QGIS API Documentation  3.18.1-Zürich (202f1bf7e5)
Public Types | Public Member Functions | List of all members
QgsVectorSimplifyMethod Class Reference

This class contains information how to simplify geometries fetched from a vector layer. More...

#include <qgsvectorsimplifymethod.h>

Public Types

enum  SimplifyAlgorithm { Distance = 0 , SnapToGrid = 1 , Visvalingam = 2 , SnappedToGridGlobal = 3 }
 Types of local simplification algorithms that can be used. More...
 
enum  SimplifyHint { NoSimplification = 0 , GeometrySimplification = 1 , AntialiasingSimplification = 2 , FullSimplification = 3 }
 Simplification flags for fast rendering of features. More...
 

Public Member Functions

 QgsVectorSimplifyMethod ()
 construct a default object More...
 
bool forceLocalOptimization () const
 Gets where the simplification executes, after fetch the geometries from provider, or when supported, in provider before fetch the geometries. More...
 
float maximumScale () const
 Gets the maximum scale at which the layer should be simplified. More...
 
void setForceLocalOptimization (bool localOptimization)
 Sets where the simplification executes, after fetch the geometries from provider, or when supported, in provider before fetch the geometries. More...
 
void setMaximumScale (float maximumScale)
 Sets the maximum scale at which the layer should be simplified. More...
 
void setSimplifyAlgorithm (SimplifyAlgorithm simplifyAlgorithm)
 Sets the local simplification algorithm of the vector layer managed. More...
 
void setSimplifyHints (SimplifyHints simplifyHints)
 Sets the simplification hints of the vector layer managed. More...
 
void setThreshold (float threshold)
 Sets the simplification threshold of the vector layer managed. More...
 
void setTolerance (double tolerance)
 Sets the tolerance of simplification in map units. Represents the maximum distance in map units between two coordinates which can be considered equal. More...
 
SimplifyAlgorithm simplifyAlgorithm () const
 Gets the local simplification algorithm of the vector layer managed. More...
 
SimplifyHints simplifyHints () const
 Gets the simplification hints of the vector layer managed. More...
 
float threshold () const
 Gets the simplification threshold of the vector layer managed. More...
 
double tolerance () const
 Gets the tolerance of simplification in map units. Represents the maximum distance in map units between two coordinates which can be considered equal. More...
 

Detailed Description

This class contains information how to simplify geometries fetched from a vector layer.

Since
QGIS 2.2

Definition at line 29 of file qgsvectorsimplifymethod.h.

Member Enumeration Documentation

◆ SimplifyAlgorithm

Types of local simplification algorithms that can be used.

Enumerator
Distance 

The simplification uses the distance between points to remove duplicate points.

SnapToGrid 

The simplification uses a grid (similar to ST_SnapToGrid) to remove duplicate points.

Visvalingam 

The simplification gives each point in a line an importance weighting, so that least important points are removed first.

SnappedToGridGlobal 

Snap to a global grid based on the tolerance. Good for consistent results for incoming vertices, regardless of their feature.

Definition at line 54 of file qgsvectorsimplifymethod.h.

◆ SimplifyHint

Simplification flags for fast rendering of features.

Enumerator
NoSimplification 

No simplification can be applied.

GeometrySimplification 

The geometries can be simplified using the current map2pixel context state.

AntialiasingSimplification 

The geometries can be rendered with 'AntiAliasing' disabled because of it is '1-pixel size'.

FullSimplification 

All simplification hints can be applied ( Geometry + AA-disabling )

Definition at line 37 of file qgsvectorsimplifymethod.h.

Constructor & Destructor Documentation

◆ QgsVectorSimplifyMethod()

QgsVectorSimplifyMethod::QgsVectorSimplifyMethod ( )

construct a default object

Definition at line 19 of file qgsvectorsimplifymethod.cpp.

Member Function Documentation

◆ forceLocalOptimization()

bool QgsVectorSimplifyMethod::forceLocalOptimization ( ) const
inline

Gets where the simplification executes, after fetch the geometries from provider, or when supported, in provider before fetch the geometries.

Definition at line 81 of file qgsvectorsimplifymethod.h.

◆ maximumScale()

float QgsVectorSimplifyMethod::maximumScale ( ) const
inline

Gets the maximum scale at which the layer should be simplified.

Definition at line 86 of file qgsvectorsimplifymethod.h.

◆ setForceLocalOptimization()

void QgsVectorSimplifyMethod::setForceLocalOptimization ( bool  localOptimization)
inline

Sets where the simplification executes, after fetch the geometries from provider, or when supported, in provider before fetch the geometries.

Definition at line 79 of file qgsvectorsimplifymethod.h.

◆ setMaximumScale()

void QgsVectorSimplifyMethod::setMaximumScale ( float  maximumScale)
inline

Sets the maximum scale at which the layer should be simplified.

Definition at line 84 of file qgsvectorsimplifymethod.h.

◆ setSimplifyAlgorithm()

void QgsVectorSimplifyMethod::setSimplifyAlgorithm ( SimplifyAlgorithm  simplifyAlgorithm)
inline

Sets the local simplification algorithm of the vector layer managed.

Definition at line 64 of file qgsvectorsimplifymethod.h.

◆ setSimplifyHints()

void QgsVectorSimplifyMethod::setSimplifyHints ( SimplifyHints  simplifyHints)
inline

Sets the simplification hints of the vector layer managed.

Definition at line 49 of file qgsvectorsimplifymethod.h.

◆ setThreshold()

void QgsVectorSimplifyMethod::setThreshold ( float  threshold)
inline

Sets the simplification threshold of the vector layer managed.

Definition at line 74 of file qgsvectorsimplifymethod.h.

◆ setTolerance()

void QgsVectorSimplifyMethod::setTolerance ( double  tolerance)
inline

Sets the tolerance of simplification in map units. Represents the maximum distance in map units between two coordinates which can be considered equal.

Definition at line 69 of file qgsvectorsimplifymethod.h.

◆ simplifyAlgorithm()

SimplifyAlgorithm QgsVectorSimplifyMethod::simplifyAlgorithm ( ) const
inline

Gets the local simplification algorithm of the vector layer managed.

Definition at line 66 of file qgsvectorsimplifymethod.h.

◆ simplifyHints()

SimplifyHints QgsVectorSimplifyMethod::simplifyHints ( ) const
inline

Gets the simplification hints of the vector layer managed.

Definition at line 51 of file qgsvectorsimplifymethod.h.

◆ threshold()

float QgsVectorSimplifyMethod::threshold ( ) const
inline

Gets the simplification threshold of the vector layer managed.

Definition at line 76 of file qgsvectorsimplifymethod.h.

◆ tolerance()

double QgsVectorSimplifyMethod::tolerance ( ) const
inline

Gets the tolerance of simplification in map units. Represents the maximum distance in map units between two coordinates which can be considered equal.

Definition at line 71 of file qgsvectorsimplifymethod.h.


The documentation for this class was generated from the following files: