Class that takes care of tessellation of polygons into triangles. More...

#include <qgstessellator.h>

Public Member Functions
	QgsTessellator (double originX, double originY, bool addNormals, bool invertNormals=false, bool addBackFaces=false)
	Creates tessellator with a specified origin point of the world (in map coordinates) More...

	QgsTessellator (const QgsRectangle &bounds, bool addNormals, bool invertNormals=false, bool addBackFaces=false, bool noZ=false)
	Creates tessellator with a specified bounds of input geometry coordinates. More...

void	addPolygon (const QgsPolygon &polygon, float extrusionHeight)
	Tessellates a triangle and adds its vertex entries to the output data array. More...

std::unique_ptr< QgsMultiPolygon >	asMultiPolygon () const
	Returns the triangulation as a multipolygon geometry. More...

QVector< float >	data () const
	Returns array of triangle vertex data. More...

int	dataVerticesCount () const
	Returns the number of vertices stored in the output data array. More...

int	stride () const
	Returns size of one vertex entry in bytes. More...

Detailed Description

Class that takes care of tessellation of polygons into triangles.

It is expected that client code will create the tessellator object, then repeatedly call addPolygon() method that will generate triangles, and finally call data() to get final vertex data.

Optionally provides extrusion by adding triangles that serve as walls when extrusion height is non-zero.

Since: QGIS 3.4 (since QGIS 3.0 in QGIS_3D library)

Definition at line 40 of file qgstessellator.h.

Constructor & Destructor Documentation

◆ QgsTessellator() [1/2]

QgsTessellator::QgsTessellator	(	double	originX,
		double	originY,
		bool	addNormals,
		bool	invertNormals = `false`,
		bool	addBackFaces = `false`
	)

Creates tessellator with a specified origin point of the world (in map coordinates)

Definition at line 71 of file qgstessellator.cpp.

◆ QgsTessellator() [2/2]

QgsTessellator::QgsTessellator	(	const QgsRectangle &	bounds,
		bool	addNormals,
		bool	invertNormals = `false`,
		bool	addBackFaces = `false`,
		bool	noZ = `false`
	)

Creates tessellator with a specified bounds of input geometry coordinates.

This constructor allows the tessellator to map input coordinates to a desirable range for numerical stability during calculations.

If noZ is true, then a 2-dimensional tessellation only will be performed and all z coordinates will be ignored.

Since: QGIS 3.10

Definition at line 81 of file qgstessellator.cpp.

Member Function Documentation

◆ addPolygon()

void QgsTessellator::addPolygon	(	const QgsPolygon &	polygon,
		float	extrusionHeight
	)

Tessellates a triangle and adds its vertex entries to the output data array.

Definition at line 423 of file qgstessellator.cpp.

◆ asMultiPolygon()

std::unique_ptr< QgsMultiPolygon > QgsTessellator::asMultiPolygon ( ) const

Returns the triangulation as a multipolygon geometry.

Definition at line 631 of file qgstessellator.cpp.

◆ data()

QVector<float> QgsTessellator::data ( ) const

inline

Returns array of triangle vertex data.

Vertice coordinates are stored as (x, z, -y)

Definition at line 65 of file qgstessellator.h.

◆ dataVerticesCount()

int QgsTessellator::dataVerticesCount ( ) const

Returns the number of vertices stored in the output data array.

Definition at line 626 of file qgstessellator.cpp.

◆ stride()

int QgsTessellator::stride ( ) const