbbtdmake(rigcompare, sizeof(int32), TBBT_FAST_INT32_COMPARE);
        if (gr_ptr->grtree == NULL)
            HGOTO_ERROR(DFE_NOSPACE, FAIL);
        gr_ptr->gr_modified=0;

        gr_ptr->gattr_count=0;
        gr_ptr->gattree = tbbtdmake(rigcompare, sizeof(int32), TBBT_FAST_INT32_COMPARE);
        if (gr_ptr->gattree == NULL)
            HGOTO_ERROR(DFE_NOSPACE, FAIL);
        gr_ptr->gattr_modified=0;
        gr_ptr->attr_cache=GR_ATTR_THRESHHOLD;

        /* Go get all the images and attributes in the file */
        if(GRIget_image_list(hdf_file_id,gr_ptr)==FAIL)
            HGOTO_ERROR(DFE_INTERNAL,FAIL);
      } /* end else */
    gr_ptr->access++;

    /* Return handle to the GR interface to the user */
    ret_value=HAregister_atom(GRIDGROUP,gr_ptr);


done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRstart() */

/*--------------------------------------------------------------------------
 NAME
    GRfileinfo
 PURPOSE
    Report high-level information about the GR*() interface for a given file.
 USAGE
    intn GRfileinfo(grid, n_datasets, n_attrs)
        int32 grid;                 IN: GR ID to get information about
        int32 *n_datasets;          OUT: the # of GR datasets in a file
        int32 *n_attrs;             OUT: the # of "global" GR attributes
 RETURNS
    SUCCEED/FAIL
 DESCRIPTION
    Reports general information about the number of datasets and "global"
    attributes for the GR interface.  This routine is generally used to find
    the range of acceptable indices for GRselect calls.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRfileinfo(int32 grid,int32 *n_datasets,int32 *n_attrs)
{
    CONSTR(FUNC, "GRfileinfo");    /* for HERROR */
    gr_info_t *gr_ptr;          /* ptr to the GR information for a file */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of file id */
    HEclear();

    /* check the validity of the GR ID */
    if (HAatom_group(grid)!=GRIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate GR's object in hash table */
    if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(grid)))
        HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

    /* Get the number of datasets & global attributes from the memory structures */
    if(n_datasets!=NULL)
        *n_datasets=gr_ptr->gr_count;
    if(n_attrs!=NULL)
        *n_attrs=gr_ptr->gattr_count;
        

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRfileinfo() */

/*--------------------------------------------------------------------------
 NAME
    GRIupdatemeta
 PURPOSE
    Internal routine to update the meta-data for an image
 USAGE
    intn GRIupdatemeta(hdf_file_id,img_ptr)
        int32 hdf_file_id;          IN: the file ID for the HDF file.
        ri_info_t *img_ptr;         IN: pointer to the image info for the
                                        image to write.
 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Write out the meta-information about an image (& palette) to an HDF file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    Shared by both GRIupdateRIG() and GRIupdateRI() calls.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
PRIVATE intn GRIupdatemeta(int32 hdf_file_id,ri_info_t *img_ptr)
{
    CONSTR(FUNC, "GRIupdatemeta");   /* for HERROR */
    uint8 GRtbuf[64];   /* local buffer for reading RIG info */
    uint8 ntstring[4];  /* temporary storage for the number type information */
    uint8 *p;           /* temporary pointer into buffer */
    intn  ret_value = SUCCEED;

    HEclear();
    if (!HDvalidfid(hdf_file_id) || img_ptr==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Weird test below to allow for tag/ref values of zero.  (I'll spare */
    /*  everyone my rant about why DFTAG_NULL should have been made zero */
    /*  instead of one... QAK) */
    if(img_ptr->img_dim.nt_tag<=(uint16)DFTAG_NULL)
        img_ptr->img_dim.nt_tag=DFTAG_NT;
    if(img_ptr->img_dim.nt_ref==DFREF_WILDCARD)
        img_ptr->img_dim.nt_ref=Htagnewref(hdf_file_id,img_ptr->img_dim.nt_tag);
    
    /* Write out the raster image's number-type record */
    ntstring[0] = DFNT_VERSION;     /* version */
    ntstring[1] = (uint8)img_ptr->img_dim.nt;       /* type */
    ntstring[2] = (uint8)(DFKNTsize(img_ptr->img_dim.nt)*8); /* width: RIG data is 8-bit chars */
    ntstring[3] = DFNTC_BYTE;       /* class: data are numeric values */
    if (Hputelement(hdf_file_id, img_ptr->img_dim.nt_tag,
            img_ptr->img_dim.nt_ref, ntstring, (int32) 4) == FAIL)
        HGOTO_ERROR(DFE_PUTELEM, FAIL);
    
    /* Check for a palette with this image */
    if(img_ptr->lut_ref!=DFREF_WILDCARD)
      {
          /* Write out the palette number-type */
          if(img_ptr->lut_dim.nt_tag<=(uint16)DFTAG_NULL)
              img_ptr->lut_dim.nt_tag=DFTAG_NT;
          if(img_ptr->lut_dim.nt_ref==DFREF_WILDCARD)
              img_ptr->lut_dim.nt_ref=Htagnewref(hdf_file_id,img_ptr->lut_dim.nt_tag);
          ntstring[0] = DFNT_VERSION;     /* version */
          ntstring[1] = DFNT_UCHAR;       /* type */
          ntstring[2] = 8;                /* width: RIG data is 8-bit chars */
          ntstring[3] = DFNTC_BYTE;       /* class: data are numeric values */
          if (Hputelement(hdf_file_id, img_ptr->lut_dim.nt_tag,
                  img_ptr->lut_dim.nt_ref, ntstring, (int32)4) == FAIL)
              HGOTO_ERROR(DFE_PUTELEM, FAIL);

          /* Write out the palette dimensions */
          p = GRtbuf;
          INT32ENCODE(p, img_ptr->lut_dim.xdim);
          INT32ENCODE(p, img_ptr->lut_dim.ydim);
          UINT16ENCODE(p, img_ptr->lut_dim.nt_tag);
          UINT16ENCODE(p, img_ptr->lut_dim.nt_ref);
          INT16ENCODE(p, img_ptr->lut_dim.ncomps);
/* Currently all data is written out in 'pixel' interlace, so force the */
/* interlace stored on disk to match, instead of the interlacing that the */
/* user created the image with. -QAK  */
#ifdef LATER
          INT16ENCODE(p, img_ptr->lut_dim.il);
#else /* LATER */
          INT16ENCODE(p, (int16)MFGR_INTERLACE_PIXEL);
#endif /* LATER */
          UINT16ENCODE(p, img_ptr->lut_dim.comp_tag);
          UINT16ENCODE(p, img_ptr->lut_dim.comp_ref);
          if(img_ptr->lut_dim.dim_ref==DFREF_WILDCARD)
              img_ptr->lut_dim.dim_ref=Htagnewref(hdf_file_id,DFTAG_LD);
          if (Hputelement(hdf_file_id, DFTAG_LD, img_ptr->lut_dim.dim_ref, GRtbuf, (int32)(p-GRtbuf)) == FAIL)
              HGOTO_ERROR(DFE_PUTELEM, FAIL);
      } /* end if */

    /* Write out the image dimensions */
    p = GRtbuf;
    INT32ENCODE(p, img_ptr->img_dim.xdim);
    INT32ENCODE(p, img_ptr->img_dim.ydim);
    UINT16ENCODE(p, img_ptr->img_dim.nt_tag);
    UINT16ENCODE(p, img_ptr->img_dim.nt_ref);
    INT16ENCODE(p, img_ptr->img_dim.ncomps);
/* Currently all data is written out in 'pixel' interlace, so force the */
/* interlace stored on disk to match, instead of the interlacing that the */
/* user created the image with. -QAK  */
#ifdef LATER
    INT16ENCODE(p, img_ptr->img_dim.il);
#else /* LATER */
    INT16ENCODE(p, (int16)MFGR_INTERLACE_PIXEL);
#endif /* LATER */
    UINT16ENCODE(p, img_ptr->img_dim.comp_tag);
    UINT16ENCODE(p, img_ptr->img_dim.comp_ref);
    if(img_ptr->img_dim.dim_ref==DFREF_WILDCARD)
        img_ptr->img_dim.dim_ref=Htagnewref(hdf_file_id,DFTAG_ID);
    if (Hputelement(hdf_file_id, DFTAG_ID, img_ptr->img_dim.dim_ref, GRtbuf, (int32)(p-GRtbuf)) == FAIL)
        HGOTO_ERROR(DFE_PUTELEM, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */

  return ret_value;
} /* end GRIupdatemeta() */

/*--------------------------------------------------------------------------
 NAME
    GRIupdateRIG
 PURPOSE
    Internal routine to update the RIG for an image
 USAGE
    intn GRIupdateRIG(hdf_file_id,img_ptr)
        int32 hdf_file_id;          IN: the file ID for the HDF file.
        ri_info_t *img_ptr;         IN: pointer to the image info for the
                                        image to write.
 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Write out the RIG structure to an HDF file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
PRIVATE intn GRIupdateRIG(int32 hdf_file_id,ri_info_t *img_ptr)
{
    CONSTR(FUNC, "GRIupdateRIG");   /* for HERROR */
    int32 GroupID;      /* RIG id for group interface */
    intn   ret_value = SUCCEED;

    HEclear();
    if (!HDvalidfid(hdf_file_id) || img_ptr==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Don't write out a RIG, unless it is compatible with the older RIGS */
    /*  which already exist.  This is to guarantee compatibility with older */
    /*  software, both application and in the library */
    if(img_ptr->img_dim.nt!=DFNT_UINT8 || (img_ptr->img_dim.ncomps!=1
            && img_ptr->img_dim.ncomps!=3))
      {
        ret_value =(SUCCEED); /* lie and say it's ok - QAK */
        goto done;
      }

    /* Write out the image/palette meta-information */
    if (GRIupdatemeta(hdf_file_id,img_ptr)==FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);

    /* Write out the RIG itself */
    if ((GroupID = DFdisetup(6)) == FAIL)    /* max 6 tag/refs in set */
        HGOTO_ERROR(DFE_GROUPSETUP, FAIL);

    /* add image dimension tag/ref to RIG */
    if (DFdiput(GroupID, DFTAG_ID, (uint16) img_ptr->img_dim.dim_ref) == FAIL)
        HGOTO_ERROR(DFE_PUTGROUP, FAIL);

    /* add image data tag/ref to RIG */
    if (DFdiput(GroupID, img_ptr->img_tag, img_ptr->img_ref) == FAIL)
        HGOTO_ERROR(DFE_PUTGROUP, FAIL);

    /* Check if we should write palette information */
    if(img_ptr->lut_ref!=DFREF_WILDCARD)
      {
          /* add palette dimension tag/ref to RIG */
          if (DFdiput(GroupID, DFTAG_LD, (uint16) img_ptr->lut_dim.dim_ref) == FAIL)
              HGOTO_ERROR(DFE_PUTGROUP, FAIL);

          /* add palette data tag/ref to RIG */
          if (DFdiput(GroupID, img_ptr->lut_tag, img_ptr->lut_ref) == FAIL)
              HGOTO_ERROR(DFE_PUTGROUP, FAIL);
      } /* end if */

    /* write out RIG */
    if(img_ptr->rig_ref==DFTAG_WILDCARD)
        img_ptr->rig_ref=Htagnewref(hdf_file_id,DFTAG_RIG);
    if(DFdiwrite(hdf_file_id, GroupID, DFTAG_RIG, img_ptr->rig_ref)==FAIL)
        HGOTO_ERROR(DFE_GROUPWRITE, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */

  return ret_value;
} /* end GRIupdateRIG() */

/*--------------------------------------------------------------------------
 NAME
    GRIupdateRI
 PURPOSE
    Internal routine to update the RI Vgroup for an image
 USAGE
    intn GRIupdateRI(hdf_file_id,img_ptr)
        int32 hdf_file_id;          IN: the file ID for the HDF file.
        ri_info_t *img_ptr;         IN: pointer to the image info for the
                                        image to write.
 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Write out the RI Vgroup to an HDF file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
PRIVATE intn GRIupdateRI(int32 hdf_file_id,ri_info_t *img_ptr)
{
    CONSTR(FUNC, "GRIupdateRI");   /* for HERROR */
    int32 GroupID;      /* RI vgroup id */
    intn  ret_value = SUCCEED;
    int32 temp_ref;     /* used to hold the returned value from a function
                                that may return a ref or a FAIL - BMR */


    HEclear();
    if (!HDvalidfid(hdf_file_id) || img_ptr==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Write out the image/palette meta-information */
    if (GRIupdatemeta(hdf_file_id,img_ptr)==FAIL)
        HGOTO_ERROR(DFE_INTERNAL, FAIL);

    /* Write out the RI Vgroup itself */
    if ((GroupID = Vattach(hdf_file_id,(img_ptr->ri_ref!=DFREF_WILDCARD ?
            img_ptr->ri_ref : -1),"w")) == FAIL)
        HGOTO_ERROR(DFE_CANTATTACH, FAIL);

    /* grab the ref. # of the new Vgroup */
    if(img_ptr->ri_ref==DFREF_WILDCARD)
    {
    /* due to uint16 type of ref, check return value of VQueryref
         and assign it to ri_ref only when it's not FAIL - BMR */
    temp_ref = VQueryref (GroupID);
    if(temp_ref == FAIL)
        HGOTO_ERROR(DFE_BADREF,FAIL);
    img_ptr->ri_ref = (uint16)temp_ref;
    }

    /* Set the name of the RI */
    if(img_ptr->name!=NULL)
        if(Vsetname(GroupID,img_ptr->name)==FAIL)
            HGOTO_ERROR(DFE_BADVSNAME,FAIL);

    /* Set the class of the RI group */
    if(Vsetclass(GroupID,RI_NAME)==FAIL)
        HGOTO_ERROR(DFE_BADVSNAME,FAIL);

    /* add image dimension tag/ref to RIG */
    if (Vaddtagref(GroupID, DFTAG_ID, (int32)img_ptr->img_dim.dim_ref) == FAIL)
        HGOTO_ERROR(DFE_CANTADDELEM, FAIL);

    /* If we don't have a tag for the image, just use DFTAG_RI for now */
    if(img_ptr->img_tag==DFTAG_NULL)
        img_ptr->img_tag=DFTAG_RI;

    /* If we don't have a ref for the image, generate a new one */
    if(img_ptr->img_ref==DFREF_WILDCARD) {
        int32 temp_aid;

        /* Assign reference number for image */
        img_ptr->img_ref=Htagnewref(hdf_file_id,img_ptr->img_tag);

        /* Make certain that the tag/ref pair is allocated in the file */
        if((temp_aid=Hstartaccess(hdf_file_id,img_ptr->img_tag,img_ptr->img_ref,DFACC_WRITE))==FAIL)
            HGOTO_ERROR(DFE_CANTADDELEM, FAIL);
        Hendaccess(temp_aid);
    } /* end if */

    /* add image data tag/ref to RIG */
    if (Vaddtagref(GroupID, (int32)img_ptr->img_tag, (int32)img_ptr->img_ref) == FAIL)
        HGOTO_ERROR(DFE_CANTADDELEM, FAIL);

    /* Check if we should write palette information */
    if(img_ptr->lut_ref!=DFREF_WILDCARD)
      {
          /* add palette dimension tag/ref to RIG */
          if (Vaddtagref(GroupID, DFTAG_LD, (int32)img_ptr->lut_dim.dim_ref) == FAIL)
              HGOTO_ERROR(DFE_CANTADDELEM, FAIL);

          /* add palette data tag/ref to RIG */
          if (Vaddtagref(GroupID, (int32)img_ptr->lut_tag, (int32)img_ptr->lut_ref) == FAIL)
              HGOTO_ERROR(DFE_CANTADDELEM, FAIL);
      } /* end if */

    /* write out RIG */
    if(Vdetach(GroupID)==FAIL)
        HGOTO_ERROR(DFE_CANTDETACH, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */

  return ret_value;
} /* end GRIupdateRI() */

/*--------------------------------------------------------------------------
 NAME
    GRIup_attr_data
 PURPOSE
    Internal routine to update/create the attribute data
 USAGE
    intn GRIup_attr_data(hdf_file_id,attr_ptr)
        int32 hdf_file_id;          IN: the file ID for the HDF file.
        at_info_t *attr_ptr;        IN: pointer to the attribute info for the
                                        attr. to write.
 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Write out the data for an attribute to an HDF file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
PRIVATE intn GRIup_attr_data(int32 hdf_file_id,at_info_t *attr_ptr)
{
    CONSTR(FUNC, "GRIup_attr_data");   /* for HERROR */
    intn   ret_value = SUCCEED;

    HEclear();
    if (!HDvalidfid(hdf_file_id) || attr_ptr==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Write out the attribute data */
    if (attr_ptr->ref==DFREF_WILDCARD)  /* create a new attribute */
      {
        if((attr_ptr->ref=(uint16)VHstoredata(hdf_file_id,attr_ptr->name,attr_ptr->data,
                attr_ptr->len,attr_ptr->nt,RIGATTRNAME,RIGATTRCLASS))==(uint16)FAIL)
            HGOTO_ERROR(DFE_VSCANTCREATE,FAIL);
        attr_ptr->new_at=TRUE;
      } /* end if */
    else    /* update an existing one */
      {
        int32 AttrID;       /* attribute Vdata id */

        if((AttrID=VSattach(hdf_file_id,(int32)attr_ptr->ref,"w"))==FAIL)
            HGOTO_ERROR(DFE_CANTATTACH,FAIL);
        if(VSsetfields(AttrID,attr_ptr->name)==FAIL)
          {
            VSdetach(AttrID);
            HGOTO_ERROR(DFE_BADFIELDS,FAIL);
          } /* end if */
        if(VSwrite(AttrID,attr_ptr->data,attr_ptr->len,FULL_INTERLACE)==FAIL)
          {
            VSdetach(AttrID);
            HGOTO_ERROR(DFE_VSWRITE,FAIL);
          } /* end if */
        if(VSdetach(AttrID)==FAIL)
            HGOTO_ERROR(DFE_CANTDETACH,FAIL);
      } /* end else */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */

  return ret_value;
} /* end GRIup_attr_data() */

/*--------------------------------------------------------------------------
 NAME
    GRend
 PURPOSE
    Terminate the GR*() interface for a given HDF file.
 USAGE
    intn GRend(grid)
        int32 grid;          IN: GR ID from GRstart
 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Terminates access to the GR*() interface for a specific file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRend(int32 grid)
{
    CONSTR(FUNC, "GRend");      /* for HERROR */
    int32 hdf_file_id;          /* HDF file ID */
    int32 GroupID;              /* VGroup ID for the GR group */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    filerec_t *file_rec;        /* File record */
    void *      *t1;
    intn   ret_value = SUCCEED;
    int32 temp_ref;     /* used to hold the returned value from a function
                                that may return a ref or a FAIL - BMR */


    /* clear error stack and check validity of file id */
    HEclear();

    /* check the validity of the GR ID */
    if (HAatom_group(grid)!=GRIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate GR's object in hash table */
    if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(grid)))
        HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

    if (--gr_ptr->access)
        HGOTO_DONE(SUCCEED);

    hdf_file_id=gr_ptr->hdf_file_id;
    file_rec = HAatom_object(hdf_file_id);

    if(((file_rec->access)&DFACC_WRITE)!=0)
      {
        /* Check if the GR group exists, and create it if not */
        if(gr_ptr->gr_ref==DFREF_WILDCARD)
          {
            if((GroupID=Vattach(gr_ptr->hdf_file_id,-1,"w"))==FAIL)
                HGOTO_ERROR(DFE_CANTATTACH,FAIL);

            /* due to uint16 type of ref, check return value of VQueryref
                then assign it to gr_ref only when it's not FAIL */
            temp_ref = VQueryref(GroupID);
            if(temp_ref == FAIL)
                HGOTO_ERROR (DFE_NOVALS,FAIL);
            gr_ptr->gr_ref = (uint16)temp_ref;
            if(Vsetname(GroupID,GR_NAME)==FAIL)
                HGOTO_ERROR(DFE_BADVSNAME,FAIL);
            if(Vsetclass(GroupID,GR_NAME)==FAIL)
                HGOTO_ERROR(DFE_BADVSNAME,FAIL);
          } /* end if */
        else
          {
            if((GroupID=Vattach(gr_ptr->hdf_file_id,(int32)gr_ptr->gr_ref,"w"))==FAIL)
                HGOTO_ERROR(DFE_CANTATTACH,FAIL);
          } /* end else */

        /* Write out the information for RIs which have been changed */
        if(gr_ptr->gr_modified==TRUE && gr_ptr->gr_count>0)
          {
              void *      *t2;
              ri_info_t *img_ptr;   /* ptr to the image */

              if (NULL == (t2 = (void **)tbbtfirst((TBBT_NODE *) * (gr_ptr->grtree))))
                {
                    HGOTO_ERROR(DFE_NOTINTABLE, FAIL);
                } /* end if */
              else
                  img_ptr = (ri_info_t *) * t2;   /* get actual pointer to the ri_info_t */

              /* cycle through all of the images in memory */
              while (t2!=NULL)
                {
                    /* check if the image data has been modified */
                    if(img_ptr->data_modified==TRUE)
                      {
                        /* do nothing currently, we are synchronously updating the image data */
                          img_ptr->data_modified=FALSE;
                      } /* end if */

                    /* check if the image meta-info has been modified */
                    if(img_ptr->meta_modified==TRUE)
                      {
                          /* Test if the tag/ref pair has been assigned yet */
                          if(img_ptr->img_tag==DFTAG_NULL || img_ptr->img_ref==DFREF_WILDCARD)
                            {
                              img_ptr->img_tag=DFTAG_RI;
                            } /* end if */

                          /* write out the RI/RIG information again */
                          if(GRIupdateRIG(gr_ptr->hdf_file_id,img_ptr)==FAIL)
                              HGOTO_ERROR(DFE_INTERNAL, FAIL);
                          if(GRIupdateRI(gr_ptr->hdf_file_id,img_ptr)==FAIL)
                              HGOTO_ERROR(DFE_INTERNAL, FAIL);
                          img_ptr->meta_modified=FALSE;
                      } /* end if */

                    /* check if the local attributes has been modified */
                    if(img_ptr->attr_modified==TRUE && img_ptr->lattr_count>0)
                      {
                          void *      *t3;
                          at_info_t *attr_ptr;   /* ptr to the attribute */

                          if (NULL == (t3 = (void **)tbbtfirst((TBBT_NODE *) * (img_ptr->lattree))))
                            {
                                HGOTO_ERROR(DFE_NOTINTABLE, FAIL);
                            } /* end if */
                          else
                              attr_ptr = (at_info_t *) * t3;   /* get actual pointer to the at_info_t */

                          /* cycle through all of the local attributes in memory */
                          while (t3!=NULL)
                            {
                                /* check if the attribute data has been modified */
                                if(attr_ptr->data_modified==TRUE)
                                  {
                                      if(GRIup_attr_data(gr_ptr->hdf_file_id,attr_ptr)==FAIL)
                                          HGOTO_ERROR(DFE_INTERNAL, FAIL);
                                      attr_ptr->data_modified=FALSE;
                                  } /* end if */

                                /* check if the attribute was added to the group */
                                if(attr_ptr->new_at==TRUE)
                                  {
                                      int32 lGroupID;  /* ID of the Vgroup */

                                      if((lGroupID=Vattach(gr_ptr->hdf_file_id,(int32)img_ptr->ri_ref,"w"))==FAIL)
                                          HGOTO_ERROR(DFE_CANTATTACH,FAIL);
                                      if(Vaddtagref(lGroupID,ATTR_TAG,(int32)attr_ptr->ref)==FAIL)
                                          HGOTO_ERROR(DFE_CANTADDELEM,FAIL);
                                      if(Vdetach(lGroupID)==FAIL)
                                          HGOTO_ERROR(DFE_CANTDETACH,FAIL);
                                      attr_ptr->new_at=FALSE;
                                  } /* end if */

                                /* get the next local attribute in the tree/list */
                                if (NULL != (t3 = (void **)tbbtnext((TBBT_NODE *) t3)))     /* get the next node in the tree */
                                    attr_ptr = (at_info_t *) * t3;     /* get actual pointer to the at_info_t */
                            } /* end while */
                          img_ptr->attr_modified=FALSE;
                      } /* end if */

                    /* Check if the RI is already in the GR, add it if not */
                    if(Vinqtagref(GroupID,RI_TAG,(int32)img_ptr->ri_ref)==FALSE)
                        if(Vaddtagref(GroupID,RI_TAG,(int32)img_ptr->ri_ref)==FAIL)
                            HGOTO_ERROR(DFE_CANTADDELEM,FAIL);

                    /* get the next image in the tree/list */
                    if (NULL != (t2 = (void **)tbbtnext((TBBT_NODE *) t2)))     /* get the next node in the tree */
                        img_ptr = (ri_info_t *) * t2;     /* get actual pointer to the ri_info_t */
                } /* end while */
          } /* end if */

        /* Write out the information for the global attributes which have been changed */
        if(gr_ptr->gattr_modified==TRUE && gr_ptr->gattr_count>0)
          {
              void *      *t2;
              at_info_t *attr_ptr;   /* ptr to the attribute */

              if (NULL == (t2 = (void **)tbbtfirst((TBBT_NODE *) * (gr_ptr->gattree))))
                {
                    HGOTO_ERROR(DFE_NOTINTABLE, FAIL);
                } /* end if */
              else
                  attr_ptr = (at_info_t *) * t2;   /* get actual pointer to the at_info_t */

              /* cycle through all of the global attributes in memory */
              while (t2!=NULL)
                {
                    /* check if the attribute data has been modified */
                    if(attr_ptr->data_modified==TRUE)
                      {
                        if(GRIup_attr_data(gr_ptr->hdf_file_id,attr_ptr)==FAIL)
                            HGOTO_ERROR(DFE_INTERNAL, FAIL);
                        attr_ptr->data_modified=FALSE;

                        /* check if the attribute was a new attribute */
                        if(attr_ptr->new_at==TRUE)
                          {
                            if(Vaddtagref(GroupID,ATTR_TAG,(int32)attr_ptr->ref)==FAIL)
                                HGOTO_ERROR(DFE_CANTADDELEM,FAIL);
                            attr_ptr->new_at=FALSE;
                          } /* end if */
                      } /* end if */

                    /* get the next global attribute in the tree/list */
                    if (NULL != (t2 = (void **)tbbtnext((TBBT_NODE *) t2)))     /* get the next node in the tree */
                        attr_ptr = (at_info_t *) * t2;     /* get actual pointer to the at_info_t */
                } /* end while */
            gr_ptr->gattr_modified=FALSE;
          } /* end if */

        /* Let go of the GR Vgroup */
        if(Vdetach(GroupID)==FAIL)
            HGOTO_ERROR(DFE_CANTDETACH,FAIL);
      } /* end if */

    /* Free all the memory we've allocated */
    tbbtdfree(gr_ptr->grtree, GRIridestroynode, NULL);
    tbbtdfree(gr_ptr->gattree, GRIattrdestroynode, NULL);

    /* Close down the entry for this file in the GR tree */
    /* Find the node in the tree */
    if (( t1 = (void **)tbbtdfind(gr_tree, &hdf_file_id, NULL)) == NULL)
        HGOTO_DONE(FAIL);

    /* Delete the node and free the gr_info_t stucture */
    tbbtrem((TBBT_NODE **) gr_tree, (TBBT_NODE *) t1, NULL);
    HDfree(gr_ptr);

    /* Close down the Vset routines we started */
    if(Vend(hdf_file_id)==FAIL)
        HGOTO_ERROR(DFE_CANTSHUTDOWN,FAIL);

    if (NULL == HAremove_atom(grid))
        HGOTO_ERROR(DFE_INTERNAL, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRend() */

/*--------------------------------------------------------------------------
 NAME
    GRselect
 PURPOSE
    Select a raster image to operate on.
 USAGE
    int32 GRselect(grid,index)
        int32 grid;          IN: GR ID from GRstart
        int32 index;         IN: Which raster image to select (indexed from 0)
 RETURNS
    A valid riid (Raster-Image ID) on success, or FAIL.

 DESCRIPTION
    Selects a raster image from the file to work on.  This ID is needed for
    all operations on the image dataset, including reading/writing data,
    annotations, etc.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int32 GRselect(int32 grid,int32 index)
{
    CONSTR(FUNC, "GRselect");   /* for HERROR */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    void * *t;                   /* temp. ptr to the image found */
    int32  ret_value = SUCCEED;

    /* clear error stack and check validity of file id */
    HEclear();

    /* check the validity of the GR ID */
    if (HAatom_group(grid)!=GRIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate GR's object in hash table */
    if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(grid)))
        HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

    /* check the index range validity */
    if(!VALIDRIINDEX(index,gr_ptr))
        HGOTO_ERROR(DFE_ARGS, FAIL);

    if((t = (void **)tbbtdfind(gr_ptr->grtree, &index, NULL))==NULL)
        HGOTO_ERROR(DFE_RINOTFOUND,FAIL);
    ri_ptr=(ri_info_t *)*t;

    ri_ptr->access++;

    ret_value=HAregister_atom(RIIDGROUP,ri_ptr);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRselect() */

/*--------------------------------------------------------------------------
 NAME
    GRcreate

 PURPOSE
    Create a new raster image.

 USAGE
    int32 GRcreate(grid, name, ncomp, nt, il, dimsizes)
        int32 grid;         IN: GR ID from GRstart
        char *name;         IN: Name of raster image to create
        int32 ncomp;        IN: Number of components in image
        int32 nt;           IN: Number type of each component
        int32 il;           IN: Interlace of the components in the image
        int32 dimsizes[2];  IN: Dimensions of the new image

 RETURNS
    A valid riid (Raster-Image ID) on success, or FAIL.

 DESCRIPTION
    Creates a new raster image in a file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    All components must be the same number-type.

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int32 GRcreate(int32 grid,const char *name,int32 ncomp,int32 nt,int32 il,int32 dimsizes[2])
{
    CONSTR(FUNC, "GRcreate");   /* for HERROR */
    int32 GroupID;              /* ID of the Vgroup created */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    int32    ret_value = SUCCEED;
    int32 temp_ref;     /* used to hold the returned value from a function
                                that may return a ref or a FAIL - BMR */

    /* clear error stack */
    HEclear();

    /* check the validity of the args */
    if (HAatom_group(grid)!=GRIDGROUP || name==NULL || ncomp<1
            || (il!=MFGR_INTERLACE_PIXEL && il!=MFGR_INTERLACE_LINE 
            && il!=MFGR_INTERLACE_COMPONENT) || dimsizes==NULL 
            || dimsizes[0]<=0 || dimsizes[1]<=0)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate GR's object in hash table */
    if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(grid)))
        HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

    /* Allocate space for the new image information */
    if((ri_ptr=(ri_info_t *)HDmalloc(sizeof(ri_info_t)))==NULL)
        HGOTO_ERROR(DFE_NOSPACE,FAIL);
    HDmemset(ri_ptr,0,sizeof(ri_info_t));
    
    /* Allocate space for the name and copy it */
    if((ri_ptr->name=(char *)HDmalloc(HDstrlen(name)+1))==NULL)
        HGOTO_ERROR(DFE_NOSPACE,FAIL);
    HDstrcpy(ri_ptr->name,name);

    /* Assign image information */
    ri_ptr->index=gr_ptr->gr_count;
#ifdef OLD_WAY
    ri_ptr->ri_ref=DFREF_WILDCARD;
#else /* OLD_WAY */
    if ((GroupID = Vattach(gr_ptr->hdf_file_id,-1,"w")) == FAIL)
        HGOTO_ERROR(DFE_CANTATTACH, FAIL);
    /* due to uint16 type of ref, check return value of VQueryref
         and assign it to ri_ref only when it's not FAIL - BMR */
    temp_ref = VQueryref(GroupID);
    if(temp_ref == FAIL)
        HGOTO_ERROR(DFE_BADREF, FAIL);
    ri_ptr->ri_ref = (uint16)temp_ref;
    if(Vdetach(GroupID)==FAIL)
        HGOTO_ERROR(DFE_CANTDETACH, FAIL);
#endif /* OLD_WAY */
    ri_ptr->rig_ref=DFREF_WILDCARD;
    ri_ptr->gr_ptr=gr_ptr;
    ri_ptr->img_dim.dim_ref=DFREF_WILDCARD;
    ri_ptr->img_dim.xdim=dimsizes[XDIM];
    ri_ptr->img_dim.ydim=dimsizes[YDIM];
    ri_ptr->img_dim.ncomps=ncomp;
    ri_ptr->img_dim.nt=nt;
    ri_ptr->img_dim.file_nt_subclass=DFNTF_HDFDEFAULT;
    ri_ptr->img_dim.il=(gr_interlace_t)il;
    ri_ptr->img_dim.nt_tag=ri_ptr->img_dim.nt_ref=DFREF_WILDCARD;
    ri_ptr->img_dim.comp_tag=ri_ptr->img_dim.comp_ref=DFREF_WILDCARD;
    ri_ptr->img_tag=ri_ptr->img_ref=DFREF_WILDCARD;
    ri_ptr->img_aid=0;
    ri_ptr->acc_perm=0;
    ri_ptr->lut_tag=ri_ptr->lut_ref=DFREF_WILDCARD;
    ri_ptr->im_il=MFGR_INTERLACE_PIXEL;
    ri_ptr->lut_il=MFGR_INTERLACE_PIXEL;
    ri_ptr->data_modified=FALSE;
    ri_ptr->meta_modified=TRUE;
    ri_ptr->attr_modified=FALSE;
    ri_ptr->lattr_count=0;
    ri_ptr->lattree = tbbtdmake(rigcompare, sizeof(int32), TBBT_FAST_INT32_COMPARE);
    if(ri_ptr->lattree==NULL)
        HGOTO_ERROR(DFE_NOSPACE, FAIL);
    ri_ptr->use_buf_drvr=FALSE;
    ri_ptr->use_cr_drvr=FALSE;
    ri_ptr->comp_img=FALSE;
    ri_ptr->ext_img=FALSE;
    ri_ptr->acc_img=FALSE;
    ri_ptr->fill_img=TRUE;
    ri_ptr->fill_value=NULL;
    ri_ptr->store_fill=FALSE;
    ri_ptr->access++;

    /* insert the new image in the global image tree */
    tbbtdins(gr_ptr->grtree, ri_ptr, NULL);    /* insert the new image into B-tree */ 

    /* indicate that the GR info has changed */
    gr_ptr->gr_modified=TRUE;
    gr_ptr->gr_count++;

    ret_value=HAregister_atom(RIIDGROUP,ri_ptr);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRcreate() */

/*--------------------------------------------------------------------------
 NAME
    GRnametoindex
 PURPOSE
    Map a raster image name to an index.
 USAGE
    int32 GRnametoindex(grid,name)
        int32 grid;          IN: GR ID from GRstart
        char *name;          IN: Name of raster image to search for
 RETURNS
    A valid index on success, or FAIL.

 DESCRIPTION
    Searches for a raster image based on the name provided.  This routine
    maps from names of raster images to indices inside the GR group.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int32 GRnametoindex(int32 grid,const char *name)
{
    CONSTR(FUNC, "GRnametoindex");   /* for HERROR */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    void * *t;                   /* temp. ptr to the image found */
    int32   ret_value = SUCCEED;

    /* clear error stack and check validity of file id */
    HEclear();

    /* check the validity of the GR ID */
    if (HAatom_group(grid)!=GRIDGROUP || name==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate GR's object in hash table */
    if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(grid)))
        HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

    if((t = (void **)tbbtfirst((TBBT_NODE *)* (gr_ptr->grtree)))==NULL)
        HGOTO_ERROR(DFE_RINOTFOUND,FAIL);
    do {
        ri_ptr=(ri_info_t *)*t;
        if(ri_ptr!=NULL && HDstrcmp(ri_ptr->name,name)==0)  /* ie. the name matches */
            HGOTO_DONE(ri_ptr->index);
    } while((t= (void **)tbbtnext((TBBT_NODE *)t))!=NULL);

    ret_value = (FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRnametoindex() */

/*--------------------------------------------------------------------------
 NAME
    GRgetiminfo

 PURPOSE
    Gets information about a raster image.

 USAGE
    intn GRgetiminfo(riid,name,ncomp,nt,il,dimsizes,n_attr)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        char *name;         OUT: name of raster image
        int32 *ncomp;       OUT: number of components in image
        int32 *nt;          OUT: number type of components
        int32 *il;          OUT: interlace of the image
        int32 *dimsizes;    OUT: size of each dimension
        int32 *n_attr;      OUT: the number of attributes for the image

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Looks up information about an image which has been selected or created
    with the GR routines.  Each of the parameters can be NULL, in which case
    that piece of information will not be retrieved.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRgetiminfo(int32 riid,char *name,int32 *ncomp,int32 *nt,int32 *il,
    int32 dimsizes[2],int32 *n_attr)
{
    CONSTR(FUNC, "GRgetiminfo");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    if(name!=NULL)
        HDstrcpy(name, ri_ptr->name);

    if(ncomp!=NULL)
        *ncomp=ri_ptr->img_dim.ncomps;

    if(nt!=NULL)
        *nt=ri_ptr->img_dim.nt;

    if(il!=NULL)
        *il=(int32)ri_ptr->img_dim.il;

    if(dimsizes!=NULL)
      {
          dimsizes[0]=ri_ptr->img_dim.xdim;
          dimsizes[1]=ri_ptr->img_dim.ydim;
      } /* end if */

    if(n_attr!=NULL)
        *n_attr=ri_ptr->lattr_count;

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRgetiminfo() */

/*--------------------------------------------------------------------------
 NAME
    GRgetnluts

 PURPOSE
    Get the number of palettes (LUTs) for an image

 USAGE
    intn GRgetnluts(riid)
        int32 riid;         IN: RI ID from GRselect/GRcreate

 RETURNS
    The number of palettes on success, FAIL (-1) on failure

 DESCRIPTION
    Determines the number of palettes for an image (0 or 1 for now).  In the
    future, if multiple palettes are supported, this function may return
    values greater than 1.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRgetnluts(int32 riid)
{
    CONSTR(FUNC, "GRgetnluts");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = FAIL;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate LUT's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    if(ri_ptr->lut_ref==DFREF_WILDCARD) /* check for no palette defined currently */
        ret_value=0;
    else        /* we've got a valid palette currently */
        ret_value=1;

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
    return ret_value;
} /* end GRgetnluts() */

/*--------------------------------------------------------------------------
 NAME
    GRwriteimage

 PURPOSE
    Writes raster data to an image

 USAGE
    intn GRwriteimage(riid,start,stride,edge,data)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        int32 start[2];     IN: array containing the offset in the image of the
                                image data to write out
        int32 stride[2];    IN: array containing interval of data being written
                                along each edge.  strides of 0 are illegal
                                (and generate an error)
                                ie. stride of 1 in each dimension means
                                writing contiguous data, stride of 2 means
                                writing every other element out along an edge.
        int32 count[2];     IN: number of elements to write out along each edge.
        void * data;         IN: pointer to the data to write out.

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Writes image data to an RI.  Partial dataset writing and subsampling is
        allowed, but only within the dimensions of the dataset (ie. no UNLIMITED
        dimension support)

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    If the stride parameter is set to NULL, a stride of 1 will be assumed.

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRwriteimage(int32 riid,int32 start[2],int32 in_stride[2],int32 count[2],void * data)
{
    CONSTR(FUNC, "GRwriteimage");   /* for HERROR */
    int32 hdf_file_id;          /* HDF file ID */
    int32 stride[2];            /* pointer to the stride array */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn solid_block=FALSE;     /* whether the image data is a solid block of data */
    intn whole_image=FALSE;     /* whether we are writing out the whole image */
    void * *img_data;            /* pointer to the converted image data to write */
    uintn pixel_mem_size,       /* size of a pixel in memory */
        pixel_disk_size;        /* size of a pixel on disk */
    uint16 scheme;  /* compression scheme used for JPEG images */
    uint32     comp_config;
    comp_coder_t comp_type; 
    comp_info cinfo;
    intn status=FAIL;
    intn convert=FALSE;         /* true if machine NT != NT to be written */
    uint8 platnumsubclass;      /* class of this NT for this platform */
    intn new_image=FALSE;       /* whether we are writing a new image out */
    intn switch_interlace=FALSE;/* whether the memory interlace needs to be switched around */
    intn ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the basic validity of the args (stride is OK to be NULL) */
    if (HAatom_group(riid)!=RIIDGROUP || start==NULL /* || in_stride==NULL */ || count==NULL
            || data==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* Get the correct parameters into the stride array */
    if(in_stride==NULL)
          stride[XDIM]=stride[YDIM]=1;
    else
      {
          stride[XDIM]=in_stride[XDIM];
          stride[YDIM]=in_stride[YDIM];
      } /* end else */

    /* Sanity check the start, stride, and count args */
    if((start[XDIM]<0 || start[YDIM]<0) || (stride[XDIM]<1 || stride[YDIM]<1)
            || (count[XDIM]<1 || count[YDIM]<1))
        HGOTO_ERROR(DFE_BADDIM, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);
    gr_ptr=ri_ptr->gr_ptr;
    hdf_file_id=gr_ptr->hdf_file_id;

    comp_type = COMP_CODE_NONE;
    scheme = ri_ptr->img_dim.comp_tag;
    if (scheme == DFTAG_JPEG5 || scheme == DFTAG_GREYJPEG5
            || scheme==DFTAG_JPEG || scheme==DFTAG_GREYJPEG)
    {
        comp_type = COMP_CODE_JPEG;
        cinfo.jpeg.quality = 0;
        cinfo.jpeg.force_baseline = 0;
    }
    else if (scheme == DFTAG_IMC)
    { /* coder no longer supported */
        HGOTO_ERROR(DFE_BADCODER,FAIL);
    }
    else
    {
        /* use lower-level routine to get the compression information */
        status = HCPgetcompinfo(ri_ptr->gr_ptr->hdf_file_id,
                        ri_ptr->img_tag, ri_ptr->img_ref,
                        &comp_type, &cinfo);
	if (status == FAIL)
            HGOTO_ERROR(DFE_INTERNAL,FAIL);
    }
    if (comp_type != COMP_CODE_NONE)
    {
        /* Check that the compression encoder is available */
        HCget_config_info(comp_type, &comp_config);
        if ((comp_config & (COMP_DECODER_ENABLED|COMP_ENCODER_ENABLED)) == 0) {
            /* coder not present?? */
             HGOTO_ERROR(DFE_BADCODER,FAIL); 
        }
        if ((comp_config & COMP_ENCODER_ENABLED) == 0) {
            /* encoder not present?? */
             HGOTO_ERROR(DFE_NOENCODER,FAIL); 
        }
    }

    if(stride[XDIM]==1 && stride[YDIM]==1)
      { /* solid block of data */
          solid_block=TRUE;
          if((start[XDIM]==0 && start[YDIM]==0) && (count[XDIM]==ri_ptr->img_dim.xdim
                && count[YDIM]==ri_ptr->img_dim.ydim))
              whole_image=TRUE;
          else
              whole_image=FALSE;
      } /* end if */
    else /* block of data spread out with strides */
          solid_block=FALSE;

    if(ri_ptr->img_dim.il!=MFGR_INTERLACE_PIXEL)
        switch_interlace=TRUE;

    /* Get the size of the pixels in memory and on disk */
    pixel_mem_size=(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize((ri_ptr->img_dim.nt | DFNT_NATIVE) & (~DFNT_LITEND)));
    pixel_disk_size=(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt));

    /* Get number-type and conversion information */
    platnumsubclass = (uint8)DFKgetPNSC(ri_ptr->img_dim.nt & (~DFNT_LITEND), DF_MT);
    convert = (ri_ptr->img_dim.file_nt_subclass != platnumsubclass) ||
  (pixel_mem_size != pixel_disk_size);  /* is conversion necessary? */

    if(convert || switch_interlace==TRUE)
      {   /* convert image data to HDF disk format */
          /* Allocate space for the conversion buffer */
          if((img_data=HDmalloc(pixel_disk_size*(size_t)count[XDIM]*(size_t)count[YDIM]))==NULL)
              HGOTO_ERROR(DFE_NOSPACE,FAIL);

          if(switch_interlace==TRUE)
            {
              void * pixel_buf;  /* buffer for the pixel interlaced data */

              /* Allocate space for the conversion buffer */
              if((pixel_buf=HDmalloc(pixel_mem_size*(size_t)count[XDIM]*(size_t)count[YDIM]))==NULL)
                  HGOTO_ERROR(DFE_NOSPACE,FAIL);

              GRIil_convert(data,ri_ptr->img_dim.il,pixel_buf,MFGR_INTERLACE_PIXEL,
                  count,ri_ptr->img_dim.ncomps,ri_ptr->img_dim.nt);

              /* convert the pixel data into the HDF disk format */
              DFKconvert(pixel_buf,img_data,ri_ptr->img_dim.nt,
                  ri_ptr->img_dim.ncomps*count[XDIM]*count[YDIM],DFACC_WRITE,0,0);

              HDfree(pixel_buf);
            } /* end if */
          else /* convert the pixel data into the HDF disk format */
              DFKconvert(data,img_data,ri_ptr->img_dim.nt,
                  ri_ptr->img_dim.ncomps*count[XDIM]*count[YDIM],DFACC_WRITE,0,0);
      } /* end if */
    else /* no conversion necessary, just use the user's buffer */
        img_data=data;

    if(ri_ptr->img_tag==DFTAG_NULL || ri_ptr->img_ref==DFREF_WILDCARD)
        new_image=TRUE;
    else {
        /* Check if the actual image data is in the file yet, or if just the tag & ref are known */
        if(Hlength(ri_ptr->gr_ptr->hdf_file_id,ri_ptr->img_tag,ri_ptr->img_ref)>0)
            new_image=FALSE;
        else
            new_image=TRUE;
    } /* end else */

    if(GRIgetaid(ri_ptr,DFACC_WRITE)==FAIL)
        HGOTO_ERROR(DFE_INTERNAL,FAIL);

    if(whole_image==TRUE)
      { /* write the whole image out */
#ifdef OLD_WAY
        if(new_image==TRUE)
          { /* Create the tag/ref for the new image */
              ri_ptr->img_tag=DFTAG_RI;
              ri_ptr->img_ref=Htagnewref(hdf_file_id,ri_ptr->img_tag);
          } /* end if */
        if(Hputelement(hdf_file_id,ri_ptr->img_tag,ri_ptr->img_ref,
                (uint8 *)img_data,(int32)pixel_disk_size*count[XDIM]*count[YDIM])==FAIL)
            HGOTO_ERROR(DFE_PUTELEM,FAIL);
#else /* OLD_WAY */
        /* Make certain we are at the beginning */
        if(Hseek(ri_ptr->img_aid,0,DF_START)==FAIL)
            HGOTO_ERROR(DFE_SEEKERROR,FAIL);

        /* Write the entire image out */
        if(Hwrite(ri_ptr->img_aid,(int32)pixel_disk_size*count[XDIM]*count[YDIM],
                (uint8 *)img_data)==FAIL)
            HGOTO_ERROR(DFE_WRITEERROR,FAIL);
#endif /* OLD_WAY */
      } /* end if */
    else
      { /* write only part of the image out */
          int32 img_offset; /* current offset in the image data */
          void * tmp_data;   /* temp. pointer to the image data to write */
          intn fill_image=FALSE;  /* whether to create fill values, etc. */
          void * fill_line=NULL;   /* array containing the fill pixels for an entire line of the image */
          int32 fill_lo_size=0,   /* number of bytes in the "low" block */
              fill_hi_size=0,     /* number of bytes in the "high" block */
              fill_line_size=0;   /* number of bytes in the "line" block */

          img_offset=((ri_ptr->img_dim.xdim*start[YDIM])+start[XDIM])*(int32)pixel_disk_size;

          /* check if this is a new image, and if we need to write fill pixels */
          if(new_image==TRUE && ri_ptr->fill_img==TRUE)
            { /* create fill value arrays for various blocks */
                void * fill_pixel; /* converted value for the filled pixel */
                int32 at_index;   /* attribute index for the fill value */

                if((fill_pixel=HDmalloc(pixel_disk_size))==NULL)
                    HGOTO_ERROR(DFE_NOSPACE,FAIL);

                /* create correct disk version of fill pixel */
                if(ri_ptr->fill_value!=NULL)
                  {
                      DFKconvert(ri_ptr->fill_value,fill_pixel,
                          ri_ptr->img_dim.nt,ri_ptr->img_dim.ncomps,
                          DFACC_WRITE,0,0);
                  } /* end if */
                else  /* create default pixel fill value of all zero components */
                  {
                    /* Try to find a fill value attribute */
                    if((at_index=GRfindattr(riid,FILL_ATTR))!=FAIL)
                      { /* Found a fill value attribute */
                          if((ri_ptr->fill_value=HDmalloc(pixel_mem_size))==NULL)
                              HGOTO_ERROR(DFE_NOSPACE,FAIL);
                          if(GRgetattr(riid,at_index,ri_ptr->fill_value)==FAIL)
                              HGOTO_ERROR(DFE_BADATTR,FAIL);
                          DFKconvert(ri_ptr->fill_value,fill_pixel,
                              ri_ptr->img_dim.nt,ri_ptr->img_dim.ncomps,
                              DFACC_WRITE,0,0);
                      } /* end if */
                    else
                        HDmemset(fill_pixel,0,pixel_disk_size);
                  } /* end else */

                /* check for "low" pixel runs */
                if(start[XDIM]>0)
                    fill_lo_size=(int32)pixel_disk_size*start[XDIM];

                /* check for "high" pixel runs */
                if((start[XDIM]+((count[XDIM]-1)*stride[XDIM])+1)<ri_ptr->img_dim.xdim)
                    fill_hi_size=(int32)pixel_disk_size*(ri_ptr->img_dim.xdim-
                        (start[XDIM]+((count[XDIM]-1)*stride[XDIM])+1));

                /* create the "line" pixel block */
                /* allocate space for the "line" block */
                fill_line_size=(int32)pixel_disk_size*ri_ptr->img_dim.xdim;
                if((fill_line=HDmalloc(fill_line_size))==NULL)
                      HGOTO_ERROR(DFE_NOSPACE,FAIL);
                HDmemfill(fill_line,fill_pixel,pixel_disk_size,(uint32)ri_ptr->img_dim.xdim);

                fill_image=TRUE;  /* set flag to write out fill pixels */
                ri_ptr->store_fill=TRUE;  /* set flag to store fill value attribute */

                /* Get rid of the fill pixel */
                if(ri_ptr->fill_value==NULL)
                    ri_ptr->fill_value=fill_pixel;
                else
                    HDfree(fill_pixel);
            } /* end if */

          tmp_data=img_data;
          if(solid_block==TRUE)
            {   /* write out runs of data in the image */
                int32 pix_len;    /* length of current row's pixel run */
                intn i;           /* temporary loop variable */

                pix_len=(int32)pixel_disk_size*count[XDIM];
                  
                if(fill_image==TRUE)
                  {   /* surround the block to write with fill values */
                      /* write out lines "below" the block */
                      if(start[YDIM]>0)
                        { /* fill in the lines leading up the block */
                          for(i=0; i<start[YDIM]; i++)
                              if(Hwrite(ri_ptr->img_aid,fill_line_size,fill_line)==FAIL)
                                  HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                        } /* end if */

                      /* write prelude of low pixels */
                      if(fill_lo_size>0)
                          if(Hwrite(ri_ptr->img_aid,fill_lo_size,fill_line)==FAIL)
                              HGOTO_ERROR(DFE_WRITEERROR,FAIL);

                      /* write out the block */
                      for(i=0; i<count[YDIM]; i++)
                        {
                            if(Hwrite(ri_ptr->img_aid,pix_len,tmp_data)==FAIL)
                                HGOTO_ERROR(DFE_WRITEERROR,FAIL);

                            /* This next write wraps around the high side */
                            /* of the block and writes the next low side */
                            /* at the same time. */
                            if((fill_hi_size+fill_lo_size)>0
                                    && i<(count[YDIM]-1))
                                if(Hwrite(ri_ptr->img_aid,(fill_hi_size+fill_lo_size),fill_line)==FAIL)
                                    HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                            tmp_data=(void *)((char *)tmp_data+pix_len);
                        } /* end for */
                        
                      /* Finish the last chunk of high side fill values */
                      if(fill_hi_size>0)
                          if(Hwrite(ri_ptr->img_aid,fill_hi_size,fill_line)==FAIL)
                              HGOTO_ERROR(DFE_WRITEERROR,FAIL);

                      /* write out lines "above" the block */
                      if((start[YDIM]+((count[YDIM]-1)*stride[YDIM])+1)
                          <ri_ptr->img_dim.ydim)
                        {
                          for(i=start[YDIM]+((count[YDIM]-1)*stride[YDIM])+1;
                                  i<ri_ptr->img_dim.ydim; i++)
                              if(Hwrite(ri_ptr->img_aid,fill_line_size,fill_line)==FAIL)
                                  HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                        } /* end if */
                  } /* end if */
                else
                  {   /* don't worry about fill values */
                      for(i=0; i<count[YDIM]; i++)
                        {
                            if(Hseek(ri_ptr->img_aid,img_offset,DF_START)==FAIL)
                                HGOTO_ERROR(DFE_SEEKERROR,FAIL);
                            if(Hwrite(ri_ptr->img_aid,pix_len,tmp_data)==FAIL)
                                HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                            img_offset+=(int32)pixel_disk_size*ri_ptr->img_dim.xdim;
                            tmp_data=(void *)((char *)tmp_data+pix_len);
                        } /* end for */
                  } /* end else */
            } /* end if */
          else
            {   /* sub-sampling, seek to each data element and write it out */
                intn i,j,k;       /* temporary loop variables */
                int32 fill_stride_size=0; /* # of pixels in the stride block */
                intn fill_xdim=FALSE, /* whether to fill in the X dimension */
                    fill_ydim=FALSE;  /* whether to fill in the Y dimension */

                /* check if we need to insert fill pixels between strides */
                if(fill_image==TRUE)
                  {   /* create the "stride" pixel block */
                      if(stride[XDIM]>1)
                        {
                          /* allocate space for the "stride" block */
                          fill_stride_size=(int32)pixel_disk_size*(stride[XDIM]-1);
                          fill_xdim=TRUE;
                        } /* end if */
                      if(stride[YDIM]>1)
                          fill_ydim=TRUE;

                      /* write fills and sub-sampled data */

                      /* write out lines "below" the block */
                      if(start[YDIM]>0)
                        { /* fill in the lines leading up the block */
                          for(i=0; i<start[YDIM]; i++)
                            {
                              if(Hwrite(ri_ptr->img_aid,fill_line_size,fill_line)==FAIL)
                                  HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                            } /* end for */
                        } /* end if */

                      /* write prelude of low pixels */
                      if(fill_lo_size>0)
                        {
                          if(Hwrite(ri_ptr->img_aid,fill_lo_size,fill_line)==FAIL)
                              HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                        } /* end if */

                      for(i=0; i<count[YDIM]; i++)
                        {
                            for(j=0; j<count[XDIM]; j++)
                              {
                                if(Hwrite(ri_ptr->img_aid,(int32)pixel_disk_size,tmp_data)==FAIL)
                                    HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                                if(fill_xdim==TRUE && j<(count[XDIM]-1))
                                  {
                                    if(Hwrite(ri_ptr->img_aid,fill_stride_size,fill_line)==FAIL)
                                        HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                                  } /* end if */
                                tmp_data=(void *)((char *)tmp_data+pixel_disk_size);
                              } /* end for */

                            /* Fill in the y-dim stride lines */
                            if(fill_ydim==TRUE)
                                for(k=1; k<stride[YDIM]; k++)
                                  {
                                    if(Hwrite(ri_ptr->img_aid,fill_line_size,fill_line)==FAIL)
                                        HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                                  } /* end for */

                            /* This next write wraps around the high side */
                            /* of the block and writes the next low side */
                            /* at the same time. */
                            if((fill_hi_size+fill_lo_size)>0
                                    && i<(count[YDIM]-1))
                              {
                                if(Hwrite(ri_ptr->img_aid,(fill_hi_size+fill_lo_size),fill_line)==FAIL)
                                    HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                              } /* end if */
                        } /* end for */

                      /* Finish the last chunk of high side fill values */
                      if(fill_hi_size>0)
                        {
                          if(Hwrite(ri_ptr->img_aid,fill_hi_size,fill_line)==FAIL)
                              HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                        } /* end if */

                  } /* end if */
                else
                  {   /* don't worry about fill values */
                    int32 stride_add; /* amount to add for stride amount */

                    stride_add=(int32)pixel_disk_size*stride[XDIM];

                      for(i=0; i<count[YDIM]; i++)
                        {
                            int32 local_offset;

                            local_offset=img_offset;
                            for(j=0; j<count[XDIM]; j++)
                              {
                                if(Hseek(ri_ptr->img_aid,local_offset,DF_START)==FAIL)
                                    HGOTO_ERROR(DFE_SEEKERROR,FAIL);
                                if(Hwrite(ri_ptr->img_aid,(int32)pixel_disk_size,tmp_data)==FAIL)
                                    HGOTO_ERROR(DFE_WRITEERROR,FAIL);
                                local_offset+=stride_add;
                                tmp_data=(void *)((char *)tmp_data+pixel_disk_size);
                              } /* end for */

                            img_offset+=ri_ptr->img_dim.xdim*stride[YDIM]*(int32)pixel_disk_size;
                        } /* end for */
                  } /* end else */
            } /* end else */
            
          if(fill_line!=NULL)     /* free the fill-value pixels if we used 'em */
              HDfree(fill_line);

      } /* end else */
    ri_ptr->data_modified=TRUE;

    /* if we've allocated a temporary buffer, free it */
    if(convert || switch_interlace==TRUE)
        HDfree(img_data);

    /* mark the image as being modified */
    ri_ptr->data_modified=TRUE;
    gr_ptr->gr_modified=TRUE;

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRwriteimage() */

/*--------------------------------------------------------------------------
 NAME
    GRreadimage

 PURPOSE
    Read raster data for an image

 USAGE
    intn GRreadimage(riid,start,stride,edge,data)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        int32 start[2];     IN: array containing the offset in the image of the
                                image data to read in
        int32 stride[2];    IN: array containing interval of data being read
                                along each edge.  strides of 0 are illegal
                                (and generate an error)
                                ie. stride of 1 in each dimension means
                                reading contiguous data, stride of 2 means
                                reading every other element out along an edge.
        int32 count[2];     IN: number of elements to read in along each edge.
        void * data;         IN: pointer to the data to read in.

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Read image data from an RI.  Partial dataset reading and subsampling is
        allowed.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    If the stride parameter is set to NULL, a stride of 1 will be assumed.

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRreadimage(int32 riid,int32 start[2],int32 in_stride[2],int32 count[2],void * data)
{
    CONSTR(FUNC, "GRreadimage");   /* for HERROR */
    int32 hdf_file_id;          /* HDF file ID */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    int32 stride[2];            /* pointer to the stride array */
    intn solid_block=FALSE;     /* whether the image data is a solid block of data */
    intn whole_image=FALSE;     /* whether we are reading in the whole image */
    intn image_data=FALSE;      /* whether there is actual image data or not */
    void * *img_data;           /* pointer to the converted image data to write */
    uintn pixel_disk_size;      /* size of a pixel on disk */
    uintn pixel_mem_size;       /* size of a pixel in memory */
    intn convert;               /* true if machine NT != NT to be written */
    uint8 platnumsubclass;      /* class of this NT for this platform */
    uint16 scheme;  /* compression scheme used for JPEG images */
    uint32     comp_config;
    comp_coder_t comp_type; 
    comp_info cinfo;
    intn status=FAIL;
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the basic validity of the args (stride is OK to be NULL) */
    if (HAatom_group(riid)!=RIIDGROUP || start==NULL /* || in_stride==NULL */ || count==NULL
            || data==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* Get the correct parameters into the stride array */
    if(in_stride==NULL)
          stride[XDIM]=stride[YDIM]=1;
    else
      {
          stride[XDIM]=in_stride[XDIM];
          stride[YDIM]=in_stride[YDIM];
      } /* end else */

    /* Sanity check the start, stride, and count args */
    if((start[XDIM]<0 || start[YDIM]<0) || (stride[XDIM]<1 || stride[YDIM]<1)
            || (count[XDIM]<1 || count[YDIM]<1))
        HGOTO_ERROR(DFE_BADDIM, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);
    gr_ptr=ri_ptr->gr_ptr;
    hdf_file_id=gr_ptr->hdf_file_id;

    comp_type = COMP_CODE_NONE;
    scheme = ri_ptr->img_dim.comp_tag;
    if (scheme == DFTAG_JPEG5 || scheme == DFTAG_GREYJPEG5
            || scheme==DFTAG_JPEG || scheme==DFTAG_GREYJPEG)
    {
	comp_type = COMP_CODE_JPEG;
	cinfo.jpeg.quality = 0;
	cinfo.jpeg.force_baseline = 0;
    }
    /* Catch old images to avoid going into HCPgetcompinfo */
    else if (scheme == DFTAG_RLE) /* old image */
        comp_type = COMP_CODE_RLE;
    else if (scheme == DFTAG_IMC) /* old image */
        comp_type = COMP_CODE_IMCOMP;
    else
    {
	/* use lower-level routine to get the compression information */
	status = HCPgetcompinfo(hdf_file_id, ri_ptr->img_tag, ri_ptr->img_ref,
                        &comp_type, &cinfo);
	if (status == FAIL)
            HGOTO_ERROR(DFE_INTERNAL,FAIL);
    }
    if (comp_type != COMP_CODE_NONE &&
	comp_type != COMP_CODE_RLE &&
	comp_type != COMP_CODE_IMCOMP)
    {   /* This is reading, why do we need encoder? -BMR */
	/* Check that the compression encoder is available */
	HCget_config_info(comp_type, &comp_config);
	if ((comp_config & (COMP_DECODER_ENABLED|COMP_ENCODER_ENABLED)) == 0)
	{ /* coder not present?? */
	    HGOTO_ERROR(DFE_BADCODER,FAIL); 
	}
	if ((comp_config & COMP_DECODER_ENABLED) == 0)
	{ /* decoder not present?? */
	    HGOTO_ERROR(DFE_NOENCODER,FAIL); 
	}
    }
    if(stride[XDIM]==1 && stride[YDIM]==1)
    { /* solid block of data */
	solid_block=TRUE;
	if ((start[XDIM]==0 && start[YDIM]==0)
	 && (count[XDIM]==ri_ptr->img_dim.xdim
	  && count[YDIM]==ri_ptr->img_dim.ydim))
	    whole_image=TRUE;
	else
	    whole_image=FALSE;
      } /* end if */
    else /* block of data spread out with strides */
        solid_block=FALSE;

    /* Get the size of the pixels in memory and on disk */
    pixel_disk_size=(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt));
    pixel_mem_size=(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize((ri_ptr->img_dim.nt | DFNT_NATIVE) & (~DFNT_LITEND)));

    /* Get number-type and conversion information */
    platnumsubclass = (uint8)DFKgetPNSC(ri_ptr->img_dim.nt & (~DFNT_LITEND), DF_MT);
    convert = (pixel_disk_size != pixel_mem_size) || (ri_ptr->img_dim.file_nt_subclass != platnumsubclass);  /* is conversion necessary? */

    /* Check if the image data is in the file */
    if(ri_ptr->img_tag==DFTAG_NULL || ri_ptr->img_ref==DFREF_WILDCARD)
        image_data=FALSE;
    else
    {
        /* Check if the actual image data is in the file yet, or if just the
	   tag & ref are known */
        if(Hlength(hdf_file_id,ri_ptr->img_tag,ri_ptr->img_ref)>0)
            image_data=TRUE;
        else
            image_data=FALSE;
    } /* end else */

    if(image_data==FALSE)
      { /* Fake an image for the user by using the pixel fill value */
          void * fill_pixel;         /* converted value for the filled pixel */
          int32 at_index;

          if((fill_pixel=HDmalloc(pixel_mem_size))==NULL)
              HGOTO_ERROR(DFE_NOSPACE,FAIL);

          /* Try to find a fill value attribute */
          if((at_index=GRfindattr(riid,FILL_ATTR))!=FAIL)
            { /* Found a fill value attribute */
                if(GRgetattr(riid,at_index,fill_pixel)==FAIL)
                    HGOTO_ERROR(DFE_BADATTR,FAIL);
            } /* end if */
          else /* no fill value attribute */
              HDmemset(fill_pixel,0,pixel_mem_size);

          /* Fill the user's buffer with the fill value */
          HDmemfill(data,fill_pixel,pixel_mem_size,(uint32)(count[XDIM]*count[YDIM]));
          HDfree(fill_pixel);
      } /* end if */
    else
      { /* an image exists in the file */
          if(convert)
            {   /* convert image data to HDF disk format */
                /* Allocate space for the conversion buffer */
                if((img_data=HDmalloc(pixel_disk_size*(size_t)count[XDIM]*(size_t)count[YDIM]))==NULL)
                    HGOTO_ERROR(DFE_NOSPACE,FAIL);
            } /* end if */
          else /* no conversion necessary, just use the user's buffer */
              img_data=data;

          if(GRIgetaid(ri_ptr, DFACC_READ)==FAIL)
              HGOTO_ERROR(DFE_INTERNAL,FAIL);

          if(whole_image==TRUE)
            { /* read the whole image in */
#ifdef OLD_WAY
                if(Hgetelement(hdf_file_id,ri_ptr->img_tag,ri_ptr->img_ref,
                        (uint8 *)img_data)==FAIL)
                    HGOTO_ERROR(DFE_GETELEM,FAIL);
#else /* OLD_WAY */
            /* Make certain we are at the beginning */
            if(Hseek(ri_ptr->img_aid,0,DF_START)==FAIL)
                HGOTO_ERROR(DFE_SEEKERROR,FAIL);

            /* Read the entire image in */

      /* This offset is relative to the element not the file and this */
      /* is where it reads and decompresses the data -BMR 09/2010 */
            if(Hread(ri_ptr->img_aid,(int32)pixel_disk_size*count[XDIM]*count[YDIM],
                    (uint8 *)img_data)==FAIL)
                HGOTO_ERROR(DFE_READERROR,FAIL);
#endif /* OLD_WAY */
            } /* end if */
          else
            { /* read only part of the image in */
                int32 img_offset; /* current offset in the image data */
                void * tmp_data;   /* temp. pointer to the image data read in */

                img_offset=((ri_ptr->img_dim.xdim*start[YDIM])+start[XDIM])*(int32)pixel_disk_size;

                tmp_data=img_data;
                if(solid_block==TRUE)
                  {   /* read in runs of data in the image */
                      int32 pix_len;    /* length of current row's pixel run */
                      intn i;           /* temporary loop variable */

                      pix_len=(int32)pixel_disk_size*count[XDIM];
                        
                      /* read in the block */
                      for(i=0; i<count[YDIM]; i++)
                        {
                            if(Hseek(ri_ptr->img_aid,img_offset,DF_START)==FAIL)
                                HGOTO_ERROR(DFE_SEEKERROR,FAIL);
                            if(Hread(ri_ptr->img_aid,pix_len,tmp_data)==FAIL)
                                HGOTO_ERROR(DFE_READERROR,FAIL);
                            img_offset+=(int32)pixel_disk_size*ri_ptr->img_dim.xdim;
                            tmp_data=(void *)((char *)tmp_data+pix_len);
                        } /* end for */
                  } /* end if */
                else
                  {   /* sub-sampling, seek to each data element and read it in */
                      intn i,j;         /* temporary loop variables */
                      int32 stride_add; /* amount to add for stride amount */

                      stride_add=(int32)pixel_disk_size*stride[XDIM];

                      for(i=0; i<count[YDIM]; i++)
                        {
                            int32 local_offset;

                            local_offset=img_offset;
                            for(j=0; j<count[XDIM]; j++)
                              {
                                if(Hseek(ri_ptr->img_aid,local_offset,DF_START)==FAIL)
                                    HGOTO_ERROR(DFE_SEEKERROR,FAIL);
                                if(Hread(ri_ptr->img_aid,(int32)pixel_disk_size,tmp_data)==FAIL)
                                    HGOTO_ERROR(DFE_READERROR,FAIL);
                                local_offset+=stride_add;
                                tmp_data=(void *)((char *)tmp_data+pixel_disk_size);
                              } /* end for */

                            img_offset+=ri_ptr->img_dim.xdim*stride[YDIM]*(int32)pixel_disk_size;
                        } /* end for */
                  } /* end else */
            } /* end else */
                  
          if(convert)
            { /* convert the pixel data into the HDF disk format */
              DFKconvert(img_data,data,ri_ptr->img_dim.nt,
                  ri_ptr->img_dim.ncomps*count[XDIM]*count[YDIM],DFACC_READ,0,0);
              HDfree(img_data);
            } /* end if */
      } /* end else */

      /* Check whether we need to convert the buffer to the user's */
      /*    requested interlace scheme. */
      /* Note: This is implemented in a horribly ugly & slow manner, but I'm */
      /*        in a bit of a hurry right now - QAK */
      if(ri_ptr->im_il!=MFGR_INTERLACE_PIXEL)
        {
          void * pixel_buf;  /* buffer for the pixel interlaced data */

          /* Allocate space for the conversion buffer */
          if((pixel_buf=HDmalloc(pixel_mem_size*(size_t)count[XDIM]*(size_t)count[YDIM]))==NULL)
              HGOTO_ERROR(DFE_NOSPACE,FAIL);

          GRIil_convert(data,MFGR_INTERLACE_PIXEL,pixel_buf,ri_ptr->im_il,
              count,ri_ptr->img_dim.ncomps,ri_ptr->img_dim.nt);

          HDmemcpy(data,pixel_buf,pixel_mem_size*(size_t)count[XDIM]*(size_t)count[YDIM]);

          HDfree(pixel_buf);
        } /* end if */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRreadimage() */

/*--------------------------------------------------------------------------
 NAME
    GRendaccess

 PURPOSE
    End access to an RI.

 USAGE
    intn GRendaccess(riid)
        int32 riid;         IN: RI ID from GRselect/GRcreate

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    End access to an RI.  Further attempts to access the RI ID will result in
    an error.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRendaccess(int32 riid)
{
    CONSTR(FUNC, "GRendaccess");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    if(!(ri_ptr->access>0))
        HGOTO_ERROR(DFE_CANTENDACCESS,FAIL);

    /* Check for writing a fill value attribute out */
    if(ri_ptr->store_fill==TRUE)
      { /* store the fill value attribute before letting go of the image */
          if(GRsetattr(riid,FILL_ATTR,ri_ptr->img_dim.nt,ri_ptr->img_dim.ncomps,ri_ptr->fill_value)==FAIL)
              HGOTO_ERROR(DFE_WRITEERROR,FAIL);
          ri_ptr->store_fill=FALSE;
      } /* end if */

    /* Reduce the number of accesses to the RI */
    ri_ptr->access--;

    /* Check if we should shut down the AID we've been holding open */
    if(!(ri_ptr->access>0) && ri_ptr->img_aid!=0)
      {
        Hendaccess(ri_ptr->img_aid);
        ri_ptr->img_aid=0;
      } /* end if */

    /* Double check on setting the GR modified flag */
    /* Maybe this should be flagged as as error? -QAK */
    if(ri_ptr->meta_modified==TRUE && ri_ptr->gr_ptr->gr_modified==FALSE)
        ri_ptr->gr_ptr->gr_modified=TRUE;

    /* Delete the atom for the RI ID */
    if(NULL==HAremove_atom(riid))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRendaccess() */

/*--------------------------------------------------------------------------
 NAME
    GRidtoref

 PURPOSE
    Maps an RI ID to a reference # for annotating or including in a Vgroup.

 USAGE
    uint16 GRidtoref(riid)
        int32 riid;         IN: RI ID from GRselect/GRcreate

 RETURNS
    A valid reference # on success or 0

 DESCRIPTION
    Maps an riid to a reference # for annotating or including in a Vgroup.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
uint16 GRidtoref(int32 riid)
{
    CONSTR(FUNC, "GRidtoref");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    uint16  ret_value = 0; /* FAIL? */

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, 0);
    
    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, 0);

#ifdef OLD_WAY
    ret_value = (ri_ptr->ri_ref!=DFREF_WILDCARD ? ri_ptr->ri_ref : ri_ptr->rig_ref);
#else /* OLD_WAY */
/* Changed to handle case when ri_ptr->rig_ref is DFREF_WILDCARD */
    if(ri_ptr->ri_ref!=DFREF_WILDCARD)
        ret_value=ri_ptr->ri_ref;
    else
      {
        if(ri_ptr->rig_ref==DFREF_WILDCARD) {
            if(ri_ptr->img_ref==DFREF_WILDCARD)
                HGOTO_ERROR(DFE_INTERNAL,0);
            ret_value=ri_ptr->img_ref;
        }
        else
            ret_value=ri_ptr->rig_ref;
      } /* end else */
#endif /* OLD_WAY */

done:
  if(ret_value == 0)   /* 0 is invalid ref */
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRidtoref() */

/*--------------------------------------------------------------------------
 NAME
    GRreftoindex

 PURPOSE
    Maps the reference # of an RI into an index which can be used with GRselect.

 USAGE
    int32 GRreftoindex(grid,ref)
        int32 grid;         IN: GR ID from GRstart
        uint16 ref;         IN: reference number of raster image to map to index

 RETURNS
    A valid index # on success or FAIL

 DESCRIPTION
    Maps the reference # of an RI into an index which can be used with GRselect.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int32 GRreftoindex(int32 grid,uint16 ref)
{
    CONSTR(FUNC, "GRreftoindex");   /* for HERROR */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    void * *t;                   /* temp. ptr to the image found */
    int32   ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(grid)!=GRIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate GR's object in hash table */
    if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(grid)))
        HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

    if((t = (void **)tbbtfirst((TBBT_NODE *) *(gr_ptr->grtree)))==NULL)
        HGOTO_ERROR(DFE_RINOTFOUND,FAIL);
    do {
        ri_ptr=(ri_info_t *)*t;
        if(ri_ptr!=NULL && ((ri_ptr->ri_ref==ref) || (ri_ptr->ri_ref==DFREF_WILDCARD && ri_ptr->rig_ref==ref)))  /* the ref matches */
            HGOTO_DONE(ri_ptr->index);
    } while((t= (void **)tbbtnext((TBBT_NODE *)t))!=NULL);

    ret_value = (FAIL);

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRreftoindex() */

/*--------------------------------------------------------------------------
 NAME
    GRreqlutil

 PURPOSE
    Request that the next LUT read from an RI have a particular interlace.

 USAGE
    intn GRreqlutil(riid,il)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        intn il;            IN: interlace for next LUT.  From the following
                                values (found in mfgr.h): 
                      MFGR_INTERLACE_PIXEL      - pixel interlacing
                      MFGR_INTERLACE_LINE       - line interlacing
                      MFGR_INTERLACE_COMPONENT  - component/plane interlacing

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Request that the next LUT read from an RI have a particular interlace.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRreqlutil(int32 riid,intn il)
{
    CONSTR(FUNC, "GRreqlutil");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP || il<(intn)MFGR_INTERLACE_PIXEL ||
            il>(intn)MFGR_INTERLACE_COMPONENT)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* Assign interlacing scheme */
    ri_ptr->lut_il=(gr_interlace_t)il;   

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRreqlutil() */

/*--------------------------------------------------------------------------
 NAME
    GRreqimageil

 PURPOSE
    Request that the image read from an RI have a particular interlace.

 USAGE
    intn GRreqimageil(riid,il)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        intn il;            IN: interlace for next RI.  From the following
                                values (found in mfgr.h): 
                      MFGR_INTERLACE_PIXEL      - pixel interlacing
                      MFGR_INTERLACE_LINE       - line interlacing
                      MFGR_INTERLACE_COMPONENT  - component/plane interlacing

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Request that the image read from an RI have a particular interlace.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRreqimageil(int32 riid,intn il)
{
    CONSTR(FUNC, "GRreqimageil");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP || il<(intn)MFGR_INTERLACE_PIXEL ||
            il>(intn)MFGR_INTERLACE_COMPONENT)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* Assign interlacing scheme */
    ri_ptr->im_il=(gr_interlace_t)il;   

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRreqimageil() */

/*--------------------------------------------------------------------------
 NAME
    GRgetlutid

 PURPOSE
    Get a LUT id ('lutid') for an RI.

 USAGE
    int32 GRgetlutid(riid,index)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        int32 lut_index;    IN: Which LUT image to select (indexed from 0)

 RETURNS
    Valid LUT ID on success, FAIL on failure

 DESCRIPTION
    Get a LUT id ('lutid') for accessing LUTs in an RI.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    Currently only supports one LUT per image, at index 0 and LUTID==RIID.

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int32 GRgetlutid(int32 riid,int32 lut_index)
{
    CONSTR(FUNC, "GRgetlutid");   /* for HERROR */
    int32  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP || lut_index!=0)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    ret_value =(riid);

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRgetlutid() */

/*--------------------------------------------------------------------------
 NAME
    GRluttoref

 PURPOSE
    Returns the ref # for a LUT.

 USAGE
    uint16 GRluttoref(lutid)
        int32 lutid;        IN: LUT ID from GRgetlutid

 RETURNS
    Valid ref # if a palette exists, or 0 when:
  - palette doesn't exist, or
  - unable to get the image from the palette id. - BMR

 DESCRIPTION
    Gets the ref # used to store the LUT in the file.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
uint16 GRluttoref(int32 lutid)
{
    CONSTR(FUNC, "GRluttoref");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    uint16 ret_value = 0;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(lutid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, 0);  /* return 0 for invalid ref # - BMR */
    
    /* locate LUT's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(lutid)))
        HGOTO_ERROR(DFE_LUTNOTFOUND, 0); /* return 0 for invalid ref # - BMR */

    ret_value=ri_ptr->lut_ref;

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRluttoref() */

/*--------------------------------------------------------------------------
 NAME
    GRgetlutinfo

 PURPOSE
    Gets information about a LUT.

 USAGE
    intn GRgetlutinfo(lutid,ncomp,nt,il,nentries)
        int32 lutid;        IN: LUT ID from GRgetlutid
        int32 *ncomp;       OUT: number of components in LUT
        int32 *nt;          OUT: number type of components
        int32 *il;          OUT: interlace of the LUT
        int32 *nentries;    OUT: the number of entries for the LUT

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Gets information about a LUT.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRgetlutinfo(int32 lutid,int32 *ncomp,int32 *nt,int32 *il,int32 *nentries)
{
    CONSTR(FUNC, "GRgetlutinfo");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(lutid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate LUT's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(lutid)))
        HGOTO_ERROR(DFE_LUTNOTFOUND, FAIL);

    if(ri_ptr->lut_ref==DFREF_WILDCARD) { /* check for no palette defined currently */
        if(ncomp!=NULL)
            *ncomp=0;
        if(nt!=NULL)
            *nt=DFNT_NONE;
        if(il!=NULL)
            *il=-1;
        if(nentries!=NULL)
            *nentries=0;
    } /* end if */
    else        /* we've got a valid palette currently */
      {
          if(ncomp!=NULL)
              *ncomp=ri_ptr->lut_dim.ncomps;
          if(nt!=NULL)
              *nt=ri_ptr->lut_dim.nt;
          if(il!=NULL)
              *il=(int32)ri_ptr->lut_dim.il;
          if(nentries!=NULL)  /* xdim for LUTs is the number of entries */
              *nentries=ri_ptr->lut_dim.xdim;
      } /* end else */

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
    return ret_value;
} /* end GRgetlutinfo() */

/*--------------------------------------------------------------------------
 NAME
    GRwritelut

 PURPOSE
    Writes out a LUT for an RI.

 USAGE
    intn GRwritelut(riid,ncomps,nt,il,nentries,data)
        int32 lutid;        IN: LUT ID from GRgetlutid
        int32 ncomp;        IN: number of components in LUT
        int32 nt;           IN: number type of components
        int32 il;           IN: interlace of the LUT
        int32 nentries;     IN: the number of entries for the LUT
        void * data;         IN: LUT data to write out

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Writes out a LUT for an RI.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRwritelut(int32 lutid,int32 ncomps,int32 nt,int32 il,int32 nentries,void * data)
{
    CONSTR(FUNC, "GRwritelut");   /* for HERROR */
    int32 hdf_file_id;          /* file ID from Hopen */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the args (how to check il?) */
    if (HAatom_group(lutid)!=RIIDGROUP || ncomps<1 || (DFKNTsize(nt)==FAIL)
            || nentries<1 || data==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate LUT's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(lutid)))
        HGOTO_ERROR(DFE_LUTNOTFOUND, FAIL);
    hdf_file_id=ri_ptr->gr_ptr->hdf_file_id;

    /* Check if this is compatible with older-style palettes */
    if(ncomps==3 && (nt==DFNT_UINT8 ||nt==DFNT_UCHAR8) && 
        il==MFGR_INTERLACE_PIXEL && nentries==256)
      {
          /* Check if LUT exists already */
          if(ri_ptr->lut_tag!=DFTAG_NULL && ri_ptr->lut_ref!=DFREF_WILDCARD)
            {   /* LUT already exists */
                if(Hputelement(hdf_file_id,ri_ptr->lut_tag,ri_ptr->lut_ref,
                        data,ncomps*nentries*DFKNTsize(nt))==FAIL)
                    HGOTO_ERROR(DFE_PUTELEM,FAIL);
            } /* end if */
          else
            {   /* LUT does not exist */
                ri_ptr->lut_tag=DFTAG_LUT;
                ri_ptr->lut_ref=Htagnewref(hdf_file_id,ri_ptr->lut_tag);
                ri_ptr->lut_dim.dim_ref=DFREF_WILDCARD;
                ri_ptr->lut_dim.xdim=256;
                ri_ptr->lut_dim.ydim=1;
                ri_ptr->lut_dim.ncomps=3;
                ri_ptr->lut_dim.nt=DFNT_UINT8;
                ri_ptr->lut_dim.file_nt_subclass=DFNTF_HDFDEFAULT;
                ri_ptr->lut_dim.il=MFGR_INTERLACE_PIXEL;
                ri_ptr->lut_dim.nt_tag=DFTAG_NULL;
                ri_ptr->lut_dim.nt_ref=DFREF_WILDCARD;
                ri_ptr->lut_dim.comp_tag=DFTAG_NULL;
                ri_ptr->lut_dim.comp_ref=DFREF_WILDCARD;
                if(Hputelement(hdf_file_id,ri_ptr->lut_tag,ri_ptr->lut_ref,
                        data,ncomps*nentries*DFKNTsize(nt))==FAIL)
                    HGOTO_ERROR(DFE_PUTELEM,FAIL);

                ri_ptr->meta_modified=TRUE;
                ri_ptr->gr_ptr->gr_modified=TRUE;
            } /* end else */
      } /* end if */
    else
      {     /* currently, we are not going to support non-standard palettes */
          HGOTO_ERROR(DFE_UNSUPPORTED,FAIL);
      } /* end else */

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRwritelut() */

/*--------------------------------------------------------------------------
 NAME
    GRreadlut

 PURPOSE
    Reads a LUT from an RI.

 USAGE
    intn GRreadlut(lutid,data)
        int32 lutid;        IN: LUT ID from GRgetlutid
        void * data;         IN: buffer for LUT data read in

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Reads a LUT from an RI.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRreadlut(int32 lutid,void * data)
{
    CONSTR(FUNC, "GRreadlut");   /* for HERROR */
    int32 hdf_file_id;          /* file ID from Hopen */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(lutid)!=RIIDGROUP || data==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate LUT's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(lutid)))
        HGOTO_ERROR(DFE_LUTNOTFOUND, FAIL);
    hdf_file_id=ri_ptr->gr_ptr->hdf_file_id;

    if(ri_ptr->lut_tag!=DFTAG_NULL && ri_ptr->lut_ref!=DFREF_WILDCARD)
      {
          if(Hgetelement(hdf_file_id,ri_ptr->lut_tag,ri_ptr->lut_ref,data)==FAIL)
              HGOTO_ERROR(DFE_GETELEM,FAIL);
      } /* end if */
    
    /* Re-format the palette into the user's requested interlacing */
    if(ri_ptr->lut_il!=MFGR_INTERLACE_PIXEL)
      {
          uintn pixel_mem_size;       /* size of a pixel in memory */
          void * pixel_buf;  /* buffer for the pixel interlaced data */
          int32 count[2];   /* "dimension" info */

          pixel_mem_size=(uintn)(ri_ptr->lut_dim.ncomps*DFKNTsize((ri_ptr->lut_dim.nt | DFNT_NATIVE) & (~DFNT_LITEND)));

          /* Allocate space for the conversion buffer */
          if((pixel_buf=HDmalloc(pixel_mem_size*(size_t)ri_ptr->lut_dim.xdim))==NULL)
              HGOTO_ERROR(DFE_NOSPACE,FAIL);

          count[XDIM]=1;
          count[YDIM]=ri_ptr->lut_dim.xdim;
          GRIil_convert(data,MFGR_INTERLACE_PIXEL,pixel_buf,ri_ptr->lut_il,
              count,ri_ptr->lut_dim.ncomps,ri_ptr->lut_dim.nt);

          HDmemcpy(data,pixel_buf,pixel_mem_size*(size_t)ri_ptr->lut_dim.xdim);

          HDfree(pixel_buf);
      } /* end if */

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRreadlut() */

/*--------------------------------------------------------------------------
 NAME
    GRsetexternalfile

 PURPOSE
    Makes the image data of an RI into an external element special element.

 USAGE
    intn GRsetexternalfile(riid,filename,offset)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        char *filename;     IN: name of the external file
        int32 offset;       IN: offset in the external file to store the image

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Makes the image data of an RI into an external element special element.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRsetexternalfile(int32 riid,const char *filename,int32 offset)
{
    CONSTR(FUNC, "GRsetexternalfile");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    int32 tmp_aid;  /* AID returned from HXcreate() */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    if((ri_ptr->ext_name=(char *)HDmalloc(HDstrlen(filename)+1))==NULL)
        HGOTO_ERROR(DFE_NOSPACE,FAIL);

    /* Mark the image as external and cache parameters */
    ri_ptr->ext_img=TRUE;
    HDstrcpy(ri_ptr->ext_name,filename);
    ri_ptr->ext_offset=offset;

    /* Create the image tag/ref if it's a new image */
    if(ri_ptr->img_tag==DFTAG_NULL || ri_ptr->img_ref==DFREF_WILDCARD)
      {
        ri_ptr->img_tag=DFTAG_RI;
        ri_ptr->img_ref=Htagnewref(ri_ptr->gr_ptr->hdf_file_id,ri_ptr->img_tag);
        ri_ptr->meta_modified=TRUE;
      } /* end if */

    /* close any existing AID, to convert to external element AID */
    if(ri_ptr->img_aid!=0)
      {
        Hendaccess(ri_ptr->img_aid);
        ri_ptr->img_aid=0;
      } /* end if */

    /* Convert the image into an external element */
    if((tmp_aid=HXcreate(ri_ptr->gr_ptr->hdf_file_id,ri_ptr->img_tag,
            ri_ptr->img_ref,filename,offset,0))==FAIL)
        HGOTO_ERROR(DFE_BADAID, FAIL);
    if(Hendaccess(tmp_aid)==FAIL)
        HGOTO_ERROR(DFE_CANTENDACCESS, FAIL);

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRsetexternalfile() */

/*--------------------------------------------------------------------------
 NAME
    GRsetaccesstype

 PURPOSE
    Sets the access for an RI to be either serial or parallel I/O.

 USAGE
    intn GRsetaccesstype(riid,accesstype)
        int32 riid;         IN: RI ID from GRselect/GRcreate
        uintn accesstype;   IN: access type for image data, from the following
           values:
        DFACC_SERIAL - for serial access
        DFACC_PARALLEL - for parallel access

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Sets the access for an RI to be either serial or parallel I/O.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRsetaccesstype(int32 riid,uintn accesstype)
{
    CONSTR(FUNC, "GRsetaccesstype");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP || (accesstype!=DFACC_DEFAULT && accesstype!=DFACC_SERIAL
            && accesstype!=DFACC_PARALLEL))
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* Mark the image as having an access-mode and cache args */
    ri_ptr->acc_img=TRUE;
    ri_ptr->acc_type=accesstype;

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRsetaccesstype() */


#ifdef H4_HAVE_LIBSZ          /* we have the library */
/*--------------------------------------------------------------------------
 NAME
    GRsetup_szip_parms( ri_info_t *ri_ptr, comp_info *c_info, int32 *cdims)

 PURPOSE
    Set up the szip parameters

 USAGE
    intn GRsetaccesstype( ri_info_t *ri_ptr, comp_info *c_info, int32 *cdims)
    ri_info_t *ri_ptr;  IN: the RI object 
    comp_info *c_info;  IN/OUT: the compression info (szip) 
    int32 *cdims;       IN: chunk dims if chunked, else NULL

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Sets the computed szip parameters before calling HCcreate.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn 
GRsetup_szip_parms( ri_info_t *ri_ptr, comp_info *c_info, int32 *cdims)
{
    int32 nt;
    int32 ndims;
    int32 ncomp;
    int32 xdims[H4_MAX_VAR_DIMS];
    intn  ret_value = SUCCEED;
    
    
    ndims = 2;
    xdims[0] = ri_ptr->img_dim.xdim;
    xdims[1] = ri_ptr->img_dim.ydim;
    
    nt = ri_ptr->img_dim.nt;
    ncomp = ri_ptr->img_dim.ncomps;
    
    ret_value = HCPsetup_szip_parms( c_info, nt, ncomp, ndims, xdims, cdims);
    
done:
    return(ret_value);
}
#endif

/*--------------------------------------------------------------------------
 NAME
    GRsetcompress

 PURPOSE
    Compressed the image data of an RI.

 USAGE
    intn GRsetcompress(riid,comp_type,cinfo)
        int32 riid;             IN: RI ID from GRselect/GRcreate
        comp_coder_t comp_type; IN: type of compression
        comp_info *cinfo;       IN: compression specific information

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Compressed the image data of an RI.
    (Makes the image data of an RI into a compressed special element)

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRsetcompress(int32 riid,comp_coder_t comp_type,comp_info *cinfo)
{
    CONSTR(FUNC, "GRsetcompress");   /* for HERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    comp_info cinfo_x;
    uint32 comp_config;
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    HDmemcpy(&cinfo_x,cinfo,sizeof(comp_info));
    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    /* Check the validity of the compression type */
    if ((comp_type < COMP_CODE_NONE || comp_type >= COMP_CODE_INVALID) 
  && comp_type!=COMP_CODE_JPEG)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* Check if the image is already special (all special elements use the buffered driver) */
    if (ri_ptr->use_buf_drvr)
        HGOTO_ERROR(DFE_CANTMOD, FAIL);

    /* Check that the compression method is enabled */
    HCget_config_info(comp_type, &comp_config);
    if ((comp_config & (COMP_DECODER_ENABLED|COMP_ENCODER_ENABLED)) == 0) {
  /* coder not present?? */
      HGOTO_ERROR(DFE_BADCODER, FAIL);
    }
    if ((comp_config & COMP_ENCODER_ENABLED) != COMP_ENCODER_ENABLED) {
     /* if ((comp_config & COMP_ENCODER_ENABLED) == 0) {
 */ 
  /* encoder not present?? */
      HGOTO_ERROR(DFE_NOENCODER, FAIL);
    }

    if (comp_type==COMP_CODE_SZIP) 
#ifndef H4_HAVE_LIBSZ
        HGOTO_ERROR(DFE_NOSZLIB, FAIL);
#else
    {
    /* szip is enabled, check and set up szip parms */
  if (GRsetup_szip_parms( ri_ptr, &cinfo_x, NULL) == FAIL) {
      HGOTO_ERROR(DFE_INTERNAL, FAIL);
  }
    }
#endif

    /* Mark the image as being compressed and cache args */
    if(comp_type==COMP_CODE_JPEG)
      {
        if(ri_ptr->img_dim.ncomps==1)
            ri_ptr->img_dim.comp_tag=DFTAG_GREYJPEG5;
        else if(ri_ptr->img_dim.ncomps==3)
            ri_ptr->img_dim.comp_tag=DFTAG_JPEG5;
        else
            HGOTO_ERROR(DFE_CANTMOD, FAIL);
        ri_ptr->use_cr_drvr=TRUE;
      } /* end if */
    else
      {
        ri_ptr->comp_img=TRUE;
        ri_ptr->comp_type=comp_type;
      } /* end else */

    /* Todo: Application may send in COMP_CODE_NONE -BMR 9/2010 */

    /* Store compression parameters */
    HDmemcpy(&(ri_ptr->cinfo),&cinfo_x,sizeof(comp_info));

    /* Mark the image as needing to be a buffered special element */
    ri_ptr->use_buf_drvr=1;

    /* Make certain the image gets created */
    if(GRIgetaid(ri_ptr, DFACC_WRITE)==FAIL)
        HGOTO_ERROR(DFE_INTERNAL,FAIL);

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRsetcompress() */

/*--------------------------------------------------------------------------
 NAME
    GRgetcompress

 PURPOSE
    Get the compression information of a raster image's data.

 USAGE
    intn GRgetcompress(riid,comp_type,cinfo)
        int32 riid;       IN: RI ID from GRselect/GRcreate
        comp_coder_t* comp_type;   OUT: type of compression
        comp_info* cinfo;     OUT: retrieved compression information

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    This routine gets the compression type of the given RI's data, then
    retrieves the appropriate information into the provided compression
    info structure.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    JPEG information is currently not retrievable because the JPEG 
    parameters, 'quality' and 'force_baseline', are irreversibly 
    mapped to a quantization table.  Thus, only the correct compression 
    type will be returned; cinfo will only contain 0s.

 EXAMPLES
 REVISION LOG
    July 2001: Added to fix bug #307 -BMR
    Apr 2005: Replaced by GRgetcompinfo due to deficiency in handling some
		special elements. -BMR
--------------------------------------------------------------------------*/
intn GRgetcompress(int32 riid, comp_coder_t* comp_type, comp_info* cinfo)
{
    CONSTR(FUNC, "GRgetcompress");   /* for HGOTO_ERROR */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    int32 file_id;
    uint16 scheme;  /* compression scheme used for JPEG images */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid) != RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* and check the output arguments */
    if (comp_type == NULL || cinfo == NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_BADPTR, FAIL);

    file_id = ri_ptr->gr_ptr->hdf_file_id;  /* temporary use */

    /* If the compression scheme used was JPEG, return the compression type
       and 0 for the 'quality' and 'force_baseline' parameters, because 
       these parameters are currently not possible to be retrieved. */
    scheme = ri_ptr->img_dim.comp_tag;
    if (scheme == DFTAG_JPEG5 || scheme == DFTAG_GREYJPEG5
            || scheme==DFTAG_JPEG || scheme==DFTAG_GREYJPEG)
    {
	*comp_type = COMP_CODE_JPEG;
	cinfo->jpeg.quality = 0;
	cinfo->jpeg.force_baseline = 0;
    }
    else
    {
	/* use lower-level routine to get the compression information */
	ret_value = HCPgetcompress(file_id, ri_ptr->img_tag, ri_ptr->img_ref,
                                comp_type, cinfo);
	if (ret_value == FAIL)
	    HGOTO_ERROR(DFE_INTERNAL, FAIL);
    }

done:
  if(ret_value == 0)
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRgetcompress() */

/*--------------------------------------------------------------------------
 NAME
    GRgetcomptype

 PURPOSE
    Get the compression type of a raster image's data.

 USAGE
    intn GRgetcomptype(riid, comp_type)
        int32 riid;     IN: RI ID from GRselect/GRcreate
        comp_coder_t* comp_type;  OUT: type of compression, including obsolete ones

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Historical note:
    This function (old name grgetcomptype) was implemented specifically
    for the hmap project.  It gets the compression type of the given
    RI's data.  The existing function GRgetcompinfo did not detect the
    obsolete compression scheme IMCOMP.  Because the hmap writer needs
    to report when an image with IMCOMP exists in the file, it needs a
    way to detect such images.  One option is to add COMP_CODE_IMCOMP
    to the enum type comp_coder_t.  However, with the consideration of
    backward/forward compatibility, it would be risky to change the
    existing public type comp_coder_t while running against deadlines.
    Instead, it was decided that a function would be made for the hmap
    project only, and would not be published in the HDF4 documentation.
    The function, grgetcomptype, will return comp_type as COMP_IMCOMP
    or one of the values included in the type comp_coder_t.  Mar 11, 2011 -BMR

    Update:
    Further investigation indicated that it is safe to add COMP_CODE_IMCOMP
    to comp_coder_t, with the value of 12 (as DFTAG_IMC/DFTAG_IMCOMP), which
    is after COMP_CODE_JPEG.  Extra care had been taken to ensure that GR
    interface cannot create or write images using IMCOMP compression.
    grgetcomptype is now changed to GRgetcomptype and published in
    release 4.2.8.  Jul 11, 2012 -BMR

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    At this time, hdp and other tools still use GRgetcompinfo.  We need to
    discuss about how to handle its limitation.  In addition, GR2bmapped is
    using grgetcomptype until we have an official GRgetcomptype or will change
    to use GRgetcompinfo if we decide not to have GRgetcomptype.  The fact that
    grgetcomptype uses int32 for comp_type makes it not a good long term option
    due to inconsistency in the library.  Mar 11, 2011 -BMR

    Update:
    GRgetcomptype is now used in place of grgetcomptype and in hdp to detect
    and report IMCOMP compression, in release 4.2.8.  Jul 11, 2012 -BMR

 EXAMPLES
 REVISION LOG

--------------------------------------------------------------------------*/
intn GRgetcomptype(int32 riid, comp_coder_t* comp_type)
{
    CONSTR(FUNC, "GRgetcomptype");  /* for HGOTO_ERROR */
    ri_info_t *ri_ptr;            /* ptr to the image to work with */
    int32 file_id;
    uint16 scheme;  /* compression scheme used for old images */
    intn  ret_value = SUCCEED;

    /* clear error */
    HEclear();

    /* Validate the RI ID */
    if (HAatom_group(riid) != RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Check the output argument */
    if (comp_type == NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_BADPTR, FAIL);

    file_id = ri_ptr->gr_ptr->hdf_file_id;  /* temporary use */

    /* Handle old compression schemes separately */
    scheme = ri_ptr->img_dim.comp_tag;
    if (scheme == DFTAG_JPEG5 || scheme == DFTAG_GREYJPEG5
            || scheme==DFTAG_JPEG || scheme==DFTAG_GREYJPEG)
    {
        *comp_type = COMP_CODE_JPEG;
    }
    else if (scheme == DFTAG_RLE)
        *comp_type = COMP_CODE_RLE;
    else if (scheme == DFTAG_IMC || scheme == DFTAG_IMCOMP)
        *comp_type = COMP_CODE_IMCOMP;

    /* Use lower-level routine to get the new compression type */
    else
    {
        comp_coder_t temp_comp_type = COMP_CODE_INVALID;
        ret_value = HCPgetcomptype(file_id, ri_ptr->img_tag, ri_ptr->img_ref,
                                &temp_comp_type);
        if (ret_value == FAIL)
            HGOTO_ERROR(DFE_INTERNAL, FAIL);
        *comp_type = temp_comp_type;
    }
done:
  if(ret_value == 0)
    { /* Error condition cleanup */
    } /* end if */
  /* Normal function cleanup */
  return ret_value;
} /* end GRgetcomptype() */

/*--------------------------------------------------------------------------
 NAME
    GRgetcompinfo

 PURPOSE
    Get the compression information of a raster image's data.

 USAGE
    intn GRgetcompinfo(riid,comp_type,cinfo)
        int32 riid;       IN: RI ID from GRselect/GRcreate
        comp_coder_t* comp_type;   OUT: type of compression
        comp_info* cinfo;     OUT: retrieved compression information

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    This routine gets the compression type of the given RI's data, then
    retrieves the appropriate information into the provided compression
    info structure.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    JPEG information is currently not retrievable because the JPEG 
    parameters, 'quality' and 'force_baseline', are irreversibly 
    mapped to a quantization table.  Thus, only the correct compression 
    type will be returned; cinfo will only contain 0s.

 EXAMPLES
 REVISION LOG
    July 2001: Added to fix bug #307 - BMR (from GRgetcompress)
    Apr 2005:  This function was actually created at this time, but it is
               almost a duplicate of GRgetcompress, which is intended to be
               removed in the future, due to its incorrect behavior.  The
               only difference is the call to the low-level routine,
               HCPgetcompinfo, instead of HCPgetcompress.

--------------------------------------------------------------------------*/
intn GRgetcompinfo(int32 riid, comp_coder_t* comp_type, comp_info* cinfo)
{
    CONSTR(FUNC, "GRgetcompinfo");  /* for HGOTO_ERROR */
    ri_info_t *ri_ptr;            /* ptr to the image to work with */
    int32 file_id;
    uint16 scheme;  /* compression scheme used for JPEG images */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(riid) != RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* and check the output arguments */
    if (comp_type == NULL || cinfo == NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_BADPTR, FAIL);

    file_id = ri_ptr->gr_ptr->hdf_file_id;  /* temporary use */

    /* If the compression scheme used was JPEG, return the compression type
       and 0 for the 'quality' and 'force_baseline' parameters, because 
       these parameters are currently not possible to be retrieved. */
    scheme = ri_ptr->img_dim.comp_tag;
    if (scheme == DFTAG_JPEG5 || scheme == DFTAG_GREYJPEG5
            || scheme==DFTAG_JPEG || scheme==DFTAG_GREYJPEG)
    {
	*comp_type = COMP_CODE_JPEG;
	cinfo->jpeg.quality = 0;
	cinfo->jpeg.force_baseline = 0;
    }
    /* Catch old images to avoid going into HCPgetcompinfo */
    else if (scheme == DFTAG_RLE) /* old image */
	*comp_type = COMP_CODE_RLE;
    else if (scheme == DFTAG_IMC) /* old image */
        *comp_type = COMP_CODE_IMCOMP;
    else
    {
	/* use lower-level routine to get the compression information */
	ret_value = HCPgetcompinfo(file_id, ri_ptr->img_tag, ri_ptr->img_ref,
                                comp_type, cinfo);
	if (ret_value == FAIL)
	    HGOTO_ERROR(DFE_INTERNAL, FAIL);
    }

done:
  if(ret_value == 0)
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRgetcompinfo() */

/*--------------------------------------------------------------------------
 NAME
    GRsetattr

 PURPOSE
    Write an attribute for an object.

 USAGE
    intn GRsetattr(dimid|riid|grid,name,attr_nt,count,data)
        int32 dimid|riid|grid;  IN: DIM|RI|GR ID
        char *name;             IN: name of attribute
        int32 attr_nt;          IN: number-type of attribute
        int32 count;            IN: number of entries of the attribute
        void * data;             IN: attribute data to write

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Write an attribute for an object (function will figure out ID type).

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    Currently does not allow changing NT of an existing attribute.

 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRsetattr(int32 id,const char *name,int32 attr_nt,int32 count,const void * data)
{
    CONSTR(FUNC, "GRsetattr");   /* for HERROR */
    int32 hdf_file_id;          /* HDF file ID from Hopen */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr=NULL;     /* ptr to the image to work with */
    void * *t;                   /* temp. ptr to the image found */
    TBBT_TREE *search_tree;     /* attribute tree to search through */
    at_info_t *at_ptr=NULL;     /* ptr to the attribute to work with */
    int32 at_size;              /* size in bytes of the attribute data */
    int32 *update_count;        /* pointer to the count of attributes in a tree */
    uintn *update_flag;         /* pointer to the flag to indicate an attribute tree is changed */
    uintn found=FALSE;          /* boolean for indicating the attribute exists already */
    intn is_riid=FALSE;         /* whether we had a RIID */
    intn ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* Make sure that count is less than MAX_ORDER(Vdata)
           and total size is less than MAX_FIELD_SIZE(Vdata) */
    if ((count > MAX_ORDER) ||
        ((count * DFKNTsize(attr_nt)) > MAX_FIELD_SIZE))
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* check the validity of the args */
    if ((HAatom_group(id)!=RIIDGROUP && HAatom_group(id)!=GRIDGROUP) || data==NULL || name==NULL
            || count<=0 || DFKNTsize(attr_nt)==FAIL)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    if (HAatom_group(id)==GRIDGROUP)
      {
          /* locate GR's object in hash table */
          if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

          hdf_file_id=gr_ptr->hdf_file_id;
          search_tree=gr_ptr->gattree;
          update_flag=&(gr_ptr->gattr_modified);
          update_count=&(gr_ptr->gattr_count);
      } /* end if */
    else if (HAatom_group(id)==RIIDGROUP)
      {
          /* Need this flag for later */
          is_riid=TRUE;

          /* locate RI's object in hash table */
          if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_RINOTFOUND, FAIL);
          gr_ptr=ri_ptr->gr_ptr;

          hdf_file_id=gr_ptr->hdf_file_id;
          search_tree=ri_ptr->lattree;
          update_flag=&(ri_ptr->attr_modified);
          update_count=&(ri_ptr->lattr_count);
      } /* end if */
    else    /* shouldn't get here, but what the heck... */
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Search for an attribute with the same name */
    if((t = (void **)tbbtfirst((TBBT_NODE *)*search_tree))!=NULL)
      {
          do {
              at_ptr=(at_info_t *)*t;
              if(at_ptr!=NULL && HDstrcmp(at_ptr->name,name)==0)  /* ie. the name matches */
                {
                    found=TRUE;
                    break;
                } /* end if */
          } while((t= (void **)tbbtnext((TBBT_NODE *)t))!=NULL);
      } /* end if */

    if(found==TRUE) /* attribute already exists, just update it */
      {
          int32 new_at_size;          /* size in bytes of the new attribute data */

          /* Catch the user if he tries to change the NT */
          if(attr_nt!=at_ptr->nt)
              HGOTO_ERROR(DFE_ARGS, FAIL);

          /* Calc. old & new attr. sizes */
          new_at_size=count*DFKNTsize((attr_nt | DFNT_NATIVE) & (~DFNT_LITEND));
          at_size=at_ptr->len*DFKNTsize((at_ptr->nt | DFNT_NATIVE) & (~DFNT_LITEND));

          if((uint32)new_at_size>gr_ptr->attr_cache)    /* check if data is cacheable */
            {   /* not cacheable, write directly out to disk and throw away old in-memory copy */
                int32 AttrID;       /* attribute Vdata id */

                /* Update data on disk */
                if((AttrID=VSattach(hdf_file_id,(int32)at_ptr->ref,"w"))==FAIL)
                    HGOTO_ERROR(DFE_CANTATTACH,FAIL);
                if(VSsetfields(AttrID,at_ptr->name)==FAIL)
                  {
                    VSdetach(AttrID);
                    HGOTO_ERROR(DFE_BADFIELDS,FAIL);
                  } /* end if */
                if(VSwrite(AttrID,data,count,FULL_INTERLACE)==FAIL)
                  {
                    VSdetach(AttrID);
                    HGOTO_ERROR(DFE_VSWRITE,FAIL);
                  } /* end if */
                if(VSdetach(AttrID)==FAIL)
                    HGOTO_ERROR(DFE_CANTDETACH,FAIL);

                /* Update in-memory fields */
                at_ptr->len=count;
                at_ptr->data_modified=FALSE;

                /* Toss the old data, it's not valid and it's un-cacheable now */
                if(at_ptr->data!=NULL)
                    HDfreenclear(at_ptr->data);
            }  /* end if */
          else
            {
                /* check if we need a bigger buffer */
                if(new_at_size>at_size || at_ptr->data==NULL)
                  {
                      if(at_ptr->data!=NULL)
                          HDfree(at_ptr->data);
                      if((at_ptr->data=HDmalloc(new_at_size))==NULL)
                          HGOTO_ERROR(DFE_NOSPACE,FAIL);
                  } /* end if */
                HDmemcpy(at_ptr->data,data,new_at_size);

                /* Update in-memory fields */
                at_ptr->len=count;
                at_ptr->data_modified=TRUE;
                *update_flag=TRUE;  /* flag the tree as changed */
            } /* end else */
      } /* end if */
    else    /* a new attribute */
      {
        if((at_ptr=(at_info_t *)HDmalloc(sizeof(at_info_t)))==NULL)
            HGOTO_ERROR(DFE_NOSPACE,FAIL);

        /* Fill in fields for the new attribute */
        at_ptr->index=*update_count;  /* get the index and update the tree's count */
        at_ptr->nt=attr_nt;
        at_ptr->len=count;

        /* allocate space for the attribute name & copy it */
        if((at_ptr->name=(char *)HDmalloc(HDstrlen(name)+1))==NULL)
            HGOTO_ERROR(DFE_NOSPACE,FAIL);
        HDstrcpy(at_ptr->name,name);

        /* calc. the attr size to see if it is worth caching */
        at_size=at_ptr->len*DFKNTsize((at_ptr->nt | DFNT_NATIVE) & (~DFNT_LITEND));
        if((uint32)at_size<gr_ptr->attr_cache)
          { /* cacheable */
              /* allocate space for the attribute name & copy it */
              if((at_ptr->data=(char *)HDmalloc(at_size))==NULL)
                  HGOTO_ERROR(DFE_NOSPACE,FAIL);
              HDmemcpy(at_ptr->data,data,at_size);
              at_ptr->data_modified=TRUE;
              at_ptr->ref=DFREF_WILDCARD;
          } /* end if */
        else
          { /* non-cacheable */
              if((at_ptr->ref=(uint16)VHstoredata(hdf_file_id,at_ptr->name,data,
                      at_ptr->len,at_ptr->nt,RIGATTRNAME,RIGATTRCLASS))==(uint16)FAIL)
                  HGOTO_ERROR(DFE_VSCANTCREATE,FAIL);
              at_ptr->data=NULL;
              at_ptr->data_modified=FALSE;
          } /* end else */
        at_ptr->new_at=TRUE;

        /* Add the attribute to the attribute tree */
        if(tbbtdins(search_tree, at_ptr, NULL)==NULL)
            HGOTO_ERROR(DFE_TBBTINS,FAIL);

        /* flag the attribute tree as being modified */
        *update_flag=TRUE;
        (*update_count)++;  /* get the index and update the tree's count */
      } /* end else */

    /* set this flag also, if we set local attributes */
    if(is_riid==TRUE) 
      {
        if(found==FALSE)    /* when adding new attributes, make certain the RI gets updated */
            ri_ptr->meta_modified=TRUE;
        gr_ptr->gr_modified=TRUE;
      } /* end if */

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRsetattr() */

/*--------------------------------------------------------------------------
 NAME
    GRattrinfo

 PURPOSE
    Get attribute information for an object.

 USAGE
    intn GRattrinfo(dimid|riid|grid,index,name,attr_nt,count)
        int32 dimid|riid|grid;  IN: DIM|RI|GR ID
        int32 index;            IN: index of the attribute for info
        char *name;             OUT: name of attribute
        int32 attr_nt;          OUT: number-type of attribute
        int32 count;            OUT: number of entries of the attribute

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Get attribute information for an object.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRattrinfo(int32 id,int32 index,char *name,int32 *attr_nt,int32 *count)
{
    CONSTR(FUNC, "GRattrinfo");   /* for HERROR */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    void * *t;                   /* temp. ptr to the image found */
    TBBT_TREE *search_tree;     /* attribute tree to search through */
    at_info_t *at_ptr;          /* ptr to the attribute to work with */
    intn   ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the ID, the index is checked below */
    if (HAatom_group(id)!=RIIDGROUP && HAatom_group(id)!=GRIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    if (HAatom_group(id)==GRIDGROUP)
      {
          /* locate GR's object in hash table */
          if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

          if(index<0 || index>=gr_ptr->gattr_count)
              HGOTO_ERROR(DFE_ARGS, FAIL);

          search_tree=gr_ptr->gattree;
      } /* end if */
    else if (HAatom_group(id)==RIIDGROUP)
      {
          /* locate RI's object in hash table */
          if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

          if(index<0 || index>=ri_ptr->lattr_count)
              HGOTO_ERROR(DFE_ARGS, FAIL); 
          search_tree=ri_ptr->lattree;
      } /* end if */
    else    /* shouldn't get here, but what the heck... */
        HGOTO_ERROR(DFE_ARGS, FAIL);

    if((t = (void **)tbbtdfind(search_tree, &index, NULL))==NULL)
        HGOTO_ERROR(DFE_RINOTFOUND,FAIL);
    at_ptr=(at_info_t *)*t;

    if(name!=NULL)
        HDstrcpy(name,at_ptr->name);
    if(attr_nt!=NULL)
        *attr_nt=at_ptr->nt;
    if(count!=NULL)
        *count=at_ptr->len;

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRattrinfo() */

/*--------------------------------------------------------------------------
 NAME
    GRgetattr

 PURPOSE
    Read an attribute for an object.

 USAGE
    intn GRgetattr(dimid|riid|grid,index,data)
        int32 dimid|riid|grid;  IN: DIM|RI|GR ID
        int32 index;            IN: index of the attribute for info
        void * data;             OUT: data read for attribute

 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Read an attribute for an object.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRgetattr(int32 id,int32 index,void * data)
{
    CONSTR(FUNC, "GRgetattr");   /* for HERROR */
    int32 hdf_file_id;          /* HDF file ID from Hopen */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    void * *t;                   /* temp. ptr to the image found */
    TBBT_TREE *search_tree;     /* attribute tree to search through */
    at_info_t *at_ptr;          /* ptr to the attribute to work with */
    int32 at_size;              /* size in bytes of the attribute data */
    intn  ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the ID & data ptr, the index is checked below */
    if ((HAatom_group(id)!=RIIDGROUP && HAatom_group(id)!=GRIDGROUP) || data==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    if (HAatom_group(id)==GRIDGROUP)
      {
          /* locate GR's object in hash table */
          if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

          if(index<0 || index>=gr_ptr->gattr_count)
              HGOTO_ERROR(DFE_ARGS, FAIL);

          search_tree=gr_ptr->gattree;
      } /* end if */
    else if (HAatom_group(id)==RIIDGROUP)
      {
          /* locate RI's object in hash table */
          if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_RINOTFOUND, FAIL);
          gr_ptr=ri_ptr->gr_ptr;

          if(index<0 || index>=ri_ptr->lattr_count)
              HGOTO_ERROR(DFE_ARGS, FAIL);

          search_tree=ri_ptr->lattree;
      } /* end if */
    else    /* shouldn't get here, but what the heck... */
        HGOTO_ERROR(DFE_ARGS, FAIL);

    hdf_file_id=gr_ptr->hdf_file_id;
    if((t = (void **)tbbtdfind(search_tree, &index, NULL))==NULL)
        HGOTO_ERROR(DFE_RINOTFOUND,FAIL);
    at_ptr=(at_info_t *)*t;

    /* Calculate the size of the attribute data */
    at_size=at_ptr->len*DFKNTsize((at_ptr->nt | DFNT_NATIVE) & (~DFNT_LITEND));

    /* Check if the attribute has been read in yet, and get it if not */
    if(at_ptr->data==NULL)
      {
        int32 AttrID;       /* attribute Vdata id */

        /* Grab some memory for the attribute data */
        if((at_ptr->data=HDmalloc(at_size))==NULL)
            HGOTO_ERROR(DFE_NOSPACE,FAIL);
            
        if((AttrID=VSattach(hdf_file_id,(int32)at_ptr->ref,"r"))==FAIL)
            HGOTO_ERROR(DFE_CANTATTACH,FAIL);
        if(VSsetfields(AttrID,at_ptr->name)==FAIL)
          {
            VSdetach(AttrID);
            HGOTO_ERROR(DFE_BADFIELDS,FAIL);
          } /* end if */
        if(VSread(AttrID,at_ptr->data,at_ptr->len,FULL_INTERLACE)==FAIL)
          {
            VSdetach(AttrID);
            HGOTO_ERROR(DFE_VSWRITE,FAIL);
          } /* end if */
        if(VSdetach(AttrID)==FAIL)
            HGOTO_ERROR(DFE_CANTDETACH,FAIL);
      } /* end if */

    /* Copy the attribute into the user's buffer */
    HDmemcpy(data,at_ptr->data,at_size);

    /* If the attribute is too large to keep in memory, chuck it again */
    if((uint32)at_size>gr_ptr->attr_cache)
        HDfreenclear(at_ptr->data);

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRgetattr() */

/*--------------------------------------------------------------------------
 NAME
    GRfindattr

 PURPOSE
    Get the index of an attribute with a given name for an object.

 USAGE
    int32 GRfindattr(int32 dimid|riid|grid,char *name)
        int32 dimid|riid|grid;  IN: DIM|RI|GR ID
        char *name;             IN: name of attribute to search for

 RETURNS
    Valid index for an attribute on success, FAIL on failure

 DESCRIPTION
    Get the index of an attribute with a given name for an object.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int32 GRfindattr(int32 id,const char *name)
{
    CONSTR(FUNC, "GRfindattr");   /* for HERROR */
    gr_info_t *gr_ptr;          /* ptr to the GR information for this grid */
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    void * *t;                   /* temp. ptr to the image found */
    TBBT_TREE *search_tree;     /* attribute tree to search through */
    at_info_t *at_ptr;          /* ptr to the attribute to work with */
    int32 ret_value = SUCCEED;

    /* clear error stack and check validity of args */
    HEclear();

    /* check the validity of the RI ID */
    if (HAatom_group(id)!=RIIDGROUP && HAatom_group(id)!=GRIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);
    
    if (HAatom_group(id)==GRIDGROUP)
      {
          /* locate GR's object in hash table */
          if (NULL == (gr_ptr = (gr_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_GRNOTFOUND, FAIL);

          search_tree=gr_ptr->gattree;
      } /* end if */
    else if (HAatom_group(id)==RIIDGROUP)
      {
          /* locate RI's object in hash table */
          if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(id)))
              HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

          search_tree=ri_ptr->lattree;
      } /* end if */
    else    /* shouldn't get here, but what the heck... */
        HGOTO_ERROR(DFE_ARGS, FAIL);

    if((t = (void **)tbbtfirst((TBBT_NODE *)*search_tree))==NULL)
        HGOTO_ERROR(DFE_RINOTFOUND,FAIL);
    do {
        at_ptr=(at_info_t *)*t;
        if(at_ptr!=NULL && HDstrcmp(at_ptr->name,name)==0)  /* ie. the name matches */
            HGOTO_DONE(at_ptr->index);
    } while((t= (void **)tbbtnext((TBBT_NODE *)t))!=NULL);

    ret_value = (FAIL);

done:
  if(ret_value == 0)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */
  return ret_value;
} /* end GRfindattr() */

/*--------------------------------------------------------------------------
 NAME
    GRIstart
 PURPOSE
    GR-level initialization routine
 USAGE
    intn GRIstart()
 RETURNS
    Returns SUCCEED/FAIL
 DESCRIPTION
    Register the shut-down routine (GRPshutdown) for call with atexit
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
PRIVATE intn GRIstart(void)
{
    CONSTR(FUNC, "GRIstart");    /* for HERROR */
    intn        ret_value = SUCCEED;

    /* Don't call this routine again... */
    library_terminate = TRUE;

    /* Install atexit() library cleanup routine */
    if (HPregister_term_func(&GRPshutdown) != 0)
      HGOTO_ERROR(DFE_CANTINIT, FAIL);

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */

    } /* end if */

  /* Normal function cleanup */

    return(ret_value);
} /* end GRIstart() */

/*--------------------------------------------------------------------------
 NAME
    GRIgetaid
 PURPOSE
    Internal routine to make certain an image has an AID attached to it.
 USAGE
    intn GRIgetaid(img_ptr, acc_perm)
        ri_info_t *img_ptr;         IN: pointer to the image info for the
                                        image to access.
        intn acc_perm;              IN: method of access desired.
 RETURNS
    SUCCEED/FAIL

 DESCRIPTION
    Attach an AID to the image's in-memory structures, in order to better
    manage I/O.  If the prior method of access for the image's AID was read
    and write permission, then the previous AID is closed and reopened for
    both read & write permission.

 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
PRIVATE intn GRIgetaid(ri_info_t *ri_ptr, intn acc_perm)
{
    CONSTR(FUNC, "GRIgetaid");  /* for HERROR */
    int32 hdf_file_id;          /* HDF file ID */
    gr_info_t *gr_ptr;          /* ptr to the file GR information for this image */
    model_info minfo;           /* Dummy modeling information structure */
    intn  ret_value = SUCCEED;

    HEclear();
    if (ri_ptr==NULL)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* initialize important values */
    gr_ptr=ri_ptr->gr_ptr;
    hdf_file_id=gr_ptr->hdf_file_id;

    /* everybody gets read permission */
    acc_perm|=DFACC_READ;

    /* Test if the tag/ref pair has been assigned yet */
    if(ri_ptr->img_tag==DFTAG_NULL || ri_ptr->img_ref==DFREF_WILDCARD)
      {

        if(ri_ptr->use_cr_drvr)
            ri_ptr->img_tag=DFTAG_CI;
        else
            ri_ptr->img_tag=DFTAG_RI;
        ri_ptr->img_ref=Htagnewref(hdf_file_id,ri_ptr->img_tag);
      } /* end if */

    /* Check if we need to increase the access permissions asked for */
    if(ri_ptr->comp_img || (ri_ptr->img_aid!=0 && (acc_perm&DFACC_WRITE)!=0 && (ri_ptr->acc_perm&DFACC_WRITE)==0))
      {
        /* Close the old AID (which only had read permission) */
        Hendaccess(ri_ptr->img_aid);
        ri_ptr->img_aid=0;
      } /* end if */

    /* Check if we are the first to open the AID */
    if(ri_ptr->img_aid==0)
      {
        /* Go get the AID */
        if(ri_ptr->comp_img)
          { /* Need to create the compressed data element */
            if((ri_ptr->img_aid=HCcreate(hdf_file_id,ri_ptr->img_tag,ri_ptr->img_ref,COMP_MODEL_STDIO,&minfo,ri_ptr->comp_type,&(ri_ptr->cinfo)))==FAIL)
                HGOTO_ERROR(DFE_BADAID,FAIL);
            ri_ptr->comp_img=0;     /* reset the compression flag */
          } /* end if */
        else
          { /* Check for old-style compressed raster or just open normally */
            if(ri_ptr->use_cr_drvr)
              { /* Use compressed raster driver */
                uintn pixel_size;        /* size of a pixel on disk */


                pixel_size=(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt));

/* BMR: HRPconvert made access_rec->special = SPECIAL_COMPRAS */
                if((ri_ptr->img_aid=HRPconvert(hdf_file_id,ri_ptr->img_tag,
                    ri_ptr->img_ref,ri_ptr->img_dim.xdim,ri_ptr->img_dim.ydim,
                    ri_ptr->img_dim.comp_tag,&(ri_ptr->cinfo),pixel_size))==FAIL)
                    HGOTO_ERROR(DFE_BADAID,FAIL);
              } /* end if */
            else
              { /* Use regular startaccess to create element */
                if((ri_ptr->img_aid=Hstartaccess(hdf_file_id,ri_ptr->img_tag,ri_ptr->img_ref,acc_perm))==FAIL)
                    HGOTO_ERROR(DFE_BADAID,FAIL);
              } /* end else */
          } /* end else */
        if(ri_ptr->use_buf_drvr)
          { /* Convert to buffered special element if needed */
            if(HBconvert(ri_ptr->img_aid)==FAIL)
                HGOTO_ERROR(DFE_CANTINIT,FAIL);
          } /* end if */
        ri_ptr->acc_perm=acc_perm;
      } /* end if */

done:
  if(ret_value == FAIL)   
    { /* Error condition cleanup */
        ri_ptr->img_aid=0;
    } /* end if */

  /* Normal function cleanup */

  return ret_value;
} /* end GRIgetaid() */

/*--------------------------------------------------------------------------
 NAME
    GRPshutdown
 PURPOSE
    Terminate various static buffers.
 USAGE
    intn GRPshutdown()
 RETURNS
    Returns SUCCEED/FAIL
 DESCRIPTION
    Free various buffers allocated in the GR routines.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    Should only ever be called by the "atexit" function HDFend
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
intn GRPshutdown(void)
{
    if(gr_tree!=NULL)
      {
          /* Free the vfile tree */
          tbbtdfree(gr_tree, GRIgrdestroynode, NULL);

          /* Destroy the atom groups for GRs and RIs */
          HAdestroy_group(GRIDGROUP);
          HAdestroy_group(RIIDGROUP);

          gr_tree=NULL;
      } /* end if */
    return(SUCCEED);
} /* end GRPshutdown() */



/*====================== Chunking Routines ================================*/

/* Debugging */
/* #define CHK_DEBUG */

/* NOTE: the definition of the union HDF_CHUNK_DEF can be found in hproto.h */

/******************************************************************************
 NAME
      GRsetchunk  -- make GR a chunked GR

 DESCRIPTION
      This routine makes the GR a chunked GR according to the chunk
      definiton passed in.

      The image currently cannot be special already.  i.e. NBIT,
      COMPRESSED, or EXTERNAL. This is an Error.

      The defintion of the HDF_CHUNK_DEF union with relvant fields is:

      typedef union hdf_chunk_def_u
      {
         int32   chunk_lengths[2];  Chunk lengths along each dimension

         struct 
          {   
            int32     chunk_lengths[2]; Chunk lengths along each dimension
            int32     comp_type;                   Compression type 
            comp_info cinfo;                       Compression info struct 
          }comp;

      } HDF_CHUNK_DEF

      The variable agruement 'flags' is a bit-or'd value which can currently be
      'HDF_CHUNK' or 'HDF_CHUNK | HDF_COMP'.

      The simplist is the 'chunk_lengths' array specifiying chunk 
      lengths for each dimension where the 'flags' argument set to 
      'HDF_CHUNK';

      COMPRESSION is set by using the 'HDF_CHUNK_DEF' union to set the
      appropriate compression information along with the required chunk lengths
      for each dimension. The compression information is the same as 
      that set in 'GRsetcompress()'. The bit-or'd 'flags' argument' is set to 
      'HDF_CHUNK | HDF_COMP'.

      See the example in pseudo-C below for further usage.

      The maximum number of Chunks in an HDF file is 65,535.

      The performance of the GRxxx interface with chunking is greatly
      affected by the users access pattern over the image and by
      the maximum number of chunks set in the chunk cache. The cache contains 
      the Least Recently Used(LRU cache replacment policy) chunks. See the
      routine GRsetchunkcache() for further info on the chunk cache and how 
      to set the maximum number of chunks in the chunk cache. A default chunk 
      cache is always created.

      The following example shows the organization of chunks for a 2D array.
      e.g. 4x4 array with 2x2 chunks. The array shows the layout of
           chunks in the chunk array.

            4 ---------------------                                           
              |         |         |                                                 
        Y     |  (0,1)  |  (1,1)  |                                       
        ^     |         |         |                                      
        |   2 ---------------------                                       
        |     |         |         |                                               
        |     |  (0,0)  |  (1,0)  |                                      
        |     |         |         |                                           
        |     ---------------------                                         
        |     0         2         4                                       
        ---------------> X                                                       

        --Without compression--:
        {                                                                    
        HDF_CHUNK_DEF chunk_def;
                                                                            
        .......                                                                    
        -- Set chunk lengths --                                                    
        chunk_def.chunk_lengths[0]= 2;                                                     
        chunk_def.chunk_lengths[1]= 2; 

        -- Set Chunking -- 
        GRsetchunk(riid, chunk_def, HDF_CHUNK);                      
         ......                                                                  
        }                                                                           

        --With compression--:
        {                                                                    
        HDF_CHUNK_DEF chunk_def;
                                                                            
        .......                
        -- Set chunk lengths first --                                                    
        chunk_def.chunk_lengths[0]= 2;                                                     
        chunk_def.chunk_lengths[1]= 2;

        -- Set compression --
        chunk_def.comp.cinfo.deflate.level = 9;
        chunk_def.comp.comp_type = COMP_CODE_DEFLATE;

        -- Set Chunking with Compression --
        GRsetchunk(riid, chunk_def, HDF_CHUNK | HDF_COMP);                      
         ......                                                                  
        }                                                                           

        NOTE:
           This routine directly calls a Special Chunked Element fcn HMCxxx.

 RETURNS
        SUCCEED/FAIL

 AUTHOR 
        -GeorgeV
******************************************************************************/
intn 
GRsetchunk(int32 riid,              /* IN: raster access id */
           HDF_CHUNK_DEF chunk_def, /* IN: chunk definition */
           int32 flags              /* IN: flags */)
{
    CONSTR(FUNC, "GRsetchunk");
    ri_info_t     *ri_ptr = NULL;    /* ptr to the image to work with */
    HCHUNK_DEF     chunk[1];         /* H-level chunk defintion */
    HDF_CHUNK_DEF *cdef   = NULL;    /* GR Chunk definition */
    model_info minfo;                /* dummy model info struct */
    comp_info  cinfo;                /* compression info - NBIT */
    int32      *cdims    = NULL;     /* array of chunk lengths */
    uintn      pixel_mem_size;       /* size of a pixel in memory */
    uintn      pixel_disk_size;      /* size of a pixel on disk */
    void *      fill_pixel = NULL;    /* converted value for the filled pixel */
    int32      at_index;             /* attribute index for the fill value */
    uint32     comp_config;
    int32      ndims    = 0;         /* # dimensions i.e. rank */
    uint8      nlevels  = 1;         /* default # levels is 1 */
    intn       i;                    /* loop variable */
    int32      hdf_file_id;          /* HDF file ID */
    gr_info_t *gr_ptr;               /* ptr to the file GR information for this image */
    intn       ret_value = SUCCEED;  /* return value */


#ifdef CHK_DEBUG
    fprintf(stderr,"GRsetchunk: called  \n");
#endif
    /* clear error stack and check validity of args */
    HEclear();

    memset(chunk,0,sizeof(chunk[0]));
    /* Check some args */

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* initialize important values */
    gr_ptr = ri_ptr->gr_ptr;
    hdf_file_id = gr_ptr->hdf_file_id;

    /* Test if the tag/ref pair has been assigned yet 
       Note that HMCcreate() needs to do the Hstartaccess on
       the special tag/ref pair that is created. If another
       GRxx routine does it then the special element cannot be
       created. Special elements require 'lazy' DD creation. */
    if(ri_ptr->img_tag == DFTAG_NULL || ri_ptr->img_ref == DFREF_WILDCARD)
      {
        ri_ptr->img_tag = DFTAG_RI;
        ri_ptr->img_ref = Htagnewref(hdf_file_id,ri_ptr->img_tag);
      } /* end if */

#ifdef CHK_DEBUG
    fprintf(stderr,"GRsetchunk: ri_ptr->img_aid=%d  \n",ri_ptr->img_aid);
#endif

    /* Decide type of defintion passed in  */
    switch (flags)
      {
      case HDF_CHUNK: /* case where chunk_def only has chunk lengths */
          cdef  = (HDF_CHUNK_DEF *)&chunk_def;
          cdims = cdef->chunk_lengths;
          chunk[0].chunk_flag = 0;  /* nothing set for this now */
          chunk[0].comp_type = COMP_CODE_NONE; /* nothing set */
          chunk[0].model_type = COMP_MODEL_STDIO; /* Default */
          chunk[0].cinfo = &cinfo; /* dummy */
          chunk[0].minfo = &minfo; /* dummy */
          break;
      case (HDF_CHUNK | HDF_COMP):
    /*  EIP 9/12/03 
     *  We have to take special care if SZIP library is not available;
     *  Fow all other compression types do
     */
          cdef  = (HDF_CHUNK_DEF *)&chunk_def;

    /* Check that the compression encoder is available */
    HCget_config_info((comp_coder_t )(cdef->comp.comp_type), &comp_config);
    if ((comp_config & (COMP_DECODER_ENABLED|COMP_ENCODER_ENABLED)) == 0) {
    /* coder not present?? */
              HGOTO_ERROR(DFE_BADCODER,FAIL); 
    }
    if ((comp_config & COMP_ENCODER_ENABLED) == 0) {
    /* encoder not present?? */
              HGOTO_ERROR(DFE_NOENCODER,FAIL); 
    }
          cdims = cdef->comp.chunk_lengths;
          chunk[0].chunk_flag = SPECIAL_COMP;  /* Compression */
          chunk[0].comp_type  = (comp_coder_t)cdef->comp.comp_type; 
          chunk[0].model_type = COMP_MODEL_STDIO; /* Default */
          chunk[0].minfo = &minfo; /* dummy */

    if ((comp_coder_t)cdef->comp.comp_type != COMP_CODE_SZIP) {
              chunk[0].cinfo = &cdef->comp.cinfo; 
    }
    else
#ifdef H4_HAVE_LIBSZ          /* we have the library */
          {
            HDmemcpy(&cinfo,&(cdef->comp.cinfo),sizeof(comp_info));
        if (GRsetup_szip_parms(ri_ptr, &cinfo, cdims) == FAIL) 
                  HGOTO_ERROR(DFE_INTERNAL,FAIL); 
              chunk[0].cinfo = &cinfo; 
    }
#else                         /* we do not have the SZIP library */
          {
        HGOTO_ERROR(DFE_NOSZLIB, FAIL);
          }
#endif /* H4_HAVE_LIBSZ */
          break;
      case (HDF_CHUNK | HDF_NBIT): /* don't support NBIT for GRs */
    HGOTO_ERROR(DFE_UNSUPPORTED, FAIL);
      default:
    HGOTO_ERROR(DFE_BADSCHEME, FAIL);
      } /* end switch */

    /* Now start setting chunk info */
    ndims = 2; /* set number of dims i.e. rank 
                  for Rasters it is 2 */

    /* allocate space for chunk dimensions */
    if ((chunk[0].pdims = (DIM_DEF *)HDmalloc(ndims*sizeof(DIM_DEF))) == NULL)
        HGOTO_ERROR(DFE_NOSPACE,FAIL);

    /* initialize image/chunk sizes using CHUNK defintion structure */
    chunk[0].chunk_size = 1;
    chunk[0].num_dims = ndims;
    for (i = 0; i < ndims; i++)
      {   /* get dimension length from shape arrays */
          if ( i == 0) /* X */
              chunk[0].pdims[i].dim_length = ri_ptr->img_dim.xdim;
          else /* Y */
              chunk[0].pdims[i].dim_length = ri_ptr->img_dim.ydim;

          /* set chunk lengths */
          if (cdims[i] >= 1)
              chunk[0].pdims[i].chunk_length = cdims[i];
          else
            { /* chunk length is less than 1 */
                ret_value = FAIL;
                goto done;
            }
#ifdef CHK_DEBUG
    fprintf(stderr,"GRsetchunk: cdims[%d]=%d \n",i,cdims[i]);
    fflush(stderr);
#endif          
          /* Data distribution along dimensions 
          *  Check dimension length agains chunk length */
          if (i == 0) /* X */
            {
                if (cdims[i] == ri_ptr->img_dim.xdim)
                    chunk[0].pdims[i].distrib_type = 0;     /* NONE */
                else
                    chunk[0].pdims[i].distrib_type = 1;     /* BLOCK */
            }
          else /* Y */
            {
                if (cdims[i] == ri_ptr->img_dim.ydim)
                    chunk[0].pdims[i].distrib_type = 0;     /* NONE */
                else
                    chunk[0].pdims[i].distrib_type = 1;     /* BLOCK */
            }

          /* compute chunk size */
          chunk[0].chunk_size *= cdims[i];
      } /* end for ndims */

    /* Get the size of the pixels in memory and on disk */
    pixel_mem_size  = (uintn)(ri_ptr->img_dim.ncomps*DFKNTsize((ri_ptr->img_dim.nt | DFNT_NATIVE) & (~DFNT_LITEND)));
    pixel_disk_size = (uintn)(ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt));

    /* Set number type size i.e. size of data type 
       number of components times the number type */
    chunk[0].nt_size = ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt);

#ifdef CHK_DEBUG
    fprintf(stderr,"GRsetchunk: datatype size =%d\n",
            ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt));
    fflush(stderr);
#endif

    /* allocate space for fill pixel */
    if((fill_pixel = HDmalloc(pixel_disk_size)) == NULL)
        HGOTO_ERROR(DFE_NOSPACE,FAIL);

    /* create correct disk version of fill pixel */
    if(ri_ptr->fill_value != NULL)
      {
          if (FAIL == DFKconvert(ri_ptr->fill_value,fill_pixel,
                                 ri_ptr->img_dim.nt,ri_ptr->img_dim.ncomps,
                                 DFACC_WRITE,0,0))
              HGOTO_ERROR(DFE_INTERNAL,FAIL); 
      } /* end if */
    else  /* create default pixel fill value of all zero components */
      {
          /* Try to find a fill value attribute */
          if((at_index = GRfindattr(riid,FILL_ATTR)) != FAIL)
            { /* Found a fill value attribute */
                if((ri_ptr->fill_value = HDmalloc(pixel_mem_size)) == NULL)
                    HGOTO_ERROR(DFE_NOSPACE,FAIL);
                if(GRgetattr(riid,at_index,ri_ptr->fill_value) == FAIL)
                    HGOTO_ERROR(DFE_BADATTR,FAIL);
                if (FAIL == DFKconvert(ri_ptr->fill_value,fill_pixel,
                                       ri_ptr->img_dim.nt,ri_ptr->img_dim.ncomps,
                                       DFACC_WRITE,0,0))
                    HGOTO_ERROR(DFE_INTERNAL,FAIL);
            } /* end if */
          else
              HDmemset(fill_pixel,0,pixel_disk_size);
      } /* end else */

#ifdef CHK_DEBUG
    fprintf(stderr,"GRsetchunk: get ready to create\n");
    fprintf(stderr,"GRsetchunk: img_tag=%d, img_ref=%d\n",
            ri_ptr->img_tag, ri_ptr->img_ref);
#endif

    /* check to see already special.
       Error if already special since doubly special elements are
       not yet handled. HMCcreate should catch this....*/
    /* Create GR as chunked element  */
    ret_value = HMCcreate(hdf_file_id, /* HDF file handle */
                          (uint16)ri_ptr->img_tag,/* Data tag */
                          (uint16)ri_ptr->img_ref,/* Data ref */
                          nlevels,                /* nlevels */
                          pixel_disk_size,        /* fill value length */
                          (VOID *)fill_pixel,     /* fill value */
                          (HCHUNK_DEF *)chunk     /* chunk definition */);

#ifdef CHK_DEBUG
    fprintf(stderr,"HMCcreate: ret_value =%d \n", ret_value);
#endif

    /* check return */
    if(ret_value != FAIL) 
      { /* close old aid and set new one
         ..hmm......this is for the doubly special hack */
          if((ri_ptr->img_aid != 0) && (ri_ptr->img_aid != FAIL))
            {
              if (FAIL == Hendaccess(ri_ptr->img_aid))
                  HGOTO_ERROR(DFE_INTERNAL,FAIL);
            }

          ri_ptr->img_aid = ret_value; /* set new access id */
          ret_value = SUCCEED; /* re-set to successful */
      } /* end if */

#ifdef CHK_DEBUG
    fprintf(stderr,"GRsetchunk: ri_ptr->img_aid =%d \n", ri_ptr->img_aid);
#endif

done:
    if (ret_value == FAIL)
      { /* Failure cleanup */

      }
    /* Normal cleanup */

    /* free fill value */
    if (fill_pixel != NULL)
        HDfree(fill_pixel);

    /* free chunk dims */
    if (chunk[0].pdims != NULL)
        HDfree(chunk[0].pdims);

    return ret_value;
} /* GRsetchunk */

/******************************************************************************
 NAME
     GRgetchunkinfo -- get Info on GR

 DESCRIPTION
     This routine gets any special information on the GR. If its chunked,
     chunked and compressed or just a regular GR. Currently it will only
     fill the array of chunk lengths for each dimension as specified in
     the 'HDF_CHUNK_DEF' union. You can pass in a NULL for 'chunk_def'
     if don't want the chunk lengths for each dimension.
     If successfull it will return a bit-or'd value in 'flags' indicating 
     if the GR is  chunked(HDF_CHUNK), chunked and compressed(HDF_CHUNK | HDF_COMP) 
     or non-chunked(HDF_NONE).
 
     e.g. 4x4 array - Pseudo-C
     {
     HDF_CHUNK_DEF rchunk_def;
     int32   cflags;
     ...
     GRgetchunkinfo(riid, &rchunk_def, &cflags);
     ...
     }

 RETURNS
        SUCCEED/FAIL

 AUTHOR 
        -GeorgeV
******************************************************************************/
intn 
GRgetchunkinfo(int32 riid,               /* IN: sds access id */
               HDF_CHUNK_DEF *chunk_def, /* IN/OUT: chunk definition */
               int32 *flags              /* IN/OUT: flags */)
{
    CONSTR(FUNC, "GRgetchunkinfo");
    ri_info_t      *ri_ptr = NULL;        /* ptr to the image to work with */
    sp_info_block_t info_block;           /* special info block */
    int16           special;              /* Special code */
    intn            i;                    /* loop variable */
    intn            ret_value = SUCCEED;  /* return value */


    /* clear error stack and check validity of args */
    HEclear();

    /* Check some args */

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* check if access id exists already */
    if(ri_ptr->img_aid == 0)
      {
          /* now get access id, use read access for now */
          if(GRIgetaid(ri_ptr,DFACC_READ)==FAIL)
              HGOTO_ERROR(DFE_INTERNAL,FAIL);
      }
    else if (ri_ptr->img_aid == FAIL)
        HGOTO_ERROR(DFE_INTERNAL,FAIL);

#ifdef CHK_DEBUG
    fprintf(stderr,"%s: ri_ptr->img_aid =%d \n", FUNC, ri_ptr->img_aid);
#endif

    /* inquire about element */
    ret_value = Hinquire(ri_ptr->img_aid, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &special);
    if (ret_value != FAIL)
      {   /* make sure it is chunked element */
          if (special == SPECIAL_CHUNKED)
            { /* get info about chunked element */
             if ((ret_value = HDget_special_info(ri_ptr->img_aid, &info_block)) != FAIL)
               {   /* Does user want chunk lengths back? */
                   if (chunk_def != NULL)
                     {
                         /* we assume user has allocat space for chunk lengths */
                         /* copy chunk lengths over */
                         for (i = 0; i < info_block.ndims; i++)
                           {
                               chunk_def->chunk_lengths[i] = info_block.cdims[i];
                           }
                     }
                   /* dont forget to free up info is special info block 
                      This space was allocated by the library */
                   HDfree(info_block.cdims);

                   /* Check to see if compressed */
                   switch(info_block.comp_type)
                     {
                     case COMP_CODE_NONE:
                         *flags = HDF_CHUNK;
                         break;
                     case COMP_CODE_NBIT: 
                         /* is this an error? 
                            NBIT can't be set in GRsetchunk(). */
                         *flags = (HDF_CHUNK | HDF_NBIT);
                         break;
                     default:
                         *flags = (HDF_CHUNK | HDF_COMP);
                         break;
                     }
               }
            }
          else /* not special chunked element */
            {
              *flags = HDF_NONE; /* regular GR */
            }
      }

  done:
    if (ret_value == FAIL)
      { /* Failure cleanup */

      }
    /* Normal cleanup */
    return ret_value;
} /* GRgetchunkinfo() */


/******************************************************************************
 NAME
     GRwritechunk   -- write the specified chunk to the GR

 DESCRIPTION
     This routine writes a whole chunk of data to the chunked GR 
     specified by chunk 'origin' for the given GR and can be used
     instead of GRwriteimage() when this information is known. This
     routine has less overhead and is much faster than using GRwriteimage().

     Origin specifies the co-ordinates of the chunk according to the chunk
     position in the overall chunk array.

     'datap' must point to a whole chunk of data.

     See GRsetchunk() for a description of the organization of chunks in an GR.

     NOTE:
           This routine directly calls a Special Chunked Element fcn HMCxxx.

 RETURNS
        SUCCEED/FAIL

 AUTHOR 
       -GeorgeV
******************************************************************************/
intn 
GRwritechunk(int32 riid,       /* IN: access aid to GR */
             int32 *origin,    /* IN: origin of chunk to write */
             const VOID *datap /* IN: buffer for data */)
{
    CONSTR(FUNC, "GRwritechunk");
    ri_info_t *ri_ptr = NULL;   /* ptr to the image to work with */
    uintn      pixel_mem_size,  /* size of a pixel in memory */
               pixel_disk_size; /* size of a pixel on disk */
    VOID      *img_data = NULL; /* buffer used for conversion */
    int16      special;         /* Special code */
    int32      csize;           /* phsical chunk size */
    sp_info_block_t info_block; /* special info block */
    uint32     byte_count;      /* bytes to write */
    int8       platnumsubclass; /* the machine type of the current platform */
    uintn      convert;         /* whether to convert or not */
    intn       i;
    uint16 scheme;  /* compression scheme used for JPEG images */
    uint32     comp_config;
    comp_coder_t comp_type; 
    comp_info cinfo;
    intn       status=FAIL;
    intn       switch_interlace = FALSE;/* whether the memory interlace needs to be switched around */
    intn       ret_value = SUCCEED;


    /* clear error stack and check validity of args */
    HEclear();

    info_block.cdims = NULL;

    /* Check args */
    if (origin == NULL || datap == NULL)
      {
        ret_value = FAIL;
        goto done;
      }

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* check if access id exists already */
    if(ri_ptr->img_aid == 0)
      {
          /* now get access id, use write access */
          if(GRIgetaid(ri_ptr,DFACC_WRITE)==FAIL)
              HGOTO_ERROR(DFE_INTERNAL,FAIL);
      }
    else if (ri_ptr->img_aid == FAIL)
        HGOTO_ERROR(DFE_INTERNAL,FAIL);

#ifdef CHK_DEBUG
    fprintf(stderr,"%s: ri_ptr->img_aid =%d \n", FUNC, ri_ptr->img_aid);
#endif
    comp_type = COMP_CODE_NONE;
    scheme = ri_ptr->img_dim.comp_tag;
    if (scheme == DFTAG_JPEG5 || scheme == DFTAG_GREYJPEG5
            || scheme==DFTAG_JPEG || scheme==DFTAG_GREYJPEG)
    {
	comp_type = COMP_CODE_JPEG;
	cinfo.jpeg.quality = 0;
	cinfo.jpeg.force_baseline = 0;
    }
    else if (scheme == DFTAG_IMC)
    { /* coder no longer supported */
        HGOTO_ERROR(DFE_BADCODER,FAIL);
    }
    else
    {
	/* use lower-level routine to get the compression information */
	status = HCPgetcompinfo(ri_ptr->gr_ptr->hdf_file_id,
                        ri_ptr->img_tag, ri_ptr->img_ref,
                        &comp_type, &cinfo);
	if (status == FAIL)
            HGOTO_ERROR(DFE_INTERNAL,FAIL);
    }
    if (comp_type != COMP_CODE_NONE)
    {
        /* Check that the compression encoder is available */
        HCget_config_info(comp_type, &comp_config);
        if ((comp_config & (COMP_DECODER_ENABLED|COMP_ENCODER_ENABLED)) == 0) {
            /* coder not present?? */
             HGOTO_ERROR(DFE_BADCODER,FAIL); 
        }
        if ((comp_config & COMP_ENCODER_ENABLED) == 0) {
            /* encoder not present?? */
             HGOTO_ERROR(DFE_NOENCODER,FAIL); 
        }
    }

   /* inquire about element */
    ret_value = Hinquire(ri_ptr->img_aid, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &special);
    if (ret_value != FAIL)
      {
          if (special == SPECIAL_CHUNKED)
            {  /* yes */

                /* get info about chunked element */
                if ((ret_value = HDget_special_info(ri_ptr->img_aid, &info_block)) != FAIL)
                  {   
                      /* calculate chunk size  */
                      csize = 1;
                      for (i = 0; i < info_block.ndims; i++)
                          csize *= info_block.cdims[i];

                      /* Get the size of the pixels in memory and on disk */
                      pixel_mem_size  =(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize((ri_ptr->img_dim.nt | DFNT_NATIVE) & (~DFNT_LITEND)));
                      pixel_disk_size =(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt));

                      /* adjust for data type size */
                      /* csize *= pixel_mem_size; */
                      byte_count = csize * pixel_mem_size;

                      /* figure out if data needs to be converted */
                      /* Get number-type and conversion information */
                      if (FAIL == (platnumsubclass = DFKgetPNSC(ri_ptr->img_dim.nt & (~DFNT_LITEND), DF_MT)))
                          HGOTO_ERROR(DFE_INTERNAL,FAIL);
                     convert = (ri_ptr->img_dim.file_nt_subclass != platnumsubclass) ||
                              (pixel_mem_size != pixel_disk_size);  /* is conversion necessary? */

                      /* check interlace */
                      if(ri_ptr->img_dim.il != MFGR_INTERLACE_PIXEL)
                          switch_interlace=TRUE;

                      /* convert if necessary */
                      if(convert || switch_interlace == TRUE) 
                        {
                            /* Allocate space for the conversion buffer */
                            if((img_data = HDmalloc(pixel_disk_size*csize)) == NULL)
                                HGOTO_ERROR(DFE_NOSPACE,FAIL);

                            if(switch_interlace == TRUE)
                              {
                                  void * pixel_buf;  /* buffer for the pixel interlaced data */

                                  /* Allocate space for the conversion buffer */
                                  if((pixel_buf = HDmalloc(pixel_mem_size*csize)) == NULL)
                                      HGOTO_ERROR(DFE_NOSPACE,FAIL);

                                  if (FAIL == GRIil_convert((VOID *)datap,ri_ptr->img_dim.il,pixel_buf,MFGR_INTERLACE_PIXEL,
                                                            info_block.cdims,ri_ptr->img_dim.ncomps,ri_ptr->img_dim.nt))
                                      HGOTO_ERROR(DFE_INTERNAL,FAIL);
                                  
                                  /* convert the pixel data into the HDF disk format */
                                  if (FAIL == DFKconvert(pixel_buf,img_data,ri_ptr->img_dim.nt,
                                                         ri_ptr->img_dim.ncomps*csize,DFACC_WRITE,0,0))
                                      HGOTO_ERROR(DFE_INTERNAL,FAIL);
                                  
                                  HDfree(pixel_buf);
                              } /* end if */
                            else /* convert the pixel data into the HDF disk format */
                              {
                                  if (FAIL == DFKconvert((VOID *)datap,img_data,ri_ptr->img_dim.nt,
                                                         ri_ptr->img_dim.ncomps*csize,DFACC_WRITE,0,0))
                                      HGOTO_ERROR(DFE_INTERNAL,FAIL);
                              }
                          /* Write chunk out, */
                          if ((ret_value = HMCwriteChunk(ri_ptr->img_aid, origin, img_data)) != FAIL)
                              ret_value = SUCCEED;
                        }
                      else { /* no conversion necessary, just use the user's buffer */
                          /* Write chunk out, */
                          if ((ret_value = HMCwriteChunk(ri_ptr->img_aid, origin, datap)) != FAIL)
                              ret_value = SUCCEED;
                      } /* end else */
                  } /* end if get special info block */
            }
          else /* not special CHUNKED */
              ret_value = FAIL;
      } /* end if Hinquire */

  done:
    if (ret_value == FAIL)
      { /* Failure cleanup */

      }
    /* Normal cleanup */
    /* dont forget to free up info is special info block 
       This space was allocated by the library */
    if (info_block.cdims != NULL)
        HDfree(info_block.cdims);

    /* free conversion buffers if we created them */
    if (img_data != NULL)
        HDfree(img_data);

    return ret_value;
} /* GRwritechunk() */

/******************************************************************************
 NAME
     GRreadchunk   -- read the specified chunk to the GR

 DESCRIPTION
     This routine reads a whole chunk of data from the chunked GR
     specified by chunk 'origin' for the given GR and can be used
     instead of GRreaddata() when this information is known. This
     routine has less overhead and is much faster than using GRreaddata().

     Origin specifies the co-ordinates of the chunk according to the chunk
     position in the overall chunk array.

     'datap' must point to a whole chunk of data.

     See GRsetchunk() for a description of the organization of chunks in an GR.

     NOTE:
         This routine directly calls a Special Chunked Element fcn HMCxxx.

 RETURNS
        SUCCEED/FAIL

 AUTHOR 
       -GeorgeV
******************************************************************************/
intn 
GRreadchunk(int32 riid,    /* IN: access aid to GR */
            int32 *origin, /* IN: origin of chunk to write */
            VOID *datap    /* IN/OUT: buffer for data */)
{
    CONSTR(FUNC, "GRreadchunk");
    ri_info_t *ri_ptr = NULL;   /* ptr to the image to work with */
    uintn      pixel_mem_size;  /* size of a pixel in memory */
    uintn      pixel_disk_size; /* size of a pixel on disk */
    VOID      *img_data = NULL; /* buffer used for conversion */
    int16      special;         /* Special code */
    int32      csize;           /* phsical chunk size */
    sp_info_block_t info_block; /* special info block */
    uint32     byte_count;      /* bytes to read */
    int8       platnumsubclass; /* the machine type of the current platform */
    uintn      convert;         /* whether to convert or not */
    intn       i;
    uint16 scheme;  /* compression scheme used for JPEG images */
    uint32     comp_config;
    comp_coder_t comp_type; 
    comp_info cinfo;
    intn       status=FAIL;
    intn       switch_interlace = FALSE;/* whether the memory interlace needs to be switched around */
    intn       ret_value = SUCCEED;


    /* clear error stack and check validity of args */
    HEclear();

    info_block.cdims = NULL;

    /* Check args */
    if (origin == NULL || datap == NULL)
      {
        ret_value = FAIL;
        goto done;
      }

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* check if access id exists already */
    if(ri_ptr->img_aid == 0)
      {
          /* now get access id, use write access */
          if(GRIgetaid(ri_ptr,DFACC_WRITE)==FAIL)
              HGOTO_ERROR(DFE_INTERNAL,FAIL);
      }
    else if (ri_ptr->img_aid == FAIL)
        HGOTO_ERROR(DFE_INTERNAL,FAIL);

#ifdef CHK_DEBUG
    fprintf(stderr,"%s: ri_ptr->img_aid =%d \n", FUNC, ri_ptr->img_aid);
#endif

    comp_type = COMP_CODE_NONE;
    scheme = ri_ptr->img_dim.comp_tag;
    if (scheme == DFTAG_JPEG5 || scheme == DFTAG_GREYJPEG5
            || scheme==DFTAG_JPEG || scheme==DFTAG_GREYJPEG)
    {
	comp_type = COMP_CODE_JPEG;
	cinfo.jpeg.quality = 0;
	cinfo.jpeg.force_baseline = 0;
    }
    /* Catch old images to avoid going into HCPgetcompinfo.  Note: I don't
       think old images have chunking, but just in case I'm wrong.  Should
       verify these later. -BMR, Jul 2012 */
    else if (scheme == DFTAG_RLE) /* old image */
	comp_type = COMP_CODE_RLE;
    else if (scheme == DFTAG_IMC) /* old image */
        comp_type = COMP_CODE_IMCOMP;
    else
    {
	/* use lower-level routine to get the compression information */
	status = HCPgetcompinfo(ri_ptr->gr_ptr->hdf_file_id,
                        ri_ptr->img_tag, ri_ptr->img_ref,
                        &comp_type, &cinfo);
	if (status == FAIL)
            HGOTO_ERROR(DFE_INTERNAL,FAIL);
    }
    if (comp_type != COMP_CODE_NONE &&
	comp_type != COMP_CODE_RLE &&
	comp_type != COMP_CODE_IMCOMP)
    {   /* BMR: this is reading, why do we need encoder? */
	/* Check that the compression encoder is available */
	HCget_config_info(comp_type, &comp_config);
	if ((comp_config & (COMP_DECODER_ENABLED|COMP_ENCODER_ENABLED)) == 0) {
    /* coder not present?? */
         HGOTO_ERROR(DFE_BADCODER,FAIL); 
      }
      if ((comp_config & COMP_DECODER_ENABLED) == 0) {
    /* decoder not present?? */
         HGOTO_ERROR(DFE_NOENCODER,FAIL); 
      } 
    }
    /* inquire about element */
    ret_value = Hinquire(ri_ptr->img_aid, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &special);
    if (ret_value != FAIL)
      {
          if (special == SPECIAL_CHUNKED)
            {  /* yes */

                /* get info about chunked element */
                if ((ret_value = HDget_special_info(ri_ptr->img_aid, &info_block)) != FAIL)
                  {   
                      /* calcualte chunk size  */
                      csize = 1;
                      for (i = 0; i < info_block.ndims; i++)
                          csize *= info_block.cdims[i];

                      /* Get the size of the pixels in memory and on disk */
                      pixel_mem_size  =(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize((ri_ptr->img_dim.nt | DFNT_NATIVE) & (~DFNT_LITEND)));
                      pixel_disk_size =(uintn)(ri_ptr->img_dim.ncomps*DFKNTsize(ri_ptr->img_dim.nt));

                      /* adjust for number type size */
                      /* csize *= pixel_mem_size; */
                      byte_count = csize * pixel_mem_size;

                      /* figure out if data needs to be converted */
                      /* Get number-type and conversion information */
                      if (FAIL ==(platnumsubclass = DFKgetPNSC(ri_ptr->img_dim.nt & (~DFNT_LITEND), DF_MT)))
                          HGOTO_ERROR(DFE_INTERNAL,FAIL);
                       convert = (ri_ptr->img_dim.file_nt_subclass != platnumsubclass) 
                                 ||  (pixel_mem_size != pixel_disk_size);  /* is conversion necessary? */

                      /* check interlace */
                      if(ri_ptr->img_dim.il != MFGR_INTERLACE_PIXEL)
                          switch_interlace=TRUE;

                      /* read chunk in */
                      if(convert) 
                        {
                            /* Allocate space for the conversion buffer */
                            if((img_data = HDmalloc(pixel_disk_size*csize)) == NULL)
                                HGOTO_ERROR(DFE_NOSPACE,FAIL);

                            /* read it in */
                            if ((ret_value = HMCreadChunk(ri_ptr->img_aid, origin, img_data)) 
                                != FAIL)
                                {
                                    if (FAIL == DFKconvert(img_data,datap,ri_ptr->img_dim.nt,
                                                           ri_ptr->img_dim.ncomps*csize,DFACC_READ,0,0))
                                        HGOTO_ERROR(DFE_INTERNAL,FAIL);

                                    ret_value = SUCCEED;
                                }
                        } /* end if */
                      else 
                        {
                          if ((ret_value = HMCreadChunk(ri_ptr->img_aid, origin, datap))
                              != FAIL)
                              ret_value = SUCCEED;
                        }

                      /* Check whether we need to convert the buffer to the user's */
                      /*    requested interlace scheme. */
                      /* Note: This is implemented in a horribly ugly & slow manner, but I'm */
                      /*        in a bit of a hurry right now - QAK */
                      /* I took this code from GRwrite() and put it here - GV */
                      if(ri_ptr->im_il != MFGR_INTERLACE_PIXEL)
                        {
                            void * pixel_buf;  /* buffer for the pixel interlaced data */

                            /* Allocate space for the conversion buffer */
                            if((pixel_buf = HDmalloc(pixel_mem_size*csize)) == NULL)
                                HGOTO_ERROR(DFE_NOSPACE,FAIL);

                            if (FAIL == GRIil_convert(datap,MFGR_INTERLACE_PIXEL,pixel_buf,ri_ptr->im_il,
                                                      info_block.cdims,ri_ptr->img_dim.ncomps,ri_ptr->img_dim.nt))
                                HGOTO_ERROR(DFE_INTERNAL,FAIL);

                            HDmemcpy(datap,pixel_buf,pixel_mem_size*csize);

                            HDfree(pixel_buf);
                        } /* end if */

                  } /* end if get special info block */
            }
          else /* not special CHUNKED */
              ret_value = FAIL;
      } /* end if Hinquire */

  done:
    if (ret_value == FAIL)
      { /* Failure cleanup */

      }
    /* Normal cleanup */
    /* dont forget to free up info is special info block 
       This space was allocated by the library */
    if (info_block.cdims != NULL)
        HDfree(info_block.cdims);

    /* free conversion buffers if any */
    if (img_data != NULL)
        HDfree(img_data);

    return ret_value;
} /* GRreadchunk() */


/******************************************************************************
NAME
     GRsetchunkcache - maximum number of chunks to cache 

DESCRIPTION
     Set the maximum number of chunks to cache.

     The cache contains the Least Recently Used(LRU cache replacment policy) 
     chunks. This routine allows the setting of maximum number of chunks that 
     can be cached, 'maxcache'.

     The performance of the GRxxx interface with chunking is greatly
     affected by the users access pattern over the image and by
     the maximum number of chunks set in the chunk cache. The number chunks 
     that can be set in the cache is process memory limited. It is a good 
     idea to always set the maximum number of chunks in the cache as the 
     default heuristic does not take into account the memory available for 
     the application.

     By default when the GR is promoted to a chunked element the 
     maximum number of chunks in the cache 'maxcache' is set to the number of
     chunks along the last dimension.

     The values set here affects the current GR object's caching behaviour.

     If the chunk cache is full and 'maxcache' is greater then the
     current 'maxcache' value, then the chunk cache is reset to the new
     'maxcache' value, else the chunk cache remains at the current
     'maxcache' value.

     If the chunk cache is not full, then the chunk cache is set to the
     new 'maxcache' value only if the new 'maxcache' value is greater than the
     current number of chunks in the cache.

     Use flags argument of 'HDF_CACHEALL' if the whole object is to be cached 
     in memory, otherwise pass in zero(0). Currently you can only
     pass in zero.

     See GRsetchunk() for a description of the organization of chunks in an GR.
     
     NOTE:
          This routine directly calls a Special Chunked Element fcn HMCxxx.

RETURNS
     Returns the 'maxcache' value for the chunk cache if successful 
     and FAIL otherwise

AUTHOR 
      -GeorgeV
******************************************************************************/
intn
GRsetchunkcache(int32 riid,     /* IN: access aid to mess with */
                int32 maxcache, /* IN: max number of chunks to cache */
                int32 flags     /* IN: flags = 0, HDF_CACHEALL */)
{
    CONSTR(FUNC, "GRsetchunkcache");
    ri_info_t *ri_ptr = NULL;        /* ptr to the image to work with */
    int16      special;              /* Special code */
    intn       ret_value = SUCCEED;


    /* clear error stack and check validity of args */
    HEclear();

    /* Check args */
    if (maxcache < 1 )
      {
        ret_value = FAIL;
        goto done;
      }

    if (flags != 0 && flags != HDF_CACHEALL)
      {
        ret_value = FAIL;
        goto done;
      }

    /* check the validity of the RI ID */
    if (HAatom_group(riid)!=RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* locate RI's object in hash table */
    if (NULL == (ri_ptr = (ri_info_t *) HAatom_object(riid)))
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* check if access id exists already */
    if(ri_ptr->img_aid == 0)
      {
          /* now get access id, use write access */
          if(GRIgetaid(ri_ptr,DFACC_WRITE)==FAIL)
              HGOTO_ERROR(DFE_INTERNAL,FAIL);
      }
    else if (ri_ptr->img_aid == FAIL)
        HGOTO_ERROR(DFE_INTERNAL,FAIL);

#ifdef CHK_DEBUG
    fprintf(stderr,"%s: ri_ptr->img_aid =%d \n", FUNC, ri_ptr->img_aid);
#endif

    /* inquire about element */
    ret_value = Hinquire(ri_ptr->img_aid, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &special);
    if (ret_value != FAIL)
      {
          if (special == SPECIAL_CHUNKED) /* set cache*/
              ret_value = HMCsetMaxcache(ri_ptr->img_aid, maxcache, flags); 
          else
              ret_value = FAIL;
      }

  done:
    if (ret_value == FAIL)
      { /* Failure cleanup */

      }
    /* Normal cleanup */
    return ret_value;
} /* GRsetchunkcache() */


/*---------------------------------------------------------------
NAME
   GRmapped - Checks whether an RI is to be mapped (hmap project)

USAGE
    intn GRmapped(riid, *tobe_mapped, *created_byGR)
        int32 riid;     IN: raster image ID
        intn *tobe_mapped;  IN: TRUE if the image should be mapped
  intn *created_byGR;  IN: TRUE if the image was created by GR API
DESCRIPTION
   GRmapped checks if the given RI satisfies the following conditions:
   + being an 8-bit RI
   + having one component
   + being non-special or RLE compressed only, i.e., no other
        compressions, no chunking,...

   The function will set tobe_mapped to TRUE if the image satisfies the
   above conditions, and FALSE, otherwise.

   In addition, the function will set the flag name_generated to indicate
   whether the image has name that was generated by the library.  Old images
   (or images created with non-GR API) didn't have a name so the library
   would generate a name for it while reading in the file.

RETURNS
   SUCCEED/FAIL
   Feb 24, 2011 -BMR

MODIFICATION
   Mar 17, 2011: Changed the function from
  intn GR2bmapped(int32 riid), returning TRUE/FALSE/FAIL, to
  intn GR2bmapped(int32 riid, intn *tobe_mapped, intn *name_generated),
  returning SUCCEED/FAIL
----------------------------------------------------------------*/
intn
GR2bmapped(int32 riid, intn *tobe_mapped, intn *name_generated)
{
    CONSTR(FUNC, "GR2bmapped");
    ri_info_t *ri_ptr;          /* ptr to the image to work with */
    intn   should_map = FALSE;  /* TRUE if the image should be mapped */
    uint16 img_tag, img_ref;  /* shortcuts image's tag/ref */
    int32  ritype;    /* image's type */
    intn   special_type=0;  /* specialness of the image data */
    int32  file_id;    /* shortcut file id */
    intn   status;
    intn   ret_value = SUCCEED;

    /* Clear error stack */
    HEclear();

    /* Check the validity of the ID */
    if (HAatom_group(riid) != RIIDGROUP)
        HGOTO_ERROR(DFE_ARGS, FAIL);

    /* Locate RI's object in hash table */
    ri_ptr = (ri_info_t *) HAatom_object(riid);
    if (NULL == ri_ptr)
        HGOTO_ERROR(DFE_RINOTFOUND, FAIL);

    /* shortcuts */
    img_tag = ri_ptr->img_tag;
    img_ref = ri_ptr->img_ref;
    file_id = ri_ptr->gr_ptr->hdf_file_id;

    /* If the image has old image tag, then make sure it is either non-special
       or compressed with RLE only */ 
    if (img_tag == DFTAG_RI8 || img_tag == DFTAG_CI8)
    {
	if (ri_ptr->img_dim.comp_tag == DFTAG_RLE ||
	    ri_ptr->img_dim.comp_tag == DFTAG_NULL)
	    should_map = TRUE;
    }
    /* If the image has new image tag, then make sure that it has 8-bit data
       and has no special storage except RLE compression before determining
       that it is mapped-able */
    else if (img_tag == DFTAG_RI || img_tag == DFTAG_CI)
    {
	/* Get the image data's type */
	status = GRgetiminfo(riid, NULL, NULL, &ritype, NULL, NULL, NULL);

	/* If it is 8-bit, set flag to check further for special storage */
	if (ritype == DFNT_UCHAR8 || ritype == DFNT_CHAR8 ||
	    ritype == DFNT_UINT8 || ritype == DFNT_INT8)
	{
	    /* Also make sure it only has one component */
	    if (ri_ptr->img_dim.ncomps ==1)
	    {
		/* Make sure no specialness or only with RLE compression */
		comp_coder_t comp_type=COMP_CODE_NONE;
		status = GRgetcomptype(riid, &comp_type);
		if (comp_type == COMP_CODE_RLE || comp_type == COMP_CODE_NONE)
		{
		    special_type = GRIisspecial_type(file_id, img_tag, img_ref);
		    /* In some cases, special_type = 0 for old image with RLE,
		    although the image has newer image tag.  Added the check
		    for 0 here, but this should be investigated more. -BMR*/
		    if (special_type == SPECIAL_COMP || special_type == 0)
			should_map = TRUE;
		}
	    }
	}
    }
    /* Set flag to return */
    *tobe_mapped = should_map;

    /* Copy flag that indicates whether this image has name that was
       generated by library, and not given by application */
    *name_generated = ri_ptr->name_generated;

done:
  if(ret_value == 0)
    { /* Error condition cleanup */
    } /* end if */
  /* Normal function cleanup */
  return ret_value;
}   /* GR2bmapped */
/*

API functions to finish:

Misc. stuff left to do:
    Deal with special elements for images.
    GRrename for images.
    GRsetflags to suppress writing fill data and to suppress fillvalue attr.
    Read/Write Interlaced data (of line & plane types, pixel is working).

Features not supported:
    Add in full support for multiple palettes with each RI.
    Add in support for named palettes with each RI.
    Add in support for palettes with non-standard formats.
    Deletion of attributes or images (would require changing the way index
        numbers are handled)

*/
