FUNCTION fHTM_Cover

Returns a table of (HtmIdStart, HtmIdEnd) that covers the area.

This is the main access function to the HTM spatial index.

The result is a record set with the schema
(HtmIdStart bigint, HtmIdEnd bigint)
The area is specified as a CIRCLE, CONVEX, or DOMAIN.
Each of these can use J2000 (ra,dec), or cartesian (xyz) coordinates.
The area parameter begins with a
[CIRCLE | CONVEX] [J2000 | CARTESIAN]
header, then it has the following params:

Depth is an int between 0...24, it specifies how fine a triangular mesh is desired.

ra is right ascencion is float64 units are degrees

dec is right declination is float64 units are degrees

rad is circle radius in arcminutes float64

x,y,z are coordinates in cartesian space, float64

d is a distance along the x, y, z vector when defining a cone (d in -1...+1).

The following examples request a 6-deep htm list covering a
a circular region, convex hull or a domain
CIRCLE J2000 6 41.4 47.9 20 CIRCLE CARTESIAN 6 1.0 0.0 0.0 10.0 CONVEX J2000 6 41.4 47.9 41.2 47.9 41.0 47.5 41.4 48 CONVEX CARTESIAN depth x1 y1 z1 x2 y2 z2 ... xn yn zn CONVEX CARTESIAN 6 1 1 1 0 1 1 1 0 DOMAIN 1 n x1 y1 z1 d1 x2 y2 z2 d2... xn yn zn dn
(See also fHTM_Cover_ErrorMessage)

Name Type Length inout pnum

@Area VARCHAR 8000 input 1

HTMIDstart BIGINT 8 output 1

HTMIDend BIGINT 8 output 2

Name	Type	Length	inout	pnum
@Area	VARCHAR	8000	input	1
HTMIDstart	BIGINT	8	output	1
HTMIDend	BIGINT	8	output	2