[labeling] Allow different obstacle geometry to feature geometry

This change makes it possible to have a different geometry used
for labeling obstacle detection to the geometry used for generating
label position candidates.

Also fixes parts of multipolygon features were not treated as
obstacles when "label only largest part" of polygon was checked.
Some inefficiencies in pal were also fixed (eg avoiding adding
features/obstacles to pal rtree indexes when they will never
be used).

Sponsored by City of Uster

Author: nyalldawson

src/core/pal/feature.cpp

@@ -74,6 +74,16 @@ namespace pal
 
   }
 
+  FeaturePart::FeaturePart( const FeaturePart& other )
+      : PointSet( other )
+      , mLF( other.mLF )
+  {
+    Q_FOREACH ( FeaturePart* part, other.mHoles )
+    {
+      mHoles << new FeaturePart( *part );
+    }
+  }
+
 
   FeaturePart::~FeaturePart()
   {

src/core/pal/feature.h

@@ -94,6 +94,8 @@ namespace pal
         */
       FeaturePart( QgsLabelFeature* lf, const GEOSGeometry* geom );
 
+      FeaturePart( const FeaturePart& other );
+
       /** Delete the feature
        */
       virtual ~FeaturePart();

src/core/pal/labelposition.h

@@ -236,7 +236,7 @@ namespace pal
       } PruneCtx;
 
       /** Check whether the candidate in ctx overlap with obstacle feat */
-      static bool pruneCallback( LabelPosition *lp, void *ctx );
+      static bool pruneCallback( LabelPosition *candidatePosition, void *ctx );
 
       // for sorting
       static bool costShrink( void *l, void *r );

src/core/pal/layer.cpp

@@ -61,7 +61,8 @@ namespace pal
       , mMergeLines( false )
       , mUpsidedownLabels( Upright )
   {
-    rtree = new RTree<FeaturePart*, double, 2, double>();
+    mFeatureIndex = new RTree<FeaturePart*, double, 2, double>();
+    mObstacleIndex = new RTree<FeaturePart*, double, 2, double>();
 
     if ( defaultPriority < 0.0001 )
       mDefaultPriority = 0.0001;
@@ -76,13 +77,13 @@ namespace pal
     mMutex.lock();
 
     qDeleteAll( mFeatureParts );
-    mFeatureParts.clear();
+    qDeleteAll( mObstacleParts );
 
     //should already be empty
     qDeleteAll( mConnectedHashtable );
-    mConnectedHashtable.clear();
 
-    delete rtree;
+    delete mFeatureIndex;
+    delete mObstacleIndex;
 
     mMutex.unlock();
   }
@@ -132,6 +133,8 @@ namespace pal
 
     GEOSContextHandle_t geosctxt = geosContext();
 
+    bool featureGeomIsObstacleGeom = !lf->obstacleGeometry();
+
     while ( simpleGeometries->size() > 0 )
     {
       const GEOSGeometry* geom = simpleGeometries->takeFirst();
@@ -168,6 +171,32 @@ namespace pal
         continue;
       }
 
+      // is the feature well defined?  TODO Check epsilon
+      bool labelWellDefined = ( lf->size().width() > 0.0000001 && lf->size().height() > 0.0000001 );
+
+      if ( lf->isObstacle() && featureGeomIsObstacleGeom )
+      {
+        //if we are not labelling the layer, only insert it into the obstacle list and avoid an
+        //unnecessary copy
+        if ( mLabelLayer && labelWellDefined )
+        {
+          addObstaclePart( new FeaturePart( *fpart ) );
+        }
+        else
+        {
+          addObstaclePart( fpart );
+          fpart = 0;
+        }
+      }
+
+      // feature has to be labeled?
+      if ( !mLabelLayer || !labelWellDefined )
+      {
+        //nothing more to do for this part
+        delete fpart;
+        continue;
+      }
+
       if ( mMode == LabelPerFeature && ( type == GEOS_POLYGON || type == GEOS_LINESTRING ) )
       {
         if ( type == GEOS_LINESTRING )
@@ -186,7 +215,6 @@ namespace pal
           delete fpart;
         }
         continue; // don't add the feature part now, do it later
-        // TODO: we should probably add also other parts to act just as obstacles
       }
 
       // feature part is ready!
@@ -195,6 +223,57 @@ namespace pal
     }
     delete simpleGeometries;
 
+    if ( !featureGeomIsObstacleGeom )
+    {
+      //do the same for the obstacle geometry
+      simpleGeometries = unmulti( lf->obstacleGeometry() );
+      if ( simpleGeometries == NULL ) // unmulti() failed?
+      {
+        mMutex.unlock();
+        throw InternalException::UnknownGeometry();
+      }
+
+      while ( simpleGeometries->size() > 0 )
+      {
+        const GEOSGeometry* geom = simpleGeometries->takeFirst();
+
+        // ignore invalid geometries (e.g. polygons with self-intersecting rings)
+        if ( GEOSisValid_r( geosctxt, geom ) != 1 ) // 0=invalid, 1=valid, 2=exception
+        {
+          continue;
+        }
+
+        int type = GEOSGeomTypeId_r( geosctxt, geom );
+
+        if ( type != GEOS_POINT && type != GEOS_LINESTRING && type != GEOS_POLYGON )
+        {
+          mMutex.unlock();
+          throw InternalException::UnknownGeometry();
+        }
+
+        FeaturePart* fpart = new FeaturePart( lf, geom );
+
+        // ignore invalid geometries
+        if (( type == GEOS_LINESTRING && fpart->nbPoints < 2 ) ||
+            ( type == GEOS_POLYGON && fpart->nbPoints < 3 ) )
+        {
+          delete fpart;
+          continue;
+        }
+
+        // polygons: reorder coordinates
+        if ( type == GEOS_POLYGON && reorderPolygon( fpart->nbPoints, fpart->x, fpart->y ) != 0 )
+        {
+          delete fpart;
+          continue;
+        }
+
+        // feature part is ready!
+        addObstaclePart( fpart );
+      }
+      delete simpleGeometries;
+    }
+
     mMutex.unlock();
 
     // if using only biggest parts...
@@ -224,7 +303,7 @@ namespace pal
     mFeatureParts << fpart;
 
     // add to r-tree for fast spatial access
-    rtree->Insert( bmin, bmax, fpart );
+    mFeatureIndex->Insert( bmin, bmax, fpart );
 
     // add to hashtable with equally named feature parts
     if ( mMergeLines && !labelText.isEmpty() )
@@ -245,6 +324,19 @@ namespace pal
     }
   }
 
+  void Layer::addObstaclePart( FeaturePart* fpart )
+  {
+    double bmin[2];
+    double bmax[2];
+    fpart->getBoundingBox( bmin, bmax );
+
+    // add to list of layer's feature parts
+    mObstacleParts.append( fpart );
+
+    // add to obstacle r-tree
+    mObstacleIndex->Insert( bmin, bmax, fpart );
+  }
+
   static FeaturePart* _findConnectedPart( FeaturePart* partCheck, QLinkedList<FeaturePart*>* otherParts )
   {
     // iterate in the rest of the parts with the same label
@@ -286,7 +378,7 @@ namespace pal
           // remove partCheck from r-tree
           double bmin[2], bmax[2];
           partCheck->getBoundingBox( bmin, bmax );
-          rtree->Remove( bmin, bmax, partCheck );
+          mFeatureIndex->Remove( bmin, bmax, partCheck );
           mFeatureParts.removeOne( partCheck );
 
           otherPart->getBoundingBox( bmin, bmax );
@@ -295,9 +387,9 @@ namespace pal
           if ( otherPart->mergeWithFeaturePart( partCheck ) )
           {
             // reinsert p->item to r-tree (probably not needed)
-            rtree->Remove( bmin, bmax, otherPart );
+            mFeatureIndex->Remove( bmin, bmax, otherPart );
             otherPart->getBoundingBox( bmin, bmax );
-            rtree->Insert( bmin, bmax, otherPart );
+            mFeatureIndex->Insert( bmin, bmax, otherPart );
           }
           delete partCheck;
         }
@@ -331,7 +423,7 @@ namespace pal
 
         double bmin[2], bmax[2];
         fpart->getBoundingBox( bmin, bmax );
-        rtree->Remove( bmin, bmax, fpart );
+        mFeatureIndex->Remove( bmin, bmax, fpart );
 
         const GEOSCoordSequence *cs = GEOSGeom_getCoordSeq_r( geosctxt, geom );
 
@@ -387,7 +479,7 @@ namespace pal
           FeaturePart* newfpart = new FeaturePart( fpart->feature(), newgeom );
           newFeatureParts.append( newfpart );
           newfpart->getBoundingBox( bmin, bmax );
-          rtree->Insert( bmin, bmax, newfpart );
+          mFeatureIndex->Insert( bmin, bmax, newfpart );
           part.clear();
           part.push_back( p );
         }
@@ -404,7 +496,7 @@ namespace pal
         FeaturePart* newfpart = new FeaturePart( fpart->feature(), newgeom );
         newFeatureParts.append( newfpart );
         newfpart->getBoundingBox( bmin, bmax );
-        rtree->Insert( bmin, bmax, newfpart );
+        mFeatureIndex->Insert( bmin, bmax, newfpart );
         delete fpart;
       }
       else

src/core/pal/layer.h

@@ -249,6 +249,9 @@ namespace pal
       /** List of feature parts */
       QLinkedList<FeaturePart*> mFeatureParts;
 
+      /** List of obstacle parts */
+      QList<FeaturePart*> mObstacleParts;
+
       Pal *pal;
 
       double mDefaultPriority;
@@ -269,10 +272,13 @@ namespace pal
       UpsideDownLabels mUpsidedownLabels;
 
       // indexes (spatial and id)
-      RTree<FeaturePart*, double, 2, double, 8, 4> *rtree;
+      RTree<FeaturePart*, double, 2, double, 8, 4> *mFeatureIndex;
       //! Lookup table of label features (owned by the label feature provider that created them)
       QHash< QgsFeatureId, QgsLabelFeature*> mHashtable;
 
+      //obstacle r-tree
+      RTree<FeaturePart*, double, 2, double, 8, 4> *mObstacleIndex;
+
       QHash< QString, QLinkedList<FeaturePart*>* > mConnectedHashtable;
       QStringList mConnectedTexts;
 
@@ -296,6 +302,9 @@ namespace pal
       /** Add newly created feature part into r tree and to the list */
       void addFeaturePart( FeaturePart* fpart, const QString &labelText = QString() );
 
+      /** Add newly created obstacle part into r tree and to the list */
+      void addObstaclePart( FeaturePart* fpart );
+
   };
 
 } // end namespace pal