#include <ConvexPolygon.h>

Inheritance diagram for lsst::sphgeom::ConvexPolygon:

Public Member Functions
	ConvexPolygon (std::vector< UnitVector3d > const &points)

	ConvexPolygon (UnitVector3d const &v0, UnitVector3d const &v1, UnitVector3d const &v2)

	ConvexPolygon (UnitVector3d const &v0, UnitVector3d const &v1, UnitVector3d const &v2, UnitVector3d const &v3)

bool	operator== (ConvexPolygon const &p) const
	Two convex polygons are equal iff they contain the same points.

bool	operator!= (ConvexPolygon const &p) const

std::vector< UnitVector3d > const &	getVertices () const

UnitVector3d	getCentroid () const

std::unique_ptr< Region >	clone () const override

bool	isEmpty () const override

Box	getBoundingBox () const override

Box3d	getBoundingBox3d () const override

Circle	getBoundingCircle () const override

Relationship	relate (Region const &r) const override

Relationship	relate (Box const &) const override

Relationship	relate (Circle const &) const override

Relationship	relate (ConvexPolygon const &) const override

Relationship	relate (Ellipse const &) const override

TriState	overlaps (Region const &other) const override

TriState	overlaps (Box const &) const override

TriState	overlaps (Circle const &) const override

TriState	overlaps (ConvexPolygon const &) const override

TriState	overlaps (Ellipse const &) const override

std::vector< std::uint8_t >	encode () const override


bool	contains (UnitVector3d const &v) const override

bool	contains (Region const &r) const


bool	isDisjointFrom (Region const &r) const


bool	intersects (Region const &r) const


bool	isWithin (Region const &r) const

Public Member Functions inherited from lsst.sphgeom._continue_class.Region
Region	from_ivoa_pos (cls, str pos)

str	to_ivoa_pos (self)

Static Public Member Functions
static ConvexPolygon	convexHull (std::vector< UnitVector3d > const &points)


static std::unique_ptr< ConvexPolygon >	decode (std::vector< std::uint8_t > const &s)

static std::unique_ptr< ConvexPolygon >	decode (std::uint8_t const *buffer, size_t n)

Static Public Attributes
static constexpr std::uint8_t	TYPE_CODE = 'p'

Detailed Description

ConvexPolygon is a closed convex polygon on the unit sphere. Its edges are great circles (geodesics), and the shorter of the two great circle segments between any two points on the polygon boundary is contained in the polygon.

The vertices of a convex polygon are distinct and have counter-clockwise orientation when viewed from outside the unit sphere. No three consecutive vertices are coplanar and edges do not intersect except at vertices.

Furthermore, if a convex polygon contains a point p of S², then we require that it be disjoint from point -p. This guarantees the existence of a unique shortest great circle segment between any 2 points contained in the polygon, but means e.g. that hemispheres and lunes cannot be represented by convex polygons.

Currently, the only way to construct a convex polygon is to compute the convex hull of a point set.

Constructor & Destructor Documentation

◆ ConvexPolygon() [1/3]

lsst::sphgeom::ConvexPolygon::ConvexPolygon ( std::vector< UnitVector3d > const & points )

explicit

This constructor creates a convex polygon that is the convex hull of the given set of points.

◆ ConvexPolygon() [2/3]

lsst::sphgeom::ConvexPolygon::ConvexPolygon	(	UnitVector3d const &	v0,
		UnitVector3d const &	v1,
		UnitVector3d const &	v2 )

inline

This constructor creates a triangle with the given vertices.

It is assumed that orientation(v0, v1, v2) = 1. Use with caution - for performance reasons, this is not verified!

◆ ConvexPolygon() [3/3]

lsst::sphgeom::ConvexPolygon::ConvexPolygon	(	UnitVector3d const &	v0,
		UnitVector3d const &	v1,
		UnitVector3d const &	v2,
		UnitVector3d const &	v3 )

inline

This constructor creates a quadrilateral with the given vertices.

It is assumed that orientation(v0, v1, v2), orientation(v1, v2, v3), orientation(v2, v3, v0), and orientation (v3, v0, v1) are all 1. Use with caution - for performance reasons, this is not verified!

Member Function Documentation

◆ contains()

bool lsst::sphgeom::ConvexPolygon::contains ( UnitVector3d const & v ) const

override

contains returns true if the intersection of this convex polygon and x is equal to x.

◆ convexHull()

static ConvexPolygon lsst::sphgeom::ConvexPolygon::convexHull ( std::vector< UnitVector3d > const & points )

inlinestatic

convexHull returns the convex hull of the given set of points if it exists and throws an exception otherwise. Though points are supplied in a vector, they really are conceptually a set - the ConvexPolygon returned is invariant under permutation of the input array.

◆ decode()

static std::unique_ptr< ConvexPolygon > lsst::sphgeom::ConvexPolygon::decode ( std::vector< std::uint8_t > const & s )

inlinestatic

decode deserializes a ConvexPolygon from a byte string produced by encode.

◆ getCentroid()

UnitVector3d lsst::sphgeom::ConvexPolygon::getCentroid ( ) const

The centroid of a polygon is its center of mass projected onto S², assuming a uniform mass distribution over the polygon surface.

◆ intersects()

bool lsst::sphgeom::ConvexPolygon::intersects ( Region const & r ) const

intersects returns true if the intersection of this convex polygon and x is non-empty.

◆ isDisjointFrom()

bool lsst::sphgeom::ConvexPolygon::isDisjointFrom ( Region const & r ) const

isDisjointFrom returns true if the intersection of this convex polygon and x is empty.

◆ isWithin()

bool lsst::sphgeom::ConvexPolygon::isWithin ( Region const & r ) const

isWithin returns true if the intersection of this convex polygon and x is this convex polygon.

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

include/lsst/sphgeom/ConvexPolygon.h
src/ConvexPolygon.cc

Public Member Functions

Static Public Member Functions

Static Public Attributes