Add method to get SingleCrs from crs

nyalldawson · nyalldawson · commit 1fac288e29ce · 2019-05-13T10:38:26.000+10:00
diff --git a/src/core/qgscoordinatereferencesystem.cpp b/src/core/qgscoordinatereferencesystem.cpp
@@ -533,15 +533,9 @@ bool QgsCoordinateReferenceSystem::loadFromDatabase( const QString &db, const QS
       QString auth = parts.at( 0 );
       QString code = parts.at( 1 );
 
-      QgsProjUtils::proj_pj_unique_ptr crs( proj_create_from_database( QgsProjContext::get(), auth.toLatin1(), code.toLatin1(), PJ_CATEGORY_CRS, false, nullptr ) );
-      if ( crs && proj_get_type( crs.get() ) == PJ_TYPE_COMPOUND_CRS )
       {
-        // freaking take a guess that 0 is horizontal, because we are only mortal
-        d->mPj.reset( proj_crs_get_sub_crs( QgsProjContext::get(), crs.get(), 0 ) );
-      }
-      else
-      {
-        d->mPj = std::move( crs );
+        QgsProjUtils::proj_pj_unique_ptr crs( proj_create_from_database( QgsProjContext::get(), auth.toLatin1(), code.toLatin1(), PJ_CATEGORY_CRS, false, nullptr ) );
+        d->mPj = QgsProjUtils::crsToSingleCrs( crs.get() );
       }
 
       d->mIsValid = static_cast< bool >( d->mPj );
@@ -625,15 +619,9 @@ bool QgsCoordinateReferenceSystem::createFromWkt( const QString &wkt )
   PROJ_STRING_LIST warnings = nullptr;
   PROJ_STRING_LIST grammerErrors = nullptr;
 
-  QgsProjUtils::proj_pj_unique_ptr crs( proj_create_from_wkt( QgsProjContext::get(), wkt.toLatin1().constData(), nullptr, &warnings, &grammerErrors ) );
-  if ( crs && proj_get_type( crs.get() ) == PJ_TYPE_COMPOUND_CRS )
-  {
-    // freaking take a guess that 0 is horizontal, because we are only mortal
-    d->mPj.reset( proj_crs_get_sub_crs( QgsProjContext::get(), crs.get(), 0 ) );
-  }
-  else
   {
-    d->mPj = std::move( crs );
+    QgsProjUtils::proj_pj_unique_ptr crs( proj_create_from_wkt( QgsProjContext::get(), wkt.toLatin1().constData(), nullptr, &warnings, &grammerErrors ) );
+    d->mPj = QgsProjUtils::crsToSingleCrs( crs.get() );
   }
 
   res = static_cast< bool >( d->mPj );
@@ -1232,20 +1220,14 @@ void QgsCoordinateReferenceSystem::setProj4String( const QString &proj4String )
   d->mProj4 = proj4String;
 
   QgsLocaleNumC l;
-  const QString trimmed = proj4String.trimmed();
+  const QString trimmed = proj4String.trimmed() + QStringLiteral( " +type=crs" );
 
 #if PROJ_VERSION_MAJOR>=6
   PJ_CONTEXT *ctx = QgsProjContext::get();
 
-  QgsProjUtils::proj_pj_unique_ptr crs( proj_create( ctx, trimmed.toLatin1().constData() ) );
-  if ( crs && proj_get_type( crs.get() ) == PJ_TYPE_COMPOUND_CRS )
   {
-    // freaking take a guess that 0 is horizontal, because we are only mortal
-    d->mPj.reset( proj_crs_get_sub_crs( QgsProjContext::get(), crs.get(), 0 ) );
-  }
-  else
-  {
-    d->mPj = std::move( crs );
+    QgsProjUtils::proj_pj_unique_ptr crs( proj_create( ctx, trimmed.toLatin1().constData() ) );
+    d->mPj = QgsProjUtils::crsToSingleCrs( crs.get() );
   }
 
   if ( !d->mPj )
@@ -2128,6 +2110,17 @@ int QgsCoordinateReferenceSystem::syncDatabase()
         continue;
       }
 
+      switch ( proj_get_type( crs.get() ) )
+      {
+        case PJ_TYPE_VERTICAL_CRS: // don't need these in the CRS db
+          continue;
+
+        default:
+          break;
+      }
+
+      crs = QgsProjUtils::crsToSingleCrs( crs.get() );
+
       QString proj4( proj_as_proj_string( pjContext, crs.get(), PJ_PROJ_4, nullptr ) );
       proj4 = proj4.trimmed();
 
diff --git a/src/core/qgsprojutils.cpp b/src/core/qgsprojutils.cpp
@@ -143,5 +143,38 @@ bool QgsProjUtils::axisOrderIsSwapped( const PJ *crs )
   return false;
 }
 
+
+QgsProjUtils::proj_pj_unique_ptr QgsProjUtils::crsToSingleCrs( const PJ *crs )
+{
+  if ( !crs )
+    return nullptr;
+
+  PJ_CONTEXT *context = QgsProjContext::get();
+  switch ( proj_get_type( crs ) )
+  {
+    case PJ_TYPE_BOUND_CRS:
+      return QgsProjUtils::proj_pj_unique_ptr( proj_get_source_crs( context, crs ) );
+
+    case PJ_TYPE_COMPOUND_CRS:
+    {
+      int i = 0;
+      QgsProjUtils::proj_pj_unique_ptr res( proj_crs_get_sub_crs( context, crs, i ) );
+      while ( res && ( proj_get_type( res.get() ) == PJ_TYPE_VERTICAL_CRS || proj_get_type( res.get() ) == PJ_TYPE_TEMPORAL_CRS ) )
+      {
+        i++;
+        res.reset( proj_crs_get_sub_crs( context, crs, i ) );
+      }
+      return res;
+    }
+
+    // maybe other types to handle??
+
+    default:
+      return QgsProjUtils::proj_pj_unique_ptr( proj_clone( context, crs ) );
+  }
+
+  return nullptr;
+}
+
 #endif
 
diff --git a/src/core/qgsprojutils.h b/src/core/qgsprojutils.h
@@ -87,6 +87,12 @@ class CORE_EXPORT QgsProjUtils
      */
     static bool axisOrderIsSwapped( const PJ *crs );
 
+    /**
+     * Given a PROJ crs (which may be a compound or bound crs, or some other type), extract a single crs
+     * from it.
+     */
+    static proj_pj_unique_ptr crsToSingleCrs( const PJ *crs );
+
 #endif
 #endif
 };
