QGIS API Documentation 3.37.0-Master (fdefdf9c27f)
qgsgeometrysimplifier.cpp
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1/***************************************************************************
2 qgsgeometrysimplifier.cpp
3 ---------------------
4 begin : December 2013
5 copyright : (C) 2013 by Alvaro Huarte
6 email : http://wiki.osgeo.org/wiki/Alvaro_Huarte
7
8 ***************************************************************************
9 * *
10 * This program is free software; you can redistribute it and/or modify *
12 * the Free Software Foundation; either version 2 of the License, or *
13 * (at your option) any later version. *
14 * *
15 ***************************************************************************/
16
17#include <limits>
19#include "qgsrectangle.h"
20#include "qgsgeometry.h"
21#include "qgsgeos.h"
22
24{
25 return ( envelope.xMaximum() - envelope.xMinimum() ) < mapToPixelTol && ( envelope.yMaximum() - envelope.yMinimum() ) < mapToPixelTol;
26}
27
28bool QgsAbstractGeometrySimplifier::isGeneralizableByDeviceBoundingBox( const QVector<QPointF> &points, float mapToPixelTol )
29{
31 r.setNull();
32
33 for ( int i = 0, numPoints = points.size(); i < numPoints; ++i )
34 {
35 r.combineExtentWith( points[i].x(), points[i].y() );
36 }
37 return isGeneralizableByDeviceBoundingBox( r, mapToPixelTol );
38}
39
40/***************************************************************************/
41
42QgsTopologyPreservingSimplifier::QgsTopologyPreservingSimplifier( double tolerance ) : mTolerance( tolerance )
43{
44}
45
47{
48 return geometry.simplify( mTolerance );
49}
50
52{
53 if ( !geometry )
54 {
55 return nullptr;
56 }
57
58 const QgsGeos geos( geometry );
59 std::unique_ptr< QgsAbstractGeometry > simplifiedGeom( geos.simplify( mTolerance ) );
60 return simplifiedGeom.release();
61}
62
static bool isGeneralizableByDeviceBoundingBox(const QgsRectangle &envelope, float mapToPixelTol=1.0f)
Returns whether the device-envelope can be replaced by its BBOX when is applied the specified toleran...
Abstract base class for all geometries.
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:162
QgsGeometry simplify(double tolerance) const
Returns a simplified version of this geometry using a specified tolerance value.
Does vector analysis using the geos library and handles import, export, exception handling*.
Definition: qgsgeos.h:98
A rectangle specified with double values.
Definition: qgsrectangle.h:42
double xMinimum() const
Returns the x minimum value (left side of rectangle).
Definition: qgsrectangle.h:201
double yMinimum() const
Returns the y minimum value (bottom side of rectangle).
Definition: qgsrectangle.h:211
double xMaximum() const
Returns the x maximum value (right side of rectangle).
Definition: qgsrectangle.h:196
double yMaximum() const
Returns the y maximum value (top side of rectangle).
Definition: qgsrectangle.h:206
void combineExtentWith(const QgsRectangle &rect)
Expands the rectangle so that it covers both the original rectangle and the given rectangle.
Definition: qgsrectangle.h:413
void setNull()
Mark a rectangle as being null (holding no spatial information).
Definition: qgsrectangle.h:176
QgsGeometry simplify(const QgsGeometry &geometry) const override
Returns a simplified version the specified geometry.
double mTolerance
Distance tolerance for the simplification.
QgsTopologyPreservingSimplifier(double tolerance)
Constructor for QgsTopologyPreservingSimplifier.
Contains geos related utilities and functions.
Definition: qgsgeos.h:36