[FEATURE][processing] "Create parallel lines" algorithm

This algorithm creates copies of line features in a layer, by creating multiple parallel versions of each feature. Each copy is offset by a preset distance.
qgis · Jul 27, 2018 · 76c84f14d795ef88ad8dafb138890386ffb300d1 · 76c84f1
1 parent b80ad5e
commit 76c84f14d795ef88ad8dafb138890386ffb300d1
diff --git a/python/plugins/processing/tests/testdata/expected/create_parallel_lines.gml b/python/plugins/processing/tests/testdata/expected/create_parallel_lines.gml
@@ -0,0 +1,188 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://ogr.maptools.org/ create_parallel_lines.xsd"
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>-1</gml:X><gml:Y>-3.6</gml:Y></gml:coord>
+      <gml:coord><gml:X>11.42426406871193</gml:X><gml:Y>5</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.0">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>6,2 9,2 9,3 11,5</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>0</ogr:instance>
+      <ogr:offset>0</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.0">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>11.1414213562373,4.85857864376269 9.2,2.91715728752538 9.2,1.8 6.0,1.8</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>1</ogr:instance>
+      <ogr:offset>-0.2</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.0">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>11.2828427124746,4.71715728752538 9.4,2.83431457505076 9.4,1.6 6.0,1.6</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>2</ogr:instance>
+      <ogr:offset>-0.4</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.0">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>11.4242640687119,4.57573593128807 9.6,2.75147186257614 9.6,1.4 6.0,1.4</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>3</ogr:instance>
+      <ogr:offset>-0.6</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.1">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>-1,-1 1,-1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>0</ogr:instance>
+      <ogr:offset>0</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.1">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>1.0,-1.2 -1.0,-1.2</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>1</ogr:instance>
+      <ogr:offset>-0.2</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.1">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>1.0,-1.4 -1.0,-1.4</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>2</ogr:instance>
+      <ogr:offset>-0.4</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.1">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>1.0,-1.6 -1.0,-1.6</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>3</ogr:instance>
+      <ogr:offset>-0.6</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines 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:instance>0</ogr:instance>
+      <ogr:offset>0</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.2">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>3.2,3.0 3.2,1.8 2.8,1.8 2.2,1.8 2.2,0.0</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>1</ogr:instance>
+      <ogr:offset>-0.2</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.2">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>3.4,3.0 3.4,1.6 2.93333333333333,1.6 2.4,1.6 2.4,0.0</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>2</ogr:instance>
+      <ogr:offset>-0.4</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.2">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>3.6,3.0 3.6,1.4 3.06666666666667,1.4 2.6,1.4 2.6,0.0</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>3</ogr:instance>
+      <ogr:offset>-0.6</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.3">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>3,1 5,1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>0</ogr:instance>
+      <ogr:offset>0</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.3">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>5.0,0.8 3.0,0.8</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>1</ogr:instance>
+      <ogr:offset>-0.2</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.3">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>5.0,0.6 3.0,0.6</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>2</ogr:instance>
+      <ogr:offset>-0.4</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.3">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>5.0,0.4 3.0,0.4</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>3</ogr:instance>
+      <ogr:offset>-0.6</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.4">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>7,-3 10,-3</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>0</ogr:instance>
+      <ogr:offset>0</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.4">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>10.0,-3.2 7.0,-3.2</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>1</ogr:instance>
+      <ogr:offset>-0.2</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.4">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>10.0,-3.4 7.0,-3.4</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>2</ogr:instance>
+      <ogr:offset>-0.4</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.4">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>10.0,-3.6 7.0,-3.6</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>3</ogr:instance>
+      <ogr:offset>-0.6</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.5">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>6,-3 10,1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>0</ogr:instance>
+      <ogr:offset>0</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.5">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>10.1414213562373,0.858578643762691 6.14142135623731,-3.14142135623731</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>1</ogr:instance>
+      <ogr:offset>-0.2</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.5">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>10.2828427124746,0.717157287525381 6.28284271247462,-3.28284271247462</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>2</ogr:instance>
+      <ogr:offset>-0.4</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.5">
+      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>10.4242640687119,0.575735931288071 6.42426406871193,-3.42426406871193</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:instance>3</ogr:instance>
+      <ogr:offset>-0.6</ogr:offset>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:create_parallel_lines fid="lines.6">
+      <ogr:instance xsi:nil="true"/>
+      <ogr:offset xsi:nil="true"/>
+    </ogr:create_parallel_lines>
+  </gml:featureMember>
+</ogr:FeatureCollection>
diff --git a/python/plugins/processing/tests/testdata/expected/create_parallel_lines.xsd b/python/plugins/processing/tests/testdata/expected/create_parallel_lines.xsd
@@ -0,0 +1,36 @@
+<?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="create_parallel_lines" type="ogr:create_parallel_lines_Type" substitutionGroup="gml:_Feature"/>
+<xs:complexType name="create_parallel_lines_Type">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureType">
+      <xs:sequence>
+        <xs:element name="geometryProperty" type="gml:LineStringPropertyType" nillable="true" minOccurs="0" maxOccurs="1"/>
+        <xs:element name="instance" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:integer">
+              <xs:totalDigits value="10"/>
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="offset" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+      </xs:sequence>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+</xs:schema>
diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -5908,5 +5908,20 @@ tests:
         name: expected/feature_array.shp
         type: vector
 
+  - algorithm: native:parallellines
+    name: Create parallel lines
+    params:
+      COUNT: 3
+      INPUT:
+        name: lines.gml
+        type: vector
+      JOIN_STYLE: 1
+      MITER_LIMIT: 2.0
+      OFFSET: -0.2
+      SEGMENTS: 8
+    results:
+      OUTPUT:
+        name: expected/create_parallel_lines.gml
+        type: vector
 
 # See ../README.md for a description of the file format
diff --git a/src/analysis/CMakeLists.txt b/src/analysis/CMakeLists.txt
@@ -61,6 +61,7 @@ SET(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmorderbyexpression.cpp
   processing/qgsalgorithmorientedminimumboundingbox.cpp
   processing/qgsalgorithmpackage.cpp
+  processing/qgsalgorithmparallellines.cpp
   processing/qgsalgorithmpointonsurface.cpp
   processing/qgsalgorithmprojectpointcartesian.cpp
   processing/qgsalgorithmpromotetomultipart.cpp

diff --git a/src/analysis/processing/qgsalgorithmarrayfeatures.cpp b/src/analysis/processing/qgsalgorithmarrayfeatures.cpp
@@ -36,12 +36,12 @@ QStringList QgsArrayFeaturesAlgorithm::tags() const
 
 QString QgsArrayFeaturesAlgorithm::group() const
 {
-  return QObject::tr( "Vector geometry" );
+  return QObject::tr( "Vector creation" );
 }
 
 QString QgsArrayFeaturesAlgorithm::groupId() const
 {
-  return QStringLiteral( "vectorgeometry" );
+  return QStringLiteral( "vectorcreation" );
 }
 
 QString QgsArrayFeaturesAlgorithm::outputName() const
@@ -69,7 +69,7 @@ void QgsArrayFeaturesAlgorithm::initParameters( const QVariantMap & )
 {
   std::unique_ptr< QgsProcessingParameterNumber > count = qgis::make_unique< QgsProcessingParameterNumber >( QStringLiteral( "COUNT" ),
       QObject::tr( "Number of features to create" ), QgsProcessingParameterNumber::Integer,
-      10, true, 1 );
+      10, false, 1 );
   count->setIsDynamic( true );
   count->setDynamicPropertyDefinition( QgsPropertyDefinition( QStringLiteral( "COUNT" ), QObject::tr( "Number of features to create" ), QgsPropertyDefinition::IntegerPositiveGreaterZero ) );
   count->setDynamicLayerParameterName( QStringLiteral( "INPUT" ) );