SphericalRegion Class Reference

Abstract class defining a region of the sphere. More...

#include <StelSphereGeometry.hpp>

Public Types
enum	SphericalRegionType {   Point = 0 , Cap = 1 , AllSky = 2 , Polygon = 3 ,   ConvexPolygon = 4 , Empty = 5 , Invalid = 6 }
	define types for all supported regions.

Public Member Functions
virtual SphericalRegionType	getType () const =0
virtual OctahedronPolygon	getOctahedronPolygon () const =0
	Return the octahedron contour representation of the polygon. More...
virtual double	getArea () const
	Return the area of the region in steradians.
virtual bool	isEmpty () const
	Return true if the region is empty.
virtual Vec3d	getPointInside () const
	Return a point located inside the region.
virtual QVector< SphericalCap >	getBoundingSphericalCaps () const
	Return the list of SphericalCap bounding the ConvexPolygon.
virtual SphericalCap	getBoundingCap () const
	Return a bounding SphericalCap. More...
virtual SphericalRegionP	getEnlarged (double margin) const
	Return an enlarged version of this SphericalRegion so that any point distant of more than the given margin now lays within the region. More...
virtual StelVertexArray	getFillVertexArray () const
	Return an OpenGL compatible array to be displayed using vertex arrays.
virtual StelVertexArray	getFillVertexArray (const Vec3d &observerVelocityForAberration)
	Return an OpenGL compatible array to be displayed using vertex arrays. More...
virtual StelVertexArray	getOutlineVertexArray () const
	Get the outline of the contours defining the SphericalPolygon. More...
virtual StelVertexArray	getOutlineVertexArray (Vec3d observerVelocityForAberration)
	Get the outline of the contours defining the SphericalPolygon. More...
virtual QVector< QVector< Vec3d > >	getSimplifiedContours () const
	Get the contours defining the SphericalPolygon when combined using a positive winding rule. More...
virtual QVariantList	toQVariant () const =0
	Serialize the region into a QVariant list matching the JSON format.
virtual void	serialize (QDataStream &out) const =0
	Serialize the region. This method must allow as fast as possible serialization and work with deserialize().
QByteArray	toJSON () const
	Output a JSON string representing the polygon. More...
bool	contains (const SphericalRegion *r) const
	Returns whether a SphericalRegion is contained into this region. More...
bool	contains (const SphericalRegionP r) const
virtual bool	contains (const Vec3d &p) const
virtual bool	contains (const SphericalPolygon &r) const
virtual bool	contains (const SphericalConvexPolygon &r) const
virtual bool	contains (const SphericalCap &r) const
virtual bool	contains (const SphericalPoint &r) const
virtual bool	contains (const AllSkySphericalRegion &r) const
bool	contains (const EmptySphericalRegion &) const
bool	intersects (const SphericalRegion *r) const
	Returns whether a SphericalRegion intersects with this region. More...
bool	intersects (const SphericalRegionP r) const
bool	intersects (const Vec3d &p) const
virtual bool	intersects (const SphericalPolygon &r) const
virtual bool	intersects (const SphericalConvexPolygon &r) const
virtual bool	intersects (const SphericalCap &r) const
virtual bool	intersects (const SphericalPoint &r) const
virtual bool	intersects (const AllSkySphericalRegion &r) const
bool	intersects (const EmptySphericalRegion &) const
SphericalRegionP	getSubtraction (const SphericalRegion *r) const
	Return a new SphericalRegion consisting of the subtraction of the given region from this. More...
SphericalRegionP	getSubtraction (const SphericalRegionP r) const
virtual SphericalRegionP	getSubtraction (const SphericalPolygon &r) const
virtual SphericalRegionP	getSubtraction (const SphericalConvexPolygon &r) const
virtual SphericalRegionP	getSubtraction (const SphericalCap &r) const
virtual SphericalRegionP	getSubtraction (const SphericalPoint &r) const
SphericalRegionP	getSubtraction (const AllSkySphericalRegion &r) const
virtual SphericalRegionP	getSubtraction (const EmptySphericalRegion &r) const

Detailed Description

Abstract class defining a region of the sphere.

It provides default implementation for the general non-convex polygon which can extend on more than 180 deg based on the OctahedronPolygon class. Subclasses provides special faster implementations of many methods.

Member Function Documentation

contains()

bool SphericalRegion::contains

(

const SphericalRegion *

r

)

const

Returns whether a SphericalRegion is contained into this region.

A default potentially very slow implementation is provided for each case.

getBoundingCap()

virtual SphericalCap SphericalRegion::getBoundingCap ( ) const

virtual

Return a bounding SphericalCap.

This method is heavily used and therefore needs to be very fast. The returned SphericalCap doesn't have to be the smallest one, but smaller is better.

Reimplemented in SphericalConvexPolygon, SphericalPolygon, EmptySphericalRegion, AllSkySphericalRegion, SphericalPoint, and SphericalCap.

getEnlarged()

virtual SphericalRegionP SphericalRegion::getEnlarged ( double  margin ) const

virtual

Return an enlarged version of this SphericalRegion so that any point distant of more than the given margin now lays within the region.

The returned region can be larger than the smallest enlarging region, therefore returning false positive on subsequent intersection tests. The default implementation always return an enlarged bounding SphericalCap.

Parameters

margin

the minimum enlargement margin in radian.

getFillVertexArray()

virtual StelVertexArray SphericalRegion::getFillVertexArray ( const Vec3d &  observerVelocityForAberration )

inlinevirtual

Return an OpenGL compatible array to be displayed using vertex arrays.

Note

Presumably these general polygons of the base class don't describe geometry that may undergo aberration, so the observerVelocity must be zero. Implementation in derived classes should show aberration correction.

Reimplemented in SphericalTexturedConvexPolygon, SphericalTexturedPolygon, and SphericalConvexPolygon.

getOctahedronPolygon()

virtual OctahedronPolygon SphericalRegion::getOctahedronPolygon ( ) const

pure virtual

Return the octahedron contour representation of the polygon.

It can be used for safe computation of intersection/union in the general case.

Implemented in SphericalConvexPolygon, SphericalPolygon, EmptySphericalRegion, AllSkySphericalRegion, SphericalPoint, and SphericalCap.

getOutlineVertexArray() [1/2]

virtual StelVertexArray SphericalRegion::getOutlineVertexArray ( ) const

inlinevirtual

Get the outline of the contours defining the SphericalPolygon.

Returns

a list of vertex which taken 2 by 2 define the contours of the polygon.

Reimplemented in SphericalConvexPolygon.

getOutlineVertexArray() [2/2]

virtual StelVertexArray SphericalRegion::getOutlineVertexArray ( Vec3d  observerVelocityForAberration )

inlinevirtual

Get the outline of the contours defining the SphericalPolygon.

Note

Presumably these general polygons of the base class don't describe geometry that may undergo aberration, so the observerVelocity must be zero. Implementation in derived classes should show aberration correction.

Reimplemented in SphericalConvexPolygon.

getSimplifiedContours()

virtual QVector<QVector<Vec3d > > SphericalRegion::getSimplifiedContours ( ) const

virtual

Get the contours defining the SphericalPolygon when combined using a positive winding rule.

The default implementation returns a list of tessellated triangles derived from the OctahedronPolygon.

getSubtraction()

SphericalRegionP SphericalRegion::getSubtraction

(

const SphericalRegion *

r

)

const

Return a new SphericalRegion consisting of the subtraction of the given region from this.

A default potentially very slow implementation is provided for each case.

intersects()

bool SphericalRegion::intersects

(

const SphericalRegion *

r

)

const

Returns whether a SphericalRegion intersects with this region.

A default potentially very slow implementation is provided for each case.

toJSON()

QByteArray SphericalRegion::toJSON

(

)

const

Output a JSON string representing the polygon.

This method is convenient for debugging.