A class to trim lines and polygons to within a rectangular region. More...

#include <qgsclipper.h>

Public Types
enum	Boundary { XMax, XMin, YMax, YMin }
	A handy way to refer to the four boundaries. More...

Static Public Member Functions
static QPolygonF	clippedLine (const QgsCurve &curve, const QgsRectangle &clipExtent)
	Takes a linestring and clips it to clipExtent. More...

static void	trimFeature (QVector< double > &x, QVector< double > &y, bool shapeOpen)
	Trims the given feature to a rectangular box. More...

static void	trimPolygon (QPolygonF &pts, const QgsRectangle &clipRect)

Static Public Attributes
static const double	MAX_X = 16000
	Maximum X-coordinate of the rectangular box used for clipping. More...

static const double	MAX_Y = 16000
	Maximum Y-coordinate of the rectangular box used for clipping. More...

static const double	MIN_X = -16000
	Minimum X-coordinate of the rectangular box used for clipping. More...

static const double	MIN_Y = -16000
	Minimum Y-coordinate of the rectangular box used for clipping. More...

Detailed Description

A class to trim lines and polygons to within a rectangular region.

The functions in this class are likely to be called from within a render loop and hence need to as CPU efficient as possible. The main purpose of the functions in this class are to trim lines and polygons to lie within a rectangular region. This is necessary for drawing items to an X11 display which have a limit on the magnitude of the screen coordinates (+/- 32768, i.e. 16 bit integer).

Definition at line 45 of file qgsclipper.h.

Member Enumeration Documentation

enum QgsClipper::Boundary

A handy way to refer to the four boundaries.

Enumerator
XMax
XMin
YMax
YMin

Definition at line 77 of file qgsclipper.h.

Member Function Documentation

QPolygonF QgsClipper::clippedLine	(	const QgsCurve &	curve,
		const QgsRectangle &	clipExtent
	)

static

Takes a linestring and clips it to clipExtent.

Parameters

curve	the linestring
clipExtent	clipping bounds

Returns: clipped line coordinates

Definition at line 41 of file qgsclipper.cpp.

void QgsClipper::trimFeature	(	QVector< double > &	x,
		QVector< double > &	y,
		bool	shapeOpen
	)

inlinestatic

Trims the given feature to a rectangular box.

Returns the trimmed feature in x and y. The shapeOpen parameter determines whether the function treats the points as a closed shape (polygon), or as an open shape (linestring).

Note: not available in Python bindings on android

Definition at line 181 of file qgsclipper.h.

void QgsClipper::trimPolygon	(	QPolygonF &	pts,
		const QgsRectangle &	clipRect
	)

inlinestatic

Definition at line 202 of file qgsclipper.h.

Member Data Documentation

const double QgsClipper::MAX_X = 16000

static

Maximum X-coordinate of the rectangular box used for clipping.

Definition at line 67 of file qgsclipper.h.

const double QgsClipper::MAX_Y = 16000

static

Maximum Y-coordinate of the rectangular box used for clipping.

Definition at line 71 of file qgsclipper.h.

const double QgsClipper::MIN_X = -16000

static

Minimum X-coordinate of the rectangular box used for clipping.

Definition at line 69 of file qgsclipper.h.

const double QgsClipper::MIN_Y = -16000

static

Minimum Y-coordinate of the rectangular box used for clipping.

Definition at line 73 of file qgsclipper.h.

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

/build/qgis-3.4.15+24xenial/src/core/qgsclipper.h
/build/qgis-3.4.15+24xenial/src/core/qgsclipper.cpp

Public Types

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Enumeration Documentation

Member Function Documentation

Member Data Documentation