QGIS API Documentation
2.10.1-Pisa
|
A geometry is the spatial representation of a feature. More...
#include <qgsgeometry.h>
Classes | |
class | Error |
Public Member Functions | |
QgsGeometry () | |
Constructor. More... | |
QgsGeometry (const QgsGeometry &) | |
copy constructor will prompt a deep copy of the object More... | |
QgsGeometry (QgsAbstractGeometryV2 *geom) | |
Creates a geometry from an abstract geometry object. More... | |
~QgsGeometry () | |
Destructor. More... | |
int | addPart (const QList< QgsPoint > &points, QGis::GeometryType geomType=QGis::UnknownGeometry) |
Adds a new island polygon to a multipolygon feature. More... | |
int | addPart (QgsAbstractGeometryV2 *part) |
Adds a new part to this geometry (takes ownership) More... | |
int | addPart (GEOSGeometry *newPart) |
Adds a new island polygon to a multipolygon feature. More... | |
int | addPart (const QgsGeometry *newPart) |
Adds a new island polygon to a multipolygon feature. More... | |
int | addRing (const QList< QgsPoint > &ring) |
Adds a new ring to this geometry. More... | |
int | addRing (QgsCurveV2 *ring) |
Adds a new ring to this geometry. More... | |
void | adjacentVertices (int atVertex, int &beforeVertex, int &afterVertex) const |
Returns the indexes of the vertices before and after the given vertex index. More... | |
double | area () const |
Returns the area of the geometry using GEOS. More... | |
QList< QgsGeometry * > | asGeometryCollection () const |
Return contents of the geometry as a list of geometries. More... | |
const GEOSGeometry * | asGeos () const |
Returns a geos geometry. More... | |
QgsMultiPoint | asMultiPoint () const |
Return contents of the geometry as a multi point if wkbType is WKBMultiPoint, otherwise an empty list. More... | |
QgsMultiPolygon | asMultiPolygon () const |
Return contents of the geometry as a multi polygon if wkbType is WKBMultiPolygon, otherwise an empty list. More... | |
QgsMultiPolyline | asMultiPolyline () const |
Return contents of the geometry as a multi linestring if wkbType is WKBMultiLineString, otherwise an empty list. More... | |
QgsPoint | asPoint () const |
Return contents of the geometry as a point if wkbType is WKBPoint, otherwise returns [0,0]. More... | |
QgsPolygon | asPolygon () const |
Return contents of the geometry as a polygon if wkbType is WKBPolygon, otherwise an empty list. More... | |
QgsPolyline | asPolyline () const |
Return contents of the geometry as a polyline if wkbType is WKBLineString, otherwise an empty list. More... | |
QPointF | asQPointF () const |
Return contents of the geometry as a QPointF if wkbType is WKBPoint, otherwise returns a null QPointF. More... | |
QPolygonF | asQPolygonF () const |
Return contents of the geometry as a QPolygonF. More... | |
const unsigned char * | asWkb () const |
Returns the buffer containing this geometry in WKB format. More... | |
int | avoidIntersections (QMap< QgsVectorLayer *, QSet< QgsFeatureId > > ignoreFeatures=(QMap< QgsVectorLayer *, QSet< QgsFeatureId > >())) |
Modifies geometry to avoid intersections with the layers specified in project properties. More... | |
QgsRectangle | boundingBox () const |
Returns the bounding box of this feature. More... | |
QgsGeometry * | buffer (double distance, int segments) const |
Returns a buffer region around this geometry having the given width and with a specified number of segments used to approximate curves. More... | |
QgsGeometry * | buffer (double distance, int segments, int endCapStyle, int joinStyle, double mitreLimit) const |
Returns a buffer region around the geometry, with additional style options. More... | |
QgsGeometry * | centroid () const |
Returns the center of mass of a geometry. More... | |
double | closestSegmentWithContext (const QgsPoint &point, QgsPoint &minDistPoint, int &afterVertex, double *leftOf=0, double epsilon=DEFAULT_SEGMENT_EPSILON) const |
Searches for the closest segment of geometry to the given point. More... | |
QgsPoint | closestVertex (const QgsPoint &point, int &atVertex, int &beforeVertex, int &afterVertex, double &sqrDist) const |
Returns the vertex closest to the given point, the corresponding vertex index, squared distance snap point / target point and the indices of the vertices before/after. More... | |
double | closestVertexWithContext (const QgsPoint &point, int &atVertex) const |
Searches for the closest vertex in this geometry to the given point. More... | |
QgsGeometry * | combine (const QgsGeometry *geometry) const |
Returns a geometry representing all the points in this geometry and other (a union geometry operation). More... | |
bool | contains (const QgsPoint *p) const |
Test for containment of a point (uses GEOS) More... | |
bool | contains (const QgsGeometry *geometry) const |
Test for if geometry is contained in another (uses GEOS) More... | |
bool | convertToMultiType () |
Converts single type geometry into multitype geometry e.g. More... | |
void | convertToStraightSegment () |
Converts the geometry to straight line segments, if it is a curved geometry type. More... | |
QgsGeometry * | convertToType (QGis::GeometryType destType, bool destMultipart=false) const |
Try to convert the geometry to the requested type. More... | |
QgsGeometry * | convexHull () const |
Returns the smallest convex polygon that contains all the points in the geometry. More... | |
bool | crosses (const QgsGeometry *geometry) const |
Test for if geometry crosses another (uses GEOS) More... | |
bool | deletePart (int partNum) |
Delete part identified by the part number. More... | |
bool | deleteRing (int ringNum, int partNum=0) |
Delete a ring in polygon or multipolygon. More... | |
bool | deleteVertex (int atVertex) |
Deletes the vertex at the given position number and item (first number is index 0) Returns false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point), or if the number of remaining verticies in the linestring would be less than two. More... | |
QgsGeometry * | difference (const QgsGeometry *geometry) const |
Returns a geometry representing the points making up this geometry that do not make up other. More... | |
bool | disjoint (const QgsGeometry *geometry) const |
Test for if geometry is disjoint of another (uses GEOS) More... | |
double | distance (const QgsGeometry &geom) const |
Returns the minimum distanace between this geometry and another geometry, using GEOS. More... | |
void | draw (QPainter &p) const |
Draws the geometry onto a QPainter. More... | |
bool | equals (const QgsGeometry *geometry) const |
Test for if geometry equals another (uses GEOS) More... | |
QString | exportToGeoJSON (const int &precision=17) const |
Exports the geometry to GeoJSON. More... | |
QString | exportToWkt (const int &precision=17) const |
Exports the geometry to WKT. More... | |
void | fromGeos (GEOSGeometry *geos) |
Set the geometry, feeding in a geometry in GEOS format. More... | |
void | fromWkb (unsigned char *wkb, size_t length) |
Set the geometry, feeding in the buffer containing OGC Well-Known Binary and the buffer's length. More... | |
const QgsAbstractGeometryV2 * | geometry () const |
Returns the underlying geometry store. More... | |
bool | insertVertex (double x, double y, int beforeVertex) |
Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted. More... | |
QgsGeometry * | interpolate (double distance) const |
QgsGeometry * | intersection (const QgsGeometry *geometry) const |
Returns a geometry representing the points shared by this geometry and other. More... | |
bool | intersects (const QgsRectangle &r) const |
Test for intersection with a rectangle (uses GEOS) More... | |
bool | intersects (const QgsGeometry *geometry) const |
Test for intersection with a geometry (uses GEOS) More... | |
bool | isEmpty () const |
Returns true if the geometry is empty (ie, contains no underlying geometry accessible via geometry). More... | |
bool | isGeosEmpty () const |
Check if the geometry is empty using GEOS. More... | |
bool | isGeosEqual (const QgsGeometry &) const |
Compares the geometry with another geometry using GEOS. More... | |
bool | isGeosValid () const |
Checks validity of the geometry using GEOS. More... | |
bool | isMultipart () const |
Returns true if WKB of the geometry is of WKBMulti* type. More... | |
double | length () const |
Returns the length of geometry using GEOS. More... | |
int | makeDifference (const QgsGeometry *other) |
Changes this geometry such that it does not intersect the other geometry. More... | |
void | mapToPixel (const QgsMapToPixel &mtp) |
Transforms the geometry from map units to pixels in place. More... | |
bool | moveVertex (double x, double y, int atVertex) |
Moves the vertex at the given position number and item (first number is index 0) to the given coordinates. More... | |
bool | moveVertex (const QgsPointV2 &p, int atVertex) |
Moves the vertex at the given position number and item (first number is index 0) to the given coordinates. More... | |
QgsGeometry * | offsetCurve (double distance, int segments, int joinStyle, double mitreLimit) const |
Returns an offset line at a given distance and side from an input line. More... | |
QgsGeometry & | operator= (QgsGeometry const &rhs) |
assignments will prompt a deep copy of the object More... | |
bool | overlaps (const QgsGeometry *geometry) const |
Test for if geometry overlaps another (uses GEOS) More... | |
QgsGeometry * | pointOnSurface () const |
Returns a point within a geometry. More... | |
bool | requiresConversionToStraightSegments () const |
Returns true if the geometry is a curved geometry type which requires conversion to display as straight line segments. More... | |
int | reshapeGeometry (const QList< QgsPoint > &reshapeWithLine) |
Replaces a part of this geometry with another line. More... | |
int | rotate (double rotation, const QgsPoint ¢er) |
Rotate this geometry around the Z axis. More... | |
void | setGeometry (QgsAbstractGeometryV2 *geometry) |
Sets the underlying geometry store. More... | |
QgsGeometry * | simplify (double tolerance) const |
Returns a simplified version of this geometry using a specified tolerance value. More... | |
QgsGeometry * | smooth (const unsigned int iterations=1, const double offset=0.25) const |
Smooths a geometry by rounding off corners using the Chaikin algorithm. More... | |
QgsPolyline | smoothLine (const QgsPolyline &polyline, const unsigned int iterations=1, const double offset=0.25) const |
Smooths a polyline using the Chaikin algorithm. More... | |
QgsPolygon | smoothPolygon (const QgsPolygon &polygon, const unsigned int iterations=1, const double offset=0.25) const |
Smooths a polygon using the Chaikin algorithm. More... | |
int | splitGeometry (const QList< QgsPoint > &splitLine, QList< QgsGeometry * > &newGeometries, bool topological, QList< QgsPoint > &topologyTestPoints) |
Splits this geometry according to a given line. More... | |
double | sqrDistToVertexAt (QgsPoint &point, int atVertex) const |
Returns the squared cartesian distance between the given point to the given vertex index (vertex at the given position number, ring and item (first number is index 0)) More... | |
QgsGeometry * | symDifference (const QgsGeometry *geometry) const |
Returns a Geometry representing the points making up this Geometry that do not make up other. More... | |
bool | touches (const QgsGeometry *geometry) const |
Test for if geometry touch another (uses GEOS) More... | |
int | transform (const QgsCoordinateTransform &ct) |
Transform this geometry as described by CoordinateTransform ct. More... | |
int | transform (const QTransform &ct) |
Transform this geometry as described by QTransform ct. More... | |
int | translate (double dx, double dy) |
Translate this geometry by dx, dy. More... | |
QGis::GeometryType | type () const |
Returns type of the geometry as a QGis::GeometryType. More... | |
void | validateGeometry (QList< Error > &errors) |
Validate geometry and produce a list of geometry errors. More... | |
QgsPoint | vertexAt (int atVertex) const |
Returns coordinates of a vertex. More... | |
bool | vertexIdFromVertexNr (int nr, QgsVertexId &id) const |
Calculates the vertex ID from a vertex number. More... | |
int | vertexNrFromVertexId (const QgsVertexId &i) const |
Returns the vertex number corresponding to a vertex idd. More... | |
bool | within (const QgsGeometry *geometry) const |
Test for if geometry is within another (uses GEOS) More... | |
size_t | wkbSize () const |
Returns the size of the WKB in asWkb(). More... | |
QGis::WkbType | wkbType () const |
Returns type of the geometry as a WKB type (point / linestring / polygon etc.) More... | |
Static Public Member Functions | |
static bool | compare (const QgsPolyline &p1, const QgsPolyline &p2, double epsilon=4 *DBL_EPSILON) |
Compares two polylines for equality within a specified tolerance. More... | |
static bool | compare (const QgsPolygon &p1, const QgsPolygon &p2, double epsilon=4 *DBL_EPSILON) |
Compares two polygons for equality within a specified tolerance. More... | |
static bool | compare (const QgsMultiPolygon &p1, const QgsMultiPolygon &p2, double epsilon=4 *DBL_EPSILON) |
Compares two multipolygons for equality within a specified tolerance. More... | |
static QgsGeometryEngine * | createGeometryEngine (const QgsAbstractGeometryV2 *geometry) |
Creates and returns a new geometry engine. More... | |
static QgsPolygon | createPolygonFromQPolygonF (const QPolygonF &polygon) |
Creates a QgsPolygon from a QPolygonF. More... | |
static QgsPolyline | createPolylineFromQPolygonF (const QPolygonF &polygon) |
Creates a QgsPolyline from a QPolygonF. More... | |
static QgsGeometry * | fromMultiPoint (const QgsMultiPoint &multipoint) |
Creates a new geometry from a QgsMultiPoint object. More... | |
static QgsGeometry * | fromMultiPolygon (const QgsMultiPolygon &multipoly) |
Creates a new geometry from a QgsMultiPolygon. More... | |
static QgsGeometry * | fromMultiPolyline (const QgsMultiPolyline &multiline) |
Creates a new geometry from a QgsMultiPolyline object. More... | |
static QgsGeometry * | fromPoint (const QgsPoint &point) |
Creates a new geometry from a QgsPoint object. More... | |
static QgsGeometry * | fromPolygon (const QgsPolygon &polygon) |
Creates a new geometry from a QgsPolygon. More... | |
static QgsGeometry * | fromPolyline (const QgsPolyline &polyline) |
Creates a new geometry from a QgsPolyline object. More... | |
static QgsGeometry * | fromQPointF (const QPointF &point) |
Construct geometry from a QPointF. More... | |
static QgsGeometry * | fromQPolygonF (const QPolygonF &polygon) |
Construct geometry from a QPolygonF. More... | |
static QgsGeometry * | fromRect (const QgsRectangle &rect) |
Creates a new geometry from a QgsRectangle. More... | |
static QgsGeometry * | fromWkt (QString wkt) |
Creates a new geometry from a WKT string. More... | |
static GEOSContextHandle_t | getGEOSHandler () |
return GEOS context handle More... | |
static QgsGeometry * | unaryUnion (const QList< QgsGeometry * > &geometryList) |
compute the unary union on a list of geometries. More... | |
A geometry is the spatial representation of a feature.
Since QGIS 2.10, QgsGeometry acts as a generic container for geometry objects. QgsGeometry is implicitly shared, so making copies of geometries is inexpensive. The geometry container class can also be stored inside a QVariant object.
The actual geometry representation is stored as a QgsAbstractGeometryV2 within the container, and can be accessed via the geometry method or set using the setGeometry method.
Definition at line 75 of file qgsgeometry.h.
QgsGeometry::QgsGeometry | ( | ) |
Constructor.
Definition at line 64 of file qgsgeometry.cpp.
QgsGeometry::QgsGeometry | ( | const QgsGeometry & | other | ) |
copy constructor will prompt a deep copy of the object
Definition at line 85 of file qgsgeometry.cpp.
QgsGeometry::QgsGeometry | ( | QgsAbstractGeometryV2 * | geom | ) |
Creates a geometry from an abstract geometry object.
Ownership of geom is transferred.
Definition at line 79 of file qgsgeometry.cpp.
QgsGeometry::~QgsGeometry | ( | ) |
Destructor.
Definition at line 68 of file qgsgeometry.cpp.
int QgsGeometry::addPart | ( | const QList< QgsPoint > & | points, |
QGis::GeometryType | geomType = QGis::UnknownGeometry |
||
) |
Adds a new island polygon to a multipolygon feature.
Definition at line 555 of file qgsgeometry.cpp.
int QgsGeometry::addPart | ( | QgsAbstractGeometryV2 * | part | ) |
Adds a new part to this geometry (takes ownership)
Definition at line 599 of file qgsgeometry.cpp.
int QgsGeometry::addPart | ( | GEOSGeometry * | newPart | ) |
Adds a new island polygon to a multipolygon feature.
Definition at line 616 of file qgsgeometry.cpp.
int QgsGeometry::addPart | ( | const QgsGeometry * | newPart | ) |
Adds a new island polygon to a multipolygon feature.
Definition at line 606 of file qgsgeometry.cpp.
Adds a new ring to this geometry.
This makes only sense for polygon and multipolygons.
Definition at line 530 of file qgsgeometry.cpp.
int QgsGeometry::addRing | ( | QgsCurveV2 * | ring | ) |
Adds a new ring to this geometry.
This makes only sense for polygon and multipolygons.
Definition at line 542 of file qgsgeometry.cpp.
void QgsGeometry::adjacentVertices | ( | int | atVertex, |
int & | beforeVertex, | ||
int & | afterVertex | ||
) | const |
Returns the indexes of the vertices before and after the given vertex index.
This function takes into account the following factors:
Definition at line 369 of file qgsgeometry.cpp.
double QgsGeometry::area | ( | ) | const |
Returns the area of the geometry using GEOS.
Definition at line 1134 of file qgsgeometry.cpp.
QList< QgsGeometry * > QgsGeometry::asGeometryCollection | ( | ) | const |
Return contents of the geometry as a list of geometries.
Definition at line 1369 of file qgsgeometry.cpp.
const GEOSGeometry * QgsGeometry::asGeos | ( | ) | const |
Returns a geos geometry.
QgsGeometry retains ownership of the geometry, so the returned object should not be deleted.
Definition at line 290 of file qgsgeometry.cpp.
QgsMultiPoint QgsGeometry::asMultiPoint | ( | ) | const |
Return contents of the geometry as a multi point if wkbType is WKBMultiPoint, otherwise an empty list.
Definition at line 1018 of file qgsgeometry.cpp.
QgsMultiPolygon QgsGeometry::asMultiPolygon | ( | ) | const |
Return contents of the geometry as a multi polygon if wkbType is WKBMultiPolygon, otherwise an empty list.
Definition at line 1091 of file qgsgeometry.cpp.
QgsMultiPolyline QgsGeometry::asMultiPolyline | ( | ) | const |
Return contents of the geometry as a multi linestring if wkbType is WKBMultiLineString, otherwise an empty list.
Definition at line 1042 of file qgsgeometry.cpp.
QgsPoint QgsGeometry::asPoint | ( | ) | const |
Return contents of the geometry as a point if wkbType is WKBPoint, otherwise returns [0,0].
Definition at line 924 of file qgsgeometry.cpp.
QgsPolygon QgsGeometry::asPolygon | ( | ) | const |
Return contents of the geometry as a polygon if wkbType is WKBPolygon, otherwise an empty list.
Definition at line 984 of file qgsgeometry.cpp.
QgsPolyline QgsGeometry::asPolyline | ( | ) | const |
Return contents of the geometry as a polyline if wkbType is WKBLineString, otherwise an empty list.
Definition at line 939 of file qgsgeometry.cpp.
QPointF QgsGeometry::asQPointF | ( | ) | const |
Return contents of the geometry as a QPointF if wkbType is WKBPoint, otherwise returns a null QPointF.
Definition at line 1394 of file qgsgeometry.cpp.
QPolygonF QgsGeometry::asQPolygonF | ( | ) | const |
Return contents of the geometry as a QPolygonF.
If geometry is a linestring, then the result will be an open QPolygonF. If the geometry is a polygon, then the result will be a closed QPolygonF of the geometry's exterior ring.
Definition at line 1400 of file qgsgeometry.cpp.
const unsigned char * QgsGeometry::asWkb | ( | ) | const |
Returns the buffer containing this geometry in WKB format.
You may wish to use in conjunction with wkbSize().
Definition at line 262 of file qgsgeometry.cpp.
int QgsGeometry::avoidIntersections | ( | QMap< QgsVectorLayer *, QSet< QgsFeatureId > > | ignoreFeatures = ( QMap<QgsVectorLayer*, QSet<QgsFeatureId> >() ) | ) |
Modifies geometry to avoid intersections with the layers specified in project properties.
ignoreFeatures | possibility to give a list of features where intersections should be ignored (not available in python bindings) |
Definition at line 1460 of file qgsgeometry.cpp.
QgsRectangle QgsGeometry::boundingBox | ( | ) | const |
Returns the bounding box of this feature.
Definition at line 745 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::buffer | ( | double | distance, |
int | segments | ||
) | const |
Returns a buffer region around this geometry having the given width and with a specified number of segments used to approximate curves.
Definition at line 1177 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::buffer | ( | double | distance, |
int | segments, | ||
int | endCapStyle, | ||
int | joinStyle, | ||
double | mitreLimit | ||
) | const |
Returns a buffer region around the geometry, with additional style options.
distance | buffer distance |
segments | For round joins, number of segments to approximate quarter-circle |
endCapStyle | Round (1) / Flat (2) / Square (3) end cap style |
joinStyle | Round (1) / Mitre (2) / Bevel (3) join style |
mitreLimit | Limit on the mitre ratio used for very sharp corners |
Definition at line 1193 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::centroid | ( | ) | const |
Returns the center of mass of a geometry.
Definition at line 1241 of file qgsgeometry.cpp.
double QgsGeometry::closestSegmentWithContext | ( | const QgsPoint & | point, |
QgsPoint & | minDistPoint, | ||
int & | afterVertex, | ||
double * | leftOf = 0 , |
||
double | epsilon = DEFAULT_SEGMENT_EPSILON |
||
) | const |
Searches for the closest segment of geometry to the given point.
point | Specifies the point for search |
minDistPoint | Receives the nearest point on the segment |
afterVertex | Receives index of the vertex after the closest segment. The vertex before the closest segment is always afterVertex - 1 |
leftOf | Out: Returns if the point lies on the left of right side of the segment ( < 0 means left, > 0 means right ) |
epsilon | epsilon for segment snapping (added in 1.8) |
Definition at line 502 of file qgsgeometry.cpp.
QgsPoint QgsGeometry::closestVertex | ( | const QgsPoint & | point, |
int & | atVertex, | ||
int & | beforeVertex, | ||
int & | afterVertex, | ||
double & | sqrDist | ||
) | const |
Returns the vertex closest to the given point, the corresponding vertex index, squared distance snap point / target point and the indices of the vertices before/after.
The vertices before/after are -1 if not present
Definition at line 347 of file qgsgeometry.cpp.
double QgsGeometry::closestVertexWithContext | ( | const QgsPoint & | point, |
int & | atVertex | ||
) | const |
Searches for the closest vertex in this geometry to the given point.
point | Specifiest the point for search |
atVertex | Receives index of the closest vertex |
Definition at line 488 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::combine | ( | const QgsGeometry * | geometry | ) | const |
Returns a geometry representing all the points in this geometry and other (a union geometry operation).
Definition at line 1318 of file qgsgeometry.cpp.
|
static |
Compares two polylines for equality within a specified tolerance.
p1 | first polyline |
p2 | second polyline |
epsilon | maximum difference for coordinates between the polylines |
Definition at line 1766 of file qgsgeometry.cpp.
|
static |
Compares two polygons for equality within a specified tolerance.
p1 | first polygon |
p2 | second polygon |
epsilon | maximum difference for coordinates between the polygons |
Definition at line 1779 of file qgsgeometry.cpp.
|
static |
Compares two multipolygons for equality within a specified tolerance.
p1 | first multipolygon |
p2 | second multipolygon |
epsilon | maximum difference for coordinates between the multipolygons |
Definition at line 1793 of file qgsgeometry.cpp.
bool QgsGeometry::contains | ( | const QgsPoint * | p | ) | const |
Test for containment of a point (uses GEOS)
Definition at line 773 of file qgsgeometry.cpp.
bool QgsGeometry::contains | ( | const QgsGeometry * | geometry | ) | const |
Test for if geometry is contained in another (uses GEOS)
Definition at line 785 of file qgsgeometry.cpp.
bool QgsGeometry::convertToMultiType | ( | ) |
Converts single type geometry into multitype geometry e.g.
a polygon into a multipolygon geometry with one polygon If it is already a multipart geometry, it will return true and not change the geometry.
Definition at line 898 of file qgsgeometry.cpp.
void QgsGeometry::convertToStraightSegment | ( | ) |
Converts the geometry to straight line segments, if it is a curved geometry type.
Definition at line 1533 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::convertToType | ( | QGis::GeometryType | destType, |
bool | destMultipart = false |
||
) | const |
Try to convert the geometry to the requested type.
destType | the geometry type to be converted to |
destMultipart | determines if the output geometry will be multipart or not |
Definition at line 880 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::convexHull | ( | ) | const |
Returns the smallest convex polygon that contains all the points in the geometry.
Definition at line 1275 of file qgsgeometry.cpp.
|
static |
Creates and returns a new geometry engine.
Definition at line 2233 of file qgsgeometry.cpp.
|
static |
Creates a QgsPolygon from a QPolygonF.
polygon | source polygon |
Definition at line 1748 of file qgsgeometry.cpp.
|
static |
Creates a QgsPolyline from a QPolygonF.
polygon | source polygon |
Definition at line 1755 of file qgsgeometry.cpp.
bool QgsGeometry::crosses | ( | const QgsGeometry * | geometry | ) | const |
Test for if geometry crosses another (uses GEOS)
Definition at line 851 of file qgsgeometry.cpp.
bool QgsGeometry::deletePart | ( | int | partNum | ) |
Delete part identified by the part number.
Definition at line 1441 of file qgsgeometry.cpp.
bool QgsGeometry::deleteRing | ( | int | ringNum, |
int | partNum = 0 |
||
) |
Delete a ring in polygon or multipolygon.
Ring 0 is outer ring and can't be deleted.
Definition at line 1429 of file qgsgeometry.cpp.
bool QgsGeometry::deleteVertex | ( | int | atVertex | ) |
Deletes the vertex at the given position number and item (first number is index 0) Returns false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point), or if the number of remaining verticies in the linestring would be less than two.
It is up to the caller to distinguish between these error conditions. (Or maybe we add another method to this object to help make the distinction?)
Definition at line 427 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::difference | ( | const QgsGeometry * | geometry | ) | const |
Returns a geometry representing the points making up this geometry that do not make up other.
Definition at line 1335 of file qgsgeometry.cpp.
bool QgsGeometry::disjoint | ( | const QgsGeometry * | geometry | ) | const |
Test for if geometry is disjoint of another (uses GEOS)
Definition at line 796 of file qgsgeometry.cpp.
double QgsGeometry::distance | ( | const QgsGeometry & | geom | ) | const |
Returns the minimum distanace between this geometry and another geometry, using GEOS.
geom | geometry to find minimum distance to |
Definition at line 1166 of file qgsgeometry.cpp.
void QgsGeometry::draw | ( | QPainter & | p | ) | const |
Draws the geometry onto a QPainter.
p | destination QPainter |
Definition at line 1604 of file qgsgeometry.cpp.
bool QgsGeometry::equals | ( | const QgsGeometry * | geometry | ) | const |
Test for if geometry equals another (uses GEOS)
Definition at line 807 of file qgsgeometry.cpp.
QString QgsGeometry::exportToGeoJSON | ( | const int & | precision = 17 | ) | const |
Exports the geometry to GeoJSON.
Definition at line 871 of file qgsgeometry.cpp.
QString QgsGeometry::exportToWkt | ( | const int & | precision = 17 | ) | const |
Exports the geometry to WKT.
Definition at line 862 of file qgsgeometry.cpp.
void QgsGeometry::fromGeos | ( | GEOSGeometry * | geos | ) |
Set the geometry, feeding in a geometry in GEOS format.
This class will take ownership of the buffer.
Definition at line 336 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsMultiPoint object.
Definition at line 197 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsMultiPolygon.
Definition at line 217 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsMultiPolyline object.
Definition at line 207 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsPoint object.
Definition at line 167 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsPolygon.
Definition at line 187 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsPolyline object.
Definition at line 177 of file qgsgeometry.cpp.
|
static |
Construct geometry from a QPointF.
point | source QPointF |
Definition at line 1731 of file qgsgeometry.cpp.
|
static |
Construct geometry from a QPolygonF.
If the polygon is closed than the resultant geometry will be a polygon, if it is open than the geometry will be a polyline.
polygon | source QPolygonF |
Definition at line 1736 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsRectangle.
Definition at line 227 of file qgsgeometry.cpp.
void QgsGeometry::fromWkb | ( | unsigned char * | wkb, |
size_t | length | ||
) |
Set the geometry, feeding in the buffer containing OGC Well-Known Binary and the buffer's length.
This class will take ownership of the buffer.
Definition at line 242 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a WKT string.
Definition at line 157 of file qgsgeometry.cpp.
const QgsAbstractGeometryV2 * QgsGeometry::geometry | ( | ) | const |
Returns the underlying geometry store.
Definition at line 137 of file qgsgeometry.cpp.
|
static |
return GEOS context handle
Definition at line 1726 of file qgsgeometry.cpp.
bool QgsGeometry::insertVertex | ( | double | x, |
double | y, | ||
int | beforeVertex | ||
) |
Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted.
Returns false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point). It is up to the caller to distinguish between these error conditions. (Or maybe we add another method to this object to help make the distinction?)
Definition at line 446 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::interpolate | ( | double | distance | ) | const |
Definition at line 1290 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::intersection | ( | const QgsGeometry * | geometry | ) | const |
Returns a geometry representing the points shared by this geometry and other.
Definition at line 1305 of file qgsgeometry.cpp.
bool QgsGeometry::intersects | ( | const QgsRectangle & | r | ) | const |
Test for intersection with a rectangle (uses GEOS)
Definition at line 754 of file qgsgeometry.cpp.
bool QgsGeometry::intersects | ( | const QgsGeometry * | geometry | ) | const |
Test for intersection with a geometry (uses GEOS)
Definition at line 762 of file qgsgeometry.cpp.
bool QgsGeometry::isEmpty | ( | ) | const |
Returns true if the geometry is empty (ie, contains no underlying geometry accessible via geometry).
Definition at line 152 of file qgsgeometry.cpp.
bool QgsGeometry::isGeosEmpty | ( | ) | const |
Check if the geometry is empty using GEOS.
Definition at line 1504 of file qgsgeometry.cpp.
bool QgsGeometry::isGeosEqual | ( | const QgsGeometry & | g | ) | const |
Compares the geometry with another geometry using GEOS.
Definition at line 1493 of file qgsgeometry.cpp.
bool QgsGeometry::isGeosValid | ( | ) | const |
Checks validity of the geometry using GEOS.
Definition at line 1482 of file qgsgeometry.cpp.
bool QgsGeometry::isMultipart | ( | ) | const |
Returns true if WKB of the geometry is of WKBMulti* type.
Definition at line 327 of file qgsgeometry.cpp.
double QgsGeometry::length | ( | ) | const |
Returns the length of geometry using GEOS.
Definition at line 1156 of file qgsgeometry.cpp.
int QgsGeometry::makeDifference | ( | const QgsGeometry * | other | ) |
Changes this geometry such that it does not intersect the other geometry.
other | geometry that should not be intersect |
Definition at line 722 of file qgsgeometry.cpp.
void QgsGeometry::mapToPixel | ( | const QgsMapToPixel & | mtp | ) |
Transforms the geometry from map units to pixels in place.
mtp | map to pixel transform |
Definition at line 1583 of file qgsgeometry.cpp.
bool QgsGeometry::moveVertex | ( | double | x, |
double | y, | ||
int | atVertex | ||
) |
Moves the vertex at the given position number and item (first number is index 0) to the given coordinates.
Returns false if atVertex does not correspond to a valid vertex on this geometry
Definition at line 389 of file qgsgeometry.cpp.
bool QgsGeometry::moveVertex | ( | const QgsPointV2 & | p, |
int | atVertex | ||
) |
Moves the vertex at the given position number and item (first number is index 0) to the given coordinates.
Returns false if atVertex does not correspond to a valid vertex on this geometry
Definition at line 408 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::offsetCurve | ( | double | distance, |
int | segments, | ||
int | joinStyle, | ||
double | mitreLimit | ||
) | const |
Returns an offset line at a given distance and side from an input line.
See buffer() method for details on parameters.
Definition at line 1209 of file qgsgeometry.cpp.
QgsGeometry & QgsGeometry::operator= | ( | QgsGeometry const & | rhs | ) |
assignments will prompt a deep copy of the object
Definition at line 91 of file qgsgeometry.cpp.
bool QgsGeometry::overlaps | ( | const QgsGeometry * | geometry | ) | const |
Test for if geometry overlaps another (uses GEOS)
Definition at line 829 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::pointOnSurface | ( | ) | const |
Returns a point within a geometry.
Definition at line 1258 of file qgsgeometry.cpp.
bool QgsGeometry::requiresConversionToStraightSegments | ( | ) | const |
Returns true if the geometry is a curved geometry type which requires conversion to display as straight line segments.
Definition at line 1547 of file qgsgeometry.cpp.
Replaces a part of this geometry with another line.
Definition at line 696 of file qgsgeometry.cpp.
int QgsGeometry::rotate | ( | double | rotation, |
const QgsPoint & | center | ||
) |
Rotate this geometry around the Z axis.
rotation | clockwise rotation in degrees |
center | rotation center |
Definition at line 644 of file qgsgeometry.cpp.
void QgsGeometry::setGeometry | ( | QgsAbstractGeometryV2 * | geometry | ) |
Sets the underlying geometry store.
Ownership of geometry is transferred.
Definition at line 146 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::simplify | ( | double | tolerance | ) | const |
Returns a simplified version of this geometry using a specified tolerance value.
Definition at line 1225 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::smooth | ( | const unsigned int | iterations = 1 , |
const double | offset = 0.25 |
||
) | const |
Smooths a geometry by rounding off corners using the Chaikin algorithm.
This operation roughly doubles the number of vertices in a geometry.
iterations | number of smoothing iterations to run. More iterations results in a smoother geometry |
offset | fraction of line to create new vertices along, between 0 and 1.0 eg the default value of 0.25 will create new vertices 25% and 75% along each line segment of the geometry for each iteration. Smaller values result in "tighter" smoothing. |
Definition at line 1806 of file qgsgeometry.cpp.
QgsPolyline QgsGeometry::smoothLine | ( | const QgsPolyline & | polyline, |
const unsigned int | iterations = 1 , |
||
const double | offset = 0.25 |
||
) | const |
Smooths a polyline using the Chaikin algorithm.
Definition at line 1871 of file qgsgeometry.cpp.
QgsPolygon QgsGeometry::smoothPolygon | ( | const QgsPolygon & | polygon, |
const unsigned int | iterations = 1 , |
||
const double | offset = 0.25 |
||
) | const |
Smooths a polygon using the Chaikin algorithm.
Definition at line 1889 of file qgsgeometry.cpp.
int QgsGeometry::splitGeometry | ( | const QList< QgsPoint > & | splitLine, |
QList< QgsGeometry * > & | newGeometries, | ||
bool | topological, | ||
QList< QgsPoint > & | topologyTestPoints | ||
) |
Splits this geometry according to a given line.
splitLine | the line that splits the geometry | |
[out] | newGeometries | list of new geometries that have been created with the split |
topological | true if topological editing is enabled | |
[out] | topologyTestPoints | points that need to be tested for topological completeness in the dataset |
Definition at line 661 of file qgsgeometry.cpp.
double QgsGeometry::sqrDistToVertexAt | ( | QgsPoint & | point, |
int | atVertex | ||
) | const |
Returns the squared cartesian distance between the given point to the given vertex index (vertex at the given position number, ring and item (first number is index 0))
Definition at line 482 of file qgsgeometry.cpp.
QgsGeometry * QgsGeometry::symDifference | ( | const QgsGeometry * | geometry | ) | const |
Returns a Geometry representing the points making up this Geometry that do not make up other.
Definition at line 1352 of file qgsgeometry.cpp.
bool QgsGeometry::touches | ( | const QgsGeometry * | geometry | ) | const |
Test for if geometry touch another (uses GEOS)
Definition at line 818 of file qgsgeometry.cpp.
int QgsGeometry::transform | ( | const QgsCoordinateTransform & | ct | ) |
Transform this geometry as described by CoordinateTransform ct.
Definition at line 1557 of file qgsgeometry.cpp.
int QgsGeometry::transform | ( | const QTransform & | ct | ) |
Transform this geometry as described by QTransform ct.
Definition at line 1570 of file qgsgeometry.cpp.
int QgsGeometry::translate | ( | double | dx, |
double | dy | ||
) |
Translate this geometry by dx, dy.
Definition at line 630 of file qgsgeometry.cpp.
QGis::GeometryType QgsGeometry::type | ( | ) | const |
Returns type of the geometry as a QGis::GeometryType.
Definition at line 318 of file qgsgeometry.cpp.
|
static |
compute the unary union on a list of geometries.
May be faster than an iterative union on a set of geometries.
geometryList | a list of QgsGeometry* as input |
Definition at line 1515 of file qgsgeometry.cpp.
Validate geometry and produce a list of geometry errors.
Definition at line 1477 of file qgsgeometry.cpp.
QgsPoint QgsGeometry::vertexAt | ( | int | atVertex | ) | const |
Returns coordinates of a vertex.
atVertex | index of the vertex |
Definition at line 465 of file qgsgeometry.cpp.
bool QgsGeometry::vertexIdFromVertexNr | ( | int | nr, |
QgsVertexId & | id | ||
) | const |
Calculates the vertex ID from a vertex number.
nr | vertex number |
id | reference to QgsVertexId for storing result |
Definition at line 1612 of file qgsgeometry.cpp.
int QgsGeometry::vertexNrFromVertexId | ( | const QgsVertexId & | i | ) | const |
Returns the vertex number corresponding to a vertex idd.
i | vertex id |
Definition at line 1645 of file qgsgeometry.cpp.
bool QgsGeometry::within | ( | const QgsGeometry * | geometry | ) | const |
Test for if geometry is within another (uses GEOS)
Definition at line 840 of file qgsgeometry.cpp.
size_t QgsGeometry::wkbSize | ( | ) | const |
Returns the size of the WKB in asWkb().
Definition at line 276 of file qgsgeometry.cpp.
QGis::WkbType QgsGeometry::wkbType | ( | ) | const |
Returns type of the geometry as a WKB type (point / linestring / polygon etc.)
Definition at line 305 of file qgsgeometry.cpp.