CPLErr AAIGRasterBand::IReadBlock( int nBlockXOff, int nBlockYOff,
void *pImage )
{
AAIGDataset *poODS = static_cast<AAIGDataset *>(poDS);
if( nBlockYOff < 0 || nBlockYOff > poODS->nRasterYSize - 1 ||
nBlockXOff != 0 || panLineOffset == nullptr || poODS->fp == nullptr )
return CE_Failure;
if( panLineOffset[nBlockYOff] == 0 )
{
for( int iPrevLine = 1; iPrevLine <= nBlockYOff; iPrevLine++ )
if( panLineOffset[iPrevLine] == 0 )
IReadBlock(nBlockXOff, iPrevLine - 1, nullptr);
}
if( panLineOffset[nBlockYOff] == 0 )
return CE_Failure;
if( poODS->Seek(panLineOffset[nBlockYOff]) != 0 )
{
CPLError(CE_Failure, CPLE_FileIO,
"Can't seek to offset %lu in input file to read data.",
static_cast<long unsigned int>(panLineOffset[nBlockYOff]));
return CE_Failure;
}
for( int iPixel = 0; iPixel < poODS->nRasterXSize; )
{
// Suck up any pre-white space.
char chNext = '\0';
do {
chNext = poODS->Getc();
} while( isspace(static_cast<unsigned char>(chNext)) );
char szToken[500] = { '\0' };
int iTokenChar = 0;
while( chNext != '\0' && !isspace((unsigned char)chNext) )
{
if( iTokenChar == sizeof(szToken) - 2 )
{
CPLError(CE_Failure, CPLE_FileIO,
"Token too long at scanline %d.", nBlockYOff);
return CE_Failure;
}
szToken[iTokenChar++] = chNext;
chNext = poODS->Getc();
}
if( chNext == '\0' &&
(iPixel != poODS->nRasterXSize - 1 ||
nBlockYOff != poODS->nRasterYSize - 1) )
{
CPLError(CE_Failure, CPLE_FileIO, "File short, can't read line %d.",
nBlockYOff);
return CE_Failure;
}
szToken[iTokenChar] = '\0';
if( pImage != nullptr )
{
if( eDataType == GDT_Float64 )
reinterpret_cast<double *>(pImage)[iPixel] = CPLAtofM(szToken);
else if( eDataType == GDT_Float32 )
reinterpret_cast<float *>(pImage)[iPixel] =
DoubleToFloatClamp(CPLAtofM(szToken));
else
reinterpret_cast<GInt32 *>(pImage)[iPixel] =
static_cast<GInt32>(atoi(szToken));
}
iPixel++;
}
if( nBlockYOff < poODS->nRasterYSize - 1 )
panLineOffset[nBlockYOff + 1] = poODS->Tell();
return CE_None;
}
g2int g2_unpack7(unsigned char *cgrib,g2int *iofst,g2int igdsnum,g2int *igdstmpl,
g2int idrsnum,g2int *idrstmpl,g2int ndpts,g2float **fld)
//$$$ SUBPROGRAM DOCUMENTATION BLOCK
// . . . .
// SUBPROGRAM: g2_unpack7
// PRGMMR: Gilbert ORG: W/NP11 DATE: 2002-10-31
//
// ABSTRACT: This subroutine unpacks Section 7 (Data Section)
// as defined in GRIB Edition 2.
//
// PROGRAM HISTORY LOG:
// 2002-10-31 Gilbert
// 2002-12-20 Gilbert - Added GDT info to arguments
// and added 5.51 processing.
// 2003-08-29 Gilbert - Added support for new templates using
// PNG and JPEG2000 algorithms/templates.
// 2004-11-29 Gilbert - JPEG2000 now allowed to use WMO Template no. 5.40
// PNG now allowed to use WMO Template no. 5.41
// 2004-12-16 Taylor - Added check on comunpack return code.
// 2008-12-23 Wesley - Initialize Number of data points unpacked
//
// USAGE: int g2_unpack7(unsigned char *cgrib,g2int *iofst,g2int igdsnum,
// g2int *igdstmpl, g2int idrsnum,
// g2int *idrstmpl, g2int ndpts,g2float **fld)
// INPUT ARGUMENTS:
// cgrib - char array containing Section 7 of the GRIB2 message
// iofst - Bit offset of the beginning of Section 7 in cgrib.
// igdsnum - Grid Definition Template Number ( see Code Table 3.0)
// ( Only used for DRS Template 5.51 )
// igdstmpl - Pointer to an integer array containing the data values for
// the specified Grid Definition
// Template ( N=igdsnum ). Each element of this integer
// array contains an entry (in the order specified) of Grid
// Definition Template 3.N
// ( Only used for DRS Template 5.51 )
// idrsnum - Data Representation Template Number ( see Code Table 5.0)
// idrstmpl - Pointer to an integer array containing the data values for
// the specified Data Representation
// Template ( N=idrsnum ). Each element of this integer
// array contains an entry (in the order specified) of Data
// Representation Template 5.N
// ndpts - Number of data points unpacked and returned.
//
// OUTPUT ARGUMENTS:
// iofst - Bit offset at the end of Section 7, returned.
// fld - Pointer to a float array containing the unpacked data field.
//
// RETURN VALUES:
// ierr - Error return code.
// 0 = no error
// 2 = Not section 7
// 4 = Unrecognized Data Representation Template
// 5 = need one of GDT 3.50 through 3.53 to decode DRT 5.51
// 6 = memory allocation error
// 7 = corrupt section 7.
//
// REMARKS: None
//
// ATTRIBUTES:
// LANGUAGE: C
// MACHINE:
//
//$$$//
{
g2int ierr,isecnum;
g2int ipos,lensec;
g2float *lfld;
ierr=0;
*fld=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 != 7 ) {
ierr=2;
//fprintf(stderr,"g2_unpack7: Not Section 7 data.\n");
return(ierr);
}
ipos=(*iofst/8);
lfld=(g2float *)calloc(ndpts ? ndpts : 1,sizeof(g2float));
if (lfld == 0) {
ierr=6;
return(ierr);
}
*fld=lfld;
if (idrsnum == 0)
simunpack(cgrib+ipos,idrstmpl,ndpts,lfld);
else if (idrsnum == 2 || idrsnum == 3) {
if (comunpack(cgrib+ipos,lensec,idrsnum,idrstmpl,ndpts,lfld) != 0) {
return 7;
}
}
else if( idrsnum == 4 ) {
// Grid point data - IEEE Floating Point Data
static const int one = 1;
int is_lsb = *((char*)&one) == 1;
if (idrstmpl[0] == 1) {
// IEEE754 single precision
memcpy(lfld, cgrib+ipos, 4 * ndpts );
if( is_lsb ) {
int i;
unsigned char* ch_fld = (unsigned char*) lfld;
for(i=0;i<ndpts;i++)
{
unsigned char temp = ch_fld[i*4];
ch_fld[i*4] = ch_fld[i*4+3];
ch_fld[i*4+3] = temp;
temp = ch_fld[i*4+1];
ch_fld[i*4+1] = ch_fld[i*4+2];
ch_fld[i*4+2] = temp;
}
}
}
else if( idrstmpl[0] == 2) {
// IEEE754 double precision
// FIXME? due to the interface: we downgrade it to float
int i;
unsigned char* src = cgrib+ipos;
if( is_lsb ) {
for(i=0;i<ndpts;i++) {
unsigned char temp[8];
double d;
{
int j;
for(j = 0; j < 8; j++ )
temp[j] = src[i * 8 + 7 - j];
}
memcpy(&d, temp, 8);
lfld[i] = DoubleToFloatClamp(d);
}
}
else {
for(i=0;i<ndpts;i++) {
double d;
memcpy(&d, src + i * 8, 8);
lfld[i] = DoubleToFloatClamp(d);
}
}
}
else {
fprintf(stderr,"g2_unpack7: Invalid precision=%ld for Data Section 5.4.\n", idrstmpl[0]);
ierr=5;
free(lfld);
*fld=0; //NULL
return(ierr);
}
}
else if (idrsnum == 50) { // Spectral Simple
simunpack(cgrib+ipos,idrstmpl,ndpts-1,lfld+1);
rdieee(idrstmpl+4,lfld+0,1);
}
else if (idrsnum == 51) // Spectral complex
if ( igdsnum>=50 && igdsnum <=53 )
specunpack(cgrib+ipos,idrstmpl,ndpts,igdstmpl[0],igdstmpl[2],igdstmpl[2],lfld);
else {
fprintf(stderr,"g2_unpack7: Cannot use GDT 3.%d to unpack Data Section 5.51.\n",(int)igdsnum);
ierr=5;
free(lfld);
*fld=0; //NULL
return(ierr);
}
#ifdef USE_JPEG2000
else if (idrsnum == 40 || idrsnum == 40000) {
jpcunpack(cgrib+ipos,lensec-5,idrstmpl,ndpts,lfld);
}
#endif /* USE_JPEG2000 */
#ifdef USE_PNG
else if (idrsnum == 41 || idrsnum == 40010) {
pngunpack(cgrib+ipos,lensec-5,idrstmpl,ndpts,lfld);
}
#endif /* USE_PNG */
else {
fprintf(stderr,"g2_unpack7: Data Representation Template 5.%d not yet implemented.\n",(int)idrsnum);
ierr=4;
free(lfld);
*fld=0; //NULL
return(ierr);
}
*iofst=*iofst+(8*lensec);
return(ierr); // End of Section 7 processing
}
