QGIS API Documentation 4.1.0-Master (60fea48833c)
Loading...
Searching...
No Matches
qgsabstractgeometry.cpp
Go to the documentation of this file.
1/***************************************************************************
2 qgsabstractgeometry.cpp
3 -------------------------------------------------------------------
4Date : 04 Sept 2014
5Copyright : (C) 2014 by Marco Hugentobler
6email : marco.hugentobler at sourcepole dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15
16#include "qgsabstractgeometry.h"
17
18#include <limits>
19#include <nlohmann/json.hpp>
20
21#include "qgsbox3d.h"
22#include "qgscurve.h"
24#include "qgspoint.h"
25#include "qgsvertexid.h"
26
27#include <QTransform>
28
29#include "moc_qgsabstractgeometry.cpp"
30
35
37{
38 if ( &geom != this )
39 {
40 clear();
41 mWkbType = geom.mWkbType;
42 }
43 return *this;
44}
45
47{
48 // compare to self
49 if ( this == other )
50 {
51 return 0;
52 }
53
54 if ( sortIndex() != other->sortIndex() )
55 {
56 //different geometry types
57 const int diff = sortIndex() - other->sortIndex();
58 return ( diff > 0 ) - ( diff < 0 );
59 }
60
61 // same types
62 if ( isEmpty() && other->isEmpty() )
63 {
64 return 0;
65 }
66
67 if ( isEmpty() )
68 {
69 return -1;
70 }
71 if ( other->isEmpty() )
72 {
73 return 1;
74 }
75
76 return compareToSameClass( other );
77}
78
80{
81 if ( !subgeom )
82 {
83 return;
84 }
85
86 //special handling for 25d types:
87 if ( baseGeomType == Qgis::WkbType::LineString && ( subgeom->wkbType() == Qgis::WkbType::Point25D || subgeom->wkbType() == Qgis::WkbType::LineString25D ) )
88 {
90 return;
91 }
92 else if ( baseGeomType == Qgis::WkbType::Polygon && ( subgeom->wkbType() == Qgis::WkbType::Point25D || subgeom->wkbType() == Qgis::WkbType::LineString25D ) )
93 {
95 return;
96 }
97
98 const bool hasZ = subgeom->is3D();
99 const bool hasM = subgeom->isMeasure();
100
101 if ( hasZ && hasM )
102 {
103 mWkbType = QgsWkbTypes::addM( QgsWkbTypes::addZ( baseGeomType ) );
104 }
105 else if ( hasZ )
106 {
107 mWkbType = QgsWkbTypes::addZ( baseGeomType );
108 }
109 else if ( hasM )
110 {
111 mWkbType = QgsWkbTypes::addM( baseGeomType );
112 }
113 else
114 {
115 mWkbType = baseGeomType;
116 }
117}
118
123
128
130{
131 double xmin = std::numeric_limits<double>::max();
132 double ymin = std::numeric_limits<double>::max();
133 double zmin = std::numeric_limits<double>::max();
134 double xmax = -std::numeric_limits<double>::max();
135 double ymax = -std::numeric_limits<double>::max();
136 double zmax = -std::numeric_limits<double>::max();
137
138 QgsVertexId id;
139 QgsPoint vertex;
140 double x, y, z;
141 if ( is3D() )
142 {
143 while ( nextVertex( id, vertex ) )
144 {
145 x = vertex.x();
146 y = vertex.y();
147 z = vertex.z();
148
149 xmin = std::min( xmin, x );
150 xmax = std::max( xmax, x );
151
152 ymin = std::min( ymin, y );
153 ymax = std::max( ymax, y );
154
155 zmin = std::min( zmin, z );
156 zmax = std::max( zmax, z );
157 }
158 }
159 else
160 {
161 while ( nextVertex( id, vertex ) )
162 {
163 x = vertex.x();
164 y = vertex.y();
165 xmin = std::min( xmin, x );
166 xmax = std::max( xmax, x );
167
168 ymin = std::min( ymin, y );
169 ymax = std::max( ymax, y );
170 }
171 zmin = std::numeric_limits<double>::quiet_NaN();
172 zmax = std::numeric_limits<double>::quiet_NaN();
173 }
174
175 return QgsBox3D( xmin, ymin, zmin, xmax, ymax, zmax );
176}
177
180
182{
183 int nCoords = 0;
184
186 for ( const QgsRingSequence &r : seq )
187 {
188 for ( const QgsPointSequence &p : r )
189 {
190 nCoords += p.size();
191 }
192 }
193
194 return nCoords;
195}
196
198{
199 return 0.0;
200}
201
203{
204 return 0.0;
205}
206
208{
209 return 0.0;
210}
211
213{
214 return 0.0;
215}
216
218{
219 QString wkt = geometryType();
220 QString suffix;
221 if ( is3D() )
222 suffix += 'Z';
223 if ( isMeasure() )
224 suffix += 'M';
225 if ( !suffix.isEmpty() )
226 {
227 wkt += ' ' + suffix;
228 }
229 return wkt;
230}
231
232QString QgsAbstractGeometry::asJson( int precision )
233{
234 return QString::fromStdString( asJsonObject( precision ).dump() );
235}
236
237json QgsAbstractGeometry::asJsonObject( int precision ) const
238{
239 Q_UNUSED( precision )
240 return nullptr;
241}
242
244{
245 if ( isEmpty() )
246 return QgsPoint();
247
248 // http://en.wikipedia.org/wiki/Centroid#Centroid_of_polygon
249 // Pick the first ring of first part for the moment
250
251 const int n = vertexCount( 0, 0 );
252 if ( n == 1 )
253 {
254 return vertexAt( QgsVertexId( 0, 0, 0 ) );
255 }
256
257 double A = 0.;
258 double Cx = 0.;
259 double Cy = 0.;
260 const QgsPoint v0 = vertexAt( QgsVertexId( 0, 0, 0 ) );
261 int i = 0, j = 1;
262 if ( vertexAt( QgsVertexId( 0, 0, 0 ) ) != vertexAt( QgsVertexId( 0, 0, n - 1 ) ) )
263 {
264 i = n - 1;
265 j = 0;
266 }
267 for ( ; j < n; i = j++ )
268 {
269 QgsPoint vi = vertexAt( QgsVertexId( 0, 0, i ) );
270 QgsPoint vj = vertexAt( QgsVertexId( 0, 0, j ) );
271 vi.rx() -= v0.x();
272 vi.ry() -= v0.y();
273 vj.rx() -= v0.x();
274 vj.ry() -= v0.y();
275 const double d = vi.x() * vj.y() - vj.x() * vi.y();
276 A += d;
277 Cx += ( vi.x() + vj.x() ) * d;
278 Cy += ( vi.y() + vj.y() ) * d;
279 }
280
281 if ( A < 1E-12 )
282 {
283 Cx = Cy = 0.;
284 for ( int i = 0; i < n - 1; ++i )
285 {
286 const QgsPoint vi = vertexAt( QgsVertexId( 0, 0, i ) );
287 Cx += vi.x();
288 Cy += vi.y();
289 }
290 return QgsPoint( Cx / ( n - 1 ), Cy / ( n - 1 ) );
291 }
292 else
293 {
294 return QgsPoint( v0.x() + Cx / ( 3. * A ), v0.y() + Cy / ( 3. * A ) );
295 }
296}
297
299{
300 if ( type == mWkbType )
301 return true;
302
304 return false;
305
306 const bool needZ = QgsWkbTypes::hasZ( type );
307 const bool needM = QgsWkbTypes::hasM( type );
308 if ( !needZ )
309 {
310 dropZValue();
311 }
312 else if ( !is3D() )
313 {
314 addZValue( std::numeric_limits<double>::quiet_NaN() );
315 }
316
317 if ( !needM )
318 {
319 dropMValue();
320 }
321 else if ( !isMeasure() )
322 {
323 addMValue( std::numeric_limits<double>::quiet_NaN() );
324 }
325
326 return true;
327}
328
330{
331 return this;
332}
333
334void QgsAbstractGeometry::filterVertices( const std::function<bool( const QgsPoint & )> & )
335{
336 // Ideally this would be pure virtual, but SIP has issues with that
337}
338
339void QgsAbstractGeometry::transformVertices( const std::function<QgsPoint( const QgsPoint & )> & )
340{
341 // Ideally this would be pure virtual, but SIP has issues with that
342}
343
349
354
359
365
370
372{
373 switch ( QgsWkbTypes::flatType( mWkbType ) )
374 {
376 return 0;
378 return 1;
380 return 2;
382 return 3;
384 return 4;
386 return 5;
388 return 6;
391 return 7;
393 return 8;
395 return 9;
397 return 10;
399 return 11;
401 return 12;
403 default:
404 break;
405 }
406 return 13;
407}
408
413
415{
416 Q_UNUSED( index )
417 return QgsPoint();
418}
419
421{
422 QgsVertexId vId;
423 QgsPoint vertex;
424 return !nextVertex( vId, vertex );
425}
426
428{
429 return false;
430}
431
433{
434 return boundingBox().intersects( rectangle );
435}
436
438{
439 return boundingBox3D().intersects( box3d );
440}
441
443{
444 Q_UNUSED( tolerance )
445 Q_UNUSED( toleranceType )
446 return clone();
447}
448
449
451 : depth( 0 )
452{
453 levels.fill( Level() );
454 levels[0].g = g;
455 levels[0].index = index;
456
457 digDown(); // go to the leaf level of the first vertex
458}
459
461{
462 if ( depth == 0 && levels[0].index >= levels[0].g->childCount() )
463 return *this; // end of geometry - nowhere else to go
464
465 Q_ASSERT( !levels[depth].g->hasChildGeometries() ); // we should be at a leaf level
466
467 ++levels[depth].index;
468
469 // traverse up if we are at the end in the current level
470 while ( depth > 0 && levels[depth].index >= levels[depth].g->childCount() )
471 {
472 --depth;
473 ++levels[depth].index;
474 }
475
476 digDown(); // go to the leaf level again
477
478 return *this;
479}
480
487
489{
490 Q_ASSERT( !levels[depth].g->hasChildGeometries() );
491 return levels[depth].g->childPoint( levels[depth].index );
492}
493
495{
496 int part = 0, ring = 0, vertex = levels[depth].index;
497 if ( depth == 0 )
498 {
499 // nothing else to do
500 }
501 else if ( depth == 1 )
502 {
503 if ( QgsWkbTypes::isMultiType( levels[0].g->wkbType() ) )
504 part = levels[0].index;
505 else
506 ring = levels[0].index;
507 }
508 else if ( depth == 2 )
509 {
510 part = levels[0].index;
511 ring = levels[1].index;
512 }
513 else
514 {
515 Q_ASSERT( false );
516 return QgsVertexId();
517 }
518
519 // get the vertex type: find out from the leaf geometry
521 if ( const QgsCurve *curve = dynamic_cast<const QgsCurve *>( levels[depth].g ) )
522 {
523 QgsPoint p;
524 curve->pointAt( vertex, p, vertexType );
525 }
526
527 return QgsVertexId( part, ring, vertex, vertexType );
528}
529
531{
532 if ( depth != other.depth )
533 return false;
534 return std::equal( std::begin( levels ), std::begin( levels ) + depth + 1, std::begin( other.levels ) );
535}
536
537void QgsAbstractGeometry::vertex_iterator::digDown()
538{
539 if ( levels[depth].g->hasChildGeometries() && levels[depth].index >= levels[depth].g->childCount() )
540 return; // first check we are not already at the end
541
542 // while not "final" depth for the geom: go one level down.
543 while ( levels[depth].g->hasChildGeometries() )
544 {
545 ++depth;
546 Q_ASSERT( depth < 3 ); // that's capacity of the levels array
547 levels[depth].index = 0;
548 levels[depth].g = levels[depth - 1].g->childGeometry( levels[depth - 1].index );
549 }
550}
551
553{
554 n = i++;
555 return *n;
556}
557
559 : mIndex( index )
560 , mGeometry( g )
561{}
562
564{
566 if ( !collection )
567 {
568 mIndex = 1;
569 return *this; // end of geometry -- nowhere else to go
570 }
571
572 if ( mIndex >= collection->partCount() )
573 return *this; // end of geometry - nowhere else to go
574
575 mIndex++;
576 return *this;
577}
578
580{
581 part_iterator it( *this );
582 ++*this;
583 return it;
584}
585
587{
589 if ( !collection )
590 {
591 return mGeometry;
592 }
593
594 return collection->geometryN( mIndex );
595}
596
598{
599 return mIndex;
600}
601
603{
604 return mGeometry == other.mGeometry && mIndex == other.mIndex;
605}
606
608{
609 n = i++;
610 return *n;
611}
612
613
615 : mIndex( index )
616 , mGeometry( g )
617{}
618
620{
622 if ( !collection )
624 mIndex = 1;
625 return *this; // end of geometry -- nowhere else to go
626 }
627
628 if ( mIndex >= collection->partCount() )
629 return *this; // end of geometry - nowhere else to go
630
631 mIndex++;
632 return *this;
633}
634
641
643{
645 if ( !collection )
646 {
647 return mGeometry;
648 }
649
650 return collection->geometryN( mIndex );
651}
652
654{
655 return mIndex;
656}
657
659{
660 return mGeometry == other.mGeometry && mIndex == other.mIndex;
661}
662
664{
665 n = i++;
666 return *n;
667}
668
669bool QgsAbstractGeometry::vertex_iterator::Level::operator==( const QgsAbstractGeometry::vertex_iterator::Level &other ) const
670{
671 return g == other.g && index == other.index;
672}
VertexType
Types of vertex.
Definition qgis.h:3179
@ Segment
The actual start or end point of a segment.
Definition qgis.h:3180
WkbType
The WKB type describes the number of dimensions a geometry has.
Definition qgis.h:294
@ LineString25D
LineString25D.
Definition qgis.h:362
@ CompoundCurve
CompoundCurve.
Definition qgis.h:305
@ Point
Point.
Definition qgis.h:296
@ LineString
LineString.
Definition qgis.h:297
@ MultiPoint
MultiPoint.
Definition qgis.h:300
@ Polygon
Polygon.
Definition qgis.h:298
@ MultiPolygon
MultiPolygon.
Definition qgis.h:302
@ Triangle
Triangle.
Definition qgis.h:299
@ NoGeometry
No geometry.
Definition qgis.h:312
@ MultiLineString
MultiLineString.
Definition qgis.h:301
@ Unknown
Unknown.
Definition qgis.h:295
@ CircularString
CircularString.
Definition qgis.h:304
@ GeometryCollection
GeometryCollection.
Definition qgis.h:303
@ MultiCurve
MultiCurve.
Definition qgis.h:307
@ CurvePolygon
CurvePolygon.
Definition qgis.h:306
@ Point25D
Point25D.
Definition qgis.h:361
@ MultiSurface
MultiSurface.
Definition qgis.h:308
@ Polygon25D
Polygon25D.
Definition qgis.h:363
The part_iterator class provides an STL-style iterator for const references to geometry parts.
const_part_iterator & operator++()
The prefix ++ operator (++it) advances the iterator to the next part and returns an iterator to the n...
const_part_iterator()=default
Create invalid iterator.
const QgsAbstractGeometry * operator*() const
Returns the current item.
int partNumber() const
Returns the part number of the current item.
bool operator==(const_part_iterator other) const
The part_iterator class provides an STL-style iterator for geometry parts.
part_iterator & operator++()
The prefix ++ operator (++it) advances the iterator to the next part and returns an iterator to the n...
part_iterator()=default
Create invalid iterator.
QgsAbstractGeometry * operator*() const
Returns the current item.
bool operator==(part_iterator other) const
int partNumber() const
Returns the part number of the current item.
The vertex_iterator class provides an STL-style iterator for vertices.
vertex_iterator()=default
Create invalid iterator.
bool operator==(const vertex_iterator &other) const
QgsPoint operator*() const
Returns the current item.
vertex_iterator & operator++()
The prefix ++ operator (++it) advances the iterator to the next vertex and returns an iterator to the...
QgsVertexId vertexId() const
Returns vertex ID of the current item.
Abstract base class for all geometries.
virtual QgsPoint childPoint(int index) const
Returns point at index (for geometries without child geometries - i.e.
virtual bool addZValue(double zValue=0)=0
Adds a z-dimension to the geometry, initialized to a preset value.
SegmentationToleranceType
Segmentation tolerance as maximum angle or maximum difference between approximation and circle.
virtual bool convertTo(Qgis::WkbType type)
Converts the geometry to a specified type.
virtual bool dropMValue()=0
Drops any measure values which exist in the geometry.
virtual QgsBox3D calculateBoundingBox3D() const
Calculates the minimal 3D bounding box for the geometry.
virtual const QgsAbstractGeometry * simplifiedTypeRef() const
Returns a reference to the simplest lossless representation of this geometry, e.g.
QgsVertexIterator vertices() const
Returns a read-only, Java-style iterator for traversal of vertices of all the geometry,...
virtual QgsAbstractGeometry * segmentize(double tolerance=M_PI/180., SegmentationToleranceType toleranceType=MaximumAngle) const
Returns a version of the geometry without curves.
virtual int vertexCount(int part=0, int ring=0) const =0
Returns the number of vertices of which this geometry is built.
bool isMeasure() const
Returns true if the geometry contains m values.
virtual QgsRectangle calculateBoundingBox() const
Default calculator for the minimal bounding box for the geometry.
virtual QgsRectangle boundingBox() const
Returns the minimal bounding box for the geometry.
virtual void transformVertices(const std::function< QgsPoint(const QgsPoint &) > &transform)
Transforms the vertices from the geometry in place, applying the transform function to every vertex.
bool is3D() const
Returns true if the geometry is 3D and contains a z-value.
virtual QgsBox3D boundingBox3D() const =0
Returns the 3D bounding box for the geometry.
virtual QString geometryType() const =0
Returns a unique string representing the geometry type.
int sortIndex() const
Returns the sort index for the geometry, used in the compareTo() method to compare geometries of diff...
QString wktTypeStr() const
Returns the WKT type string of the geometry.
virtual double perimeter() const
Returns the planar, 2-dimensional perimeter of the geometry.
virtual int nCoordinates() const
Returns the number of nodes contained in the geometry.
virtual double area3D() const
Returns the 3-dimensional surface area of the geometry.
virtual QgsPoint vertexAt(QgsVertexId id) const =0
Returns the point corresponding to a specified vertex id.
virtual void clearCache() const
Clears any cached parameters associated with the geometry, e.g., bounding boxes.
QgsAbstractGeometry & operator=(const QgsAbstractGeometry &geom)
virtual bool addMValue(double mValue=0)=0
Adds a measure to the geometry, initialized to a preset value.
Qgis::WkbType wkbType() const
Returns the WKB type of the geometry.
QString asJson(int precision=17)
Returns a GeoJSON representation of the geometry as a QString.
part_iterator parts_end()
Returns STL-style iterator pointing to the imaginary part after the last part of the geometry.
void setZMTypeFromSubGeometry(const QgsAbstractGeometry *subggeom, Qgis::WkbType baseGeomType)
Updates the geometry type based on whether sub geometries contain z or m values.
virtual double length() const
Returns the planar, 2-dimensional length of the geometry.
const_part_iterator const_parts_end() const
Returns STL-style iterator pointing to the imaginary const part after the last part of the geometry.
virtual bool isEmpty() const
Returns true if the geometry is empty.
virtual json asJsonObject(int precision=17) const
Returns a json object representation of the geometry.
virtual QgsCoordinateSequence coordinateSequence() const =0
Retrieves the sequence of geometries, rings and nodes.
virtual bool hasChildGeometries() const
Returns whether the geometry has any child geometries (false for point / curve, true otherwise).
virtual bool boundingBoxIntersects(const QgsRectangle &rectangle) const
Returns true if the bounding box of this geometry intersects with a rectangle.
virtual bool hasCurvedSegments() const
Returns true if the geometry contains curved segments.
virtual void clear()=0
Clears the geometry, ie reset it to a null geometry.
virtual void filterVertices(const std::function< bool(const QgsPoint &) > &filter)
Filters the vertices from the geometry in place, removing any which do not return true for the filter...
virtual bool dropZValue()=0
Drops any z-dimensions which exist in the geometry.
virtual QgsPoint centroid() const
Returns the centroid of the geometry.
virtual int dimension() const =0
Returns the inherent dimension of the geometry.
virtual int compareTo(const QgsAbstractGeometry *other) const
Comparator for sorting of geometry.
QgsAbstractGeometry()=default
virtual double area() const
Returns the planar, 2-dimensional area of the geometry.
virtual int compareToSameClass(const QgsAbstractGeometry *other) const =0
Compares to an other geometry of the same class, and returns a integer for sorting of the two geometr...
QgsGeometryConstPartIterator parts() const
Returns Java-style iterator for traversal of parts of the geometry.
virtual bool nextVertex(QgsVertexId &id, QgsPoint &vertex) const =0
Returns next vertex id and coordinates.
virtual QgsAbstractGeometry * clone() const =0
Clones the geometry by performing a deep copy.
A 3-dimensional box composed of x, y, z coordinates.
Definition qgsbox3d.h:45
bool intersects(const QgsBox3D &other) const
Returns true if box intersects with another box.
Definition qgsbox3d.cpp:147
QgsRectangle toRectangle() const
Converts the box to a 2D rectangle.
Definition qgsbox3d.h:388
Abstract base class for curved geometry type.
Definition qgscurve.h:36
int partCount() const override
Returns count of parts contained in the geometry.
const QgsAbstractGeometry * geometryN(int n) const
Returns a const reference to a geometry from within the collection.
Java-style iterator for const traversal of parts of a geometry.
const QgsAbstractGeometry * next()
Returns next part of the geometry (undefined behavior if hasNext() returns false before calling next(...
Java-style iterator for traversal of parts of a geometry.
QgsAbstractGeometry * next()
Returns next part of the geometry (undefined behavior if hasNext() returns false before calling next(...
Point geometry type, with support for z-dimension and m-values.
Definition qgspoint.h:53
double & rx()
Returns a reference to the x-coordinate of this point.
Definition qgspoint.h:342
double z
Definition qgspoint.h:58
double x
Definition qgspoint.h:56
double & ry()
Returns a reference to the y-coordinate of this point.
Definition qgspoint.h:351
double y
Definition qgspoint.h:57
A rectangle specified with double values.
bool intersects(const QgsRectangle &rect) const
Returns true when rectangle intersects with other rectangle.
Java-style iterator for traversal of vertices of a geometry.
QgsPoint next()
Returns next vertex of the geometry (undefined behavior if hasNext() returns false before calling nex...
static Qgis::WkbType addM(Qgis::WkbType type)
Adds the m dimension to a WKB type and returns the new type.
static Qgis::WkbType addZ(Qgis::WkbType type)
Adds the z dimension to a WKB type and returns the new type.
static Q_INVOKABLE bool hasZ(Qgis::WkbType type)
Tests whether a WKB type contains the z-dimension.
static Q_INVOKABLE bool hasM(Qgis::WkbType type)
Tests whether a WKB type contains m values.
static Qgis::WkbType flatType(Qgis::WkbType type)
Returns the flat type for a WKB type.
static Q_INVOKABLE bool isMultiType(Qgis::WkbType type)
Returns true if the WKB type is a multi type.
T qgsgeometry_cast(QgsAbstractGeometry *geom)
QVector< QgsRingSequence > QgsCoordinateSequence
QVector< QgsPointSequence > QgsRingSequence
QVector< QgsPoint > QgsPointSequence
Utility class for identifying a unique vertex within a geometry.
Definition qgsvertexid.h:34