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https://github.com/qgis/QGIS.git
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dbe830b0bb
The maintenance of three R-trees was too complicated, using a lot of memory and the performance benefit was questionable :) The approach with just one R-tree leads to much simpler code Removed k-NN queries in the process - they were not used in QGIS code. They can be reintroduced later, but there is not much use for them right now...
88 lines
3.2 KiB
Plaintext
88 lines
3.2 KiB
Plaintext
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class QgsPointLocator : QObject
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{
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%TypeHeaderCode
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#include <qgspointlocator.h>
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%End
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public:
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/** Construct point locator for a layer.
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* @arg destCRS if not null, will do the searches on data reprojected to the given CRS
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* @arg extent if not null, will index only a subset of the layer
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*/
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explicit QgsPointLocator( QgsVectorLayer* layer, const QgsCoordinateReferenceSystem* destCRS = 0, const QgsRectangle* extent = 0 );
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~QgsPointLocator();
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enum Type { Invalid, Vertex, Edge, Area, All };
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/** Prepare the index for queries. Does nothing if the index already exists */
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void init();
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struct Match
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{
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//! consruct invalid match
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Match();
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Match( QgsPointLocator::Type t, QgsVectorLayer* vl, QgsFeatureId fid, double dist, const QgsPoint& pt, int vertexIndex = 0 );
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QgsPointLocator::Type type() const;
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bool isValid() const;
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bool hasVertex() const;
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bool hasEdge() const;
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bool hasArea() const;
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//! for vertex / edge match
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//! units depending on what class returns it (geom.cache: layer units, map canvas snapper: dest crs units)
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double distance() const;
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//! for vertex / edge match
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//! coords depending on what class returns it (geom.cache: layer coords, map canvas snapper: dest coords)
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QgsPoint point() const;
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//! for vertex / edge match (first vertex of the edge)
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int vertexIndex() const;
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//! reference vector layer
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QgsVectorLayer* layer() const;
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QgsFeatureId featureId() const;
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//! Only for a valid edge match - obtain endpoints of the edge
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void edgePoints( QgsPoint& pt1 /Out/, QgsPoint& pt2 /Out/ ) const;
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};
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typedef QList<QgsPointLocator::Match> MatchList;
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//! Interface that allows rejection of some matches in intersection queries
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//! (e.g. a match can only belong to a particular feature / match must not be a particular point).
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//! Implement the interface and pass its instance to QgsPointLocator or QgsSnappingUtils methods.
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struct MatchFilter
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{
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virtual bool acceptMatch( const QgsPointLocator::Match& match ) = 0;
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};
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// intersection queries
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//! Find nearest vertex to the specified point - up to distance specified by tolerance
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//! Optional filter may discard unwanted matches.
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Match nearestVertex( const QgsPoint& point, double tolerance, QgsPointLocator::MatchFilter* filter = 0 );
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//! Find nearest edges to the specified point - up to distance specified by tolerance
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//! Optional filter may discard unwanted matches.
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Match nearestEdge( const QgsPoint& point, double tolerance, QgsPointLocator::MatchFilter* filter = 0 );
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//! Find edges within a specified recangle
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//! Optional filter may discard unwanted matches.
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MatchList edgesInRect( const QgsRectangle& rect, QgsPointLocator::MatchFilter* filter = 0 );
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//! Override of edgesInRect that construct rectangle from a center point and tolerance
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MatchList edgesInRect( const QgsPoint& point, double tolerance, QgsPointLocator::MatchFilter* filter = 0 );
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// point-in-polygon query
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// TODO: function to return just the first match?
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//! find out if the point is in any polygons
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MatchList pointInPolygon( const QgsPoint& point );
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};
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