[FEATURE][NEEDS-DOCS] Add sinuosity expression

qgis · Jul 28, 2021 · 8111171 · 8111171
1 parent 3cd62b3
commit 8111171
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Showing 2 changed files with 22 additions and 1 deletion.
diff --git a/src/core/expression/qgsexpressionfunction.cpp b/src/core/expression/qgsexpressionfunction.cpp
@@ -3572,6 +3572,19 @@ static QVariant fcnMMax( const QVariantList &values, const QgsExpressionContext
   return QVariant( max );
 }
 
+static QVariant fcnSinuosity( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * )
+{
+  QgsGeometry geom = QgsExpressionUtils::getGeometry( values.at( 0 ), parent );
+  const QgsCurve *curve = qgsgeometry_cast< const QgsCurve * >( geom.constGet() );
+  if ( ( geom.type() != QgsWkbTypes::LineGeometry ) || !curve )
+  {
+    parent->setEvalErrorString( QObject::tr( "Function `sinuosity` requires a line geometry." ) );
+    return QVariant();
+  }
+
+  return QVariant( curve->sinuosity() );
+}
+
 static QVariant fcnFlipCoordinates( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * )
 {
   QgsGeometry geom = QgsExpressionUtils::getGeometry( values.at( 0 ), parent );
@@ -7004,7 +7017,9 @@ const QList<QgsExpressionFunction *> &QgsExpression::Functions()
         << new QgsStaticExpressionFunction( QStringLiteral( "m_max" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "geometry" ) ),
                                             fcnMMax, QStringLiteral( "GeometryGroup" ) )
         << new QgsStaticExpressionFunction( QStringLiteral( "m_min" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "geometry" ) ),
-                                            fcnMMin, QStringLiteral( "GeometryGroup" ) );
+                                            fcnMMin, QStringLiteral( "GeometryGroup" ) )
+        << new QgsStaticExpressionFunction( QStringLiteral( "sinuosity" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "geometry" ) ),
+                                            fcnSinuosity, QStringLiteral( "GeometryGroup" ) );
 
 
     QgsStaticExpressionFunction *orderPartsFunc = new QgsStaticExpressionFunction( QStringLiteral( "order_parts" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "geometry" ) )

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -1316,6 +1316,12 @@ class TestQgsExpression: public QObject
       QTest::newRow( "main angle line" ) << "round(main_angle( geom_from_wkt('LINESTRING (-1 2, 9 12)') ))" << false << QVariant( 45 );
       QTest::newRow( "main angle not geom" ) << "main_angle('g')" << true << QVariant();
       QTest::newRow( "main angle null" ) << "main_angle(NULL)" << false << QVariant();
+      QTest::newRow( "sinuosity not geom" ) << "sinuosity('g')" << true << QVariant();
+      QTest::newRow( "sinuosity null" ) << "sinuosity(NULL)" << false << QVariant();
+      QTest::newRow( "sinuosity point" ) << "sinuosity(geom_from_wkt('POINT(1 2)'))" << true << QVariant( );
+      QTest::newRow( "sinuosity multi linestring" ) << "sinuosity(geom_from_wkt('MULTILINESTRING( (0 0, 1 1), (2 2, 3 3) )'))" << true << QVariant( );
+      QTest::newRow( "sinuosity linestring" ) << "round(sinuosity(geom_from_wkt(' LINESTRING(2 0, 2 2, 3 2, 3 3)')), 3)" << false << QVariant( 1.265 );
+      QTest::newRow( "sinuosity linestring" ) << "sinuosity(geom_from_wkt(' LINESTRING( 3 1, 5 1) '))" << false << QVariant( 1.0 );
 
       // string functions
       QTest::newRow( "format_number" ) << "format_number(1999.567,2)" << false << QVariant( "1,999.57" );