Merge pull request #5791 from nyalldawson/geom_snapper_vertices

Fix geometry snapper sometimes creates unwanted overlapping segments when snapping line layers

python/analysis/vector/qgsgeometrysnapper.sip

@@ -28,6 +28,8 @@ class QgsGeometrySnapper : QObject
     {
       PreferNodes,
       PreferClosest,
+      PreferNodesNoExtraVertices,
+      PreferClosestNoExtraVertices,
       EndPointPreferNodes,
       EndPointPreferClosest,
       EndPointToEndPoint,

python/core/geometry/qgsabstractgeometry.sip

@@ -436,6 +436,29 @@ Returns the centroid of the geometry
  :rtype: QgsAbstractGeometry
 %End
 
+    virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false ) = 0;
+%Docstring
+ Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a
+ degenerate geometry.
+
+ The ``epsilon`` parameter specifies the tolerance for coordinates when determining that
+ vertices are identical.
+
+ By default, z values are not considered when detecting duplicate nodes. E.g. two nodes
+ with the same x and y coordinate but different z values will still be considered
+ duplicate and one will be removed. If ``useZValues`` is true, then the z values are
+ also tested and nodes with the same x and y but different z will be maintained.
+
+ Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g.
+ a multipoint geometry with overlapping points will not be changed by this method.
+
+ The function will return true if nodes were removed, or false if no duplicate nodes
+ were found.
+
+.. versionadded:: 3.0
+ :rtype: bool
+%End
+
     virtual double vertexAngle( QgsVertexId vertex ) const = 0;
 %Docstring
  Returns approximate angle at a vertex. This is usually the average angle between adjacent

python/core/geometry/qgscircularstring.sip

@@ -83,6 +83,9 @@ class QgsCircularString: QgsCurve
 
     virtual QgsCircularString *snappedToGrid( double hSpacing, double vSpacing, double dSpacing = 0, double mSpacing = 0 ) const /Factory/;
 
+    virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
+
+
     virtual void draw( QPainter &p ) const;
 
      virtual void transform( const QgsCoordinateTransform &ct, QgsCoordinateTransform::TransformDirection d = QgsCoordinateTransform::ForwardTransform,

python/core/geometry/qgscompoundcurve.sip

@@ -79,6 +79,8 @@ class QgsCompoundCurve: QgsCurve
 
     virtual QgsCompoundCurve *snappedToGrid( double hSpacing, double vSpacing, double dSpacing = 0, double mSpacing = 0 ) const /Factory/;
 
+    virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
+
 
     int nCurves() const;
 %Docstring

python/core/geometry/qgscurvepolygon.sip

@@ -67,6 +67,8 @@ class QgsCurvePolygon: QgsSurface
 
     virtual QgsCurvePolygon *snappedToGrid( double hSpacing, double vSpacing, double dSpacing = 0, double mSpacing = 0 ) const /Factory/;
 
+    virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
+
 
     int numInteriorRings() const;
 %Docstring

python/core/geometry/qgsgeometry.sip

@@ -501,7 +501,7 @@ Returns true if WKB of the geometry is of WKBMulti* type
  \param afterVertex Receives index of the vertex after the closest segment. The vertex
  before the closest segment is always afterVertex - 1
  \param leftOf Out: Returns if the point lies on the left of left side of the geometry ( < 0 means left, > 0 means right, 0 indicates
- that the test was unsuccesful, e.g. for a point exactly on the line)
+ that the test was unsuccessful, e.g. for a point exactly on the line)
  \param epsilon epsilon for segment snapping
  :return: The squared Cartesian distance is also returned in sqrDist, negative number on error
  :rtype: float
@@ -688,6 +688,29 @@ Returns true if WKB of the geometry is of WKBMulti* type
  :rtype: QgsGeometry
 %End
 
+    bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
+%Docstring
+ Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a
+ degenerate geometry.
+
+ The ``epsilon`` parameter specifies the tolerance for coordinates when determining that
+ vertices are identical.
+
+ By default, z values are not considered when detecting duplicate nodes. E.g. two nodes
+ with the same x and y coordinate but different z values will still be considered
+ duplicate and one will be removed. If ``useZValues`` is true, then the z values are
+ also tested and nodes with the same x and y but different z will be maintained.
+
+ Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g.
+ a multipoint geometry with overlapping points will not be changed by this method.
+
+ The function will return true if nodes were removed, or false if no duplicate nodes
+ were found.
+
+.. versionadded:: 3.0
+ :rtype: bool
+%End
+
     bool intersects( const QgsRectangle &r ) const;
 %Docstring
 Tests for intersection with a rectangle (uses GEOS)

python/core/geometry/qgsgeometrycollection.sip

@@ -52,6 +52,9 @@ class QgsGeometryCollection: QgsAbstractGeometry
     virtual void clear();
 
     virtual QgsGeometryCollection *snappedToGrid( double hSpacing, double vSpacing, double dSpacing = 0, double mSpacing = 0 ) const /Factory/;
+
+    virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
+
     virtual QgsAbstractGeometry *boundary() const /Factory/;
 
     virtual void adjacentVertices( QgsVertexId vertex, QgsVertexId &previousVertex /Out/, QgsVertexId &nextVertex /Out/ ) const;

python/core/geometry/qgslinestring.sip

@@ -179,6 +179,8 @@ Closes the line string by appending the first point to the end of the line, if i
 
     virtual QgsLineString *snappedToGrid( double hSpacing, double vSpacing, double dSpacing = 0, double mSpacing = 0 ) const /Factory/;
 
+    virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
+
 
     virtual bool fromWkb( QgsConstWkbPtr &wkb );
 

python/core/geometry/qgspoint.sip

@@ -339,6 +339,9 @@ class QgsPoint: QgsAbstractGeometry
     virtual QgsPoint *clone() const /Factory/;
 
     virtual QgsPoint *snappedToGrid( double hSpacing, double vSpacing, double dSpacing = 0, double mSpacing = 0 ) const /Factory/;
+
+    virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
+
     virtual void clear();
 
     virtual bool fromWkb( QgsConstWkbPtr &wkb );

python/plugins/processing/algs/qgis/CheckValidity.py

@@ -68,6 +68,9 @@ def icon(self):
     def group(self):
         return self.tr('Vector geometry')
 
+    def tags(self):
+        return self.tr('valid,invalid,detect').split(',')
+
     def __init__(self):
         super().__init__()
 
@@ -79,7 +82,7 @@ def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT_LAYER,
                                                               self.tr('Input layer')))
         self.addParameter(QgsProcessingParameterEnum(self.METHOD,
-                                                     self.tr('Method'), self.methods))
+                                                     self.tr('Method'), self.methods, defaultValue=2))
         self.parameterDefinition(self.METHOD).setMetadata({
             'widget_wrapper': {
                 'class': 'processing.gui.wrappers.EnumWidgetWrapper',

python/plugins/processing/algs/qgis/SnapGeometries.py

@@ -61,8 +61,10 @@ def initAlgorithm(self, config=None):
         self.addParameter(QgsProcessingParameterNumber(self.TOLERANCE, self.tr('Tolerance (layer units)'), type=QgsProcessingParameterNumber.Double,
                                                        minValue=0.00000001, maxValue=9999999999, defaultValue=10.0))
 
-        self.modes = [self.tr('Prefer aligning nodes'),
-                      self.tr('Prefer closest point'),
+        self.modes = [self.tr('Prefer aligning nodes, insert extra vertices where required'),
+                      self.tr('Prefer closest point, insert extra vertices where required'),
+                      self.tr('Prefer aligning nodes, don\'t insert new vertices'),
+                      self.tr('Prefer closest point, don\'t insert new vertices'),
                       self.tr('Move end points only, prefer aligning nodes'),
                       self.tr('Move end points only, prefer closest point'),
                       self.tr('Snap end points to end points only')]

python/plugins/processing/tests/testdata/custom/line_duplicate_nodes.gml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://ogr.maptools.org/ line_duplicate_nodes.xsd"
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>2</gml:X><gml:Y>0</gml:Y></gml:coord>
+      <gml:coord><gml:X>3</gml:X><gml:Y>3</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:line_duplicate_nodes fid="lines.2">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>2,0 2,2 3,2 3,3 3,3</gml:coordinates></gml:LineString></ogr:geometryProperty>
+    </ogr:line_duplicate_nodes>
+  </gml:featureMember>
+</ogr:FeatureCollection>

python/plugins/processing/tests/testdata/custom/line_duplicate_nodes.xsd

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xs:schema targetNamespace="http://ogr.maptools.org/" xmlns:ogr="http://ogr.maptools.org/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:gml="http://www.opengis.net/gml" elementFormDefault="qualified" version="1.0">
+<xs:import namespace="http://www.opengis.net/gml" schemaLocation="http://schemas.opengis.net/gml/2.1.2/feature.xsd"/>
+<xs:element name="FeatureCollection" type="ogr:FeatureCollectionType" substitutionGroup="gml:_FeatureCollection"/>
+<xs:complexType name="FeatureCollectionType">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureCollectionType">
+      <xs:attribute name="lockId" type="xs:string" use="optional"/>
+      <xs:attribute name="scope" type="xs:string" use="optional"/>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+<xs:element name="line_duplicate_nodes" type="ogr:line_duplicate_nodes_Type" substitutionGroup="gml:_Feature"/>
+<xs:complexType name="line_duplicate_nodes_Type">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureType">
+      <xs:sequence>
+        <xs:element name="geometryProperty" type="gml:LineStringPropertyType" nillable="true" minOccurs="0" maxOccurs="1"/>
+      </xs:sequence>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+</xs:schema>

python/plugins/processing/tests/testdata/expected/removed_duplicated_nodes_line.gml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://ogr.maptools.org/ removed_duplicated_nodes_line.xsd"
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>2</gml:X><gml:Y>0</gml:Y></gml:coord>
+      <gml:coord><gml:X>3</gml:X><gml:Y>3</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:removed_duplicated_nodes_line fid="lines.2">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>2,0 2,2 3,2 3,3</gml:coordinates></gml:LineString></ogr:geometryProperty>
+    </ogr:removed_duplicated_nodes_line>
+  </gml:featureMember>
+</ogr:FeatureCollection>

python/plugins/processing/tests/testdata/expected/removed_duplicated_nodes_line.xsd

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xs:schema targetNamespace="http://ogr.maptools.org/" xmlns:ogr="http://ogr.maptools.org/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:gml="http://www.opengis.net/gml" elementFormDefault="qualified" version="1.0">
+<xs:import namespace="http://www.opengis.net/gml" schemaLocation="http://schemas.opengis.net/gml/2.1.2/feature.xsd"/>
+<xs:element name="FeatureCollection" type="ogr:FeatureCollectionType" substitutionGroup="gml:_FeatureCollection"/>
+<xs:complexType name="FeatureCollectionType">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureCollectionType">
+      <xs:attribute name="lockId" type="xs:string" use="optional"/>
+      <xs:attribute name="scope" type="xs:string" use="optional"/>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+<xs:element name="removed_duplicated_nodes_line" type="ogr:removed_duplicated_nodes_line_Type" substitutionGroup="gml:_Feature"/>
+<xs:complexType name="removed_duplicated_nodes_line_Type">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureType">
+      <xs:sequence>
+        <xs:element name="geometryProperty" type="gml:LineStringPropertyType" nillable="true" minOccurs="0" maxOccurs="1"/>
+      </xs:sequence>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+</xs:schema>

python/plugins/processing/tests/testdata/expected/snap_lines_to_lines.gml

@@ -23,7 +23,7 @@
   </gml:featureMember>
   <gml:featureMember>
     <ogr:snap_lines_to_lines fid="lines.2">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>2,0 2,2 2,2 3,2</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>2,0 2,2 3,2</gml:coordinates></gml:LineString></ogr:geometryProperty>
     </ogr:snap_lines_to_lines>
   </gml:featureMember>
   <gml:featureMember>

python/plugins/processing/tests/testdata/expected/snap_polys_to_polys.gml

@@ -13,7 +13,7 @@
 
   <gml:featureMember>
     <ogr:snap_polys_to_polys fid="polys.0">
-      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>-1,-1 -1,3 3,3 3,2 2,2 2,2 2,2 2,-1 -1,-1</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>-1,-1 -1,3 3,3 3,2 2,2 2,-1 -1,-1</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
       <ogr:name>aaaaa</ogr:name>
       <ogr:intval>33</ogr:intval>
       <ogr:floatval>44.123456</ogr:floatval>

python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml

@@ -4582,3 +4582,15 @@ tests:
         name: expected/difference.gml
         type: vector
 
+  - algorithm: native:removeduplicatenodes
+    name: Remove duplicate nodes lines
+    params:
+      INPUT:
+        name: custom/line_duplicate_nodes.gml
+        type: vector
+      TOLERANCE: 1.0e-06
+      USE_Z_VALUE: false
+    results:
+      OUTPUT:
+        name: expected/removed_duplicated_nodes_line.gml
+        type: vector

src/analysis/CMakeLists.txt

@@ -51,6 +51,7 @@ SET(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmpackage.cpp
   processing/qgsalgorithmpromotetomultipart.cpp
   processing/qgsalgorithmrasterlayeruniquevalues.cpp
+  processing/qgsalgorithmremoveduplicatenodes
   processing/qgsalgorithmremovenullgeometry.cpp
   processing/qgsalgorithmrenamelayer.cpp
   processing/qgsalgorithmsaveselectedfeatures.cpp

src/analysis/processing/qgsalgorithmremoveduplicatenodes.cpp

@@ -0,0 +1,96 @@
+/***************************************************************************
+                         qgsalgorithmremoveduplicatenodes.cpp
+                         ---------------------
+    begin                : November 2017
+    copyright            : (C) 2017 by Nyall Dawson
+    email                : nyall dot dawson at gmail dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsalgorithmremoveduplicatenodes.h"
+
+///@cond PRIVATE
+
+QString QgsAlgorithmRemoveDuplicateNodes::name() const
+{
+  return QStringLiteral( "removeduplicatenodes" );
+}
+
+QString QgsAlgorithmRemoveDuplicateNodes::displayName() const
+{
+  return QObject::tr( "Remove duplicate nodes" );
+}
+
+QStringList QgsAlgorithmRemoveDuplicateNodes::tags() const
+{
+  return QObject::tr( "points,valid,overlapping" ).split( ',' );
+}
+
+QString QgsAlgorithmRemoveDuplicateNodes::group() const
+{
+  return QObject::tr( "Vector geometry" );
+}
+
+QString QgsAlgorithmRemoveDuplicateNodes::outputName() const
+{
+  return QObject::tr( "Cleaned" );
+}
+
+QString QgsAlgorithmRemoveDuplicateNodes::shortHelpString() const
+{
+  return QObject::tr( "This algorithm removes duplicate nodes from features, wherever removing the nodes does "
+                      "not result in a degenerate geometry.\n\n"
+                      "The tolerance parameter specifies the tolerance for coordinates when determining whether "
+                      "vertices are identical.\n\n"
+                      "By default, z values are not considered when detecting duplicate nodes. E.g. two nodes "
+                      "with the same x and y coordinate but different z values will still be considered "
+                      "duplicate and one will be removed. If the Use Z Value parameter is true, then the z values are "
+                      "also tested and nodes with the same x and y but different z will be maintained.\n\n"
+                      "Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g. "
+                      "a multipoint geometry with overlapping points will not be changed by this method." );
+}
+
+QgsAlgorithmRemoveDuplicateNodes *QgsAlgorithmRemoveDuplicateNodes::createInstance() const
+{
+  return new QgsAlgorithmRemoveDuplicateNodes();
+}
+
+void QgsAlgorithmRemoveDuplicateNodes::initParameters( const QVariantMap & )
+{
+  addParameter( new QgsProcessingParameterNumber( QStringLiteral( "TOLERANCE" ),
+                QObject::tr( "Tolerance" ), QgsProcessingParameterNumber::Double,
+                0.000001, false, 0, 10000000.0 ) );
+  addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "USE_Z_VALUE" ),
+                QObject::tr( "Use Z Value" ), false ) );
+}
+
+bool QgsAlgorithmRemoveDuplicateNodes::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * )
+{
+  mTolerance = parameterAsDouble( parameters, QStringLiteral( "TOLERANCE" ), context );
+  mUseZValues = parameterAsBool( parameters, QStringLiteral( "USE_Z_VALUE" ), context );
+  return true;
+}
+
+QgsFeature QgsAlgorithmRemoveDuplicateNodes::processFeature( const QgsFeature &feature, QgsProcessingContext &, QgsProcessingFeedback * )
+{
+  QgsFeature f = feature;
+  if ( f.hasGeometry() )
+  {
+    QgsGeometry geometry = f.geometry();
+    geometry.removeDuplicateNodes( mTolerance, mUseZValues );
+    f.setGeometry( geometry );
+  }
+  return f;
+}
+
+///@endcond
+
+