#8275-R: simplification on a per-iterator basis

qgis · Jan 15, 2014 · 7cb8ff7 · 7cb8ff7
1 parent 61c8cad
commit 7cb8ff7
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Showing 9 changed files with 75 additions and 45 deletions.
diff --git a/src/core/qgsfeatureiterator.cpp b/src/core/qgsfeatureiterator.cpp
@@ -23,6 +23,7 @@ QgsAbstractFeatureIterator::QgsAbstractFeatureIterator( const QgsFeatureRequest&
     , mClosed( false )
     , refs( 0 )
     , mGeometrySimplifier( NULL )
+    , mLocalSimplification( false )
 {
 }
 
@@ -52,7 +53,7 @@ bool QgsAbstractFeatureIterator::nextFeature( QgsFeature& f )
   }
 
   // simplify the geometry using the simplifier configured
-  if ( dataOk )
+  if ( dataOk && mLocalSimplification )
   {
     QgsGeometry* geometry = f.geometry();
     if ( geometry ) simplify( f );
@@ -82,6 +83,11 @@ bool QgsAbstractFeatureIterator::nextFeatureFilterFids( QgsFeature& f )
 
 void QgsAbstractFeatureIterator::ref()
 {
+  // prepare if required the simplification of geometries to fetch
+  if ( refs == 0 )
+  {
+    prepareSimplification( mRequest.simplifyMethod() );
+  }
   refs++;
 }
 
@@ -94,18 +100,26 @@ void QgsAbstractFeatureIterator::deref()
 
 bool QgsAbstractFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simplifyMethod )
 {
+  mLocalSimplification = false;
+
   delete mGeometrySimplifier;
   mGeometrySimplifier = NULL;
 
-  // setup the local simplification of geometries to fetch
-  if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && simplifyMethod.forceLocalOptimization() && !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) )
+  // setup the simplification of geometries to fetch
+  if ( !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) && simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && ( simplifyMethod.forceLocalOptimization() || !providerCanSimplify( simplifyMethod.methodType() ) ) )
   {
     mGeometrySimplifier = QgsSimplifyMethod::createGeometrySimplifier( simplifyMethod );
-    return mGeometrySimplifier != NULL;
+    mLocalSimplification = mGeometrySimplifier != NULL;
+    return mLocalSimplification;
   }
   return false;
 }
 
+bool QgsAbstractFeatureIterator::providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const
+{
+  return false;
+}
+
 bool QgsAbstractFeatureIterator::simplify( QgsFeature& feature )
 {
   // simplify locally the geometry using the configured simplifier

diff --git a/src/core/qgsfeatureiterator.h b/src/core/qgsfeatureiterator.h
@@ -93,6 +93,11 @@ class CORE_EXPORT QgsAbstractFeatureIterator
   private:
     //! optional object to locally simplify geometries fetched by this feature iterator
     QgsAbstractGeometrySimplifier* mGeometrySimplifier;
+    //! this iterator runs local simplification
+    bool mLocalSimplification;
+
+    //! returns whether the iterator can simplify on provider side the geometries to fetch using the specified method type
+    virtual bool providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const;
 
     //! simplify the specified geometry if it was configured
     virtual bool simplify( QgsFeature& feature );

diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -737,13 +737,6 @@ bool QgsVectorLayer::draw( QgsRenderContext& rendererContext )
     simplifyMethod.setTolerance( map2pixelTol );
     simplifyMethod.setForceLocalOptimization( mSimplifyMethod.forceLocalOptimization() );
 
-    // fix simplification non supported on server side
-    if ( !simplifyMethod.forceLocalOptimization() && !( mDataProvider->capabilities() & QgsVectorDataProvider::SimplifyGeometries ) )
-    {
-      QgsDebugMsg( "Data provider does not support geometry simplification on provider side" );
-      simplifyMethod.setForceLocalOptimization( true );
-    }
-
     featureRequest.setSimplifyMethod( simplifyMethod );
   }
 

diff --git a/src/core/qgsvectorlayerfeatureiterator.cpp b/src/core/qgsvectorlayerfeatureiterator.cpp
@@ -70,15 +70,6 @@ QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator( QgsVectorLayer* la
   }
   else // no filter or filter by rect
   {
-    QgsSimplifyMethod simplifyMethod = request.simplifyMethod();
-
-    // if required, local simplification will be configured for all providers, then avoid simplify twice (this iterator and provider iterator)
-    if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && simplifyMethod.forceLocalOptimization() )
-    {
-      simplifyMethod.setMethodType( QgsSimplifyMethod::NoSimplification );
-      if ( L->editBuffer() ) mChangedFeaturesRequest.setSimplifyMethod( simplifyMethod ); else mProviderRequest.setSimplifyMethod( simplifyMethod );
-    }
-
     if ( L->editBuffer() )
     {
       mChangedFeaturesIterator = L->dataProvider()->getFeatures( mChangedFeaturesRequest );
@@ -95,9 +86,6 @@ QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator( QgsVectorLayer* la
   {
     mRequest.filterExpression()->prepare( L->pendingFields() );
   }
-
-  // prepare if required the local simplification of geometries to fetch
-  prepareSimplification( request.simplifyMethod() );
 }
 
 
@@ -466,13 +454,34 @@ bool QgsVectorLayerFeatureIterator::prepareSimplification( const QgsSimplifyMeth
   delete mEditGeometrySimplifier;
   mEditGeometrySimplifier = NULL;
 
-  // setup the simplification of edited geometries to fetch
-  if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) )
+  // setup simplification for edited geometries to fetch
+  if ( !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) && simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification )
   {
     mEditGeometrySimplifier = QgsSimplifyMethod::createGeometrySimplifier( simplifyMethod );
+    return mEditGeometrySimplifier != NULL;
   }
+  return false;
+}
+
+bool QgsVectorLayerFeatureIterator::providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const
+{
+  QgsVectorDataProvider* provider = L->dataProvider();
 
-  return QgsAbstractFeatureIterator::prepareSimplification( simplifyMethod );
+  if ( provider && methodType != QgsSimplifyMethod::NoSimplification )
+  {
+    int capabilities = provider->capabilities();
+
+    if ( methodType == QgsSimplifyMethod::OptimizeForRendering )
+    {
+      return ( capabilities & QgsVectorDataProvider::SimplifyGeometries );
+    }
+    else
+    if ( methodType == QgsSimplifyMethod::PreserveTopology )
+    {
+      return ( capabilities & QgsVectorDataProvider::SimplifyGeometriesWithTopologicalValidation );
+    }
+  }
+  return false;
 }
 
 

diff --git a/src/core/qgsvectorlayerfeatureiterator.h b/src/core/qgsvectorlayerfeatureiterator.h
@@ -121,6 +121,9 @@ class CORE_EXPORT QgsVectorLayerFeatureIterator : public QgsAbstractFeatureItera
   private:
     //! optional object to locally simplify edited (changed or added) geometries fetched by this feature iterator
     QgsAbstractGeometrySimplifier* mEditGeometrySimplifier;
+
+    //! returns whether the iterator can simplify on provider side the geometries to fetch using the specified method type
+    virtual bool providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const;
 };
 
 #endif // QGSVECTORLAYERFEATUREITERATOR_H
diff --git a/src/providers/ogr/qgsogrfeatureiterator.cpp b/src/providers/ogr/qgsogrfeatureiterator.cpp
@@ -80,9 +80,6 @@ QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrProvider* p, const QgsFeatur
     OGR_L_SetSpatialFilter( ogrLayer, 0 );
   }
 
-  //setup if required the simplification of OGR-geometries fetched
-  prepareSimplification( request.simplifyMethod() );
-
   //start with first feature
   rewind();
 }
@@ -105,34 +102,37 @@ void QgsOgrFeatureIterator::ensureRelevantFields()
 
 bool QgsOgrFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simplifyMethod )
 {
-  bool providerSimplification = false;
-
   delete mGeometrySimplifier;
   mGeometrySimplifier = NULL;
 
-  // setup if required the simplification of OGR-geometries fetched
-  if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && !simplifyMethod.forceLocalOptimization() && !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) )
+  // setup simplification of OGR-geometries fetched
+  if ( !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) && simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && !simplifyMethod.forceLocalOptimization() )
   {
     QgsSimplifyMethod::MethodType methodType = simplifyMethod.methodType();
 
     if ( methodType == QgsSimplifyMethod::OptimizeForRendering )
     {
       int simplifyFlags = QgsMapToPixelSimplifier::SimplifyGeometry | QgsMapToPixelSimplifier::SimplifyEnvelope;
       mGeometrySimplifier = new QgsOgrMapToPixelSimplifier( simplifyFlags, simplifyMethod.tolerance() );
-      providerSimplification = true;
+      return true;
     }
     else
     if ( methodType == QgsSimplifyMethod::PreserveTopology )
     {
       mGeometrySimplifier = new QgsOgrTopologyPreservingSimplifier( simplifyMethod.tolerance() );
-      providerSimplification = true;
+      return true;
     }
     else
     {
       QgsDebugMsg( QString( "Simplification method type (%1) is not recognised by OgrFeatureIterator class" ).arg( methodType ) );
     }
   }
-  return QgsAbstractFeatureIterator::prepareSimplification( simplifyMethod ) || providerSimplification;
+  return QgsAbstractFeatureIterator::prepareSimplification( simplifyMethod );
+}
+
+bool QgsOgrFeatureIterator::providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const
+{
+  return methodType == QgsSimplifyMethod::OptimizeForRendering || methodType == QgsSimplifyMethod::PreserveTopology;
 }
 
 bool QgsOgrFeatureIterator::fetchFeature( QgsFeature& feature )

diff --git a/src/providers/ogr/qgsogrfeatureiterator.h b/src/providers/ogr/qgsogrfeatureiterator.h
@@ -64,6 +64,9 @@ class QgsOgrFeatureIterator : public QgsAbstractFeatureIterator
   private:
     //! optional object to simplify OGR-geometries fecthed by this feature iterator
     QgsOgrAbstractGeometrySimplifier* mGeometrySimplifier;
+
+    //! returns whether the iterator can simplify on provider side the geometries to fetch using the specified method type
+    virtual bool providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const;
 };
 
 #endif // QGSOGRFEATUREITERATOR_H
diff --git a/src/providers/postgres/qgspostgresfeatureiterator.cpp b/src/providers/postgres/qgspostgresfeatureiterator.cpp
@@ -80,9 +80,6 @@ QgsPostgresFeatureIterator::QgsPostgresFeatureIterator( QgsPostgresProvider* p,
     return;
   }
 
-  //setup if required the simplification of geometries to fetch
-  prepareSimplification( request.simplifyMethod() );
-
   mFetched = 0;
 }
 
@@ -175,23 +172,26 @@ bool QgsPostgresFeatureIterator::fetchFeature( QgsFeature& feature )
 
 bool QgsPostgresFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simplifyMethod )
 {
-  bool providerSimplification = false;
-
-  // validate settings of simplification of geometries to fetch
-  if ( simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && !simplifyMethod.forceLocalOptimization() && !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) )
+  // setup simplification of geometries to fetch
+  if ( !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) && simplifyMethod.methodType() != QgsSimplifyMethod::NoSimplification && !simplifyMethod.forceLocalOptimization() )
   {
     QgsSimplifyMethod::MethodType methodType = simplifyMethod.methodType();
 
     if ( methodType == QgsSimplifyMethod::OptimizeForRendering || methodType == QgsSimplifyMethod::PreserveTopology )
     {
-      providerSimplification = true;
+      return true;
     }
     else
     {
       QgsDebugMsg( QString( "Simplification method type (%1) is not recognised by PostgresFeatureIterator" ).arg( methodType ) );
     }
   }
-  return QgsAbstractFeatureIterator::prepareSimplification( simplifyMethod ) || providerSimplification;
+  return QgsAbstractFeatureIterator::prepareSimplification( simplifyMethod );
+}
+
+bool QgsPostgresFeatureIterator::providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const
+{
+  return methodType == QgsSimplifyMethod::OptimizeForRendering || methodType == QgsSimplifyMethod::PreserveTopology;
 }
 
 bool QgsPostgresFeatureIterator::rewind()

diff --git a/src/providers/postgres/qgspostgresfeatureiterator.h b/src/providers/postgres/qgspostgresfeatureiterator.h
@@ -69,6 +69,9 @@ class QgsPostgresFeatureIterator : public QgsAbstractFeatureIterator
 
     static const int sFeatureQueueSize;
 
+  private:
+    //! returns whether the iterator can simplify on provider side the geometries to fetch using the specified method type
+    virtual bool providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const;
 };
 
 #endif // QGSPOSTGRESFEATUREITERATOR_H