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wonder-skwonder-sk
committedOct 14, 2017
New API for traversal of geometry's vertices using iterator pattern
Introducing: 1. STL-style iterator: QgsAbstractGeometry::vertex_iterator 2. Java-style iterator: QgsVertexIterator (built on top of STL-style) The iterators are modeled after Qt's STL-style and Java-style iterators, the idea is to replace nextVertex() method and later introduce iterators for other bits (e.g. part_iterator, ring_iterator).
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ltr-3_40final-3_0_0
1 parent b91b854 commit 7e34bee

20 files changed

+731
-0
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‎python/core/geometry/qgsabstractgeometry.sip

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@@ -463,6 +463,56 @@ Returns the centroid of the geometry
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:rtype: bool
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%End
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QgsVertexIterator vertices() const;
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%Docstring
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Returns Java-style iterator for traversal of vertices of the geometry
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.. versionadded:: 3.0
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:rtype: QgsVertexIterator
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%End
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protected:
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virtual bool hasChildGeometries() const;
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%Docstring
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Returns whether the geometry has any child geometries (false for point / curve, true otherwise)
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.. note::
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used for vertex_iterator implementation
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.. versionadded:: 3.0
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:rtype: bool
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%End
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virtual int childCount() const;
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%Docstring
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Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e. curve / point)
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.. note::
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used for vertex_iterator implementation
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.. versionadded:: 3.0
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:rtype: int
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%End
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virtual QgsAbstractGeometry *childGeometry( int index ) const;
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%Docstring
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Returns pointer to child geometry (for geometries with child geometries - i.e. geom. collection / polygon)
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.. note::
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used for vertex_iterator implementation
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.. versionadded:: 3.0
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:rtype: QgsAbstractGeometry
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%End
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virtual QgsPoint childPoint( int index ) const;
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%Docstring
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Returns point at index (for geometries without child geometries - i.e. curve / point)
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.. note::
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used for vertex_iterator implementation
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.. versionadded:: 3.0
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:rtype: QgsPoint
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%End
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protected:
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void setZMTypeFromSubGeometry( const QgsAbstractGeometry *subggeom, QgsWkbTypes::Type baseGeomType );
@@ -531,6 +581,54 @@ struct QgsVertexId
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class QgsVertexIterator
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{
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%Docstring
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Java-style iterator for traversal of vertices of a geometry
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.. versionadded:: 3.0
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%End
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%TypeHeaderCode
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#include "qgsabstractgeometry.h"
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%End
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public:
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QgsVertexIterator();
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QgsVertexIterator( const QgsAbstractGeometry *geometry );
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%Docstring
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Constructs iterator for the given geometry
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%End
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bool hasNext() const;
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%Docstring
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Find out whether there are more vertices
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:rtype: bool
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%End
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QgsPoint next();
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%Docstring
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Return next vertex of the geometry (undefined behavior if hasNext() returns false before calling next())
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:rtype: QgsPoint
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%End
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QgsVertexIterator *__iter__();
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%Docstring
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:rtype: QgsVertexIterator
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%End
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%MethodCode
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sipRes = sipCpp;
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%End
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SIP_PYOBJECT __next__();
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%MethodCode
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if ( sipCpp->hasNext() )
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sipRes = sipConvertFromType( new QgsPoint( sipCpp->next() ), sipType_QgsPoint, Py_None );
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else
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PyErr_SetString( PyExc_StopIteration, "" );
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%End
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};
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/************************************************************************
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* This file has been generated automatically from *
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* *

‎python/core/geometry/qgscurve.sip

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@@ -177,6 +177,9 @@ class QgsCurve: QgsAbstractGeometry
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virtual void clearCache() const;
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virtual int childCount() const;
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virtual QgsPoint childPoint( int index ) const;
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};
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/************************************************************************

‎python/core/geometry/qgscurvepolygon.sip

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@@ -192,6 +192,10 @@ Adds an interior ring to the geometry (takes ownership)
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virtual QgsCurvePolygon *toCurveType() const /Factory/;
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protected:
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virtual int childCount() const;
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virtual QgsAbstractGeometry *childGeometry( int index ) const;
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protected:
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‎python/core/geometry/qgsgeometry.sip

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@@ -241,6 +241,14 @@ Returns true if WKB of the geometry is of WKBMulti* type
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:rtype: float
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%End
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QgsVertexIterator vertices() const;
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%Docstring
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Returns Java-style iterator for traversal of vertices of the geometry
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.. versionadded:: 3.0
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:rtype: QgsVertexIterator
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%End
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double hausdorffDistance( const QgsGeometry &geom ) const;
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%Docstring
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Returns the Hausdorff distance between this geometry and ``geom``. This is basically a measure of how similar or dissimilar 2 geometries are.

‎python/core/geometry/qgsgeometrycollection.sip

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@@ -168,6 +168,10 @@ Adds a geometry and takes ownership. Returns true in case of success.
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protected:
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virtual int childCount() const;
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virtual QgsAbstractGeometry *childGeometry( int index ) const;
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protected:
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virtual bool wktOmitChildType() const;

‎python/core/geometry/qgspoint.sip

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@@ -410,6 +410,11 @@ class QgsPoint: QgsAbstractGeometry
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virtual bool convertTo( QgsWkbTypes::Type type );
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protected:
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virtual int childCount() const;
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virtual QgsPoint childPoint( int index ) const;
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};
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‎src/core/geometry/qgsabstractgeometry.cpp

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@@ -246,6 +246,22 @@ bool QgsAbstractGeometry::convertTo( QgsWkbTypes::Type type )
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return true;
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}
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QgsVertexIterator QgsAbstractGeometry::vertices() const
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{
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return QgsVertexIterator( this );
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}
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bool QgsAbstractGeometry::hasChildGeometries() const
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{
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return QgsWkbTypes::isMultiType( wkbType() ) || dimension() == 2;
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}
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QgsPoint QgsAbstractGeometry::childPoint( int index ) const
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{
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Q_UNUSED( index );
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return QgsPoint();
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}
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bool QgsAbstractGeometry::isEmpty() const
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{
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QgsVertexId vId;
@@ -265,3 +281,112 @@ QgsAbstractGeometry *QgsAbstractGeometry::segmentize( double tolerance, Segmenta
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return clone();
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}
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QgsAbstractGeometry::vertex_iterator::vertex_iterator( const QgsAbstractGeometry *g, int index )
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: depth( 0 )
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{
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::memset( levels, 0, sizeof( Level ) * 3 ); // make sure we clean up also the padding areas (for memcmp test in operator==)
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levels[0].g = g;
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levels[0].index = index;
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digDown(); // go to the leaf level of the first vertex
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}
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QgsAbstractGeometry::vertex_iterator &QgsAbstractGeometry::vertex_iterator::operator++()
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{
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if ( depth == 0 && levels[0].index >= levels[0].g->childCount() )
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return *this; // end of geometry - nowhere else to go
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Q_ASSERT( !levels[depth].g->hasChildGeometries() ); // we should be at a leaf level
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++levels[depth].index;
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// traverse up if we are at the end in the current level
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while ( depth > 0 && levels[depth].index >= levels[depth].g->childCount() )
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{
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--depth;
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++levels[depth].index;
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}
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digDown(); // go to the leaf level again
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return *this;
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}
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QgsAbstractGeometry::vertex_iterator QgsAbstractGeometry::vertex_iterator::operator++( int )
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{
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vertex_iterator it( *this );
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++*this;
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return it;
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}
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QgsPoint QgsAbstractGeometry::vertex_iterator::operator*() const
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{
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Q_ASSERT( !levels[depth].g->hasChildGeometries() );
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return levels[depth].g->childPoint( levels[depth].index );
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}
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QgsVertexId QgsAbstractGeometry::vertex_iterator::vertexId() const
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{
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int part = 0, ring = 0, vertex = levels[depth].index;
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if ( depth == 0 )
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{
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// nothing else to do
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}
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else if ( depth == 1 )
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{
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if ( QgsWkbTypes::isMultiType( levels[0].g->wkbType() ) )
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part = levels[0].index;
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else
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ring = levels[0].index;
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}
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else if ( depth == 2 )
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{
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part = levels[0].index;
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ring = levels[1].index;
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}
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else
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{
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Q_ASSERT( false );
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return QgsVertexId();
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}
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// get the vertex type: find out from the leaf geometry
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QgsVertexId::VertexType vertexType = QgsVertexId::SegmentVertex;
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if ( const QgsCurve *curve = dynamic_cast<const QgsCurve *>( levels[depth].g ) )
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{
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QgsPoint p;
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curve->pointAt( vertex, p, vertexType );
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}
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return QgsVertexId( part, ring, vertex, vertexType );
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}
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bool QgsAbstractGeometry::vertex_iterator::operator==( const QgsAbstractGeometry::vertex_iterator &other ) const
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{
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if ( depth != other.depth )
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return false;
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int res = ::memcmp( levels, other.levels, sizeof( Level ) * ( depth + 1 ) );
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return res == 0;
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}
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void QgsAbstractGeometry::vertex_iterator::digDown()
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{
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if ( levels[depth].g->hasChildGeometries() && levels[depth].index >= levels[depth].g->childCount() )
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return; // first check we are not already at the end
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// while not "final" depth for the geom: go one level down.
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while ( levels[depth].g->hasChildGeometries() )
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{
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++depth;
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Q_ASSERT( depth < 3 ); // that's capacity of the levels array
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levels[depth].index = 0;
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levels[depth].g = levels[depth - 1].g->childGeometry( levels[depth - 1].index );
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}
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}
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QgsPoint QgsVertexIterator::next()
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{
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n = i++;
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return *n;
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}

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