Split qgscoordinatetransform_p into .h/cpp

src/core/CMakeLists.txt

@@ -128,6 +128,7 @@ SET(QGIS_CORE_SRCS
   qgscontexthelp.cpp
   qgscoordinatereferencesystem.cpp
   qgscoordinatetransform.cpp
+  qgscoordinatetransform_p.cpp
   qgscoordinateutils.cpp
   qgscredentials.cpp
   qgscrscache.cpp

src/core/qgscoordinatetransform_p.cpp

@@ -0,0 +1,312 @@
+/***************************************************************************
+               qgscoordinatetransform_p.cpp
+               ----------------------------
+    begin                : May 2017
+    copyright            : (C) 2017 Nyall Dawson
+    email                : nyall dot dawson at gmail dot 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 "qgscoordinatetransform_p.h"
+#include "qgslogger.h"
+#include "qgsapplication.h"
+
+extern "C"
+{
+#include <proj_api.h>
+}
+#include <sqlite3.h>
+
+#include <QStringList>
+
+/// @cond PRIVATE
+
+QgsCoordinateTransformPrivate::QgsCoordinateTransformPrivate()
+  : mIsValid( false )
+  , mShortCircuit( false )
+  , mSourceProjection( nullptr )
+  , mDestinationProjection( nullptr )
+  , mSourceDatumTransform( -1 )
+  , mDestinationDatumTransform( -1 )
+{
+  setFinder();
+}
+
+QgsCoordinateTransformPrivate::QgsCoordinateTransformPrivate( const QgsCoordinateReferenceSystem &source, const QgsCoordinateReferenceSystem &destination )
+  : mIsValid( false )
+  , mShortCircuit( false )
+  , mSourceCRS( source )
+  , mDestCRS( destination )
+  , mSourceProjection( nullptr )
+  , mDestinationProjection( nullptr )
+  , mSourceDatumTransform( -1 )
+  , mDestinationDatumTransform( -1 )
+{
+  setFinder();
+  initialize();
+}
+
+QgsCoordinateTransformPrivate::QgsCoordinateTransformPrivate( const QgsCoordinateTransformPrivate &other )
+  : QSharedData( other )
+  , mIsValid( other.mIsValid )
+  , mShortCircuit( other.mShortCircuit )
+  , mSourceCRS( other.mSourceCRS )
+  , mDestCRS( other.mDestCRS )
+  , mSourceProjection( nullptr )
+  , mDestinationProjection( nullptr )
+  , mSourceDatumTransform( other.mSourceDatumTransform )
+  , mDestinationDatumTransform( other.mDestinationDatumTransform )
+{
+  //must reinitialize to setup mSourceProjection and mDestinationProjection
+  initialize();
+}
+
+QgsCoordinateTransformPrivate::~QgsCoordinateTransformPrivate()
+{
+  // free the proj objects
+  if ( mSourceProjection )
+  {
+    pj_free( mSourceProjection );
+  }
+  if ( mDestinationProjection )
+  {
+    pj_free( mDestinationProjection );
+  }
+}
+
+bool QgsCoordinateTransformPrivate::initialize()
+{
+  mShortCircuit = true;
+  mIsValid = false;
+
+  if ( !mSourceCRS.isValid() )
+  {
+    // Pass through with no projection since we have no idea what the layer
+    // coordinates are and projecting them may not be appropriate
+    QgsDebugMsgLevel( "Source CRS is invalid!", 4 );
+    return false;
+  }
+
+  if ( !mDestCRS.isValid() )
+  {
+    //No destination projection is set so we set the default output projection to
+    //be the same as input proj.
+    mDestCRS = mSourceCRS;
+    QgsDebugMsgLevel( "Destination CRS is invalid!", 4 );
+    return false;
+  }
+
+  mIsValid = true;
+
+  bool useDefaultDatumTransform = ( mSourceDatumTransform == - 1 && mDestinationDatumTransform == -1 );
+
+  // init the projections (destination and source)
+
+  pj_free( mSourceProjection );
+  QString sourceProjString = mSourceCRS.toProj4();
+  if ( !useDefaultDatumTransform )
+  {
+    sourceProjString = stripDatumTransform( sourceProjString );
+  }
+  if ( mSourceDatumTransform != -1 )
+  {
+    sourceProjString += ( ' ' + datumTransformString( mSourceDatumTransform ) );
+  }
+
+  pj_free( mDestinationProjection );
+  QString destProjString = mDestCRS.toProj4();
+  if ( !useDefaultDatumTransform )
+  {
+    destProjString = stripDatumTransform( destProjString );
+  }
+  if ( mDestinationDatumTransform != -1 )
+  {
+    destProjString += ( ' ' +  datumTransformString( mDestinationDatumTransform ) );
+  }
+
+  if ( !useDefaultDatumTransform )
+  {
+    addNullGridShifts( sourceProjString, destProjString );
+  }
+
+  mSourceProjection = pj_init_plus( sourceProjString.toUtf8() );
+  mDestinationProjection = pj_init_plus( destProjString.toUtf8() );
+
+#ifdef COORDINATE_TRANSFORM_VERBOSE
+  QgsDebugMsg( "From proj : " + mSourceCRS.toProj4() );
+  QgsDebugMsg( "To proj   : " + mDestCRS.toProj4() );
+#endif
+
+  if ( !mDestinationProjection || !mSourceProjection )
+  {
+    mIsValid = false;
+  }
+
+#ifdef COORDINATE_TRANSFORM_VERBOSE
+  if ( mIsValid )
+  {
+    QgsDebugMsg( "------------------------------------------------------------" );
+    QgsDebugMsg( "The OGR Coordinate transformation for this layer was set to" );
+    QgsLogger::debug<QgsCoordinateReferenceSystem>( "Input", mSourceCRS, __FILE__, __FUNCTION__, __LINE__ );
+    QgsLogger::debug<QgsCoordinateReferenceSystem>( "Output", mDestCRS, __FILE__, __FUNCTION__, __LINE__ );
+    QgsDebugMsg( "------------------------------------------------------------" );
+  }
+  else
+  {
+    QgsDebugMsg( "------------------------------------------------------------" );
+    QgsDebugMsg( "The OGR Coordinate transformation FAILED TO INITIALIZE!" );
+    QgsDebugMsg( "------------------------------------------------------------" );
+  }
+#else
+  if ( !mIsValid )
+  {
+    QgsDebugMsg( "Coordinate transformation failed to initialize!" );
+  }
+#endif
+
+  //XXX todo overload == operator for QgsCoordinateReferenceSystem
+  //at the moment srs.parameters contains the whole proj def...soon it won't...
+  //if (mSourceCRS->toProj4() == mDestCRS->toProj4())
+  if ( mSourceCRS == mDestCRS )
+  {
+    // If the source and destination projection are the same, set the short
+    // circuit flag (no transform takes place)
+    mShortCircuit = true;
+    QgsDebugMsgLevel( "Source/Dest CRS equal, shortcircuit is set.", 3 );
+  }
+  else
+  {
+    // Transform must take place
+    mShortCircuit = false;
+    QgsDebugMsgLevel( "Source/Dest CRS not equal, shortcircuit is not set.", 3 );
+  }
+  return mIsValid;
+}
+
+QString QgsCoordinateTransformPrivate::stripDatumTransform( const QString &proj4 ) const
+{
+  QStringList parameterSplit = proj4.split( '+', QString::SkipEmptyParts );
+  QString currentParameter;
+  QString newProjString;
+
+  for ( int i = 0; i < parameterSplit.size(); ++i )
+  {
+    currentParameter = parameterSplit.at( i );
+    if ( !currentParameter.startsWith( QLatin1String( "towgs84" ), Qt::CaseInsensitive )
+         && !currentParameter.startsWith( QLatin1String( "nadgrids" ), Qt::CaseInsensitive ) )
+    {
+      newProjString.append( '+' );
+      newProjString.append( currentParameter );
+      newProjString.append( ' ' );
+    }
+  }
+  return newProjString;
+}
+
+QString QgsCoordinateTransformPrivate::datumTransformString( int datumTransform )
+{
+  QString transformString;
+
+  sqlite3 *db = nullptr;
+  int openResult = sqlite3_open_v2( QgsApplication::srsDatabaseFilePath().toUtf8().constData(), &db, SQLITE_OPEN_READONLY, 0 );
+  if ( openResult != SQLITE_OK )
+  {
+    sqlite3_close( db );
+    return transformString;
+  }
+
+  sqlite3_stmt *stmt = nullptr;
+  QString sql = QStringLiteral( "SELECT coord_op_method_code,p1,p2,p3,p4,p5,p6,p7 FROM tbl_datum_transform WHERE coord_op_code=%1" ).arg( datumTransform );
+  int prepareRes = sqlite3_prepare( db, sql.toLatin1(), sql.size(), &stmt, nullptr );
+  if ( prepareRes != SQLITE_OK )
+  {
+    sqlite3_finalize( stmt );
+    sqlite3_close( db );
+    return transformString;
+  }
+
+  if ( sqlite3_step( stmt ) == SQLITE_ROW )
+  {
+    //coord_op_methode_code
+    int methodCode = sqlite3_column_int( stmt, 0 );
+    if ( methodCode == 9615 ) //ntv2
+    {
+      transformString = "+nadgrids=" + QString( reinterpret_cast< const char * >( sqlite3_column_text( stmt, 1 ) ) );
+    }
+    else if ( methodCode == 9603 || methodCode == 9606 || methodCode == 9607 )
+    {
+      transformString += QLatin1String( "+towgs84=" );
+      double p1 = sqlite3_column_double( stmt, 1 );
+      double p2 = sqlite3_column_double( stmt, 2 );
+      double p3 = sqlite3_column_double( stmt, 3 );
+      double p4 = sqlite3_column_double( stmt, 4 );
+      double p5 = sqlite3_column_double( stmt, 5 );
+      double p6 = sqlite3_column_double( stmt, 6 );
+      double p7 = sqlite3_column_double( stmt, 7 );
+      if ( methodCode == 9603 ) //3 parameter transformation
+      {
+        transformString += QStringLiteral( "%1,%2,%3" ).arg( p1 ).arg( p2 ).arg( p3 );
+      }
+      else //7 parameter transformation
+      {
+        transformString += QStringLiteral( "%1,%2,%3,%4,%5,%6,%7" ).arg( p1 ).arg( p2 ).arg( p3 ).arg( p4 ).arg( p5 ).arg( p6 ).arg( p7 );
+      }
+    }
+  }
+
+  sqlite3_finalize( stmt );
+  sqlite3_close( db );
+  return transformString;
+}
+
+void QgsCoordinateTransformPrivate::addNullGridShifts( QString &srcProjString, QString &destProjString ) const
+{
+  //if one transformation uses ntv2, the other one needs to be null grid shift
+  if ( mDestinationDatumTransform == -1 && srcProjString.contains( QLatin1String( "+nadgrids" ) ) ) //add null grid if source transformation is ntv2
+  {
+    destProjString += QLatin1String( " +nadgrids=@null" );
+    return;
+  }
+  if ( mSourceDatumTransform == -1 && destProjString.contains( QLatin1String( "+nadgrids" ) ) )
+  {
+    srcProjString += QLatin1String( " +nadgrids=@null" );
+    return;
+  }
+
+  //add null shift grid for google mercator
+  //(see e.g. http://trac.osgeo.org/proj/wiki/FAQ#ChangingEllipsoidWhycantIconvertfromWGS84toGoogleEarthVirtualGlobeMercator)
+  if ( mSourceCRS.authid().compare( QLatin1String( "EPSG:3857" ), Qt::CaseInsensitive ) == 0 && mSourceDatumTransform == -1 )
+  {
+    srcProjString += QLatin1String( " +nadgrids=@null" );
+  }
+  if ( mDestCRS.authid().compare( QLatin1String( "EPSG:3857" ), Qt::CaseInsensitive ) == 0 && mDestinationDatumTransform == -1 )
+  {
+    destProjString += QLatin1String( " +nadgrids=@null" );
+  }
+}
+
+void QgsCoordinateTransformPrivate::setFinder()
+{
+#if 0
+  // Attention! It should be possible to set PROJ_LIB
+  // but it can happen that it was previously set by installer
+  // (version 0.7) and the old installation was deleted
+
+  // Another problem: PROJ checks if pj_finder was set before
+  // PROJ_LIB environment variable. pj_finder is probably set in
+  // GRASS gproj library when plugin is loaded, consequently
+  // PROJ_LIB is ignored
+
+  pj_set_finder( finder );
+#endif
+}
+
+///@endcond