Reintroduce geometry caching while rendering (used esp. for snapping)

Author: wonder-sk

src/core/qgsmaprendererjob.cpp

@@ -14,6 +14,7 @@
 #include "qgsmaplayerrenderer.h"
 #include "qgsmaprenderercache.h"
 #include "qgspallabeling.h"
+#include "qgsvectorlayerrenderer.h"
 
 
 QgsMapRendererJob::QgsMapRendererJob( const QgsMapSettings& settings )
@@ -438,6 +439,17 @@ void QgsMapRendererJob::drawNewLabeling( const QgsMapSettings& settings, QgsRend
   }
 }
 
+void QgsMapRendererJob::updateLayerGeometryCaches()
+{
+  foreach ( QString id, mGeometryCaches.keys() )
+  {
+    const QgsGeometryCache& cache = mGeometryCaches[id];
+    if ( QgsVectorLayer* vl = qobject_cast<QgsVectorLayer*>( QgsMapLayerRegistry::instance()->mapLayer( id ) ) )
+      *vl->cache() = cache;
+  }
+  mGeometryCaches.clear();
+}
+
 
 bool QgsMapRendererJob::needTemporaryImage( QgsMapLayer* ml )
 {
@@ -525,6 +537,8 @@ LayerRenderJobs QgsMapRendererJob::prepareJobs( QPainter* painter, QgsPalLabelin
     qDebug("CACHE VALID: %d", cacheValid);
   }
 
+  mGeometryCaches.clear();
+
   while ( li.hasPrevious() )
   {
     QString layerId = li.previous();
@@ -629,6 +643,14 @@ LayerRenderJobs QgsMapRendererJob::prepareJobs( QPainter* painter, QgsPalLabelin
 
     job.renderer = ml->createMapRenderer( job.context );
 
+    if ( mRequestedGeomCacheForLayers.contains( ml->id() ) )
+    {
+      if ( QgsVectorLayerRenderer* vlr = dynamic_cast<QgsVectorLayerRenderer*>( job.renderer ) )
+      {
+        vlr->setGeometryCachePointer( &mGeometryCaches[ ml->id() ] );
+      }
+    }
+
     /*
     // TODO: split extent
     if ( split )
@@ -675,6 +697,8 @@ void QgsMapRendererJob::cleanupJobs( LayerRenderJobs& jobs )
   }
 
   jobs.clear();
+
+  updateLayerGeometryCaches();
 }
 
 /////////////

src/core/qgsmaprendererjob.h

@@ -12,6 +12,7 @@
 
 #include "qgsmapsettings.h"
 
+#include "qgsgeometrycache.h"
 
 class QgsLabelingResults;
 class QgsMapLayerRenderer;
@@ -77,6 +78,9 @@ class CORE_EXPORT QgsMapRendererJob : public QObject
   //! Does not take ownership of the object.
   void setCache( QgsMapRendererCache* cache );
 
+  //! Set which vector layers should be cached while rendering
+  //! @note The way how geometries are cached is really suboptimal - this method may be removed in future releases
+  void setRequestedGeometryCacheForLayers( const QStringList& layerIds ) { mRequestedGeomCacheForLayers = layerIds; }
 
   //! Find out how log it took to finish the job (in miliseconds)
   int renderingTime() const { return mRenderingTime; }
@@ -108,11 +112,19 @@ class CORE_EXPORT QgsMapRendererJob : public QObject
   static void drawOldLabeling( const QgsMapSettings& settings, QgsRenderContext& renderContext );
   static void drawNewLabeling( const QgsMapSettings& settings, QgsRenderContext& renderContext, QgsPalLabeling* labelingEngine );
 
+  //! called when rendering has finished to update all layers' geometry caches
+  void updateLayerGeometryCaches();
+
   QgsMapSettings mSettings;
   Errors mErrors;
 
   QgsMapRendererCache* mCache;
 
+  //! list of layer IDs for which the geometry cache should be updated
+  QStringList mRequestedGeomCacheForLayers;
+  //! map of geometry caches
+  QMap<QString, QgsGeometryCache> mGeometryCaches;
+
   QTime mRenderingStart;
   int mRenderingTime;
 };

src/core/qgsvectorlayerrenderer.cpp

@@ -35,11 +35,6 @@ QgsVectorLayerRenderer::QgsVectorLayerRenderer( QgsVectorLayer* layer, QgsRender
   mSelectedFeatureIds = layer->selectedFeaturesIds();
 
   mDrawVertexMarkers = ( layer->editBuffer() != 0 );
-  mCacheFeatures = ( layer->editBuffer() != 0 );
-  if ( mCacheFeatures )
-  {
-    mCache = new QgsGeometryCache();
-  }
 
   mGeometryType = layer->geometryType();
 
@@ -70,11 +65,8 @@ QgsVectorLayerRenderer::QgsVectorLayerRenderer( QgsVectorLayer* layer, QgsRender
 
   QgsDebugMsg( "rendering v2:\n" + mRendererV2->dump() );
 
-  if ( mCacheFeatures )
+  if ( mDrawVertexMarkers )
   {
-    // Destroy all cached geometries and clear the references to them
-    mCache->setCachedGeometriesRect( mContext.extent() );
-
     // set editing vertex markers style
     mRendererV2->setVertexMarkerAppearance( mVertexMarkerStyle, mVertexMarkerSize );
   }
@@ -91,7 +83,6 @@ QgsVectorLayerRenderer::QgsVectorLayerRenderer( QgsVectorLayer* layer, QgsRender
 QgsVectorLayerRenderer::~QgsVectorLayerRenderer()
 {
   delete mRendererV2;
-  delete mCache;
   delete mSource;
 }
 
@@ -142,6 +133,17 @@ bool QgsVectorLayerRenderer::render()
   return true;
 }
 
+void QgsVectorLayerRenderer::setGeometryCachePointer( QgsGeometryCache* cache )
+{
+  mCache = cache;
+
+  if ( mCache )
+  {
+    // Destroy all cached geometries and clear the references to them
+    mCache->setCachedGeometriesRect( mContext.extent() );
+  }
+}
+
 
 
 void QgsVectorLayerRenderer::drawRendererV2( QgsFeatureIterator& fit )
@@ -166,7 +168,7 @@ void QgsVectorLayerRenderer::drawRendererV2( QgsFeatureIterator& fit )
       // render feature
       bool rendered = mRendererV2->renderFeature( fet, mContext, -1, sel, drawMarker );
 
-      if ( mCacheFeatures )
+      if ( mCache )
       {
         // Cache this for the use of (e.g.) modifying the feature's uncommitted geometry.
         mCache->cacheGeometry( fet.id(), *fet.geometry() );
@@ -236,7 +238,7 @@ void QgsVectorLayerRenderer::drawRendererV2Levels( QgsFeatureIterator& fit )
     }
     features[sym].append( fet );
 
-    if ( mCacheFeatures )
+    if ( mCache )
     {
       // Cache this for the use of (e.g.) modifying the feature's uncommitted geometry.
       mCache->cacheGeometry( fet.id(), *fet.geometry() );

src/core/qgsvectorlayerrenderer.h

@@ -34,6 +34,10 @@ class QgsVectorLayerRenderer : public QgsMapLayerRenderer
 
   virtual bool render();
 
+  //! where to save the cached geometries
+  //! @note The way how geometries are cached is really suboptimal - this method may be removed in future releases
+  void setGeometryCachePointer( QgsGeometryCache* cache );
+
 private:
 
   /**Registers label and diagram layer

src/gui/qgsmapcanvas.cpp

@@ -652,6 +652,18 @@ void QgsMapCanvas::refreshMap()
     mJob = new QgsMapRendererSequentialJob( mSettings );
   connect(mJob, SIGNAL( finished() ), SLOT( rendererJobFinished() ) );
   mJob->setCache( mCache );
+
+  QStringList layersForGeometryCache;
+  foreach ( QString id, mSettings.layers() )
+  {
+    if ( QgsVectorLayer* vl = qobject_cast<QgsVectorLayer*>( QgsMapLayerRegistry::instance()->mapLayer( id ) ) )
+    {
+      if ( vl->isEditable() )
+        layersForGeometryCache << id;
+    }
+  }
+  mJob->setRequestedGeometryCacheForLayers( layersForGeometryCache );
+
   mJob->start();
 
   mMapUpdateTimer.start();