Implementation of GeometrySimplifier using the "MapToPixel" algorithm. More...

#include <qgsmaptopixelgeometrysimplifier.h>

Inheritance diagram for QgsMapToPixelSimplifier:

Public Types
enum	SimplifyAlgorithm { Distance = 0, SnapToGrid = 1, Visvalingam = 2 }
	Types of simplification algorithms that can be used. More...

enum	SimplifyFlag { NoFlags = 0, SimplifyGeometry = 1, SimplifyEnvelope = 2 }
	Applicable simplification flags. More...

Public Member Functions
	QgsMapToPixelSimplifier (int simplifyFlags, double tolerance, SimplifyAlgorithm simplifyAlgorithm=Distance)
	Constructor. More...

virtual	~QgsMapToPixelSimplifier ()

bool	isGeneralizableByMapBoundingBox (const QgsRectangle &envelope) const
	Returns whether the envelope can be replaced by its BBOX when is applied the specified map2pixel context. More...

void	setSimplifyAlgorithm (SimplifyAlgorithm simplifyAlgorithm)
	Sets the local simplification algorithm of the vector layer managed. More...

void	setSimplifyFlags (int simplifyFlags)
	Sets the simplification hints of the vector layer managed. More...

virtual QgsGeometry *	simplify (QgsGeometry *geometry) const override
	Returns a simplified version the specified geometry. More...

SimplifyAlgorithm	simplifyAlgorithm () const
	Gets the local simplification algorithm of the vector layer managed. More...

int	simplifyFlags () const
	Gets the simplification hints of the vector layer managed. More...

virtual bool	simplifyGeometry (QgsGeometry *geometry) const override
	Simplifies the specified geometry. More...

virtual bool	simplifyPoints (QgsWKBTypes::Type wkbType, QgsConstWkbPtr &sourceWkbPtr, QPolygonF &targetPoints) const
	Simplifies the specified WKB-point array. More...

Public Member Functions inherited from QgsAbstractGeometrySimplifier
virtual	~QgsAbstractGeometrySimplifier ()

Static Public Member Functions
static bool	isGeneralizableByMapBoundingBox (const QgsRectangle &envelope, double map2pixelTol)
	Returns whether the envelope can be replaced by its BBOX when is applied the specified map2pixel context. More...

static bool	simplifyGeometry (QgsGeometry *geometry, int simplifyFlags, double tolerance, SimplifyAlgorithm simplifyAlgorithm=Distance)
	Simplifies the geometry when is applied the specified map2pixel context. More...

static bool	simplifyPoints (QgsWKBTypes::Type wkbType, QgsConstWkbPtr &sourceWkbPtr, QPolygonF &targetPoints, int simplifyFlags, double tolerance, SimplifyAlgorithm simplifyAlgorithm=Distance)
	Simplifies the WKB-point array when is applied the specified map2pixel context. More...

Static Public Member Functions inherited from QgsAbstractGeometrySimplifier
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 tolerance. More...

static bool	isGeneralizableByDeviceBoundingBox (const QVector< QPointF > &points, float mapToPixelTol=1.0f)
	Returns whether the device-geometry can be replaced by its BBOX when is applied the specified tolerance. More...

Static Protected Member Functions
static float	calculateLengthSquared2D (double x1, double y1, double x2, double y2)
	Returns the squared 2D-distance of the vector defined by the two points specified. More...

static bool	equalSnapToGrid (double x1, double y1, double x2, double y2, double gridOriginX, double gridOriginY, float gridInverseSizeXY)
	Returns whether the points belong to the same grid. More...

Protected Attributes
SimplifyAlgorithm	mSimplifyAlgorithm
	Current algorithm. More...

int	mSimplifyFlags
	Current simplification flags. More...

double	mTolerance
	Distance tolerance for the simplification. More...

Detailed Description

Implementation of GeometrySimplifier using the "MapToPixel" algorithm.

Simplifies a geometry removing points within of the maximum distance difference that defines the MapToPixel info of a RenderContext request. This class enables simplify the geometries to be rendered in a MapCanvas target to speed up the vector drawing.

Definition at line 32 of file qgsmaptopixelgeometrysimplifier.h.

Member Enumeration Documentation

◆ SimplifyAlgorithm

enum QgsMapToPixelSimplifier::SimplifyAlgorithm

Types of 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.

Definition at line 36 of file qgsmaptopixelgeometrysimplifier.h.

◆ SimplifyFlag

enum QgsMapToPixelSimplifier::SimplifyFlag

Applicable simplification flags.

Enumerator
NoFlags	No simplification can be applied.
SimplifyGeometry	The geometries can be simplified using the current map2pixel context state.
SimplifyEnvelope	The geometries can be fully simplified by its BoundingBox.

Definition at line 48 of file qgsmaptopixelgeometrysimplifier.h.

Constructor & Destructor Documentation

◆ QgsMapToPixelSimplifier()

QgsMapToPixelSimplifier::QgsMapToPixelSimplifier	(	int	simplifyFlags,
		double	tolerance,
		SimplifyAlgorithm	simplifyAlgorithm = `Distance`
	)

Constructor.

Definition at line 24 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ ~QgsMapToPixelSimplifier()

QgsMapToPixelSimplifier::~QgsMapToPixelSimplifier ( )

virtual

Definition at line 31 of file qgsmaptopixelgeometrysimplifier.cpp.

Member Function Documentation

◆ calculateLengthSquared2D()

float QgsMapToPixelSimplifier::calculateLengthSquared2D	(	double	x1,
		double	y1,
		double	x2,
		double	y2
	)

staticprotected

Returns the squared 2D-distance of the vector defined by the two points specified.

Definition at line 39 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ equalSnapToGrid()

bool QgsMapToPixelSimplifier::equalSnapToGrid	(	double	x1,
		double	y1,
		double	x2,
		double	y2,
		double	gridOriginX,
		double	gridOriginY,
		float	gridInverseSizeXY
	)

staticprotected

Returns whether the points belong to the same grid.

Definition at line 48 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ isGeneralizableByMapBoundingBox() [1/2]

bool QgsMapToPixelSimplifier::isGeneralizableByMapBoundingBox	(	const QgsRectangle &	envelope,
		double	map2pixelTol
	)

static

Returns whether the envelope can be replaced by its BBOX when is applied the specified map2pixel context.

Definition at line 471 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ isGeneralizableByMapBoundingBox() [2/2]

bool QgsMapToPixelSimplifier::isGeneralizableByMapBoundingBox ( const QgsRectangle & envelope ) const

inline

Returns whether the envelope can be replaced by its BBOX when is applied the specified map2pixel context.

Definition at line 101 of file qgsmaptopixelgeometrysimplifier.h.

◆ setSimplifyAlgorithm()

void QgsMapToPixelSimplifier::setSimplifyAlgorithm ( SimplifyAlgorithm simplifyAlgorithm )

inline

Sets the local simplification algorithm of the vector layer managed.

Definition at line 84 of file qgsmaptopixelgeometrysimplifier.h.

◆ setSimplifyFlags()

void QgsMapToPixelSimplifier::setSimplifyFlags ( int simplifyFlags )

inline

Sets the simplification hints of the vector layer managed.

Definition at line 79 of file qgsmaptopixelgeometrysimplifier.h.

◆ simplify()

QgsGeometry * QgsMapToPixelSimplifier::simplify ( QgsGeometry * geometry ) const

overridevirtual

Returns a simplified version the specified geometry.

Returns a simplified version the specified geometry (Removing duplicated points) when is applied the specified map2pixel context.

Implements QgsAbstractGeometrySimplifier.

Definition at line 478 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ simplifyAlgorithm()

SimplifyAlgorithm QgsMapToPixelSimplifier::simplifyAlgorithm ( ) const

inline

Gets the local simplification algorithm of the vector layer managed.

Definition at line 82 of file qgsmaptopixelgeometrysimplifier.h.

◆ simplifyFlags()

int QgsMapToPixelSimplifier::simplifyFlags ( ) const

inline

Gets the simplification hints of the vector layer managed.

Definition at line 77 of file qgsmaptopixelgeometrysimplifier.h.

◆ simplifyGeometry() [1/2]

bool QgsMapToPixelSimplifier::simplifyGeometry ( QgsGeometry * geometry ) const

overridevirtual

Simplifies the specified geometry.

Simplifies the geometry (Removing duplicated points) when is applied the specified map2pixel context.

Implements QgsAbstractGeometrySimplifier.

Definition at line 531 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ simplifyGeometry() [2/2]

bool QgsMapToPixelSimplifier::simplifyGeometry	(	QgsGeometry *	geometry,
		int	simplifyFlags,
		double	tolerance,
		SimplifyAlgorithm	simplifyAlgorithm = `Distance`
	)

static

Simplifies the geometry when is applied the specified map2pixel context.

Simplifies the geometry (Removing duplicated points) when is applied the specified map2pixel context.

Definition at line 492 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ simplifyPoints() [1/2]

bool QgsMapToPixelSimplifier::simplifyPoints	(	QgsWKBTypes::Type	wkbType,
		QgsConstWkbPtr &	sourceWkbPtr,
		QPolygonF &	targetPoints
	)		const

virtual

Simplifies the specified WKB-point array.

Definition at line 589 of file qgsmaptopixelgeometrysimplifier.cpp.

◆ simplifyPoints() [2/2]

bool QgsMapToPixelSimplifier::simplifyPoints	(	QgsWKBTypes::Type	wkbType,
		QgsConstWkbPtr &	sourceWkbPtr,
		QPolygonF &	targetPoints,
		int	simplifyFlags,
		double	tolerance,
		SimplifyAlgorithm	simplifyAlgorithm = `Distance`
	)

static

Simplifies the WKB-point array when is applied the specified map2pixel context.

Simplifies the WKB-point array (Removing duplicated points) when is applied the specified map2pixel context.

Simplify the WKB-geometry using the specified tolerance

Definition at line 537 of file qgsmaptopixelgeometrysimplifier.cpp.

Member Data Documentation

◆ mSimplifyAlgorithm

SimplifyAlgorithm QgsMapToPixelSimplifier::mSimplifyAlgorithm

protected

Current algorithm.

Definition at line 64 of file qgsmaptopixelgeometrysimplifier.h.

◆ mSimplifyFlags

int QgsMapToPixelSimplifier::mSimplifyFlags

protected

Current simplification flags.

Definition at line 61 of file qgsmaptopixelgeometrysimplifier.h.

◆ mTolerance

double QgsMapToPixelSimplifier::mTolerance

protected

Distance tolerance for the simplification.

Definition at line 67 of file qgsmaptopixelgeometrysimplifier.h.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaptopixelgeometrysimplifier.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaptopixelgeometrysimplifier.cpp

Public Types

Public Member Functions

Static Public Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

◆ SimplifyAlgorithm

◆ SimplifyFlag

Constructor & Destructor Documentation

◆ QgsMapToPixelSimplifier()

◆ ~QgsMapToPixelSimplifier()

Member Function Documentation

◆ calculateLengthSquared2D()

◆ equalSnapToGrid()

◆ isGeneralizableByMapBoundingBox() [1/2]

◆ isGeneralizableByMapBoundingBox() [2/2]

◆ setSimplifyAlgorithm()

◆ setSimplifyFlags()

◆ simplify()

◆ simplifyAlgorithm()

◆ simplifyFlags()

◆ simplifyGeometry() [1/2]

◆ simplifyGeometry() [2/2]

◆ simplifyPoints() [1/2]

◆ simplifyPoints() [2/2]

Member Data Documentation

◆ mSimplifyAlgorithm

◆ mSimplifyFlags

◆ mTolerance