StelGeodesicGrid Class Reference

Grid of triangles (zones) on the sphere with radius 1, generated by subdividing the icosahedron. More...

#include <StelGeodesicGrid.hpp>

Public Types
typedef void(	VisitFunc) (int lev, int index, const Vec3f &c0, const Vec3f &c1, const Vec3f &c2, void *context)

Public Member Functions
	StelGeodesicGrid (int maxLevel)
int	getMaxLevel (void) const
int	getNrOfZones (void) const
void	visitTriangles (int maxVisitLevel, VisitFunc *func, void *context) const
int	getZoneNumberForPoint (const Vec3f &v, int searchLevel) const
	Find the zone number in which a given point lies. More...
void	getTriangleCorners (int lev, int index, Vec3f &c0, Vec3f &c1, Vec3f &c2) const
	Return the position of the 3 corners for the triangle at the given level and index.
int	getPartnerTriangle (int lev, int index) const
	Return the index of the partner triangle with which to form a parallelogram.
const GeodesicSearchResult *	search (const QVector< SphericalCap > &convex, int maxSearchLevel) const
	Return a search result matching the given spatial region The result is cached, meaning that it is very fast to search the same region consecutively. More...

Static Public Member Functions
static int	nrOfZones (int level)

Friends
class	GeodesicSearchResult

Detailed Description

level 0: just the icosahedron, 20 zones level 1: 80 zones, level 2: 320 zones, ... Each zone has a unique integer number in the range [0,getNrOfZones()-1].

Member Function Documentation

int StelGeodesicGrid::getZoneNumberForPoint	(	const Vec3f &	v,
		int	searchLevel
	)		const

prerequisite: v*v==1 When the point lies on the border of two or more zones, one such zone is returned (always the same one, because the algorithm is deterministic).

const GeodesicSearchResult* StelGeodesicGrid::search	(	const QVector< SphericalCap > &	convex,
		int	maxSearchLevel
	)		const

Returns

a GeodesicSearchResult instance which must be used with GeodesicSearchBorderIterator and GeodesicSearchInsideIterator