Add QgsCircularString::append( const QgsCircularString* )

Appends the contents of one circular string to the end of another
qgis · Apr 27, 2021 · a9a6e38 · a9a6e38
1 parent 12066cc
commit a9a6e38
Show file tree

Hide file tree

Showing 4 changed files with 214 additions and 0 deletions.
diff --git a/python/core/auto_generated/geometry/qgscircularstring.sip.in b/python/core/auto_generated/geometry/qgscircularstring.sip.in
@@ -122,6 +122,21 @@ Returns the point at index i within the circular string.
     void setPoints( const QgsPointSequence &points );
 %Docstring
 Sets the circular string's points
+%End
+
+    void append( const QgsCircularString *string );
+%Docstring
+Appends the contents of another circular ``string`` to the end of this circular string.
+
+:param string: circular string to append. Ownership is not transferred.
+
+.. warning::
+
+   It is the caller's responsibility to ensure that the first point in the appended
+   ``string`` matches the last point in the existing curve, or the result will be undefined.
+
+
+.. versionadded:: 3.20
 %End
 
     virtual double length() const;

diff --git a/src/core/geometry/qgscircularstring.cpp b/src/core/geometry/qgscircularstring.cpp
@@ -853,6 +853,71 @@ void QgsCircularString::setPoints( const QgsPointSequence &points )
   }
 }
 
+void QgsCircularString::append( const QgsCircularString *line )
+{
+  if ( !line )
+  {
+    return;
+  }
+
+  if ( numPoints() < 1 )
+  {
+    setZMTypeFromSubGeometry( line, QgsWkbTypes::CircularString );
+  }
+
+  // do not store duplicate points
+  if ( numPoints() > 0 &&
+       line->numPoints() > 0 &&
+       qgsDoubleNear( endPoint().x(), line->startPoint().x() ) &&
+       qgsDoubleNear( endPoint().y(), line->startPoint().y() ) &&
+       ( !is3D() || !line->is3D() || qgsDoubleNear( endPoint().z(), line->startPoint().z() ) ) &&
+       ( !isMeasure() || !line->isMeasure() || qgsDoubleNear( endPoint().m(), line->startPoint().m() ) ) )
+  {
+    mX.pop_back();
+    mY.pop_back();
+
+    if ( is3D() && line->is3D() )
+    {
+      mZ.pop_back();
+    }
+    if ( isMeasure() && line->isMeasure() )
+    {
+      mM.pop_back();
+    }
+  }
+
+  mX += line->mX;
+  mY += line->mY;
+
+  if ( is3D() )
+  {
+    if ( line->is3D() )
+    {
+      mZ += line->mZ;
+    }
+    else
+    {
+      // if append line does not have z coordinates, fill with NaN to match number of points in final line
+      mZ.insert( mZ.count(), mX.size() - mZ.size(), std::numeric_limits<double>::quiet_NaN() );
+    }
+  }
+
+  if ( isMeasure() )
+  {
+    if ( line->isMeasure() )
+    {
+      mM += line->mM;
+    }
+    else
+    {
+      // if append line does not have m values, fill with NaN to match number of points in final line
+      mM.insert( mM.count(), mX.size() - mM.size(), std::numeric_limits<double>::quiet_NaN() );
+    }
+  }
+
+  clearCache(); //set bounding box invalid
+}
+
 void QgsCircularString::draw( QPainter &p ) const
 {
   QPainterPath path;

diff --git a/src/core/geometry/qgscircularstring.h b/src/core/geometry/qgscircularstring.h
@@ -118,6 +118,18 @@ class CORE_EXPORT QgsCircularString: public QgsCurve
      */
     void setPoints( const QgsPointSequence &points );
 
+    /**
+     * Appends the contents of another circular \a string to the end of this circular string.
+     *
+     * \param string circular string to append. Ownership is not transferred.
+     *
+     * \warning It is the caller's responsibility to ensure that the first point in the appended
+     * \a string matches the last point in the existing curve, or the result will be undefined.
+     *
+     * \since QGIS 3.20
+     */
+    void append( const QgsCircularString *string );
+
     double length() const override;
     QgsPoint startPoint() const override SIP_HOLDGIL;
     QgsPoint endPoint() const override SIP_HOLDGIL;

diff --git a/tests/src/core/testqgsgeometry.cpp b/tests/src/core/testqgsgeometry.cpp
@@ -126,6 +126,7 @@ class TestQgsGeometry : public QObject
     void lineString(); //test QgsLineString
     void circularString();
     void circularStringFromArray();
+    void circularStringAppend();
     void polygon(); //test QgsPolygon
     void curvePolygon();
     void triangle();
@@ -3163,6 +3164,127 @@ void TestQgsGeometry::circularStringFromArray()
   QCOMPARE( fromArray8.pointN( 2 ).m(), 33.0 );
 }
 
+void TestQgsGeometry::circularStringAppend()
+{
+  //append circularstring
+
+  //append to empty
+  QgsCircularString l10;
+  l10.append( nullptr );
+  QVERIFY( l10.isEmpty() );
+  QCOMPARE( l10.numPoints(), 0 );
+
+  std::unique_ptr<QgsCircularString> toAppend( new QgsCircularString() );
+  toAppend->setPoints( QgsPointSequence() << QgsPoint( 1, 2 )
+                       << QgsPoint( 11, 12 )
+                       << QgsPoint( 21, 22 ) );
+  l10.append( toAppend.get() );
+  QVERIFY( !l10.is3D() );
+  QVERIFY( !l10.isMeasure() );
+  QCOMPARE( l10.numPoints(), 3 );
+  QCOMPARE( l10.vertexCount(), 3 );
+  QCOMPARE( l10.nCoordinates(), 3 );
+  QCOMPARE( l10.ringCount(), 1 );
+  QCOMPARE( l10.partCount(), 1 );
+  QCOMPARE( l10.wkbType(), QgsWkbTypes::CircularString );
+  QCOMPARE( l10.pointN( 0 ), toAppend->pointN( 0 ) );
+  QCOMPARE( l10.pointN( 1 ), toAppend->pointN( 1 ) );
+  QCOMPARE( l10.pointN( 2 ), toAppend->pointN( 2 ) );
+
+  //add more points
+  toAppend.reset( new QgsCircularString() );
+  toAppend->setPoints( QgsPointSequence() << QgsPoint( 21, 22 )
+                       << QgsPoint( 41, 42 )
+                       << QgsPoint( 51, 52 ) );
+  l10.append( toAppend.get() );
+  QCOMPARE( l10.numPoints(), 5 );
+  QCOMPARE( l10.vertexCount(), 5 );
+  QCOMPARE( l10.nCoordinates(), 5 );
+  QCOMPARE( l10.ringCount(), 1 );
+  QCOMPARE( l10.partCount(), 1 );
+  QCOMPARE( l10.pointN( 2 ), toAppend->pointN( 0 ) );
+  QCOMPARE( l10.pointN( 3 ), toAppend->pointN( 1 ) );
+  QCOMPARE( l10.pointN( 4 ), toAppend->pointN( 2 ) );
+
+  //check dimensionality is inherited from append line if initially empty
+  l10.clear();
+  toAppend.reset( new QgsCircularString() );
+  toAppend->setPoints( QgsPointSequence() << QgsPoint( QgsWkbTypes::PointZM, 31, 32, 33, 34 )
+                       << QgsPoint( QgsWkbTypes::PointZM, 41, 42, 43, 44 )
+                       << QgsPoint( QgsWkbTypes::PointZM, 51, 52, 53, 54 ) );
+  l10.append( toAppend.get() );
+  QVERIFY( l10.is3D() );
+  QVERIFY( l10.isMeasure() );
+  QCOMPARE( l10.numPoints(), 3 );
+  QCOMPARE( l10.ringCount(), 1 );
+  QCOMPARE( l10.partCount(), 1 );
+  QCOMPARE( l10.wkbType(), QgsWkbTypes::CircularStringZM );
+  QCOMPARE( l10.pointN( 0 ), toAppend->pointN( 0 ) );
+  QCOMPARE( l10.pointN( 1 ), toAppend->pointN( 1 ) );
+  QCOMPARE( l10.pointN( 2 ), toAppend->pointN( 2 ) );
+
+  //append points with z to non z circular string
+  l10.clear();
+  l10.setPoints( QgsPointSequence() << QgsPoint( QgsWkbTypes::Point, 31, 32 )
+                 << QgsPoint( QgsWkbTypes::Point, 41, 42 )
+                 << QgsPoint( QgsWkbTypes::Point, 51, 52 ) );
+  QVERIFY( !l10.is3D() );
+  QCOMPARE( l10.wkbType(), QgsWkbTypes::CircularString );
+  toAppend.reset( new QgsCircularString() );
+  toAppend->setPoints( QgsPointSequence() << QgsPoint( QgsWkbTypes::PointZM, 51, 52, 33, 34 )
+                       << QgsPoint( QgsWkbTypes::PointZM, 141, 142, 43, 44 )
+                       << QgsPoint( QgsWkbTypes::PointZM, 151, 152, 53, 54 ) );
+  l10.append( toAppend.get() );
+  QCOMPARE( l10.wkbType(), QgsWkbTypes::CircularString );
+  QCOMPARE( l10.pointN( 0 ), QgsPoint( 31, 32 ) );
+  QCOMPARE( l10.pointN( 1 ), QgsPoint( 41, 42 ) );
+  QCOMPARE( l10.pointN( 2 ), QgsPoint( 51, 52 ) );
+  QCOMPARE( l10.pointN( 3 ), QgsPoint( 141, 142 ) );
+  QCOMPARE( l10.pointN( 4 ), QgsPoint( 151, 152 ) );
+
+  //append points without z/m to circularstring with z & m
+  l10.clear();
+  l10.setPoints( QgsPointSequence() << QgsPoint( QgsWkbTypes::PointZM, 31, 32, 11, 21 )
+                 << QgsPoint( QgsWkbTypes::PointZM, 41, 42, 12, 22 )
+                 << QgsPoint( QgsWkbTypes::PointZM, 51, 52, 13, 23 ) );
+  QVERIFY( l10.is3D() );
+  QVERIFY( l10.isMeasure() );
+  QCOMPARE( l10.wkbType(), QgsWkbTypes::CircularStringZM );
+  toAppend.reset( new QgsCircularString() );
+  toAppend->setPoints( QgsPointSequence() << QgsPoint( 51, 52 )
+                       << QgsPoint( 141, 142 )
+                       << QgsPoint( 151, 152 ) );
+  l10.append( toAppend.get() );
+  QCOMPARE( l10.wkbType(), QgsWkbTypes::CircularStringZM );
+  QCOMPARE( l10.pointN( 0 ), QgsPoint( QgsWkbTypes::PointZM, 31, 32, 11, 21 ) );
+  QCOMPARE( l10.pointN( 1 ), QgsPoint( QgsWkbTypes::PointZM, 41, 42, 12, 22 ) );
+  QCOMPARE( l10.pointN( 2 ), QgsPoint( QgsWkbTypes::PointZM, 51, 52, 13, 23 ) );
+  QCOMPARE( l10.pointN( 3 ), QgsPoint( QgsWkbTypes::PointZM, 141, 142 ) );
+  QCOMPARE( l10.pointN( 4 ), QgsPoint( QgsWkbTypes::PointZM, 151, 152 ) );
+
+  //append another line the closes the original geometry.
+  //Make sure there are not duplicate points except start and end point
+  l10.clear();
+  toAppend.reset( new QgsCircularString() );
+  toAppend->setPoints( QgsPointSequence()
+                       << QgsPoint( 1, 1 )
+                       << QgsPoint( 5, 5 )
+                       << QgsPoint( 10, 1 ) );
+  l10.append( toAppend.get() );
+  QCOMPARE( l10.numPoints(), 3 );
+  QCOMPARE( l10.vertexCount(), 3 );
+  toAppend.reset( new QgsCircularString() );
+  toAppend->setPoints( QgsPointSequence()
+                       << QgsPoint( 10, 1 )
+                       << QgsPoint( 5, 2 )
+                       << QgsPoint( 1, 1 ) );
+  l10.append( toAppend.get() );
+
+  QVERIFY( l10.isClosed() );
+  QCOMPARE( l10.numPoints(), 5 );
+  QCOMPARE( l10.vertexCount(), 5 );
+}
+
 void TestQgsGeometry::lineString()
 {
   //test constructors