ST_ForceRHR

Introduction: Sets the orientation of polygon vertex orderings to follow the Right-Hand-Rule convention. The exterior ring will have a clockwise winding order, while any interior rings are oriented counter-clockwise. This ensures the area bounded by the polygon falls on the right-hand side relative to the ring directions. The function is an alias for ST_ForcePolygonCW.

Format: ST_ForceRHR(geom: Geometry)

Since: v1.6.1

SQL Example:

SELECT ST_AsText(ST_ForceRHR(ST_GeomFromText('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35),(30 20, 20 15, 20 25, 30 20))')))

Output:

POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))