Snap Rounding Common

Functions to round segments or polygons safely.

Functions
template<class Traits , class InputIterator , class OutputContainer >
void	CGAL::snap_rounding_2 (InputIterator begin, InputIterator end, OutputContainer &output_container, typename Traits::NT pixel_size, bool do_isr=true, bool int_output=true, unsigned int number_of_kd_trees=1)
template<class SegmentRange , class OutputContainer , class NamedParameters = parameters::Default_named_parameters>
OutputContainer	CGAL::snap_rounding_2 (const SegmentRange &segments, OutputContainer &out, const NamedParameters &np=parameters::default_values())
	subdivides and rounds a range of segments so that they are pairwise disjoint in their interiors.
template<class PolygonRange , class OutputContainer , class NamedParameters = parameters::Default_named_parameters>
void	CGAL::snap_rounding_2 (const PolygonRange &polygons, OutputContainer &out, const NamedParameters &np=parameters::default_values())
	subdivides and rounds a range of polygons so that their boundary segments are pairwise disjoint in their interiors.

Function Documentation

snap_rounding_2() [1/3]

template<class PolygonRange , class OutputContainer , class NamedParameters = parameters::Default_named_parameters>

void CGAL::snap_rounding_2	(	const PolygonRange &	polygons,
		OutputContainer &	out,
		const NamedParameters &	np = parameters::default_values()
	)

#include <CGAL/Snap_rounding_2.h>

subdivides and rounds a range of polygons so that their boundary segments are pairwise disjoint in their interiors.

If the input polygons are disjoint, the output polygons remain non-overlapping, although they may share vertices or edges. Each output polygon is free of self-intersections but may present pinched sections.

By default, this function rounds on double precision coordinates using CGAL::vertical_slab_snap_rounding_2(). Other rounding schemes or methods can be used by providing a geom_traits that is model of VerticalSlabSnapRoundingTraits_2 or HotPixelSnapRoundingTraits_2.

Template Parameters

PolygonRange	model of a ConstRange whose iterator is model of ForwardIterator and whose value_type is model of CGAL::Polygon_2.
OutputContainer	model of the concept BackInsertionSequence whose value type is model of CGAL::Polygon_2.
NamedParameters	a sequence of Named Parameters

Parameters

polygons	the range of input polygons
out	the output inserter
np	an optional sequence of Named Parameters including the one listed below

Optional Named Parameters

geom_traits an instance of a geometric traits class Type: The traits class must respect the concept of VerticalSlabSnapRoundingTraits_2 Default: an instance of CGAL::Double_grid_snap_rounding_traits_2<Kernel> where Kernel is deduced from the point type of the polygons, using CGAL::Kernel_traits

Warning

a convex input polygon might no longer be convex after rounding.

snap_rounding_2() [2/3]

template<class SegmentRange , class OutputContainer , class NamedParameters = parameters::Default_named_parameters>

OutputContainer CGAL::snap_rounding_2	(	const SegmentRange &	segments,
		OutputContainer &	out,
		const NamedParameters &	np = parameters::default_values()
	)

#include <CGAL/Snap_rounding_2.h>

subdivides and rounds a range of segments so that they are pairwise disjoint in their interiors.

By default, each polyline of the output corresponds to an input segment. Consequently, duplicate segments may appear in the output, for instance when multiple input segments collapse. When the parameter output_unique_segments is set to true, the polylines are decomposed into individual segments (represented as polylines with two points), and duplicates are removed.

By default, this function rounds on double precision coordinates using CGAL::vertical_slab_snap_rounding_2(). Other rounding schemes or methods can be used by providing a geom_traits that is model of VerticalSlabSnapRoundingTraits_2 or HotPixelSnapRoundingTraits_2.

Template Parameters

SegmentRange	model of the concept ConstRange whose iterator is model of ForwardIterator and whose value_type is geom_traits::Segment_2, where the type of geom_traits is detailed by np::geom_traits.
OutputContainer	model of the concept BackInsertionSequence whose value type is itself a model of the concepts DefaultConstructible and BackInsertionSequence whose value type is geom_traits::Point_2
NamedParameters	a sequence of Named Parameters

Parameters

segments	the input segment range
out	the output container
np	an optional sequence of Named Parameters including the ones listed below

Optional Named Parameters

geom_traits an instance of a geometric traits class Type: The traits class must respect the concept of VerticalSlabSnapRoundingTraits_2 or HotPixelSnapRoundingTraits_2 Default: an instance of CGAL::Double_grid_snap_rounding_traits_2<Kernel> where Kernel is deduced from the segment type, using CGAL::Kernel_traits
output_unique_segments If set to true, the output polylines are unique pairs of distinct points represented a segment. As a result, the total number of output polylines may differ from the number of input segments. Type: Boolean Default: true

snap_rounding_2() [3/3]

template<class Traits , class InputIterator , class OutputContainer >

void CGAL::snap_rounding_2	(	InputIterator	begin,
		InputIterator	end,
		OutputContainer &	output_container,
		typename Traits::NT	pixel_size,
		bool	do_isr = true,
		bool	int_output = true,
		unsigned int	number_of_kd_trees = 1
	)

#include <CGAL/Snap_rounding_2.h>

Deprecated:

This function is deprecated since CGAL 6.2, use newer API of CGAL::snap_rounding_2() or CGAL::hot_pixel_snap_rounding_2()

Template Parameters

Traits	must be a model of HotPixelSnapRoundingTraits_2.
InputIterator	must be an iterator with value type Traits::Segment_2.
OutputContainer	must be a container with a method push_back(const OutputContainer::value_type& c), where OutputContainer::value_type must be a container with a method push_back(const Traits::Point_2& p)

Parameters

begin,end	denote the iterator range of the input segments.
output_container	is a reference to a container of the output polylines. Since a polyline is composed of a sequence of points, a polyline is a container itself.
pixel_size	denotes the pixel size w. The plane will be tiled with square pixels of width w such that the origin is the center of a pixel. pixel_size must have a positive value.
do_isr	determines whether to apply ISR or SR.
int_output	If set to true, the output coordinates are expressed in the integer grid (pixel indices). Otherwise, they are given in the input coordinate system.
number_of_kd_trees	The seventh parameter is briefly described later on this page; for a detailed description see [3].

Examples

Snap_rounding_2/snap_rounding_to_double.cpp.