Merge pull request #9241 from m-kuhn/merge-lines-on-dissolve

[processing] Merge lines on dissolve
qgis · Feb 26, 2019 · 81f0c5c · 81f0c5c
2 parents fb324f3 + 7f30680
commit 81f0c5c
Show file tree

Hide file tree

Showing 5 changed files with 110 additions and 0 deletions.
diff --git a/python/plugins/processing/tests/testdata/custom/consecutivelines.gml b/python/plugins/processing/tests/testdata/custom/consecutivelines.gml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://ogr.maptools.org/ consecutivelines.xsd"
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>-0.9142351900972591</gml:X><gml:Y>-0.1405835543766578</gml:Y></gml:coord>
+      <gml:coord><gml:X>0.5411140583554377</gml:X><gml:Y>0.6870026525198939</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:consecutivelines fid="consecutivelines.0">
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>-0.914235190097259,0.687002652519894 -0.799292661361627,0.184792219274978 -0.36604774535809,0.19893899204244</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
+      <ogr:id xsi:nil="true"/>
+    </ogr:consecutivelines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:consecutivelines fid="consecutivelines.1">
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>-0.199823165340407,0.679929266136163 -0.076038903625111,0.315649867374005 0.541114058355438,-0.09814323607427</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
+      <ogr:id xsi:nil="true"/>
+    </ogr:consecutivelines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:consecutivelines fid="consecutivelines.2">
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>0.541114058355438,-0.09814323607427 0.173297966401415,-0.140583554376658</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
+      <ogr:id xsi:nil="true"/>
+    </ogr:consecutivelines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:consecutivelines fid="consecutivelines.3">
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>0.173297966401415,-0.140583554376658 -0.205128205128205,-0.057471264367816</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
+      <ogr:id xsi:nil="true"/>
+    </ogr:consecutivelines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:consecutivelines fid="consecutivelines.4">
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>-0.364279398762157,0.013262599469496 -0.205128205128205,-0.057471264367816</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
+      <ogr:id xsi:nil="true"/>
+    </ogr:consecutivelines>
+  </gml:featureMember>
+</ogr:FeatureCollection>
diff --git a/python/plugins/processing/tests/testdata/custom/consecutivelines.xsd b/python/plugins/processing/tests/testdata/custom/consecutivelines.xsd
@@ -0,0 +1,30 @@
+<?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="consecutivelines" type="ogr:consecutivelines_Type" substitutionGroup="gml:_Feature"/>
+<xs:complexType name="consecutivelines_Type">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureType">
+      <xs:sequence>
+        <xs:element name="geometryProperty" type="gml:MultiLineStringPropertyType" nillable="true" minOccurs="0" maxOccurs="1"/>
+        <xs:element name="id" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:long">
+              <xs:totalDigits value="10"/>
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+      </xs:sequence>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+</xs:schema>
diff --git a/python/plugins/processing/tests/testdata/expected/dissolved_consecutive_lines.gml b/python/plugins/processing/tests/testdata/expected/dissolved_consecutive_lines.gml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://ogr.maptools.org/ dissolved_consecutive_lines.xsd"
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>-0.914235190097259</gml:X><gml:Y>-0.140583554376658</gml:Y></gml:coord>
+      <gml:coord><gml:X>0.541114058355438</gml:X><gml:Y>0.687002652519894</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:dissolved_consecutive_lines fid="consecutivelines.0">
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>-0.914235190097259,0.687002652519894 -0.799292661361627,0.184792219274978 -0.36604774535809,0.19893899204244</gml:coordinates></gml:LineString></gml:lineStringMember><gml:lineStringMember><gml:LineString><gml:coordinates>-0.199823165340407,0.679929266136163 -0.076038903625111,0.315649867374005 0.541114058355438,-0.09814323607427 0.173297966401415,-0.140583554376658 -0.205128205128205,-0.057471264367816 -0.364279398762157,0.013262599469496</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
+      <ogr:id xsi:nil="true"/>
+    </ogr:dissolved_consecutive_lines>
+  </gml:featureMember>
+</ogr:FeatureCollection>
diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -7009,4 +7009,16 @@ tests:
         name: expected/surface_vol_gaps.gml
         type: vector
 
+  - algorithm: native:dissolve
+    name: Test dissolve with consecutive lines
+    params:
+      INPUT:
+        name: custom/consecutivelines.gml|layername=consecutivelines
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/dissolved_consecutive_lines.gml
+        type: vector
+
+
 # See ../README.md for a description of the file format
diff --git a/src/analysis/processing/qgsalgorithmdissolve.cpp b/src/analysis/processing/qgsalgorithmdissolve.cpp
@@ -215,6 +215,8 @@ QVariantMap QgsDissolveAlgorithm::processAlgorithm( const QVariantMap &parameter
   return processCollection( parameters, context, feedback, [ & ]( const QVector< QgsGeometry > &parts )->QgsGeometry
   {
     QgsGeometry result( QgsGeometry::unaryUnion( parts ) );
+    if ( QgsWkbTypes::geometryType( result.wkbType() ) == QgsWkbTypes::LineGeometry )
+      result = result.mergeLines();
     // Geos may fail in some cases, let's try a slower but safer approach
     // See: https://issues.qgis.org/issues/20591 - Dissolve tool failing to produce outputs
     if ( ! result.lastError().isEmpty() && parts.count() >  2 )
@@ -227,6 +229,8 @@ QVariantMap QgsDissolveAlgorithm::processAlgorithm( const QVariantMap &parameter
       for ( const auto &p : parts )
       {
         result = QgsGeometry::unaryUnion( QVector< QgsGeometry >() << result << p );
+        if ( QgsWkbTypes::geometryType( result.wkbType() ) == QgsWkbTypes::LineGeometry )
+          result = result.mergeLines();
         if ( feedback->isCanceled() )
           return result;
       }