Add DE-9IM variant which tests against a specified pattern

(available in PyQGIS/expression engine)
qgis · Nov 4, 2015 · da94223 · da94223
1 parent 9e84fca
commit da94223
Show file tree

Hide file tree

Showing 7 changed files with 90 additions and 14 deletions.
diff --git a/python/core/geometry/qgsgeometryengine.sip b/python/core/geometry/qgsgeometryengine.sip
@@ -42,6 +42,16 @@ class QgsGeometryEngine
      */
     virtual QString relate( const QgsAbstractGeometryV2& geom, QString* errorMsg = 0 ) const = 0;
 
+    /** Tests whether two geometries are related by a specified Dimensional Extended 9 Intersection Model (DE-9IM)
+     * pattern.
+     * @param geom geometry to relate to
+     * @param pattern DE-9IM pattern for match
+     * @param errorMsg destination storage for any error message
+     * @returns true if geometry relationship matches with pattern
+     * @note added in QGIS 2.14
+     */
+    virtual bool relatePattern( const QgsAbstractGeometryV2& geom, const QString& pattern, QString* errorMsg = 0 ) const = 0;
+
     virtual double area( QString* errorMsg = 0 ) const = 0;
     virtual double length( QString* errorMsg = 0 ) const = 0;
     virtual bool isValid( QString* errorMsg = 0 ) const = 0;

diff --git a/resources/function_help/json/relate b/resources/function_help/json/relate
@@ -1,12 +1,23 @@
 {
   "name": "relate",
   "type": "function",
-  "description": "Returns the Dimensional Extended 9 Intersection Model (DE-9IM) representation of the relationship between two geometries.",
-  "arguments": [
-	{"arg":"geometry","description":"a geometry"},
-	{"arg":"geometry","description":"a geometry"}
-  ],
-  "examples": [
-	{ "expression":"relate( geom_from_wkt( 'LINESTRING(40 40,120 120)' ), geom_from_wkt( 'LINESTRING(40 40,60 120)' ) )", "returns":"'FF1F00102'"}
-  ]
+  "description": "Tests the Dimensional Extended 9 Intersection Model (DE-9IM) representation of the relationship between two geometries.",
+  "variants": [
+  { "variant": "Relationship variant",
+      "variant_description": "Returns the Dimensional Extended 9 Intersection Model (DE-9IM) representation of the relationship between two geometries.",
+      "arguments": [
+    	{"arg":"geometry","description":"a geometry"},
+    	{"arg":"geometry","description":"a geometry"}
+      ],
+      "examples": [ { "expression":"relate( geom_from_wkt( 'LINESTRING(40 40,120 120)' ), geom_from_wkt( 'LINESTRING(40 40,60 120)' ) )", "returns":"'FF1F00102'" } ] },
+      {
+      "variant": "Pattern match variant",
+      "variant_description": "Tests whether the DE-9IM relationship between two geometries matches a specified pattern.",
+      "arguments": [
+	    {"arg":"geometry","description":"a geometry"},
+     	{"arg":"geometry","description":"a geometry"},
+     	{"arg":"pattern","description":"DE-9IM pattern to match"}
+      ],
+      "examples": [ { "expression":"relate( geom_from_wkt( 'LINESTRING(40 40,120 120)' ), geom_from_wkt( 'LINESTRING(40 40,60 120)' ), '**1F001**' )", "returns":true}]
+  }]
 }
diff --git a/src/core/geometry/qgsgeometryengine.h b/src/core/geometry/qgsgeometryengine.h
@@ -69,6 +69,16 @@ class CORE_EXPORT QgsGeometryEngine
      */
     virtual QString relate( const QgsAbstractGeometryV2& geom, QString* errorMsg = 0 ) const = 0;
 
+    /** Tests whether two geometries are related by a specified Dimensional Extended 9 Intersection Model (DE-9IM)
+     * pattern.
+     * @param geom geometry to relate to
+     * @param pattern DE-9IM pattern for match
+     * @param errorMsg destination storage for any error message
+     * @returns true if geometry relationship matches with pattern
+     * @note added in QGIS 2.14
+     */
+    virtual bool relatePattern( const QgsAbstractGeometryV2& geom, const QString& pattern, QString* errorMsg = 0 ) const = 0;
+
     virtual double area( QString* errorMsg = 0 ) const = 0;
     virtual double length( QString* errorMsg = 0 ) const = 0;
     virtual bool isValid( QString* errorMsg = 0 ) const = 0;

diff --git a/src/core/geometry/qgsgeos.cpp b/src/core/geometry/qgsgeos.cpp
@@ -300,6 +300,35 @@ QString QgsGeos::relate( const QgsAbstractGeometryV2& geom, QString* errorMsg )
   return result;
 }
 
+bool QgsGeos::relatePattern( const QgsAbstractGeometryV2& geom, const QString& pattern, QString* errorMsg ) const
+{
+  if ( !mGeos )
+  {
+    return false;
+  }
+
+  GEOSGeomScopedPtr geosGeom( asGeos( &geom, mPrecision ) );
+  if ( !geosGeom )
+  {
+    return false;
+  }
+
+  bool result = false;
+  try
+  {
+    result = ( GEOSRelatePattern_r( geosinit.ctxt, mGeos, geosGeom.get(), pattern.toLocal8Bit().constData() ) == 1 );
+  }
+  catch ( GEOSException &e )
+  {
+    if ( errorMsg )
+    {
+      *errorMsg = e.what();
+    }
+  }
+
+  return result;
+}
+
 double QgsGeos::area( QString* errorMsg ) const
 {
   double area = -1.0;
@@ -1527,7 +1556,7 @@ GEOSGeometry* QgsGeos::createGeosPoint( const QgsAbstractGeometryV2* point, int
       }
     }
 #if 0 //disabled until geos supports m-coordinates
-    if (pt->isMeasure() )
+    if ( pt->isMeasure() )
     {
       GEOSCoordSeq_setOrdinate_r( geosinit.ctxt, coordSeq, 0, 3, pt->m() );
     }

diff --git a/src/core/geometry/qgsgeos.h b/src/core/geometry/qgsgeos.h
@@ -62,6 +62,7 @@ class CORE_EXPORT QgsGeos: public QgsGeometryEngine
     bool contains( const QgsAbstractGeometryV2& geom, QString* errorMsg = 0 ) const override;
     bool disjoint( const QgsAbstractGeometryV2& geom, QString* errorMsg = 0 ) const override;
     QString relate( const QgsAbstractGeometryV2& geom, QString* errorMsg = 0 ) const override;
+    bool relatePattern( const QgsAbstractGeometryV2& geom, const QString& pattern, QString* errorMsg = 0 ) const override;
     double area( QString* errorMsg = 0 ) const override;
     double length( QString* errorMsg = 0 ) const override;
     bool isValid( QString* errorMsg = 0 ) const override;

diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -1477,17 +1477,30 @@ static QVariant fcnYMax( const QVariantList& values, const QgsExpressionContext*
 
 static QVariant fcnRelate( const QVariantList& values, const QgsExpressionContext*, QgsExpression* parent )
 {
+  if ( values.length() < 2 || values.length() > 3 )
+    return QVariant();
+
   QgsGeometry fGeom = getGeometry( values.at( 0 ), parent );
   QgsGeometry sGeom = getGeometry( values.at( 1 ), parent );
 
   if ( fGeom.isEmpty() || sGeom.isEmpty() )
     return QVariant();
 
-  QgsGeometryEngine* engine = QgsGeometry::createGeometryEngine( fGeom.geometry() );
-  QString result = engine->relate( *sGeom.geometry() );
-  delete engine;
+  QScopedPointer<QgsGeometryEngine> engine( QgsGeometry::createGeometryEngine( fGeom.geometry() ) );
 
-  return QVariant::fromValue( result );
+  if ( values.length() == 2 )
+  {
+    //two geometry arguments, return relation
+    QString result = engine->relate( *sGeom.geometry() );
+    return QVariant::fromValue( result );
+  }
+  else
+  {
+    //three arguments, test pattern
+    QString pattern = getStringValue( values.at( 2 ), parent );
+    bool result = engine->relatePattern( *sGeom.geometry(), pattern );
+    return QVariant::fromValue( result );
+  }
 }
 
 static QVariant fcnBbox( const QVariantList& values, const QgsExpressionContext*, QgsExpression* parent )
@@ -2309,7 +2322,7 @@ const QList<QgsExpression::Function*>& QgsExpression::Functions()
     << new StaticFunction( "y_max", 1, fcnYMax, "GeometryGroup", QString(), false, QStringList(), false, QStringList() << "ymax" )
     << new StaticFunction( "geom_from_wkt", 1, fcnGeomFromWKT, "GeometryGroup", QString(), false, QStringList(), false, QStringList() << "geomFromWKT" )
     << new StaticFunction( "geom_from_gml", 1, fcnGeomFromGML, "GeometryGroup", QString(), false, QStringList(), false, QStringList() << "geomFromGML" )
-    << new StaticFunction( "relate", 2, fcnRelate, "GeometryGroup" )
+    << new StaticFunction( "relate", -1, fcnRelate, "GeometryGroup" )
     << new StaticFunction( "intersects_bbox", 2, fcnBbox, "GeometryGroup", QString(), false, QStringList(), false, QStringList() << "bbox" )
     << new StaticFunction( "disjoint", 2, fcnDisjoint, "GeometryGroup" )
     << new StaticFunction( "intersects", 2, fcnIntersects, "GeometryGroup" )

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -452,6 +452,8 @@ class TestQgsExpression: public QObject
       QTest::newRow( "relate valid" ) << "relate(geom_from_wkt('POINT(110 120)'),geom_from_wkt('POLYGON((60 120,60 40,160 40,160 120,60 120))'))" << false << QVariant( "F0FFFF212" );
       QTest::newRow( "relate bad 1" ) << "relate(geom_from_wkt(''),geom_from_wkt('POLYGON((60 120,60 40,160 40,160 120,60 120))'))" << false << QVariant();
       QTest::newRow( "relate bad 2" ) << "relate(geom_from_wkt('POINT(110 120)'),geom_from_wkt(''))" << false << QVariant();
+      QTest::newRow( "relate pattern true" ) << "relate( geom_from_wkt( 'LINESTRING(40 40,120 120)' ), geom_from_wkt( 'LINESTRING(40 40,60 120)' ), '**1F001**' )" << false << QVariant( true );
+      QTest::newRow( "relate pattern false" ) << "relate( geom_from_wkt( 'LINESTRING(40 40,120 120)' ), geom_from_wkt( 'LINESTRING(40 40,60 120)' ), '**1F002**' )" << false << QVariant( false );
 
       // string functions
       QTest::newRow( "lower" ) << "lower('HeLLo')" << false << QVariant( "hello" );