GDALDataset* SGIDataset::Open(GDALOpenInfo* poOpenInfo)
{
/* -------------------------------------------------------------------- */
/* First we check to see if the file has the expected header */
/* bytes. */
/* -------------------------------------------------------------------- */
if(poOpenInfo->nHeaderBytes < 12 || poOpenInfo->fpL == nullptr )
return nullptr;
ImageRec tmpImage;
memcpy(&tmpImage.imagic, poOpenInfo->pabyHeader + 0, 2);
memcpy(&tmpImage.type, poOpenInfo->pabyHeader + 2, 1);
memcpy(&tmpImage.bpc, poOpenInfo->pabyHeader + 3, 1);
memcpy(&tmpImage.dim, poOpenInfo->pabyHeader + 4, 2);
memcpy(&tmpImage.xsize, poOpenInfo->pabyHeader + 6, 2);
memcpy(&tmpImage.ysize, poOpenInfo->pabyHeader + 8, 2);
memcpy(&tmpImage.zsize, poOpenInfo->pabyHeader + 10, 2);
tmpImage.Swap();
if(tmpImage.imagic != 474)
return nullptr;
if (tmpImage.type != 0 && tmpImage.type != 1)
return nullptr;
if (tmpImage.bpc != 1 && tmpImage.bpc != 2)
return nullptr;
if (tmpImage.dim != 1 && tmpImage.dim != 2 && tmpImage.dim != 3)
return nullptr;
if(tmpImage.bpc != 1)
{
CPLError(CE_Failure, CPLE_NotSupported,
"The SGI driver only supports 1 byte channel values.\n");
return nullptr;
}
/* -------------------------------------------------------------------- */
/* Create a corresponding GDALDataset. */
/* -------------------------------------------------------------------- */
SGIDataset* poDS = new SGIDataset();
poDS->eAccess = poOpenInfo->eAccess;
poDS->fpImage = poOpenInfo->fpL;
poOpenInfo->fpL = nullptr;
/* -------------------------------------------------------------------- */
/* Read pre-image data after ensuring the file is rewound. */
/* -------------------------------------------------------------------- */
VSIFSeekL(poDS->fpImage, 0, SEEK_SET);
if(VSIFReadL(reinterpret_cast<void*>( &(poDS->image) ),
1, 12, poDS->fpImage)
!= 12)
{
CPLError(CE_Failure, CPLE_OpenFailed, "file read error while reading header in sgidataset.cpp");
delete poDS;
return nullptr;
}
poDS->image.Swap();
poDS->image.file = poDS->fpImage;
poDS->image.fileName = poOpenInfo->pszFilename;
/* -------------------------------------------------------------------- */
/* Capture some information from the file that is of interest. */
/* -------------------------------------------------------------------- */
poDS->nRasterXSize = poDS->image.xsize;
poDS->nRasterYSize = poDS->image.ysize;
if (poDS->nRasterXSize <= 0 || poDS->nRasterYSize <= 0)
{
CPLError(CE_Failure, CPLE_OpenFailed,
"Invalid image dimensions : %d x %d", poDS->nRasterXSize, poDS->nRasterYSize);
delete poDS;
return nullptr;
}
poDS->nBands = std::max(static_cast<GUInt16>(1), poDS->image.zsize);
if (poDS->nBands > 256)
{
CPLError(CE_Failure, CPLE_OpenFailed,
"Too many bands : %d", poDS->nBands);
delete poDS;
return nullptr;
}
const int numItems
= (static_cast<int>( poDS->image.bpc ) == 1) ? 256 : 65536;
if( poDS->image.xsize > INT_MAX / numItems )
{
delete poDS;
return nullptr;
}
poDS->image.tmpSize = poDS->image.xsize * numItems;
poDS->image.tmp = (unsigned char*)VSI_CALLOC_VERBOSE(poDS->image.xsize,numItems);
if (poDS->image.tmp == nullptr)
{
delete poDS;
return nullptr;
}
/* -------------------------------------------------------------------- */
/* Read RLE Pointer tables. */
/* -------------------------------------------------------------------- */
if( static_cast<int>( poDS->image.type ) == 1 ) // RLE compressed
{
const size_t x = static_cast<size_t>(poDS->image.ysize) * poDS->nBands * sizeof(GUInt32);
poDS->image.rowStart = reinterpret_cast<GUInt32*>(
VSI_MALLOC2_VERBOSE(poDS->image.ysize, poDS->nBands * sizeof(GUInt32) ) );
poDS->image.rowSize = reinterpret_cast<GInt32 *>(
VSI_MALLOC2_VERBOSE(poDS->image.ysize, poDS->nBands * sizeof(GUInt32) ) );
if (poDS->image.rowStart == nullptr || poDS->image.rowSize == nullptr)
{
delete poDS;
return nullptr;
}
memset(poDS->image.rowStart, 0, x);
memset(poDS->image.rowSize, 0, x);
poDS->image.rleEnd = static_cast<GUInt32>(512 + (2 * x));
VSIFSeekL(poDS->fpImage, 512, SEEK_SET);
if( VSIFReadL(poDS->image.rowStart, 1, x, poDS->image.file ) != x )
{
delete poDS;
CPLError(CE_Failure, CPLE_OpenFailed,
"file read error while reading start positions in sgidataset.cpp");
return nullptr;
}
if( VSIFReadL(poDS->image.rowSize, 1, x, poDS->image.file) != x)
{
delete poDS;
CPLError(CE_Failure, CPLE_OpenFailed,
"file read error while reading row lengths in sgidataset.cpp");
return nullptr;
}
ConvertLong(poDS->image.rowStart,
static_cast<int>(x / static_cast<int>( sizeof(GUInt32))) );
ConvertLong(reinterpret_cast<GUInt32 *>( poDS->image.rowSize ),
static_cast<int>(x / static_cast<int>( sizeof(GInt32) )) );
}
else // uncompressed.
{
poDS->image.rowStart = nullptr;
poDS->image.rowSize = nullptr;
}
/* -------------------------------------------------------------------- */
/* Create band information objects. */
/* -------------------------------------------------------------------- */
for(int iBand = 0; iBand < poDS->nBands; iBand++)
poDS->SetBand(iBand+1, new SGIRasterBand(poDS, iBand+1));
/* -------------------------------------------------------------------- */
/* Check for world file. */
/* -------------------------------------------------------------------- */
poDS->bGeoTransformValid =
GDALReadWorldFile(poOpenInfo->pszFilename, ".wld",
poDS->adfGeoTransform);
/* -------------------------------------------------------------------- */
/* Initialize any PAM information. */
/* -------------------------------------------------------------------- */
poDS->SetDescription(poOpenInfo->pszFilename);
poDS->TryLoadXML();
/* -------------------------------------------------------------------- */
/* Check for overviews. */
/* -------------------------------------------------------------------- */
poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename );
return poDS;
}
GDALDataset* SGIDataset::Open(GDALOpenInfo* poOpenInfo)
{
/* -------------------------------------------------------------------- */
/* First we check to see if the file has the expected header */
/* bytes. */
/* -------------------------------------------------------------------- */
if(poOpenInfo->nHeaderBytes < 12)
return NULL;
ImageRec tmpImage;
memcpy(&tmpImage, poOpenInfo->pabyHeader, 12);
tmpImage.Swap();
if(tmpImage.imagic != 474)
return NULL;
if (tmpImage.type != 0 && tmpImage.type != 1)
return NULL;
if (tmpImage.bpc != 1 && tmpImage.bpc != 2)
return NULL;
if (tmpImage.dim != 1 && tmpImage.dim != 2 && tmpImage.dim != 3)
return NULL;
if(tmpImage.bpc != 1)
{
CPLError(CE_Failure, CPLE_NotSupported,
"The SGI driver only supports 1 byte channel values.\n");
return NULL;
}
/* -------------------------------------------------------------------- */
/* Create a corresponding GDALDataset. */
/* -------------------------------------------------------------------- */
SGIDataset* poDS;
poDS = new SGIDataset();
poDS->eAccess = poOpenInfo->eAccess;
/* -------------------------------------------------------------------- */
/* Open the file using the large file api. */
/* -------------------------------------------------------------------- */
if( poDS->eAccess == GA_ReadOnly )
poDS->fpImage = VSIFOpenL(poOpenInfo->pszFilename, "rb");
else
poDS->fpImage = VSIFOpenL(poOpenInfo->pszFilename, "rb+");
if(poDS->fpImage == NULL)
{
CPLError(CE_Failure, CPLE_OpenFailed,
"VSIFOpenL(%s) failed unexpectedly in sgidataset.cpp\n%s",
poOpenInfo->pszFilename,
VSIStrerror( errno ) );
delete poDS;
return NULL;
}
/* -------------------------------------------------------------------- */
/* Read pre-image data after ensuring the file is rewound. */
/* -------------------------------------------------------------------- */
VSIFSeekL(poDS->fpImage, 0, SEEK_SET);
if(VSIFReadL((void*)(&(poDS->image)), 1, 12, poDS->fpImage) != 12)
{
CPLError(CE_Failure, CPLE_OpenFailed, "file read error while reading header in sgidataset.cpp");
delete poDS;
return NULL;
}
poDS->image.Swap();
poDS->image.file = poDS->fpImage;
poDS->image.fileName = poOpenInfo->pszFilename;
/* -------------------------------------------------------------------- */
/* Capture some information from the file that is of interest. */
/* -------------------------------------------------------------------- */
poDS->nRasterXSize = poDS->image.xsize;
poDS->nRasterYSize = poDS->image.ysize;
if (poDS->nRasterXSize <= 0 || poDS->nRasterYSize <= 0)
{
CPLError(CE_Failure, CPLE_OpenFailed,
"Invalid image dimensions : %d x %d", poDS->nRasterXSize, poDS->nRasterYSize);
delete poDS;
return NULL;
}
poDS->nBands = MAX(1,poDS->image.zsize);
if (poDS->nBands > 256)
{
CPLError(CE_Failure, CPLE_OpenFailed,
"Too many bands : %d", poDS->nBands);
delete poDS;
return NULL;
}
int numItems = (int(poDS->image.bpc) == 1) ? 256 : 65536;
poDS->image.tmp = (unsigned char*)VSICalloc(poDS->image.xsize,numItems);
if (poDS->image.tmp == NULL)
{
CPLError(CE_Failure, CPLE_OutOfMemory, "Out of memory");
delete poDS;
return NULL;
}
/* -------------------------------------------------------------------- */
/* Read RLE Pointer tables. */
/* -------------------------------------------------------------------- */
if(int(poDS->image.type) == 1) // RLE compressed
{
int x = poDS->image.ysize * poDS->nBands * sizeof(GUInt32);
poDS->image.rowStart = (GUInt32*)VSIMalloc2(poDS->image.ysize, poDS->nBands * sizeof(GUInt32));
poDS->image.rowSize = (GInt32*)VSIMalloc2(poDS->image.ysize, poDS->nBands * sizeof(GUInt32));
if (poDS->image.rowStart == NULL || poDS->image.rowSize == NULL)
{
CPLError(CE_Failure, CPLE_OutOfMemory, "Out of memory");
delete poDS;
return NULL;
}
memset(poDS->image.rowStart, 0, x);
memset(poDS->image.rowSize, 0, x);
poDS->image.rleEnd = 512 + (2 * x);
VSIFSeekL(poDS->fpImage, 512, SEEK_SET);
if((int) VSIFReadL(poDS->image.rowStart, 1, x, poDS->image.file) != x)
{
delete poDS;
CPLError(CE_Failure, CPLE_OpenFailed,
"file read error while reading start positions in sgidataset.cpp");
return NULL;
}
if((int) VSIFReadL(poDS->image.rowSize, 1, x, poDS->image.file) != x)
{
delete poDS;
CPLError(CE_Failure, CPLE_OpenFailed,
"file read error while reading row lengths in sgidataset.cpp");
return NULL;
}
ConvertLong(poDS->image.rowStart, x/(int)sizeof(GUInt32));
ConvertLong((GUInt32*)poDS->image.rowSize, x/(int)sizeof(GInt32));
}
else // uncompressed.
{
poDS->image.rowStart = NULL;
poDS->image.rowSize = NULL;
}
/* -------------------------------------------------------------------- */
/* Create band information objects. */
/* -------------------------------------------------------------------- */
for(int iBand = 0; iBand < poDS->nBands; iBand++)
poDS->SetBand(iBand+1, new SGIRasterBand(poDS, iBand+1));
/* -------------------------------------------------------------------- */
/* Check for world file. */
/* -------------------------------------------------------------------- */
poDS->bGeoTransformValid =
GDALReadWorldFile(poOpenInfo->pszFilename, ".wld",
poDS->adfGeoTransform);
/* -------------------------------------------------------------------- */
/* Initialize any PAM information. */
/* -------------------------------------------------------------------- */
poDS->SetDescription(poOpenInfo->pszFilename);
poDS->TryLoadXML();
/* -------------------------------------------------------------------- */
/* Check for overviews. */
/* -------------------------------------------------------------------- */
poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename );
return poDS;
}