QGIS API Documentation  2.5.0-Master
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Modules Pages
Public Types | Public Member Functions | Static Public Member Functions | Static Protected Member Functions | Protected Attributes | List of all members
QgsMapToPixelSimplifier Class Reference

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

#include <qgsmaptopixelgeometrysimplifier.h>

Inheritance diagram for QgsMapToPixelSimplifier:
Inheritance graph
[legend]

Public Types

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

Public Member Functions

 QgsMapToPixelSimplifier (int simplifyFlags, double tolerance)
 
virtual ~QgsMapToPixelSimplifier ()
 
int simplifyFlags () const
 
void setSimplifyFlags (int simplifyFlags)
 
virtual QgsGeometrysimplify (QgsGeometry *geometry) const
 Returns a simplified version the specified geometry. More...
 
virtual bool simplifyGeometry (QgsGeometry *geometry) const
 Simplifies the specified geometry. More...
 
bool isGeneralizableByMapBoundingBox (const QgsRectangle &envelope) const
 Returns whether the envelope can be replaced by its BBOX when is applied the specified map2pixel context. 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)
 Simplifies the geometry 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...
 

Protected Attributes

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.

Member Enumeration Documentation

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.

Constructor & Destructor Documentation

QgsMapToPixelSimplifier::QgsMapToPixelSimplifier ( int  simplifyFlags,
double  tolerance 
)
QgsMapToPixelSimplifier::~QgsMapToPixelSimplifier ( )
virtual

Member Function Documentation

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.

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.

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.

void QgsMapToPixelSimplifier::setSimplifyFlags ( int  simplifyFlags)
inline
QgsGeometry * QgsMapToPixelSimplifier::simplify ( QgsGeometry geometry) const
virtual

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.

int QgsMapToPixelSimplifier::simplifyFlags ( ) const
inline
bool QgsMapToPixelSimplifier::simplifyGeometry ( QgsGeometry geometry) const
virtual

Simplifies the specified geometry.

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

Implements QgsAbstractGeometrySimplifier.

bool QgsMapToPixelSimplifier::simplifyGeometry ( QgsGeometry geometry,
int  simplifyFlags,
double  tolerance 
)
static

Simplifies the geometry when is applied the specified map2pixel context.

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

Member Data Documentation

int QgsMapToPixelSimplifier::mSimplifyFlags
protected

Current simplification flags.

double QgsMapToPixelSimplifier::mTolerance
protected

Distance tolerance for the simplification.


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