Types

hex_orientation

create type hex_orientation as (
    name        text,
    f           float[],
    b           float[],
    sinuses     float[],
    cosinuses   float[]
);

hexgrid

create type hexgrid as (
    orientation hex_orientation,
    srid        int,
    origin      geometry(point),
    size        geometry(point)
);

where

  • orientation - orientation of hexgrid
  • srid - SRID on a geometry
  • origin - center of hexgrid
  • size - size of hexagon in grid

Predefined orientations

hex_OrientationPointy

Pointy topped orientation

hex_OrientationFlat

Flat topped orientation

Helpers functions

morton_pack

function morton_pack(
    q int8,
    r int8
) returns int8

Example:

=# select morton_pack(10,20) as code;
 code
------
  612
(1 row)

morton_unpack

function morton_unpack(
    code int8
) returns int8[]

Example:

=# select morton_unpack(612) as qr;
   qr
---------
 {10,20}
(1 row)

Main functions

ST_Hexagon

Get hexagon for given point

function ST_Hexagon(
    point   geometry(point),
    grid_id int default 1
) returns hexagon

Example:

=# select ST_Hexagon('SRID=3857;POINT(1000 1000)') as hex;
  hex
-------
 (3,1)
(1 row)

ST_Centroid

Get center point of hexagon

function ST_Centroid(
    hexagon     hexagon
) returns geometry(point)

ST_HexagonCoverage

Make hexagons for given region 

ST_HexagonCoverage(
    region geometry,
    grid_id int default 1
) returns setof hexagon