/****************************************************************************** * $Id: gxfdataset.cpp,v 1.17 2005/05/05 15:52:48 fwarmerdam Exp $ * * Project: GXF Reader * Purpose: GDAL binding for GXF reader. * Author: Frank Warmerdam, warmerdam@pobox.com * ****************************************************************************** * Copyright (c) 1998, 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. ****************************************************************************** * * $Log: gxfdataset.cpp,v $ * Revision 1.17 2005/05/05 15:52:48 fwarmerdam * PAM Enabled * * Revision 1.16 2004/11/03 01:17:58 fwarmerdam * added extra testing to avoid mis-identification * * Revision 1.15 2004/04/06 19:23:48 warmerda * Don't forget to close the dataset! * * Revision 1.14 2003/10/06 20:50:45 warmerda * fixed author email * * Revision 1.13 2003/07/08 21:20:21 warmerda * avoid warnings * * Revision 1.12 2002/09/04 06:50:37 warmerda * avoid static driver pointers * * Revision 1.11 2002/06/12 21:12:25 warmerda * update to metadata based driver info * * Revision 1.10 2001/11/11 23:51:00 warmerda * added required class keyword to friend declarations * * Revision 1.9 2001/07/18 04:51:57 warmerda * added CPL_CVSID * * Revision 1.8 2000/11/16 14:56:16 warmerda * fail testopen on zero char, reduce min header size * * Revision 1.7 2000/02/28 16:33:49 warmerda * use SetBand method * * Revision 1.6 2000/02/14 16:24:57 warmerda * Fixed comment. * * Revision 1.5 1999/10/29 17:30:23 warmerda * read OGC rather than PROJ.4 definition * * Revision 1.4 1999/10/27 20:21:45 warmerda * added projection/transform support * * Revision 1.3 1999/01/11 15:32:12 warmerda * Added testing of file to verify it is GXF. * * Revision 1.2 1998/12/15 19:06:49 warmerda * IReadBlock(), and GXFGetRawInfo() * * Revision 1.1 1998/12/06 02:53:22 warmerda * New * */ #include "gxfopen.h" #include "gdal_pam.h" CPL_CVSID("$Id: gxfdataset.cpp,v 1.17 2005/05/05 15:52:48 fwarmerdam Exp $"); #ifndef PI # define PI 3.14159265358979323846 #endif CPL_C_START void GDALRegister_GXF(void); CPL_C_END /************************************************************************/ /* ==================================================================== */ /* GXFDataset */ /* ==================================================================== */ /************************************************************************/ class GXFRasterBand; class GXFDataset : public GDALPamDataset { friend class GXFRasterBand; GXFHandle hGXF; char *pszProjection; public: GXFDataset(); ~GXFDataset(); static GDALDataset *Open( GDALOpenInfo * ); CPLErr GetGeoTransform( double * padfTransform ); const char *GetProjectionRef(); }; /************************************************************************/ /* ==================================================================== */ /* GXFRasterBand */ /* ==================================================================== */ /************************************************************************/ class GXFRasterBand : public GDALPamRasterBand { friend class GXFDataset; public: GXFRasterBand( GXFDataset *, int ); virtual CPLErr IReadBlock( int, int, void * ); }; /************************************************************************/ /* GXFRasterBand() */ /************************************************************************/ GXFRasterBand::GXFRasterBand( GXFDataset *poDS, int nBand ) { this->poDS = poDS; this->nBand = nBand; eDataType = GDT_Float32; nBlockXSize = poDS->GetRasterXSize(); nBlockYSize = 1; } /************************************************************************/ /* IReadBlock() */ /************************************************************************/ CPLErr GXFRasterBand::IReadBlock( int nBlockXOff, int nBlockYOff, void * pImage ) { GXFDataset *poGXF_DS = (GXFDataset *) poDS; double *padfBuffer; float *pafBuffer = (float *) pImage; int i; CPLErr eErr; CPLAssert( nBlockXOff == 0 ); padfBuffer = (double *) CPLMalloc(sizeof(double) * nBlockXSize); eErr = GXFGetRawScanline( poGXF_DS->hGXF, nBlockYOff, padfBuffer ); for( i = 0; i < nBlockXSize; i++ ) pafBuffer[i] = (float) padfBuffer[i]; CPLFree( padfBuffer ); return eErr; } /************************************************************************/ /* ==================================================================== */ /* GXFDataset */ /* ==================================================================== */ /************************************************************************/ /************************************************************************/ /* GXFDataset() */ /************************************************************************/ GXFDataset::GXFDataset() { pszProjection = NULL; hGXF = NULL; } /************************************************************************/ /* ~GXFDataset() */ /************************************************************************/ GXFDataset::~GXFDataset() { FlushCache(); if( hGXF != NULL ) GXFClose( hGXF ); CPLFree( pszProjection ); } /************************************************************************/ /* GetGeoTransform() */ /************************************************************************/ CPLErr GXFDataset::GetGeoTransform( double * padfTransform ) { CPLErr eErr; double dfXOrigin, dfYOrigin, dfXSize, dfYSize, dfRotation; eErr = GXFGetPosition( hGXF, &dfXOrigin, &dfYOrigin, &dfXSize, &dfYSize, &dfRotation ); if( eErr != CE_None ) return eErr; // Transform to radians. dfRotation = (dfRotation / 360.0) * 2 * PI; padfTransform[1] = dfXSize * cos(dfRotation); padfTransform[2] = dfYSize * sin(dfRotation); padfTransform[4] = dfXSize * sin(dfRotation); padfTransform[5] = -1 * dfYSize * cos(dfRotation); // take into account that GXF is point or center of pixel oriented. padfTransform[0] = dfXOrigin - 0.5*padfTransform[1] - 0.5*padfTransform[2]; padfTransform[3] = dfYOrigin - 0.5*padfTransform[4] - 0.5*padfTransform[5]; return CE_None; } /************************************************************************/ /* GetProjectionRef() */ /************************************************************************/ const char *GXFDataset::GetProjectionRef() { return( pszProjection ); } /************************************************************************/ /* Open() */ /************************************************************************/ GDALDataset *GXFDataset::Open( GDALOpenInfo * poOpenInfo ) { GXFHandle hGXF; int i, bFoundKeyword, bFoundIllegal; /* -------------------------------------------------------------------- */ /* Before trying GXFOpen() we first verify that there is at */ /* least one "\n#keyword" type signature in the first chunk of */ /* the file. */ /* -------------------------------------------------------------------- */ if( poOpenInfo->fp == NULL || poOpenInfo->nHeaderBytes < 50 ) return NULL; bFoundKeyword = FALSE; bFoundIllegal = FALSE; for( i = 0; i < poOpenInfo->nHeaderBytes-1; i++ ) { if( (poOpenInfo->pabyHeader[i] == 10 || poOpenInfo->pabyHeader[i] == 13) && poOpenInfo->pabyHeader[i+1] == '#' ) { bFoundKeyword = TRUE; } if( poOpenInfo->pabyHeader[i] == 0 ) { bFoundIllegal = TRUE; break; } } if( !bFoundKeyword || bFoundIllegal ) return NULL; /* -------------------------------------------------------------------- */ /* At this point it is plausible that this is a GXF file, but */ /* we also now verify that there is a #GRID keyword before */ /* passing it off to GXFOpen(). We check in the first 50K. */ /* -------------------------------------------------------------------- */ int nBytesRead, bGotGrid = FALSE; char szBigBuf[50000]; FILE *fp; fp = VSIFOpen( poOpenInfo->pszFilename, "rb" ); if( fp == NULL ) return NULL; nBytesRead = VSIFRead( szBigBuf, 1, sizeof(szBigBuf), fp ); VSIFClose( fp ); for( i = 0; i < nBytesRead - 5 && !bGotGrid; i++ ) { if( szBigBuf[i] == '#' && EQUALN(szBigBuf+i+1,"GRID",4) ) bGotGrid = TRUE; } if( !bGotGrid ) return NULL; /* -------------------------------------------------------------------- */ /* Try opening the dataset. */ /* -------------------------------------------------------------------- */ hGXF = GXFOpen( poOpenInfo->pszFilename ); if( hGXF == NULL ) return( NULL ); /* -------------------------------------------------------------------- */ /* Create a corresponding GDALDataset. */ /* -------------------------------------------------------------------- */ GXFDataset *poDS; poDS = new GXFDataset(); poDS->hGXF = hGXF; /* -------------------------------------------------------------------- */ /* Establish the projection. */ /* -------------------------------------------------------------------- */ poDS->pszProjection = GXFGetMapProjectionAsOGCWKT( hGXF ); /* -------------------------------------------------------------------- */ /* Capture some information from the file that is of interest. */ /* -------------------------------------------------------------------- */ GXFGetRawInfo( hGXF, &(poDS->nRasterXSize), &(poDS->nRasterYSize), NULL, NULL, NULL, NULL ); /* -------------------------------------------------------------------- */ /* Create band information objects. */ /* -------------------------------------------------------------------- */ poDS->nBands = 1; poDS->SetBand( 1, new GXFRasterBand( poDS, 1 )); /* -------------------------------------------------------------------- */ /* Initialize any PAM information. */ /* -------------------------------------------------------------------- */ poDS->SetDescription( poOpenInfo->pszFilename ); poDS->TryLoadXML(); return( poDS ); } /************************************************************************/ /* GDALRegister_GXF() */ /************************************************************************/ void GDALRegister_GXF() { GDALDriver *poDriver; if( GDALGetDriverByName( "GXF" ) == NULL ) { poDriver = new GDALDriver(); poDriver->SetDescription( "GXF" ); poDriver->SetMetadataItem( GDAL_DMD_LONGNAME, "GeoSoft Grid Exchange Format" ); poDriver->SetMetadataItem( GDAL_DMD_HELPTOPIC, "frmt_various.html#GXF" ); poDriver->SetMetadataItem( GDAL_DMD_EXTENSION, "gxf" ); poDriver->pfnOpen = GXFDataset::Open; GetGDALDriverManager()->RegisterDriver( poDriver ); } }