/******************************************************************************
* $Id: jdemdataset.cpp.html,v 1.7 2002/12/21 19:13:13 warmerda Exp $
*
* Project: JDEM Reader
* Purpose: All code for Japanese DEM Reader
* Author: Frank Warmerdam, warmerdam@pobox.com
*
******************************************************************************
* Copyright (c) 2000, Frank Warmerdam <warmerdam@pobox.com>
*
* 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: jdemdataset.cpp.html,v $
* Revision 1.7 2002/12/21 19:13:13 warmerda
* updated
*
* Revision 1.7 2002/09/04 06:50:37 warmerda
* avoid static driver pointers
*
* Revision 1.6 2002/06/12 21:12:25 warmerda
* update to metadata based driver info
*
* Revision 1.5 2001/11/11 23:51:00 warmerda
* added required class keyword to friend declarations
*
* Revision 1.4 2001/07/18 04:51:57 warmerda
* added CPL_CVSID
*
* Revision 1.3 2001/06/21 19:59:51 warmerda
* added help link
*
* Revision 1.2 2000/11/28 02:28:54 warmerda
* Added error checks, GetGeoTransform and GetProjection
*
* Revision 1.1 2000/11/27 19:03:26 warmerda
* New
*
*/
#include "gdal_priv.h"
CPL_CVSID("$Id: jdemdataset.cpp.html,v 1.7 2002/12/21 19:13:13 warmerda Exp $");
CPL_C_START
void GDALRegister_JDEM(void);
CPL_C_END
/************************************************************************/
/* JDEMGetField() */
/************************************************************************/
static int JDEMGetField( char *pszField, int nWidth )
{
char szWork[32];
CPLAssert( nWidth < (int) sizeof(szWork) );
strncpy( szWork, pszField, nWidth );
szWork[nWidth] = '\0';
return atoi(szWork);
}
/************************************************************************/
/* JDEMGetAngle() */
/************************************************************************/
static double JDEMGetAngle( char *pszField )
{
int nAngle = JDEMGetField( pszField, 7 );
int nDegree, nMin, nSec;
// Note, this isn't very general purpose, but it would appear
// from the field widths that angles are never negative. Nice
// to be a country in the "first quadrant".
nDegree = nAngle / 10000;
nMin = (nAngle / 100) % 100;
nSec = nAngle % 100;
return nDegree + nMin / 60.0 + nSec / 3600.0;
}
/************************************************************************/
/* ==================================================================== */
/* JDEMDataset */
/* ==================================================================== */
/************************************************************************/
class JDEMRasterBand;
class JDEMDataset : public GDALDataset
{
friend class JDEMRasterBand;
FILE *fp;
GByte abyHeader[1012];
public:
~JDEMDataset();
static GDALDataset *Open( GDALOpenInfo * );
CPLErr GetGeoTransform( double * padfTransform );
const char *GetProjectionRef();
};
/************************************************************************/
/* ==================================================================== */
/* JDEMRasterBand */
/* ==================================================================== */
/************************************************************************/
class JDEMRasterBand : public GDALRasterBand
{
friend class JDEMDataset;
public:
JDEMRasterBand( JDEMDataset *, int );
virtual CPLErr IReadBlock( int, int, void * );
};
/************************************************************************/
/* JDEMRasterBand() */
/************************************************************************/
JDEMRasterBand::JDEMRasterBand( JDEMDataset *poDS, int nBand )
{
this->poDS = poDS;
this->nBand = nBand;
eDataType = GDT_Float32;
nBlockXSize = poDS->GetRasterXSize();
nBlockYSize = 1;
}
/************************************************************************/
/* IReadBlock() */
/************************************************************************/
CPLErr JDEMRasterBand::IReadBlock( int nBlockXOff, int nBlockYOff,
void * pImage )
{
JDEMDataset *poGDS = (JDEMDataset *) poDS;
char *pszRecord;
int nRecordSize = nBlockXSize*5 + 9 + 2;
int i;
VSIFSeek( poGDS->fp, 1011 + nRecordSize*nBlockYOff, SEEK_SET );
pszRecord = (char *) CPLMalloc(nRecordSize);
VSIFRead( pszRecord, 1, nRecordSize, poGDS->fp );
if( !EQUALN((char *) poGDS->abyHeader,pszRecord,6) )
{
CPLFree( pszRecord );
CPLError( CE_Failure, CPLE_AppDefined,
"JDEM Scanline corrupt. Perhaps file was not transferred\n"
"in binary mode?" );
return CE_Failure;
}
if( JDEMGetField( pszRecord + 6, 3 ) != nBlockYOff + 1 )
{
CPLFree( pszRecord );
CPLError( CE_Failure, CPLE_AppDefined,
"JDEM scanline out of order, JDEM driver does not\n"
"currently support partial datasets." );
return CE_Failure;
}
for( i = 0; i < nBlockXSize; i++ )
((float *) pImage)[i] = JDEMGetField( pszRecord + 9 + 5 * i, 5) * 0.1;
return CE_None;
}
/************************************************************************/
/* ==================================================================== */
/* JDEMDataset */
/* ==================================================================== */
/************************************************************************/
/************************************************************************/
/* ~JDEMDataset() */
/************************************************************************/
JDEMDataset::~JDEMDataset()
{
if( fp != NULL )
VSIFClose( fp );
}
/************************************************************************/
/* GetGeoTransform() */
/************************************************************************/
CPLErr JDEMDataset::GetGeoTransform( double * padfTransform )
{
double dfLLLat, dfLLLong, dfURLat, dfURLong;
dfLLLat = JDEMGetAngle( (char *) abyHeader + 29 );
dfLLLong = JDEMGetAngle( (char *) abyHeader + 36 );
dfURLat = JDEMGetAngle( (char *) abyHeader + 43 );
dfURLong = JDEMGetAngle( (char *) abyHeader + 50 );
padfTransform[0] = dfLLLong;
padfTransform[3] = dfURLat;
padfTransform[1] = (dfURLong - dfLLLong) / GetRasterXSize();
padfTransform[2] = 0.0;
padfTransform[4] = 0.0;
padfTransform[5] = -1 * (dfURLat - dfLLLat) / GetRasterYSize();
return CE_None;
}
/************************************************************************/
/* GetProjectionRef() */
/************************************************************************/
const char *JDEMDataset::GetProjectionRef()
{
return( "GEOGCS[\"Tokyo\",DATUM[\"Tokyo\",SPHEROID[\"Bessel 1841\",6377397.155,299.1528128,AUTHORITY[\"EPSG\",7004]],TOWGS84[-148,507,685,0,0,0,0],AUTHORITY[\"EPSG\",6301]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",8901]],UNIT[\"DMSH\",0.0174532925199433,AUTHORITY[\"EPSG\",9108]],AXIS[\"Lat\",NORTH],AXIS[\"Long\",EAST],AUTHORITY[\"EPSG\",4301]]" );
}
/************************************************************************/
/* Open() */
/************************************************************************/
GDALDataset *JDEMDataset::Open( GDALOpenInfo * poOpenInfo )
{
/* -------------------------------------------------------------------- */
/* Before trying JDEMOpen() 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;
/* check if century values seem reasonable */
if( (!EQUALN((char *)poOpenInfo->pabyHeader+11,"19",2)
&& !EQUALN((char *)poOpenInfo->pabyHeader+11,"20",2))
|| (!EQUALN((char *)poOpenInfo->pabyHeader+15,"19",2)
&& !EQUALN((char *)poOpenInfo->pabyHeader+15,"20",2))
|| (!EQUALN((char *)poOpenInfo->pabyHeader+19,"19",2)
&& !EQUALN((char *)poOpenInfo->pabyHeader+19,"20",2)) )
{
return NULL;
}
/* -------------------------------------------------------------------- */
/* Create a corresponding GDALDataset. */
/* -------------------------------------------------------------------- */
JDEMDataset *poDS;
poDS = new JDEMDataset();
poDS->fp = poOpenInfo->fp;
poOpenInfo->fp = NULL;
/* -------------------------------------------------------------------- */
/* Read the header. */
/* -------------------------------------------------------------------- */
VSIFSeek( poDS->fp, 0, SEEK_SET );
VSIFRead( poDS->abyHeader, 1, 1012, poDS->fp );
poDS->nRasterXSize = JDEMGetField( (char *) poDS->abyHeader + 23, 3 );
poDS->nRasterYSize = JDEMGetField( (char *) poDS->abyHeader + 26, 3 );
/* -------------------------------------------------------------------- */
/* Create band information objects. */
/* -------------------------------------------------------------------- */
poDS->SetBand( 1, new JDEMRasterBand( poDS, 1 ));
return( poDS );
}
/************************************************************************/
/* GDALRegister_JDEM() */
/************************************************************************/
void GDALRegister_JDEM()
{
GDALDriver *poDriver;
if( GDALGetDriverByName( "JDEM" ) == NULL )
{
poDriver = new GDALDriver();
poDriver->SetDescription( "JDEM" );
poDriver->SetMetadataItem( GDAL_DMD_LONGNAME,
"Japanese DEM (.mem)" );
poDriver->SetMetadataItem( GDAL_DMD_HELPTOPIC,
"frmt_various.html#JDEM" );
poDriver->SetMetadataItem( GDAL_DMD_EXTENSION, "mem" );
poDriver->pfnOpen = JDEMDataset::Open;
GetGDALDriverManager()->RegisterDriver( poDriver );
}
}
1.2.3-20001105 written by Dimitri van Heesch,
© 1997-2000