Name

ST_AsMVTGeom — Transform a geometry into the coordinate space of a Mapbox Vector Tile.

Synopsis

geometry ST_AsMVTGeom(geometry geom, box2d bounds, int4 extent, int4 buffer, bool clip_geom);

Description

Transform a geometry into the coordinate space of a Mapbox Vector Tile of a set of rows corresponding to a Layer. Makes best effort to keep and even correct validity and might collapse geometry into a lower dimension in the process.

geom is the geometry to transform.

bounds is the geometric bounds of the tile contents without buffer.

extent is the tile extent in tile coordinate space as defined by the specification. If NULL it will default to 4096.

buffer is the buffer distance in tile coordinate space to optionally clip geometries. If NULL it will default to 0.

clip_geom is a boolean to control if geometries should be clipped or encoded as is. If NULL it will default to true.

Availability: 2.4.0

Examples

SELECT ST_AsText(ST_AsMVTGeom(
	ST_GeomFromText('POLYGON ((0 0, 10 0, 10 5, 0 -5, 0 0))'),
	ST_MakeBox2D(ST_Point(0, 0), ST_Point(4096, 4096)),
	4096, 0, false));
                              st_astext
--------------------------------------------------------------------
 MULTIPOLYGON(((5 4096,10 4096,10 4091,5 4096)),((5 4096,0 4096,0 4101,5 4096)))