g2int g2_addgrid(unsigned char *cgrib,g2int *igds,g2int *igdstmpl,g2int *ideflist,g2int idefnum)
//$$$ SUBPROGRAM DOCUMENTATION BLOCK
// . . . .
// SUBPROGRAM: g2_addgrid
// PRGMMR: Gilbert ORG: W/NP11 DATE: 2002-11-01
//
// ABSTRACT: This routine packs up a Grid Definition Section (Section 3)
// and adds it to a GRIB2 message. It is used with routines "g2_create",
// "g2_addlocal", "g2_addfield",
// and "g2_gribend" to create a complete GRIB2 message.
// g2_create must be called first to initialize a new GRIB2 message.
//
// PROGRAM HISTORY LOG:
// 2002-11-01 Gilbert
// 2009-01-14 Vuong Changed structure name template to gtemplate
//
// USAGE: int g2_addgrid(unsigned char *cgrib,g2int *igds,g2int *igdstmpl,
// g2int *ideflist,g2int idefnum)
// INPUT ARGUMENTS:
// cgrib - Char array that contains the GRIB2 message to which
// section should be added.
// igds - Contains information needed for GRIB Grid Definition Section 3
// Must be dimensioned >= 5.
// igds[0]=Source of grid definition (see Code Table 3.0)
// igds[1]=Number of grid points in the defined grid.
// igds[2]=Number of octets needed for each
// additional grid points definition.
// Used to define number of
// points in each row ( or column ) for
// non-regular grids.
// = 0, if using regular grid.
// igds[3]=Interpretation of list for optional points
// definition. (Code Table 3.11)
// igds[4]=Grid Definition Template Number (Code Table 3.1)
// igdstmpl - Contains the data values for the specified Grid Definition
// Template ( NN=igds[4] ). Each element of this integer
// array contains an entry (in the order specified) of Grid
// Defintion Template 3.NN
// ideflist - (Used if igds[2] != 0) This array contains the
// number of grid points contained in each row ( or column )
// idefnum - (Used if igds[2] != 0) The number of entries
// in array ideflist. i.e. number of rows ( or columns )
// for which optional grid points are defined.
//
// OUTPUT ARGUMENTS:
// cgrib - Char array to contain the updated GRIB2 message.
// Must be allocated large enough to store the entire
// GRIB2 message.
//
// RETURN VALUES:
// ierr - Return code.
// > 0 = Current size of updated GRIB2 message
// -1 = GRIB message was not initialized. Need to call
// routine gribcreate first.
// -2 = GRIB message already complete. Cannot add new section.
// -3 = Sum of Section byte counts doesn't add to total byte count
// -4 = Previous Section was not 1, 2 or 7.
// -5 = Could not find requested Grid Definition Template.
//
// REMARKS: Note that the Grid Def Section ( Section 3 ) can only follow
// Section 1, 2 or Section 7 in a GRIB2 message.
//
// ATTRIBUTES:
// LANGUAGE: C
// MACHINE:
//
//$$$
{
g2int ierr;
static unsigned char G=0x47; // 'G'
static unsigned char R=0x52; // 'R'
static unsigned char I=0x49; // 'I'
static unsigned char B=0x42; // 'B'
static unsigned char seven=0x37; // '7'
static g2int one=1,three=3,miss=65535;
g2int lensec3,iofst,ibeg,lencurr,len;
g2int i,j,temp,ilen,isecnum,nbits;
gtemplate *mapgrid=0;
ierr=0;
//
// Check to see if beginning of GRIB message exists
//
if ( cgrib[0]!=G || cgrib[1]!=R || cgrib[2]!=I || cgrib[3]!=B ) {
// printf("g2_addgrid: GRIB not found in given message.\n");
// printf("g2_addgrid: Call to routine gribcreate required to initialize GRIB messge.\n");
ierr=-1;
return(ierr);
}
//
// Get current length of GRIB message
//
gbit(cgrib,&lencurr,96,32);
//
// Check to see if GRIB message is already complete
//
if ( cgrib[lencurr-4]==seven && cgrib[lencurr-3]==seven &&
cgrib[lencurr-2]==seven && cgrib[lencurr-1]==seven ) {
// printf("g2_addgrid: GRIB message already complete. Cannot add new section.\n");
ierr=-2;
return(ierr);
}
//
// Loop through all current sections of the GRIB message to
// find the last section number.
//
len=16; // length of Section 0
for (;;) {
// Get section number and length of next section
iofst=len*8;
gbit(cgrib,&ilen,iofst,32);
iofst=iofst+32;
gbit(cgrib,&isecnum,iofst,8);
len=len+ilen;
// Exit loop if last section reached
if ( len == lencurr ) break;
// If byte count for each section doesn't match current
// total length, then there is a problem.
if ( len > lencurr ) {
// printf("g2_addgrid: Section byte counts don''t add to total.\n");
// printf("g2_addgrid: Sum of section byte counts = %ld\n",len);
// printf("g2_addgrid: Total byte count in Section 0 = %ld\n",lencurr);
ierr=-3;
return(ierr);
}
}
//
// Section 3 can only be added after sections 1, 2 and 7.
//
if ( (isecnum!=1) && (isecnum!=2) && (isecnum!=7) ) {
// printf("g2_addgrid: Section 3 can only be added after Section 1, 2 or 7.\n");
// printf("g2_addgrid: Section ',isecnum,' was the last found in given GRIB message.\n");
ierr=-4;
return(ierr);
}
//
// Add Section 3 - Grid Definition Section
//
ibeg=lencurr*8; // Calculate offset for beginning of section 3
iofst=ibeg+32; // leave space for length of section
sbit(cgrib,&three,iofst,8); // Store section number ( 3 )
iofst=iofst+8;
sbit(cgrib,igds+0,iofst,8); // Store source of Grid def.
iofst=iofst+8;
sbit(cgrib,igds+1,iofst,32); // Store number of data pts.
iofst=iofst+32;
sbit(cgrib,igds+2,iofst,8); // Store number of extra octets.
iofst=iofst+8;
sbit(cgrib,igds+3,iofst,8); // Store interp. of extra octets.
iofst=iofst+8;
// if Octet 6 is not equal to zero, Grid Definition Template may
// not be supplied.
if ( igds[0] == 0 )
sbit(cgrib,igds+4,iofst,16); // Store Grid Def Template num.
else
sbit(cgrib,&miss,iofst,16); // Store missing value as Grid Def Template num.
iofst=iofst+16;
//
// Get Grid Definition Template
//
if (igds[0] == 0) {
mapgrid=getgridtemplate(igds[4]);
if (mapgrid == 0) { // undefined template
ierr=-5;
return(ierr);
}
//
// Extend the Grid Definition Template, if necessary.
// The number of values in a specific template may vary
// depending on data specified in the "static" part of the
// template.
//
if ( mapgrid->needext ) {
free(mapgrid);
mapgrid=extgridtemplate(igds[4],igdstmpl);
}
}
//
// Pack up each input value in array igdstmpl into the
// the appropriate number of octets, which are specified in
// corresponding entries in array mapgrid.
//
for (i=0;i<mapgrid->maplen;i++) {
nbits=abs(mapgrid->map[i])*8;
if ( (mapgrid->map[i] >= 0) || (igdstmpl[i] >= 0) )
sbit(cgrib,igdstmpl+i,iofst,nbits);
else {
sbit(cgrib,&one,iofst,1);
temp=abs(igdstmpl[i]);
sbit(cgrib,&temp,iofst+1,nbits-1);
}
iofst=iofst+nbits;
}
// Pack template extension, if appropriate
j=mapgrid->maplen;
if ( mapgrid->needext && (mapgrid->extlen > 0) ) {
for (i=0;i<mapgrid->extlen;i++) {
nbits=abs(mapgrid->ext[i])*8;
if ( (mapgrid->ext[i] >= 0) || (igdstmpl[j] >= 0) )
sbit(cgrib,igdstmpl+j,iofst,nbits);
else {
sbit(cgrib,&one,iofst,1);
temp=abs(igdstmpl[j]);
sbit(cgrib,&temp,iofst+1,nbits-1);
}
iofst=iofst+nbits;
j++;
}
}
free(mapgrid);
//
// If requested,
// Insert optional list of numbers defining number of points
// in each row or column. This is used for non regular
// grids.
//
if ( igds[2] != 0 ) {
nbits=igds[2]*8;
sbits(cgrib,ideflist,iofst,nbits,0,idefnum);
iofst=iofst+(nbits*idefnum);
}
//
// Calculate length of section 3 and store it in octets
// 1-4 of section 3.
//
lensec3=(iofst-ibeg)/8;
sbit(cgrib,&lensec3,ibeg,32);
//
// Update current byte total of message in Section 0
//
lencurr+=lensec3;
sbit(cgrib,&lencurr,96,32);
return(lencurr);
}
g2int g2_unpack3(unsigned char *cgrib,g2int *iofst,g2int **igds,g2int **igdstmpl,
g2int *mapgridlen,g2int **ideflist,g2int *idefnum)
////$$$ SUBPROGRAM DOCUMENTATION BLOCK
// . . . .
// SUBPROGRAM: g2_unpack3
// PRGMMR: Gilbert ORG: W/NP11 DATE: 2002-10-31
//
// ABSTRACT: This routine unpacks Section 3 (Grid Definition Section)
// as defined in GRIB Edition 2.
//
// PROGRAM HISTORY LOG:
// 2002-10-31 Gilbert
//
// USAGE: int g2_unpack3(unsigned char *cgrib,g2int *iofst,g2int **igds,
// g2int **igdstmpl,g2int *mapgridlen,
// g2int **ideflist,g2int *idefnum)
// INPUT ARGUMENTS:
// cgrib - Char array ontaining Section 3 of the GRIB2 message
// iofst - Bit offset for the beginning of Section 3 in cgrib.
//
// OUTPUT ARGUMENTS:
// iofst - Bit offset at the end of Section 3, returned.
// igds - Contains information read from the appropriate GRIB Grid
// Definition Section 3 for the field being returned.
// igds[0]=Source of grid definition (see Code Table 3.0)
// igds[1]=Number of grid points in the defined grid.
// igds[2]=Number of octets needed for each
// additional grid points definition.
// Used to define number of
// points in each row ( or column ) for
// non-regular grids.
// = 0, if using regular grid.
// igds[3]=Interpretation of list for optional points
// definition. (Code Table 3.11)
// igds[4]=Grid Definition Template Number (Code Table 3.1)
// igdstmpl - Pointer to integer array containing the data values for
// the specified Grid Definition
// Template ( NN=igds[4] ). Each element of this integer
// array contains an entry (in the order specified) of Grid
// Defintion Template 3.NN
// mapgridlen- Number of elements in igdstmpl[]. i.e. number of entries
// in Grid Defintion Template 3.NN ( NN=igds[4] ).
// ideflist - (Used if igds[2] .ne. 0) Pointer to integer array containing
// the number of grid points contained in each row ( or column ).
// (part of Section 3)
// idefnum - (Used if igds[2] .ne. 0) The number of entries
// in array ideflist. i.e. number of rows ( or columns )
// for which optional grid points are defined.
// ierr - Error return code.
// 0 = no error
// 2 = Not Section 3
// 5 = "GRIB" message contains an undefined Grid Definition
// Template.
// 6 = memory allocation error
//
// REMARKS:
//
// ATTRIBUTES:
// LANGUAGE: C
// MACHINE:
//
//$$$
{
g2int ierr,i,j,nbits,isecnum;
g2int lensec,ibyttem=0,isign,newlen;
g2int *ligds,*ligdstmpl=0,*lideflist=0;
xxtemplate *mapgrid;
ierr=0;
*igds=0; // NULL
*igdstmpl=0; // NULL
*ideflist=0; // NULL
gbit(cgrib,&lensec,*iofst,32); // Get Length of Section
*iofst=*iofst+32;
gbit(cgrib,&isecnum,*iofst,8); // Get Section Number
*iofst=*iofst+8;
if ( isecnum != 3 ) {
ierr=2;
*idefnum=0;
*mapgridlen=0;
// fprintf(stderr,"g2_unpack3: Not Section 3 data.\n");
return(ierr);
}
ligds=(g2int *)calloc(5,sizeof(g2int));
*igds=ligds;
gbit(cgrib,ligds+0,*iofst,8); // Get source of Grid def.
*iofst=*iofst+8;
gbit(cgrib,ligds+1,*iofst,32); // Get number of grid pts.
*iofst=*iofst+32;
gbit(cgrib,ligds+2,*iofst,8); // Get num octets for opt. list
*iofst=*iofst+8;
gbit(cgrib,ligds+3,*iofst,8); // Get interpret. for opt. list
*iofst=*iofst+8;
gbit(cgrib,ligds+4,*iofst,16); // Get Grid Def Template num.
*iofst=*iofst+16;
if (ligds[4] != 65535) {
// Get Grid Definition Template
mapgrid=getgridtemplate(ligds[4]);
if (mapgrid == 0) { // undefined template
ierr=5;
return(ierr);
}
*mapgridlen=mapgrid->maplen;
//
// Unpack each value into array igdstmpl from the
// the appropriate number of octets, which are specified in
// corresponding entries in array mapgrid.
//
if (*mapgridlen > 0) {
ligdstmpl=0;
ligdstmpl=(g2int *)calloc(*mapgridlen,sizeof(g2int));
if (ligdstmpl == 0) {
ierr=6;
*mapgridlen=0;
*igdstmpl=0; //NULL
if( mapgrid != 0 ) free(mapgrid);
return(ierr);
}
else {
*igdstmpl=ligdstmpl;
}
}
ibyttem=0;
for (i=0;i<*mapgridlen;i++) {
nbits=abs(mapgrid->map[i])*8;
if ( mapgrid->map[i] >= 0 ) {
gbit(cgrib,ligdstmpl+i,*iofst,nbits);
}
else {
gbit(cgrib,&isign,*iofst,1);
gbit(cgrib,ligdstmpl+i,*iofst+1,nbits-1);
if (isign == 1) ligdstmpl[i]=-1*ligdstmpl[i];
}
*iofst=*iofst+nbits;
ibyttem=ibyttem+abs(mapgrid->map[i]);
}
//
// Check to see if the Grid Definition Template needs to be
// extended.
// The number of values in a specific template may vary
// depending on data specified in the "static" part of the
// template.
//
if ( mapgrid->needext == 1 ) {
free(mapgrid);
mapgrid=extgridtemplate(ligds[4],ligdstmpl);
// Unpack the rest of the Grid Definition Template
newlen=mapgrid->maplen+mapgrid->extlen;
ligdstmpl=(g2int *)realloc(ligdstmpl,newlen*sizeof(g2int));
*igdstmpl=ligdstmpl;
j=0;
for (i=*mapgridlen;i<newlen;i++) {
nbits=abs(mapgrid->ext[j])*8;
if ( mapgrid->ext[j] >= 0 ) {
gbit(cgrib,ligdstmpl+i,*iofst,nbits);
}
else {
gbit(cgrib,&isign,*iofst,1);
gbit(cgrib,ligdstmpl+i,*iofst+1,nbits-1);
if (isign == 1) ligdstmpl[i]=-1*ligdstmpl[i];
}
*iofst=*iofst+nbits;
ibyttem=ibyttem+abs(mapgrid->ext[j]);
j++;
}
*mapgridlen=newlen;
}
if( mapgrid->ext != 0 ) free(mapgrid->ext);
if( mapgrid != 0 ) free(mapgrid);
}
else { // No Grid Definition Template
*mapgridlen=0;
*igdstmpl=0;
}
//
// Unpack optional list of numbers defining number of points
// in each row or column, if included. This is used for non regular
// grids.
//
if ( ligds[2] != 0 ) {
nbits=ligds[2]*8;
*idefnum=(lensec-14-ibyttem)/ligds[2];
if (*idefnum > 0) lideflist=(g2int *)calloc(*idefnum,sizeof(g2int));
if (lideflist == 0) {
ierr=6;
*idefnum=0;
*ideflist=0; //NULL
return(ierr);
}
else {
*ideflist=lideflist;
}
gbits(cgrib,lideflist,*iofst,nbits,0,*idefnum);
*iofst=*iofst+(nbits*(*idefnum));
}
else {
*idefnum=0;
*ideflist=0; // NULL
}
return(ierr); // End of Section 3 processing
}
