qgsgdalutils.cpp

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/***************************************************************************
                             qgsgdalutils.cpp
                             ----------------
    begin                : September 2018
    copyright            : (C) 2018 Even Rouault
    email                : even.rouault at spatialys.com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgsgdalutils.h"
#include "qgslogger.h"
#include "qgsnetworkaccessmanager.h"
#include "qgssettings.h"
 
#define CPL_SUPRESS_CPLUSPLUS  //#spellok
#include "gdal.h"
#include "gdalwarper.h"
#include "cpl_string.h"
 
#include <QNetworkProxy>
#include <QString>
#include <QImage>
 
bool QgsGdalUtils::supportsRasterCreate( GDALDriverH driver )
{
  QString driverShortName = GDALGetDriverShortName( driver );
  if ( driverShortName == QLatin1String( "SQLite" ) )
  {
    // it supports Create() but only for vector side
    return false;
  }
  char **driverMetadata = GDALGetMetadata( driver, nullptr );
  return  CSLFetchBoolean( driverMetadata, GDAL_DCAP_CREATE, false ) &&
          CSLFetchBoolean( driverMetadata, GDAL_DCAP_RASTER, false );
}
 
gdal::dataset_unique_ptr QgsGdalUtils::createSingleBandMemoryDataset( GDALDataType dataType, const QgsRectangle &extent, int width, int height, const QgsCoordinateReferenceSystem &crs )
{
  return createMultiBandMemoryDataset( dataType, 1, extent, width, height, crs );
}
 
gdal::dataset_unique_ptr QgsGdalUtils::createMultiBandMemoryDataset( GDALDataType dataType, int bands, const QgsRectangle &extent, int width, int height, const QgsCoordinateReferenceSystem &crs )
{
  GDALDriverH hDriverMem = GDALGetDriverByName( "MEM" );
  if ( !hDriverMem )
  {
    return gdal::dataset_unique_ptr();
  }
 
  gdal::dataset_unique_ptr hSrcDS( GDALCreate( hDriverMem, "", width, height, bands, dataType, nullptr ) );
 
  double cellSizeX = extent.width() / width;
  double cellSizeY = extent.height() / height;
  double geoTransform[6];
  geoTransform[0] = extent.xMinimum();
  geoTransform[1] = cellSizeX;
  geoTransform[2] = 0;
  geoTransform[3] = extent.yMinimum() + ( cellSizeY * height );
  geoTransform[4] = 0;
  geoTransform[5] = -cellSizeY;
 
  GDALSetProjection( hSrcDS.get(), crs.toWkt( QgsCoordinateReferenceSystem::WKT_PREFERRED_GDAL ).toLatin1().constData() );
  GDALSetGeoTransform( hSrcDS.get(), geoTransform );
  return hSrcDS;
}
 
gdal::dataset_unique_ptr QgsGdalUtils::createSingleBandTiffDataset( const QString &filename, GDALDataType dataType, const QgsRectangle &extent, int width, int height, const QgsCoordinateReferenceSystem &crs )
{
  double cellSizeX = extent.width() / width;
  double cellSizeY = extent.height() / height;
  double geoTransform[6];
  geoTransform[0] = extent.xMinimum();
  geoTransform[1] = cellSizeX;
  geoTransform[2] = 0;
  geoTransform[3] = extent.yMinimum() + ( cellSizeY * height );
  geoTransform[4] = 0;
  geoTransform[5] = -cellSizeY;
 
  GDALDriverH hDriver = GDALGetDriverByName( "GTiff" );
  if ( !hDriver )
  {
    return gdal::dataset_unique_ptr();
  }
 
  // Create the output file.
  gdal::dataset_unique_ptr hDstDS( GDALCreate( hDriver, filename.toLocal8Bit().constData(), width, height, 1, dataType, nullptr ) );
  if ( !hDstDS )
  {
    return gdal::dataset_unique_ptr();
  }
 
  // Write out the projection definition.
  GDALSetProjection( hDstDS.get(), crs.toWkt( QgsCoordinateReferenceSystem::WKT_PREFERRED_GDAL ).toLatin1().constData() );
  GDALSetGeoTransform( hDstDS.get(), geoTransform );
  return hDstDS;
}
 
gdal::dataset_unique_ptr QgsGdalUtils::imageToMemoryDataset( const QImage &image )
{
  if ( image.isNull() )
    return nullptr;
 
  const QRgb *rgb = reinterpret_cast<const QRgb *>( image.constBits() );
  GDALDriverH hDriverMem = GDALGetDriverByName( "MEM" );
  if ( !hDriverMem )
  {
    return nullptr;
  }
  gdal::dataset_unique_ptr hSrcDS( GDALCreate( hDriverMem, "",  image.width(), image.height(), 0, GDT_Byte, nullptr ) );
 
  char **papszOptions = QgsGdalUtils::papszFromStringList( QStringList()
                        << QStringLiteral( "PIXELOFFSET=%1" ).arg( sizeof( QRgb ) )
                        << QStringLiteral( "LINEOFFSET=%1" ).arg( image.bytesPerLine() )
                        << QStringLiteral( "DATAPOINTER=%1" ).arg( reinterpret_cast< qulonglong >( rgb ) + 2 ) );
  GDALAddBand( hSrcDS.get(), GDT_Byte, papszOptions );
  CSLDestroy( papszOptions );
 
  papszOptions = QgsGdalUtils::papszFromStringList( QStringList()
                 << QStringLiteral( "PIXELOFFSET=%1" ).arg( sizeof( QRgb ) )
                 << QStringLiteral( "LINEOFFSET=%1" ).arg( image.bytesPerLine() )
                 << QStringLiteral( "DATAPOINTER=%1" ).arg( reinterpret_cast< qulonglong >( rgb ) + 1 ) );
  GDALAddBand( hSrcDS.get(), GDT_Byte, papszOptions );
  CSLDestroy( papszOptions );
 
  papszOptions = QgsGdalUtils::papszFromStringList( QStringList()
                 << QStringLiteral( "PIXELOFFSET=%1" ).arg( sizeof( QRgb ) )
                 << QStringLiteral( "LINEOFFSET=%1" ).arg( image.bytesPerLine() )
                 << QStringLiteral( "DATAPOINTER=%1" ).arg( reinterpret_cast< qulonglong >( rgb ) ) );
  GDALAddBand( hSrcDS.get(), GDT_Byte, papszOptions );
  CSLDestroy( papszOptions );
 
  papszOptions = QgsGdalUtils::papszFromStringList( QStringList()
                 << QStringLiteral( "PIXELOFFSET=%1" ).arg( sizeof( QRgb ) )
                 << QStringLiteral( "LINEOFFSET=%1" ).arg( image.bytesPerLine() )
                 << QStringLiteral( "DATAPOINTER=%1" ).arg( reinterpret_cast< qulonglong >( rgb ) + 3 ) );
  GDALAddBand( hSrcDS.get(), GDT_Byte, papszOptions );
  CSLDestroy( papszOptions );
 
  return hSrcDS;
}
 
bool QgsGdalUtils::resampleSingleBandRaster( GDALDatasetH hSrcDS, GDALDatasetH hDstDS, GDALResampleAlg resampleAlg, const char *pszCoordinateOperation )
{
  gdal::warp_options_unique_ptr psWarpOptions( GDALCreateWarpOptions() );
  psWarpOptions->hSrcDS = hSrcDS;
  psWarpOptions->hDstDS = hDstDS;
 
  psWarpOptions->nBandCount = 1;
  psWarpOptions->panSrcBands = reinterpret_cast< int * >( CPLMalloc( sizeof( int ) * 1 ) );
  psWarpOptions->panDstBands = reinterpret_cast< int * >( CPLMalloc( sizeof( int ) * 1 ) );
  psWarpOptions->panSrcBands[0] = 1;
  psWarpOptions->panDstBands[0] = 1;
 
  psWarpOptions->eResampleAlg = resampleAlg;
 
  // Establish reprojection transformer.
  char **papszOptions = nullptr;
  if ( pszCoordinateOperation != nullptr )
    papszOptions = CSLSetNameValue( papszOptions, "COORDINATE_OPERATION", pszCoordinateOperation );
  psWarpOptions->pTransformerArg = GDALCreateGenImgProjTransformer2( hSrcDS, hDstDS, papszOptions );
  CSLDestroy( papszOptions );
 
  if ( ! psWarpOptions->pTransformerArg )
  {
    return false;
  }
 
  psWarpOptions->pfnTransformer = GDALGenImgProjTransform;
 
  // Initialize and execute the warp operation.
  GDALWarpOperation oOperation;
  oOperation.Initialize( psWarpOptions.get() );
 
  const bool retVal { oOperation.ChunkAndWarpImage( 0, 0, GDALGetRasterXSize( hDstDS ), GDALGetRasterYSize( hDstDS ) ) == CE_None };
  GDALDestroyGenImgProjTransformer( psWarpOptions->pTransformerArg );
  return retVal;
}
 
QImage QgsGdalUtils::resampleImage( const QImage &image, QSize outputSize, GDALRIOResampleAlg resampleAlg )
{
  gdal::dataset_unique_ptr srcDS = QgsGdalUtils::imageToMemoryDataset( image );
  if ( !srcDS )
    return QImage();
 
  GDALRasterIOExtraArg extra;
  INIT_RASTERIO_EXTRA_ARG( extra );
  extra.eResampleAlg = resampleAlg;
 
  QImage res( outputSize, image.format() );
  if ( res.isNull() )
    return QImage();
 
  GByte *rgb = reinterpret_cast<GByte *>( res.bits() );
 
  CPLErr err = GDALRasterIOEx( GDALGetRasterBand( srcDS.get(), 1 ), GF_Read, 0, 0, image.width(), image.height(), rgb + 2, outputSize.width(),
                               outputSize.height(), GDT_Byte, sizeof( QRgb ), res.bytesPerLine(), &extra );
  if ( err != CE_None )
  {
    QgsDebugMsg( QStringLiteral( "failed to read red band" ) );
    return QImage();
  }
 
  err = GDALRasterIOEx( GDALGetRasterBand( srcDS.get(), 2 ), GF_Read, 0, 0, image.width(), image.height(), rgb + 1, outputSize.width(),
                        outputSize.height(), GDT_Byte, sizeof( QRgb ), res.bytesPerLine(), &extra );
  if ( err != CE_None )
  {
    QgsDebugMsg( QStringLiteral( "failed to read green band" ) );
    return QImage();
  }
 
  err = GDALRasterIOEx( GDALGetRasterBand( srcDS.get(), 3 ), GF_Read, 0, 0, image.width(), image.height(), rgb, outputSize.width(),
                        outputSize.height(), GDT_Byte, sizeof( QRgb ), res.bytesPerLine(), &extra );
  if ( err != CE_None )
  {
    QgsDebugMsg( QStringLiteral( "failed to read blue band" ) );
    return QImage();
  }
 
  err = GDALRasterIOEx( GDALGetRasterBand( srcDS.get(), 4 ), GF_Read, 0, 0, image.width(), image.height(), rgb + 3, outputSize.width(),
                        outputSize.height(), GDT_Byte, sizeof( QRgb ), res.bytesPerLine(), &extra );
  if ( err != CE_None )
  {
    QgsDebugMsg( QStringLiteral( "failed to read alpha band" ) );
    return QImage();
  }
 
  return res;
}
 
QString QgsGdalUtils::helpCreationOptionsFormat( const QString &format )
{
  QString message;
  GDALDriverH myGdalDriver = GDALGetDriverByName( format.toLocal8Bit().constData() );
  if ( myGdalDriver )
  {
    // first report details and help page
    char **GDALmetadata = GDALGetMetadata( myGdalDriver, nullptr );
    message += QLatin1String( "Format Details:\n" );
    message += QStringLiteral( "  Extension: %1\n" ).arg( CSLFetchNameValue( GDALmetadata, GDAL_DMD_EXTENSION ) );
    message += QStringLiteral( "  Short Name: %1" ).arg( GDALGetDriverShortName( myGdalDriver ) );
    message += QStringLiteral( "  /  Long Name: %1\n" ).arg( GDALGetDriverLongName( myGdalDriver ) );
    message += QStringLiteral( "  Help page:  http://www.gdal.org/%1\n\n" ).arg( CSLFetchNameValue( GDALmetadata, GDAL_DMD_HELPTOPIC ) );
 
    // next get creation options
    // need to serialize xml to get newlines, should we make the basic xml prettier?
    CPLXMLNode *psCOL = CPLParseXMLString( GDALGetMetadataItem( myGdalDriver,
                                           GDAL_DMD_CREATIONOPTIONLIST, "" ) );
    char *pszFormattedXML = CPLSerializeXMLTree( psCOL );
    if ( pszFormattedXML )
      message += QString( pszFormattedXML );
    if ( psCOL )
      CPLDestroyXMLNode( psCOL );
    if ( pszFormattedXML )
      CPLFree( pszFormattedXML );
  }
  return message;
}
 
char **QgsGdalUtils::papszFromStringList( const QStringList &list )
{
  char **papszRetList = nullptr;
  const auto constList = list;
  for ( const QString &elem : constList )
  {
    papszRetList = CSLAddString( papszRetList, elem.toLocal8Bit().constData() );
  }
  return papszRetList;
}
 
QString QgsGdalUtils::validateCreationOptionsFormat( const QStringList &createOptions, const QString &format )
{
  GDALDriverH myGdalDriver = GDALGetDriverByName( format.toLocal8Bit().constData() );
  if ( ! myGdalDriver )
    return QStringLiteral( "invalid GDAL driver" );
 
  char **papszOptions = papszFromStringList( createOptions );
  // get error string?
  int ok = GDALValidateCreationOptions( myGdalDriver, papszOptions );
  CSLDestroy( papszOptions );
 
  if ( !ok )
    return QStringLiteral( "Failed GDALValidateCreationOptions() test" );
  return QString();
}
 
#if GDAL_VERSION_NUM < GDAL_COMPUTE_VERSION(2,3,0)
// GDAL < 2.3 does not come with GDALWarpInitDefaultBandMapping and GDALWarpInitNoDataReal
// in the public API so we define them here for rpcAwareAutoCreateWarpedVrt()
 
static void GDALWarpInitDefaultBandMapping( GDALWarpOptions *psOptionsIn, int nBandCount )
{
  if ( psOptionsIn->nBandCount != 0 ) { return; }
 
  psOptionsIn->nBandCount = nBandCount;
 
  psOptionsIn->panSrcBands = static_cast<int *>(
                               CPLMalloc( sizeof( int ) * psOptionsIn->nBandCount ) );
  psOptionsIn->panDstBands = static_cast<int *>(
                               CPLMalloc( sizeof( int ) * psOptionsIn->nBandCount ) );
 
  for ( int i = 0; i < psOptionsIn->nBandCount; i++ )
  {
    psOptionsIn->panSrcBands[i] = i + 1;
    psOptionsIn->panDstBands[i] = i + 1;
  }
}
 
static void InitNoData( int nBandCount, double **ppdNoDataReal, double dDataReal )
{
  if ( nBandCount <= 0 ) { return; }
  if ( *ppdNoDataReal != nullptr ) { return; }
 
  *ppdNoDataReal = static_cast<double *>(
                     CPLMalloc( sizeof( double ) * nBandCount ) );
 
  for ( int i = 0; i < nBandCount; ++i )
  {
    ( *ppdNoDataReal )[i] = dDataReal;
  }
}
 
static void GDALWarpInitNoDataReal( GDALWarpOptions *psOptionsIn, double  dNoDataReal )
{
  InitNoData( psOptionsIn->nBandCount, &psOptionsIn->padfDstNoDataReal, dNoDataReal );
  InitNoData( psOptionsIn->nBandCount, &psOptionsIn->padfSrcNoDataReal, dNoDataReal );
  // older GDAL also requires imaginary values to be set
  InitNoData( psOptionsIn->nBandCount, &psOptionsIn->padfDstNoDataImag, 0 );
  InitNoData( psOptionsIn->nBandCount, &psOptionsIn->padfSrcNoDataImag, 0 );
}
#endif
 
#if GDAL_VERSION_NUM < GDAL_COMPUTE_VERSION(3,2,0)
 
GDALDatasetH GDALAutoCreateWarpedVRTEx( GDALDatasetH hSrcDS, const char *pszSrcWKT, const char *pszDstWKT, GDALResampleAlg eResampleAlg,
                                        double dfMaxError, const GDALWarpOptions *psOptionsIn, char **papszTransformerOptions )
{
  VALIDATE_POINTER1( hSrcDS, "GDALAutoCreateWarpedVRT", nullptr );
 
  /* -------------------------------------------------------------------- */
  /*      Populate the warp options.                                      */
  /* -------------------------------------------------------------------- */
  GDALWarpOptions *psWO = nullptr;
  if ( psOptionsIn != nullptr )
    psWO = GDALCloneWarpOptions( psOptionsIn );
  else
    psWO = GDALCreateWarpOptions();
 
  psWO->eResampleAlg = eResampleAlg;
 
  psWO->hSrcDS = hSrcDS;
 
  GDALWarpInitDefaultBandMapping( psWO, GDALGetRasterCount( hSrcDS ) );
 
  /* -------------------------------------------------------------------- */
  /*      Setup no data values                                            */
  /* -------------------------------------------------------------------- */
  for ( int i = 0; i < psWO->nBandCount; i++ )
  {
    GDALRasterBandH rasterBand = GDALGetRasterBand( psWO->hSrcDS, psWO->panSrcBands[i] );
 
    int hasNoDataValue;
    double noDataValue = GDALGetRasterNoDataValue( rasterBand, &hasNoDataValue );
 
    if ( hasNoDataValue )
    {
      // Check if the nodata value is out of range
      int bClamped = FALSE;
      int bRounded = FALSE;
      CPL_IGNORE_RET_VAL(
        GDALAdjustValueToDataType( GDALGetRasterDataType( rasterBand ),
                                   noDataValue, &bClamped, &bRounded ) );
      if ( !bClamped )
      {
        GDALWarpInitNoDataReal( psWO, -1e10 );
 
        psWO->padfSrcNoDataReal[i] = noDataValue;
        psWO->padfDstNoDataReal[i] = noDataValue;
      }
    }
  }
 
  if ( psWO->padfDstNoDataReal != nullptr )
  {
    if ( CSLFetchNameValue( psWO->papszWarpOptions, "INIT_DEST" ) == nullptr )
    {
      psWO->papszWarpOptions =
        CSLSetNameValue( psWO->papszWarpOptions, "INIT_DEST", "NO_DATA" );
    }
  }
 
  /* -------------------------------------------------------------------- */
  /*      Create the transformer.                                         */
  /* -------------------------------------------------------------------- */
  psWO->pfnTransformer = GDALGenImgProjTransform;
 
  char **papszOptions = nullptr;
  if ( pszSrcWKT != nullptr )
    papszOptions = CSLSetNameValue( papszOptions, "SRC_SRS", pszSrcWKT );
  if ( pszDstWKT != nullptr )
    papszOptions = CSLSetNameValue( papszOptions, "DST_SRS", pszDstWKT );
  papszOptions = CSLMerge( papszOptions, papszTransformerOptions );
  psWO->pTransformerArg =
    GDALCreateGenImgProjTransformer2( psWO->hSrcDS, nullptr,
                                      papszOptions );
  CSLDestroy( papszOptions );
 
  if ( psWO->pTransformerArg == nullptr )
  {
    GDALDestroyWarpOptions( psWO );
    return nullptr;
  }
 
  /* -------------------------------------------------------------------- */
  /*      Figure out the desired output bounds and resolution.            */
  /* -------------------------------------------------------------------- */
  double adfDstGeoTransform[6] = { 0.0 };
  int nDstPixels = 0;
  int nDstLines = 0;
  CPLErr eErr =
    GDALSuggestedWarpOutput( hSrcDS, psWO->pfnTransformer,
                             psWO->pTransformerArg,
                             adfDstGeoTransform, &nDstPixels, &nDstLines );
  if ( eErr != CE_None )
  {
    GDALDestroyTransformer( psWO->pTransformerArg );
    GDALDestroyWarpOptions( psWO );
    return nullptr;
  }
 
  /* -------------------------------------------------------------------- */
  /*      Update the transformer to include an output geotransform        */
  /*      back to pixel/line coordinates.                                 */
  /*                                                                      */
  /* -------------------------------------------------------------------- */
  GDALSetGenImgProjTransformerDstGeoTransform(
    psWO->pTransformerArg, adfDstGeoTransform );
 
  /* -------------------------------------------------------------------- */
  /*      Do we want to apply an approximating transformation?            */
  /* -------------------------------------------------------------------- */
  if ( dfMaxError > 0.0 )
  {
    psWO->pTransformerArg =
      GDALCreateApproxTransformer( psWO->pfnTransformer,
                                   psWO->pTransformerArg,
                                   dfMaxError );
    psWO->pfnTransformer = GDALApproxTransform;
    GDALApproxTransformerOwnsSubtransformer( psWO->pTransformerArg, TRUE );
  }
 
  /* -------------------------------------------------------------------- */
  /*      Create the VRT file.                                            */
  /* -------------------------------------------------------------------- */
  GDALDatasetH hDstDS
    = GDALCreateWarpedVRT( hSrcDS, nDstPixels, nDstLines,
                           adfDstGeoTransform, psWO );
 
  GDALDestroyWarpOptions( psWO );
 
  if ( pszDstWKT != nullptr )
    GDALSetProjection( hDstDS, pszDstWKT );
  else if ( pszSrcWKT != nullptr )
    GDALSetProjection( hDstDS, pszSrcWKT );
  else if ( GDALGetGCPCount( hSrcDS ) > 0 )
    GDALSetProjection( hDstDS, GDALGetGCPProjection( hSrcDS ) );
  else
    GDALSetProjection( hDstDS, GDALGetProjectionRef( hSrcDS ) );
 
  return hDstDS;
}
#endif
 
 
GDALDatasetH QgsGdalUtils::rpcAwareAutoCreateWarpedVrt(
  GDALDatasetH hSrcDS,
  const char *pszSrcWKT,
  const char *pszDstWKT,
  GDALResampleAlg eResampleAlg,
  double dfMaxError,
  const GDALWarpOptions *psOptionsIn )
{
  char **opts = nullptr;
  if ( GDALGetMetadata( hSrcDS, "RPC" ) )
  {
    // well-behaved RPC should have height offset a good value for RPC_HEIGHT
    const char *heightOffStr = GDALGetMetadataItem( hSrcDS, "HEIGHT_OFF", "RPC" );
    if ( heightOffStr )
      opts = CSLAddNameValue( opts, "RPC_HEIGHT", heightOffStr );
  }
 
  return GDALAutoCreateWarpedVRTEx( hSrcDS, pszSrcWKT, pszDstWKT, eResampleAlg, dfMaxError, psOptionsIn, opts );
}
 
void *QgsGdalUtils::rpcAwareCreateTransformer( GDALDatasetH hSrcDS, GDALDatasetH hDstDS, char **papszOptions )
{
  char **opts = CSLDuplicate( papszOptions );
  if ( GDALGetMetadata( hSrcDS, "RPC" ) )
  {
    // well-behaved RPC should have height offset a good value for RPC_HEIGHT
    const char *heightOffStr = GDALGetMetadataItem( hSrcDS, "HEIGHT_OFF", "RPC" );
    if ( heightOffStr )
      opts = CSLAddNameValue( opts, "RPC_HEIGHT", heightOffStr );
  }
  void *transformer = GDALCreateGenImgProjTransformer2( hSrcDS, hDstDS, opts );
  CSLDestroy( opts );
  return transformer;
}
 
#ifndef QT_NO_NETWORKPROXY
void QgsGdalUtils::setupProxy()
{
  // Check proxy configuration, they are application level but
  // instead of adding an API and complex signal/slot connections
  // given the limited cost of checking them on every provider instantiation
  // we can do it here so that new settings are applied whenever a new layer
  // is created.
  QgsSettings settings;
  // Check that proxy is enabled
  if ( settings.value( QStringLiteral( "proxy/proxyEnabled" ), false ).toBool() )
  {
    // Get the first configured proxy
    QList<QNetworkProxy> proxies( QgsNetworkAccessManager::instance()->proxyFactory()->queryProxy( ) );
    if ( ! proxies.isEmpty() )
    {
      QNetworkProxy proxy( proxies.first() );
      // TODO/FIXME: check excludes (the GDAL config options are global, we need a per-connection config option)
      //QStringList excludes;
      //excludes = settings.value( QStringLiteral( "proxy/proxyExcludedUrls" ), "" ).toStringList();
 
      QString proxyHost( proxy.hostName() );
      qint16 proxyPort( proxy.port() );
 
      QString proxyUser( proxy.user() );
      QString proxyPassword( proxy.password() );
 
      if ( ! proxyHost.isEmpty() )
      {
        QString connection( proxyHost );
        if ( proxyPort )
        {
          connection += ':' +  QString::number( proxyPort );
        }
        CPLSetConfigOption( "GDAL_HTTP_PROXY", connection.toUtf8() );
        if ( !  proxyUser.isEmpty( ) )
        {
          QString credentials( proxyUser );
          if ( !  proxyPassword.isEmpty( ) )
          {
            credentials += ':' + proxyPassword;
          }
          CPLSetConfigOption( "GDAL_HTTP_PROXYUSERPWD", credentials.toUtf8() );
        }
      }
    }
  }
}
#endif