#include <stdio.h>
#include <stdlib.h>
#include "dprints.h" /* debug prints */
#include "gribfuncs.h" /* prototypes */
/*
*
*********************************************************************
* A. FUNCTION: apply_bitmap
* apply the bitmap to the float array. The input float array is
* expanded and filled with 'fill_value' in places where data
* points are missing.
*
* INTERFACE:
* int apply_bitmap (bms, pgrib_data, fill_value, bds_head, errmsg)
*
* ARGUMENTS (I=input, O=output, I&O=input and output):
* (I) BMS_INPUT *bms;
* pointer to the internal BitMap header structure; bit set means
* datapoint is present, bit clear means datapoint is missing.
* (I&O) float **pgrib_data;
* pointer to Data that was unpacked from BDS's bitstr; Incoming
* size is bms->ulbits_set or (ROW*COL - #missingpts) elements;
* (I) float fill_value;
* float value used for missing datapoints in expanded array;
* (O) BDS_HEAD_INPUT *bds_head;
* attribute 'ulGrid_size' to be updated;
* (O) char *errmsg;
* Empty array that's returned filled if error occurred;
*
* RETURN CODE:
* 0> Success; float **pgrib_data probably have been expanded, OR
* Predefined bitmap used, no action taken (float array unchanged);
* 1> NULL bitmap encountered, errmsg filled;
* 2> Error Mallocing space for data array, errmsg filled;
* 3> Tried to access more than available in message, errmsg filled;
* 4> No bits set in BMS, errmsg filled;
**********************************************************************
*/
#if PROTOTYPE_NEEDED
int apply_bitmap ( BMS_INPUT *bms, float **pgrib_data, float fill_value,
BDS_HEAD_INPUT *bds_head, char *errmsg)
#else
int apply_bitmap ( bms, pgrib_data, fill_value, bds_head, errmsg)
BMS_INPUT *bms;
float **pgrib_data;
float fill_value;
BDS_HEAD_INPUT *bds_head;
char *errmsg;
#endif
{
char *func= "apply_bitmap";
int i,j; /* temp var */
int val; /* temp var */
int buf_indx; /* index for expanded float *buff array */
int gribdata_indx; /* index for float *Grid_data array */
int tot_bits_set; /* must be < expanded size */
char *pbms; /* BIT ptr beg. at BMS data array */
float *fbuff; /* holds expanded float array */
int gridsize; /* expanded size r*c */
/*
*
* A.0 DEBUG printing
*/
DPRINT1 ("Enter %s()\n", func);
/*
*
* A.1 IF (using pre-defined bitmap)
* FILL errmsg ! 'case not supported'
* RETURN 0 !success
* ENDIF
*/
if (bms->uslength == 6) /* References pre-defined bitmap */
{
/* Not currently supported. User can add code inside this IF
* to retreive the bitmap from local storage if available.
* For now, code prints warning and leaves data array alone */
fprintf(stdout,
"\n%s Warning: Predefined bitmap encountered! Not supported; " \
"Must apply bitmap to data externally.\n", func);
DPRINT1("Leaving %s: Predefined bitmap used, no action taken\n",func);
return(0);
}
/*
*
* A.2 IF (Bitmap pointer is NULL)
* FILL errmsg !null pointer
* RETURN 1
* ENDIF
*/
if (bms->bit_map==NULL) {
DPRINT1 ("Leaving %s: bitmap is Null, no action taken\n", func);
return(1);
}
/*
*
* A.3 IF (count of bits set in BMS is Zero)
* FILL errmsg
* RETURN 4 !no bits set
* ENDIF
*/
if ((tot_bits_set=bms->ulbits_set) == 0) {
sprintf(errmsg,"%s: No bits set in bitmap. No data retrieved!!\n",func);
DPRINT1("Leaving %s: No bits set in bitmap\n",func);
return(4);
}
/*
*
* A.4 CALCULATE grid_size from total number of bits in BMS;
*/
/* = (BMS length)*8 bits - 48 header bits - # of unsused bits */
gridsize=(bms->uslength)*8 - 48 - bms->usUnused_bits;
DPRINT2 ("Apply Bitmap: expanding array from [%d] to [%d]; ",
tot_bits_set, gridsize);
/*
*
* A.5 ALLOCATE storage for expanded array
* IF (Malloc error)
* RETURN 2
* ENDIF
*/
fbuff= (float *)malloc (gridsize * sizeof(float));
if (fbuff==(float *)NULL)
{
sprintf(errmsg, "%s: Error mallocing %ld bytes\n", func,gridsize);
DPRINT1 ("Leaving %s, malloc error\n",func);
return(2);
}
/*
*
* A.6 FOR (each point expected)
*/
pbms= bms->bit_map; /* pts to char arry bstr of BMS */
gribdata_indx=0; /* index for incoming float arr */
for (buf_indx=0; buf_indx < gridsize; ++pbms) {
/*
* A.6.1 GET next byte from Bitmap Section Data
*/
val= (int)*pbms & 0x0000ff ; /* BMS bitstream */
/*
* A.6.2 LOOP, check each Bit of byte read (left to rightmost)
*/
for (j=7; j>=0 && buf_indx < gridsize; j--) {
/*
* A.6.2.1 IF (bit is set) !means datapoint is present
*/
if (val & (1<<j))
{
/*
* A.6.2.1.1 IF (trying to access more than #elements in Incoming Array)
* FILL errmsg
* RETURN 3 ! incoming float array unchanged
* ENDIF
*/
if (gribdata_indx == tot_bits_set) {
sprintf(errmsg,
"%s: accessing more than %d elements in Grib_data[]\n",
func, tot_bits_set);
DPRINT1("Leaving %s, access out of range element\n",func);
return(3); /* incoming Float array is unchanged */
}
/*
* A.6.2.1.2 !still within range
* STORE datapoint at correct place in expanded array
*/
fbuff[buf_indx++]= (*pgrib_data)[gribdata_indx++];
}
/*
* ELSE ! means data point is missing
*/
else {
/*
* A.6.2.2 STORE Missing Value at correct place in expanded array
*/
fbuff[buf_indx++]= fill_value;
}
/*
* A.6.2.1 ENDIF
*/
} /* bit loop */
/*
* A.6.2 ENDLOOP
*/
} /* for every datapt */
/*
* A.6 ENDFOR !for every datapoint
*/
/*
*
* A.7 STORE the grid size into caller's argument
*/
bds_head->ulGrid_size= (unsigned long)gridsize; /* store new sz */
/*
*
* A.8 FREE old float array
*/
free (*pgrib_data);
/*
*
* A.9 ASSIGN new expanded array to pointer
*/
*pgrib_data= fbuff; /* give it addr of expanded arr */
/*
*
* A.10 RETURN 0 !success
*/
DPRINT1("Leaving %s, Stat=0", func);
return (0);
/*
*
* END OF FUNCTION
*
*
*/
}