qgsgdalutils.cpp

Go to the documentation of this file.

/***************************************************************************
                             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"

#define CPL_SUPRESS_CPLUSPLUS  //#spellok
#include "gdal.h"
#include "cpl_string.h"

#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::WKT2_2018 ).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::WKT2_2018 ).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;
}

void QgsGdalUtils::resampleSingleBandRaster( GDALDatasetH hSrcDS, GDALDatasetH hDstDS, GDALResampleAlg resampleAlg )
{
  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.
  psWarpOptions->pTransformerArg =
    GDALCreateGenImgProjTransformer( hSrcDS, GDALGetProjectionRef( hSrcDS ),
                                     hDstDS, GDALGetProjectionRef( hDstDS ),
                                     FALSE, 0.0, 1 );
  psWarpOptions->pfnTransformer = GDALGenImgProjTransform;

  // Initialize and execute the warp operation.
  GDALWarpOperation oOperation;
  oOperation.Initialize( psWarpOptions.get() );

  oOperation.ChunkAndWarpImage( 0, 0, GDALGetRasterXSize( hDstDS ), GDALGetRasterYSize( hDstDS ) );

  GDALDestroyGenImgProjTransformer( psWarpOptions->pTransformerArg );
}

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();
}