QgsClipper Class Reference
[QGIS core library]

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

#include <qgsclipper.h>

List of all members.

Public Types
enum	Boundary { XMax, XMin, YMax, YMin }
Static Public Member Functions
static void	trimFeature (std::vector< double > &x, std::vector< double > &y, bool shapeOpen)
Static Public Attributes
static const double	MAX_X = 16000
static const double	MIN_X = -16000
static const double	MAX_Y = 16000
static const double	MIN_Y = -16000
Static Private Member Functions
static void	trimFeatureToBoundary (const std::vector< double > &inX, const std::vector< double > &inY, std::vector< double > &outX, std::vector< double > &outY, Boundary b, bool shapeOpen)
static bool	inside (const double x, const double y, Boundary b)
static QgsPoint	intersect (const double x1, const double y1, const double x2, const double y2, Boundary b)
Static Private Attributes
static const double	SMALL_NUM = 1e-12

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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 40 of file qgsclipper.h.

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Member Enumeration Documentation

enum QgsClipper::Boundary

Enumerator:

XMax
XMin
YMax
YMin

Definition at line 70 of file qgsclipper.h.

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Member Function Documentation

void QgsClipper::trimFeature	(	std::vector< double > &	x,
		std::vector< double > &	y,
		bool	shapeOpen
	)			[inline, static]

Definition at line 116 of file qgsclipper.h.

References trimFeatureToBoundary(), XMax, XMin, YMax, and YMin.

Referenced by QgsVectorLayer::drawLineString(), and QgsVectorLayer::drawPolygon().

void QgsClipper::trimFeatureToBoundary	(	const std::vector< double > &	inX,
		const std::vector< double > &	inY,
		std::vector< double > &	outX,
		std::vector< double > &	outY,
		Boundary	b,
		bool	shapeOpen
	)			[inline, static, private]

Definition at line 142 of file qgsclipper.h.

References inside(), intersect(), QgsPoint::x(), and QgsPoint::y().

Referenced by trimFeature().

bool QgsClipper::inside	(	const double	x,
		const double	y,
		Boundary	b
	)			[inline, static, private]

Definition at line 200 of file qgsclipper.h.

References MAX_X, MAX_Y, MIN_X, MIN_Y, XMax, XMin, YMax, and YMin.

Referenced by trimFeatureToBoundary().

QgsPoint QgsClipper::intersect	(	const double	x1,
		const double	y1,
		const double	x2,
		const double	y2,
		Boundary	b
	)			[inline, static, private]

Definition at line 229 of file qgsclipper.h.

References MAX_X, MAX_Y, MIN_X, MIN_Y, QgsPoint::set(), SMALL_NUM, XMax, XMin, YMax, and YMin.

Referenced by trimFeatureToBoundary().

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Member Data Documentation

const double QgsClipper::MAX_X = 16000 [static]

Definition at line 63 of file qgsclipper.h.

Referenced by QgsVectorLayer::drawFeature(), QgsVectorLayer::drawLineString(), QgsVectorLayer::drawPolygon(), inside(), and intersect().

const double QgsClipper::MIN_X = -16000 [static]

Definition at line 64 of file qgsclipper.h.

Referenced by inside(), and intersect().

const double QgsClipper::MAX_Y = 16000 [static]

Definition at line 65 of file qgsclipper.h.

Referenced by QgsVectorLayer::drawFeature(), QgsVectorLayer::drawLineString(), QgsVectorLayer::drawPolygon(), inside(), and intersect().

const double QgsClipper::MIN_Y = -16000 [static]

Definition at line 66 of file qgsclipper.h.

Referenced by inside(), and intersect().

const double QgsClipper::SMALL_NUM = 1e-12 [static, private]

Definition at line 83 of file qgsclipper.h.

Referenced by intersect().

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

• src/core/qgsclipper.h
• src/core/qgsclipper.cpp