/****************************************************************************** * * Project: Horizontal Datum Formats * Purpose: Implementation of NOAA/NADCON los/las datum shift format. * Author: Frank Warmerdam, warmerdam@pobox.com * Financial Support: i-cubed (http://www.i-cubed.com) * ****************************************************************************** * Copyright (c) 2010, Frank Warmerdam * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. ****************************************************************************/ #include "cpl_string.h" #include "gdal_frmts.h" #include "ogr_srs_api.h" #include "rawdataset.h" CPL_CVSID("$Id: loslasdataset.cpp b2723bb9ee29fb36de5c3afec9e9a6b757ef743c 2018-05-10 21:21:26 +0200 Even Rouault $") /** NOAA .LOS/.LAS Datum Grid Shift Format All values are little endian Header ------ char[56] "NADCON EXTRACTED REGION" char[8] "NADGRD " int32 grid width int32 grid height int32 z count (1) float32 origin longitude float32 grid cell width longitude float32 origin latitude float32 grid cell height latitude float32 angle (0.0) Data ---- int32 ? always 0 float32*gridwidth offset in arcseconds. Note that the record length is always gridwidth*4 + 4, and even the header record is this length though it means some waste. **/ /************************************************************************/ /* ==================================================================== */ /* LOSLASDataset */ /* ==================================================================== */ /************************************************************************/ class LOSLASDataset final: public RawDataset { VSILFILE *fpImage; // image data file. int nRecordLength; double adfGeoTransform[6]; CPL_DISALLOW_COPY_ASSIGN(LOSLASDataset) public: LOSLASDataset(); ~LOSLASDataset() override; CPLErr GetGeoTransform( double * padfTransform ) override; const char *GetProjectionRef() override; static GDALDataset *Open( GDALOpenInfo * ); static int Identify( GDALOpenInfo * ); }; /************************************************************************/ /* ==================================================================== */ /* LOSLASDataset */ /* ==================================================================== */ /************************************************************************/ /************************************************************************/ /* LOSLASDataset() */ /************************************************************************/ LOSLASDataset::LOSLASDataset() : fpImage(nullptr), nRecordLength(0) { memset( adfGeoTransform, 0, sizeof(adfGeoTransform) ); } /************************************************************************/ /* ~LOSLASDataset() */ /************************************************************************/ LOSLASDataset::~LOSLASDataset() { FlushCache(); if( fpImage != nullptr ) CPL_IGNORE_RET_VAL(VSIFCloseL( fpImage )); } /************************************************************************/ /* Identify() */ /************************************************************************/ int LOSLASDataset::Identify( GDALOpenInfo *poOpenInfo ) { if( poOpenInfo->nHeaderBytes < 64 ) return FALSE; #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION if( !EQUAL(CPLGetExtension(poOpenInfo->pszFilename),"las") && !EQUAL(CPLGetExtension(poOpenInfo->pszFilename),"los") ) return FALSE; #endif if( !STARTS_WITH_CI((const char *)poOpenInfo->pabyHeader + 56, "NADGRD") ) return FALSE; return TRUE; } /************************************************************************/ /* Open() */ /************************************************************************/ GDALDataset *LOSLASDataset::Open( GDALOpenInfo * poOpenInfo ) { if( !Identify( poOpenInfo ) || poOpenInfo->fpL == nullptr ) return nullptr; /* -------------------------------------------------------------------- */ /* Confirm the requested access is supported. */ /* -------------------------------------------------------------------- */ if( poOpenInfo->eAccess == GA_Update ) { CPLError( CE_Failure, CPLE_NotSupported, "The LOSLAS driver does not support update access to existing" " datasets." ); return nullptr; } /* -------------------------------------------------------------------- */ /* Create a corresponding GDALDataset. */ /* -------------------------------------------------------------------- */ LOSLASDataset *poDS = new LOSLASDataset(); poDS->fpImage = poOpenInfo->fpL; poOpenInfo->fpL = nullptr; /* -------------------------------------------------------------------- */ /* Read the header. */ /* -------------------------------------------------------------------- */ CPL_IGNORE_RET_VAL(VSIFSeekL( poDS->fpImage, 64, SEEK_SET )); CPL_IGNORE_RET_VAL(VSIFReadL( &(poDS->nRasterXSize), 4, 1, poDS->fpImage )); CPL_IGNORE_RET_VAL(VSIFReadL( &(poDS->nRasterYSize), 4, 1, poDS->fpImage )); CPL_LSBPTR32( &(poDS->nRasterXSize) ); CPL_LSBPTR32( &(poDS->nRasterYSize) ); if (!GDALCheckDatasetDimensions(poDS->nRasterXSize, poDS->nRasterYSize) || poDS->nRasterXSize > (INT_MAX - 4) / 4 ) { delete poDS; return nullptr; } CPL_IGNORE_RET_VAL(VSIFSeekL( poDS->fpImage, 76, SEEK_SET )); float min_lon, min_lat, delta_lon, delta_lat; CPL_IGNORE_RET_VAL(VSIFReadL( &min_lon, 4, 1, poDS->fpImage )); CPL_IGNORE_RET_VAL(VSIFReadL( &delta_lon, 4, 1, poDS->fpImage )); CPL_IGNORE_RET_VAL(VSIFReadL( &min_lat, 4, 1, poDS->fpImage )); CPL_IGNORE_RET_VAL(VSIFReadL( &delta_lat, 4, 1, poDS->fpImage )); CPL_LSBPTR32( &min_lon ); CPL_LSBPTR32( &delta_lon ); CPL_LSBPTR32( &min_lat ); CPL_LSBPTR32( &delta_lat ); poDS->nRecordLength = poDS->nRasterXSize * 4 + 4; /* -------------------------------------------------------------------- */ /* Create band information object. */ /* */ /* Note we are setting up to read from the last image record to */ /* the first since the data comes with the southern most record */ /* first, not the northernmost like we would want. */ /* -------------------------------------------------------------------- */ poDS->SetBand( 1, new RawRasterBand( poDS, 1, poDS->fpImage, static_cast(poDS->nRasterYSize) * poDS->nRecordLength + 4, 4, -1 * poDS->nRecordLength, GDT_Float32, CPL_IS_LSB, RawRasterBand::OwnFP::NO ) ); /* -------------------------------------------------------------------- */ /* Setup georeferencing. */ /* -------------------------------------------------------------------- */ poDS->adfGeoTransform[0] = min_lon - delta_lon*0.5; poDS->adfGeoTransform[1] = delta_lon; poDS->adfGeoTransform[2] = 0.0; poDS->adfGeoTransform[3] = min_lat + (poDS->nRasterYSize-0.5) * delta_lat; poDS->adfGeoTransform[4] = 0.0; poDS->adfGeoTransform[5] = -1 * delta_lat; /* -------------------------------------------------------------------- */ /* Initialize any PAM information. */ /* -------------------------------------------------------------------- */ poDS->SetDescription( poOpenInfo->pszFilename ); poDS->TryLoadXML(); /* -------------------------------------------------------------------- */ /* Check for overviews. */ /* -------------------------------------------------------------------- */ poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename ); return poDS; } /************************************************************************/ /* GetGeoTransform() */ /************************************************************************/ CPLErr LOSLASDataset::GetGeoTransform( double * padfTransform ) { memcpy( padfTransform, adfGeoTransform, sizeof(double)*6 ); return CE_None; } /************************************************************************/ /* GetProjectionRef() */ /************************************************************************/ const char *LOSLASDataset::GetProjectionRef() { return SRS_WKT_WGS84; } /************************************************************************/ /* GDALRegister_LOSLAS() */ /************************************************************************/ void GDALRegister_LOSLAS() { if( GDALGetDriverByName( "LOSLAS" ) != nullptr ) return; GDALDriver *poDriver = new GDALDriver(); poDriver->SetDescription( "LOSLAS" ); poDriver->SetMetadataItem( GDAL_DCAP_RASTER, "YES" ); poDriver->SetMetadataItem( GDAL_DMD_LONGNAME, "NADCON .los/.las Datum Grid Shift" ); poDriver->SetMetadataItem( GDAL_DCAP_VIRTUALIO, "YES" ); poDriver->pfnOpen = LOSLASDataset::Open; poDriver->pfnIdentify = LOSLASDataset::Identify; GetGDALDriverManager()->RegisterDriver( poDriver ); }